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Sample records for human homo sapiens

  1. Spatial Construction Skills of Chimpanzees ("Pan Troglodytes") and Young Human Children ("Homo Sapiens Sapiens")

    ERIC Educational Resources Information Center

    Poti, Patrizia; Hayashi, Misato; Matsuzawa, Tetsuro

    2009-01-01

    Spatial construction tasks are basic tests of visual-spatial processing. Two studies have assessed spatial construction skills in chimpanzees (Pan troglodytes) and young children (Homo sapiens sapiens) with a block modelling task. Study 1a subjects were three young chimpanzees and five adult chimpanzees. Study 1b subjects were 30 human children…

  2. Grunt communication in human infants (Homo sapiens).

    PubMed

    McCune, L; Vihman, M M; Roug-Hellichius, L; Delery, D B; Gogate, L

    1996-03-01

    Laryngeally produced vocalizations termed grunts function communicatively in many species. The vocalizations and accompanying behavior of 5 human infants videorecorded monthly at the transition to speech were analyzed to determine the frequency, physiological basis, and functional status of grunt production, a phenomenon systematically studied for the first time here. Earliest grunts occurred accompanying movement or effort; next, they accompanied acts of focal attention; and finally they were used in communication. Communicative use was followed by the onset of referential ability in language. This sequence is interpreted in relation to the physiological basis of these vocalizations in respiratory function and to additional developmental variables observed in the children. The findings have implications for the transition to the communicative repertoire in other species in which laryngeal function contributes to communication.

  3. The Emergence of Homo sapiens.

    ERIC Educational Resources Information Center

    Rensberger, Boyce

    1980-01-01

    Describes chronologically the evolution of the human race on earth so as to refute Darwin's theory of descent from animals. Skull fragments from sites around the world suggest at least two possible routes toward the emergence of Homo sapiens sapiens. (Author/SK)

  4. Spatial construction skills of chimpanzees (Pan troglodytes) and young human children (Homo sapiens sapiens).

    PubMed

    Potì, Patrizia; Hayashi, Misato; Matsuzawa, Tetsuro

    2009-07-01

    Spatial construction tasks are basic tests of visual-spatial processing. Two studies have assessed spatial construction skills in chimpanzees (Pan troglodytes) and young children (Homo sapiens sapiens) with a block modelling task. Study 1a subjects were three young chimpanzees and five adult chimpanzees. Study 1b subjects were 30 human children belonging to five age groups (24, 30, 36, 42, 48 months). Subjects were given three model constructions to reproduce: Line, Cross-Stack and Arch, which differed in type and number of spatial relations and dimensions, but required comparable configurational understanding. Subjects' constructions were rated for accuracy. Our results show that: (1) chimpanzees are relatively advanced in constructing in the vertical dimension; (2) Among chimpanzees only adults make accurate copies of constructions; (3) Chimpanzees do not develop in the direction of constructing in two dimensions as human children do starting from age 30 months. The pattern of development of construction skills in chimpanzees partially diverges from that of human children and indicates that spatial analysis and spatial representation are partially different in the two species. PMID:19635081

  5. Homo Sapiens, All Too Homo Sapiens: Wise Man, All Too Human

    ERIC Educational Resources Information Center

    Ketcham, Amaris

    2015-01-01

    The emphasis on STEM education should not be interpreted as an omen of the death of humanities; art, literature, history, and philosophy can inform and enlighten STEM studies if the walls of academic silos are broken down and taught in combination. Where the physical universe collides with the fanciful and flawed human experience of life, there is…

  6. LB1 and LB6 Homo floresiensis are not modern human (Homo sapiens) cretins.

    PubMed

    Brown, Peter

    2012-02-01

    Excavations in the late Pleistocene deposits at Liang Bua cave, Flores, have uncovered the skeletal remains of several small-bodied and small-brained hominins in association with stone artefacts and the bones of Stegodon. Due to their combination of plesiomorphic, unique and derived traits, they were ascribed to a new species, Homo floresiensis, which, along with Stegodon, appears to have become extinct ∼17 ka (thousand years ago). However, recently it has been argued that several characteristics of H. floresiensis were consistent with dwarfism and evidence of delayed development in modern human (Homo sapiens) myxoedematous endemic (ME) cretins. This research compares the skeletal and dental morphology in H. floresiensis with the clinical and osteological indicators of cretinism, and the traits that have been argued to be associated with ME cretinism in LB1 and LB6. Contrary to published claims, morphological and statistical comparisons did not identify the distinctive skeletal and dental indicators of cretinism in LB1 or LB6 H. floresiensis. Brain mass, skeletal proportions, epiphyseal union, orofacial morphology, dental development, size of the pituitary fossa and development of the paranasal sinuses, vault bone thickness and dimensions of the hands and feet all distinguish H. floresiensis from modern humans with ME cretinism. The research team responsible for the diagnosis of ME cretinism had not examined the original H. floresiensis skeletal materials, and perhaps, as a result, their research confused taphonomic damage with evidence of disease, and thus contained critical errors of fact and interpretation. Behavioural scenarios attempting to explain the presence of cretinous H. sapiens in the Liang Bua Pleistocene deposits, but not unaffected H. sapiens, are both unnecessary and not supported by the available archaeological and geochronological evidence from Flores.

  7. LB1 and LB6 Homo floresiensis are not modern human (Homo sapiens) cretins.

    PubMed

    Brown, Peter

    2012-02-01

    Excavations in the late Pleistocene deposits at Liang Bua cave, Flores, have uncovered the skeletal remains of several small-bodied and small-brained hominins in association with stone artefacts and the bones of Stegodon. Due to their combination of plesiomorphic, unique and derived traits, they were ascribed to a new species, Homo floresiensis, which, along with Stegodon, appears to have become extinct ∼17 ka (thousand years ago). However, recently it has been argued that several characteristics of H. floresiensis were consistent with dwarfism and evidence of delayed development in modern human (Homo sapiens) myxoedematous endemic (ME) cretins. This research compares the skeletal and dental morphology in H. floresiensis with the clinical and osteological indicators of cretinism, and the traits that have been argued to be associated with ME cretinism in LB1 and LB6. Contrary to published claims, morphological and statistical comparisons did not identify the distinctive skeletal and dental indicators of cretinism in LB1 or LB6 H. floresiensis. Brain mass, skeletal proportions, epiphyseal union, orofacial morphology, dental development, size of the pituitary fossa and development of the paranasal sinuses, vault bone thickness and dimensions of the hands and feet all distinguish H. floresiensis from modern humans with ME cretinism. The research team responsible for the diagnosis of ME cretinism had not examined the original H. floresiensis skeletal materials, and perhaps, as a result, their research confused taphonomic damage with evidence of disease, and thus contained critical errors of fact and interpretation. Behavioural scenarios attempting to explain the presence of cretinous H. sapiens in the Liang Bua Pleistocene deposits, but not unaffected H. sapiens, are both unnecessary and not supported by the available archaeological and geochronological evidence from Flores. PMID:22277102

  8. Rational maximizing by humans (Homo sapiens) in an ultimatum game.

    PubMed

    Smith, Phillip; Silberberg, Alan

    2010-07-01

    In the human mini-ultimatum game, a proposer splits a sum of money with a responder. If the responder accepts, both are paid. If not, neither is paid. Typically, responders reject inequitable distributions, favoring punishing over maximizing. In Jensen et al.'s (Science 318:107-109, 2007) adaptation with apes, a proposer selects between two distributions of raisins. Despite inequitable offers, responders often accept, thereby maximizing. The rejection response differs between the human and ape versions of this game. For humans, rejection is instantaneous; for apes, it requires 1 min of inaction. We replicate Jensen et al.'s procedure in humans with money. When waiting 1 min to reject, humans favor punishing over maximizing; however, when rejection requires 5 min of inaction, humans, like apes, maximize. If species differences in time horizons are accommodated, Jensen et al.'s ape data are reproducible in humans.

  9. Body composition in Pan paniscus compared with Homo sapiens has implications for changes during human evolution.

    PubMed

    Zihlman, Adrienne L; Bolter, Debra R

    2015-06-16

    The human body has been shaped by natural selection during the past 4-5 million years. Fossils preserve bones and teeth but lack muscle, skin, fat, and organs. To understand the evolution of the human form, information about both soft and hard tissues of our ancestors is needed. Our closest living relatives of the genus Pan provide the best comparative model to those ancestors. Here, we present data on the body composition of 13 bonobos (Pan paniscus) measured during anatomical dissections and compare the data with Homo sapiens. These comparative data suggest that both females and males (i) increased body fat, (ii) decreased relative muscle mass, (iii) redistributed muscle mass to lower limbs, and (iv) decreased relative mass of skin during human evolution. Comparison of soft tissues between Pan and Homo provides new insights into the function and evolution of body composition.

  10. Body composition in Pan paniscus compared with Homo sapiens has implications for changes during human evolution.

    PubMed

    Zihlman, Adrienne L; Bolter, Debra R

    2015-06-16

    The human body has been shaped by natural selection during the past 4-5 million years. Fossils preserve bones and teeth but lack muscle, skin, fat, and organs. To understand the evolution of the human form, information about both soft and hard tissues of our ancestors is needed. Our closest living relatives of the genus Pan provide the best comparative model to those ancestors. Here, we present data on the body composition of 13 bonobos (Pan paniscus) measured during anatomical dissections and compare the data with Homo sapiens. These comparative data suggest that both females and males (i) increased body fat, (ii) decreased relative muscle mass, (iii) redistributed muscle mass to lower limbs, and (iv) decreased relative mass of skin during human evolution. Comparison of soft tissues between Pan and Homo provides new insights into the function and evolution of body composition. PMID:26034269

  11. Body composition in Pan paniscus compared with Homo sapiens has implications for changes during human evolution

    PubMed Central

    Zihlman, Adrienne L.; Bolter, Debra R.

    2015-01-01

    The human body has been shaped by natural selection during the past 4–5 million years. Fossils preserve bones and teeth but lack muscle, skin, fat, and organs. To understand the evolution of the human form, information about both soft and hard tissues of our ancestors is needed. Our closest living relatives of the genus Pan provide the best comparative model to those ancestors. Here, we present data on the body composition of 13 bonobos (Pan paniscus) measured during anatomical dissections and compare the data with Homo sapiens. These comparative data suggest that both females and males (i) increased body fat, (ii) decreased relative muscle mass, (iii) redistributed muscle mass to lower limbs, and (iv) decreased relative mass of skin during human evolution. Comparison of soft tissues between Pan and Homo provides new insights into the function and evolution of body composition. PMID:26034269

  12. Leukotriene signaling in the extinct human subspecies Homo denisovan and Homo neanderthalensis. Structural and functional comparison with Homo sapiens.

    PubMed

    Adel, Susan; Kakularam, Kumar Reddy; Horn, Thomas; Reddanna, Pallu; Kuhn, Hartmut; Heydeck, Dagmar

    2015-01-01

    Mammalian lipoxygenases (LOXs) have been implicated in cell differentiation and in the biosynthesis of pro- and anti-inflammatory lipid mediators. The initial draft sequence of the Homo neanderthalensis genome (coverage of 1.3-fold) suggested defective leukotriene signaling in this archaic human subspecies since expression of essential proteins appeared to be corrupted. Meanwhile high quality genomic sequence data became available for two extinct human subspecies (H. neanderthalensis, Homo denisovan) and completion of the human 1000 genome project provided a comprehensive database characterizing the genetic variability of the human genome. For this study we extracted the nucleotide sequences of selected eicosanoid relevant genes (ALOX5, ALOX15, ALOX12, ALOX15B, ALOX12B, ALOXE3, COX1, COX2, LTA4H, LTC4S, ALOX5AP, CYSLTR1, CYSLTR2, BLTR1, BLTR2) from the corresponding databases. Comparison of the deduced amino acid sequences in connection with site-directed mutagenesis studies and structural modeling suggested that the major enzymes and receptors of leukotriene signaling as well as the two cyclooxygenase isoforms were fully functional in these two extinct human subspecies.

  13. Female condition influences preferences for sexual dimorphism in faces of male humans (Homo sapiens).

    PubMed

    Penton-Voak, I S; Little, A C; Jones, B C; Burt, D M; Tiddeman, B P; Perrett, D I

    2003-09-01

    In some species, female condition correlates positively with preferences for male secondary sexual traits. Women's preferences for sexually dimorphic characteristics in male faces (facial masculinity) have recently been reported to covary with self-reported attractiveness. As women's attractiveness has been proposed to signal reproductive condition, the findings in human (Homo sapiens) and other species may reflect similar processes. The current study investigated whether the covariation between condition and preferences for masculinity would generalize to 2 further measures of female attractiveness: other-rated facial attractiveness and waist-to-hip ratio (WHR). Women with high (unattractive) WHR and/or relatively low other-rated facial attractiveness preferred more "feminine" male faces when choosing faces for a long-term relationship than when choosing for a short-term relationship, possibly reflecting diverse tactics in female mate choice. PMID:14498802

  14. Temporal coherence for pure tones in budgerigars (Melopsittacus undulatus) and humans (Homo sapiens).

    PubMed

    Neilans, Erikson G; Dent, Micheal L

    2015-02-01

    Auditory scene analysis has been suggested as a universal process that exists across all animals. Relative to humans, however, little work has been devoted to how animals perceptually isolate different sound sources. Frequency separation of sounds is arguably the most common parameter studied in auditory streaming, but it is not the only factor contributing to how the auditory scene is perceived. Researchers have found that in humans, even at large frequency separations, synchronous tones are heard as a single auditory stream, whereas asynchronous tones with the same frequency separations are perceived as 2 distinct sounds. These findings demonstrate how both the timing and frequency separation of sounds are important for auditory scene analysis. It is unclear how animals, such as budgerigars (Melopsittacus undulatus), perceive synchronous and asynchronous sounds. In this study, budgerigars and humans (Homo sapiens) were tested on their perception of synchronous, asynchronous, and partially overlapping pure tones using the same psychophysical procedures. Species differences were found between budgerigars and humans in how partially overlapping sounds were perceived, with budgerigars more likely to segregate overlapping sounds and humans more apt to fuse the 2 sounds together. The results also illustrated that temporal cues are particularly important for stream segregation of overlapping sounds. Lastly, budgerigars were found to segregate partially overlapping sounds in a manner predicted by computational models of streaming, whereas humans were not. PMID:25419717

  15. What makes us human (Homo sapiens)? The challenge of cognitive cross-species comparison.

    PubMed

    Boesch, Christophe

    2007-08-01

    Two major theoretical approaches have dominated the quest for uniquely human cognitive abilities: a developmentalist approach stressing the importance of environmental and social conditions, and a predominant approach in experimental and comparative psychology, the deterministic approach suggesting the effect of environmental and social conditions to be minimal. As a consequence, most claims of human cognitive uniqueness are based on comparisons of White middle class Westerner humans (Homo sapiens) with captive chimpanzees (Pan troglodytes). However, humans are much more than only White middle class Westerners, and chimpanzees are much more than only captives. A review of some data available on different populations of humans and chimpanzees reveals that only the predictions of the developmentalist approach are supported. In addition, systematic biases are too often introduced in experiment protocols when comparing humans with apes that further cast doubts on cross-species comparisons. The author argues that only with consideration of within-species population differences in the cognitive domains and the use of well-matched cross-species experimental procedures will an objective understanding of the different cognitive abilities between species emerge. This will require a shift in the theoretical approach adopted by many in experimental and comparative psychology.

  16. The origin and evolution of Homo sapiens.

    PubMed

    Stringer, Chris

    2016-07-01

    If we restrict the use of Homo sapiens in the fossil record to specimens which share a significant number of derived features in the skeleton with extant H. sapiens, the origin of our species would be placed in the African late middle Pleistocene, based on fossils such as Omo Kibish 1, Herto 1 and 2, and the Levantine material from Skhul and Qafzeh. However, genetic data suggest that we and our sister species Homo neanderthalensis shared a last common ancestor in the middle Pleistocene approximately 400-700 ka, which is at least 200 000 years earlier than the species origin indicated from the fossils already mentioned. Thus, it is likely that the African fossil record will document early members of the sapiens lineage showing only some of the derived features of late members of the lineage. On that basis, I argue that human fossils such as those from Jebel Irhoud, Florisbad, Eliye Springs and Omo Kibish 2 do represent early members of the species, but variation across the African later middle Pleistocene/early Middle Stone Age fossils shows that there was not a simple linear progression towards later sapiens morphology, and there was chronological overlap between different 'archaic' and 'modern' morphs. Even in the late Pleistocene within and outside Africa, we find H. sapiens specimens which are clearly outside the range of Holocene members of the species, showing the complexity of recent human evolution. The impact on species recognition of late Pleistocene gene flow between the lineages of modern humans, Neanderthals and Denisovans is also discussed, and finally, I reconsider the nature of the middle Pleistocene ancestor of these lineages, based on recent morphological and genetic data.This article is part of the themed issue 'Major transitions in human evolution'.

  17. The origin and evolution of Homo sapiens.

    PubMed

    Stringer, Chris

    2016-07-01

    If we restrict the use of Homo sapiens in the fossil record to specimens which share a significant number of derived features in the skeleton with extant H. sapiens, the origin of our species would be placed in the African late middle Pleistocene, based on fossils such as Omo Kibish 1, Herto 1 and 2, and the Levantine material from Skhul and Qafzeh. However, genetic data suggest that we and our sister species Homo neanderthalensis shared a last common ancestor in the middle Pleistocene approximately 400-700 ka, which is at least 200 000 years earlier than the species origin indicated from the fossils already mentioned. Thus, it is likely that the African fossil record will document early members of the sapiens lineage showing only some of the derived features of late members of the lineage. On that basis, I argue that human fossils such as those from Jebel Irhoud, Florisbad, Eliye Springs and Omo Kibish 2 do represent early members of the species, but variation across the African later middle Pleistocene/early Middle Stone Age fossils shows that there was not a simple linear progression towards later sapiens morphology, and there was chronological overlap between different 'archaic' and 'modern' morphs. Even in the late Pleistocene within and outside Africa, we find H. sapiens specimens which are clearly outside the range of Holocene members of the species, showing the complexity of recent human evolution. The impact on species recognition of late Pleistocene gene flow between the lineages of modern humans, Neanderthals and Denisovans is also discussed, and finally, I reconsider the nature of the middle Pleistocene ancestor of these lineages, based on recent morphological and genetic data.This article is part of the themed issue 'Major transitions in human evolution'. PMID:27298468

  18. What constitutes Homo sapiens? Morphology versus received wisdom.

    PubMed

    Schwartz, Jeffrey

    2016-06-20

    Although Linnaeus coined Homo sapiens in 1735, it was Blumenbach forty years later who provided the first morphological definition of the species. Since humans were not then allowed to be ante-Diluvian, his effort applied to the genus, as well. After the Feldhofer Grotto Neanderthal disproved this creationist notion, and human-fossil hunting became legitimate, new specimens were allocated either to sapiens or new species within Homo, or even to new species within new genera. Yet as these taxonomic acts reflected the morphological differences between specimens, they failed to address the question: What constitutes H. sapiens? When in 1950 Mayr collapsed all human fossils into Homo, he not only denied humans a diverse evolutionary past, he also shifted the key to identifying its species from morphology to geological age - a practice most paleoanthropologists still follow. Thus, for example, H. erectus is the species that preceded H. sapiens, and H. sapiens is the species into which H. erectus morphed. In order to deal with a growing morass of morphologically dissimilar specimens, the non-taxonomic terms "archaic" (AS) and "anatomically modern" (AMS) were introduced to distinguish between the earlier and later versions of H. sapiens, thereby making the species impossible to define. In attempting to disentangle fact from scenario, I begin from the beginning, trying to delineate features that may be distinctive of extant humans (ES), and then turning to the fossils that have been included in the species. With the exception of Upper Paleolithic humans - e.g. from Cro-Magnon, Dolni Vestonice, Mladeč - I argue that many specimens regarded as AMS, and all those deemed AS, are not H. sapiens. The features these AMS do share with ES suggest the existence of a sapiens clade. Further, restudy of near-recent fossils, especially from southwestern China (∼11-14.5 ka), reinforces what discoveries such as H. floresiensis indicate: "If it's recent, it's not necessarily H. sapiens

  19. What constitutes Homo sapiens? Morphology versus received wisdom.

    PubMed

    Schwartz, Jeffrey

    2016-06-20

    Although Linnaeus coined Homo sapiens in 1735, it was Blumenbach forty years later who provided the first morphological definition of the species. Since humans were not then allowed to be ante-Diluvian, his effort applied to the genus, as well. After the Feldhofer Grotto Neanderthal disproved this creationist notion, and human-fossil hunting became legitimate, new specimens were allocated either to sapiens or new species within Homo, or even to new species within new genera. Yet as these taxonomic acts reflected the morphological differences between specimens, they failed to address the question: What constitutes H. sapiens? When in 1950 Mayr collapsed all human fossils into Homo, he not only denied humans a diverse evolutionary past, he also shifted the key to identifying its species from morphology to geological age - a practice most paleoanthropologists still follow. Thus, for example, H. erectus is the species that preceded H. sapiens, and H. sapiens is the species into which H. erectus morphed. In order to deal with a growing morass of morphologically dissimilar specimens, the non-taxonomic terms "archaic" (AS) and "anatomically modern" (AMS) were introduced to distinguish between the earlier and later versions of H. sapiens, thereby making the species impossible to define. In attempting to disentangle fact from scenario, I begin from the beginning, trying to delineate features that may be distinctive of extant humans (ES), and then turning to the fossils that have been included in the species. With the exception of Upper Paleolithic humans - e.g. from Cro-Magnon, Dolni Vestonice, Mladeč - I argue that many specimens regarded as AMS, and all those deemed AS, are not H. sapiens. The features these AMS do share with ES suggest the existence of a sapiens clade. Further, restudy of near-recent fossils, especially from southwestern China (∼11-14.5 ka), reinforces what discoveries such as H. floresiensis indicate: "If it's recent, it's not necessarily H. sapiens".

  20. A genome-wide linkage scan for quantitative trait loci influencing the craniofacial complex in humans(Homo sapiens sapiens)

    PubMed Central

    Sherwood, Richard J.; Duren, Dana L.; Mahaney, Michael C.; Blangero, John; Dyer, Thomas D.; Cole, Shelley A.; Czerwinski, Stefan A.; Chumlea, Wm. Cameron; Siervogel, Roger M.; Choh, Audrey C.; Nahhas, Ramzi W.; Lee, Miryoung; Towne, Bradford

    2011-01-01

    The genetic architecture of the craniofacial complex has been the subject of intense scrutiny because of the high frequency of congenital malformations. Numerous animal models have been used to document the early development of the craniofacial complex, but few studies have focused directly on the genetic underpinnings of normal variation in the human craniofacial complex. The current study examines 80 quantitative traits derived from lateral cephalographs of 981 participants in the Fels Longitudinal Study, Wright State University, Dayton, Ohio. Quantitative genetic analyses were conducted using the SOLAR analytic platform, a maximum-likelihood variance components method that incorporates all familial information for parameter estimation. Heritability estimates were significant and of moderate to high magnitude for all craniofacial traits. Additionally, significant quantitative trait loci (QTL) were identified for 10 traits from the three developmental components (basicranium, splanchnocranium, and neurocranium) of the craniofacial complex. These QTL were found on chromosomes 3, 6, 11, 12, and 14. This study of the genetic architecture of the craniofacial complex elucidates fundamental information of the genetic architecture of the craniofacial complex in humans. PMID:21328561

  1. Yawn Contagion and Empathy in Homo sapiens

    PubMed Central

    Norscia, Ivan; Palagi, Elisabetta

    2011-01-01

    The ability to share others' emotions, or empathy, is crucial for complex social interactions. Clinical, psychological, and neurobiological clues suggest a link between yawn contagion and empathy in humans (Homo sapiens). However, no behavioral evidence has been provided so far. We tested the effect of different variables (e.g., country of origin, sex, yawn characteristics) on yawn contagion by running mixed models applied to observational data collected over 1 year on adult (>16 years old) human subjects. Only social bonding predicted the occurrence, frequency, and latency of yawn contagion. As with other measures of empathy, the rate of contagion was greatest in response to kin, then friends, then acquaintances, and lastly strangers. Related individuals (r≥0.25) showed the greatest contagion, in terms of both occurrence of yawning and frequency of yawns. Strangers and acquaintances showed a longer delay in the yawn response (latency) compared to friends and kin. This outcome suggests that the neuronal activation magnitude related to yawn contagion can differ as a function of subject familiarity. In conclusion, our results demonstrate that yawn contagion is primarily driven by the emotional closeness between individuals and not by other variables, such as gender and nationality. PMID:22163307

  2. Homo Sapiens as Geological Agents

    NASA Astrophysics Data System (ADS)

    Holloway, T.; Bedsworth, L. W.; Caldeira, K.; Rosenzweig, C.; Kelley, G.; Rosenzweig, C.; Caldeira, K.; Bedsworth, L. W.; Holloway, T.; Purdy, J. S.; Vince, G.; Syvitski, J. A.; Bondre, N. R.; Kelly, J.; Vince, G.; Seto, K. C.; Steffen, W.; Oreskes, N.

    2015-12-01

    In the 18th and 19th centuries, earth scientists came to understand the magnitude and power of geological and geophysical processes. In comparison, the activities of humans seemed paltry if not insignificant. With the development of radiometric dating in the 20th century, scientists realized that human history was but a miniscule part of Earth history. Metaphors to this effect abounded, and filled textbooks: If Earth history were a 24-hour day, human history would not occupy even the final second. If Earth history were a yardstick, the human portion would not even be visible to the naked eye. Generations of scientists were taught that one of the principal contributions of geology, qua science, was the demonstration of our insignificance. The Anthropocene concept disrupts this. To affirms its existence is to insist that human activities compete in scale and significance with other Earth processes, and may threaten to overwhelm them. It also inverts our relation to normative claims. For more than a century earth scientists and evolutionary biologists insisted that their theories were descriptive and not normative—that there was no moral conclusion to be drawn from either planetary or human evolution. Now, we confront the suggestion that there is a moral component to our new paradigm: we can scarcely claim that humans are disrupting the climate, destroying biodiversity, and acidifying the oceans without implying that there is something troubling about these developments. Thus, the Anthropocene concept suggests both a radical redefinition of the scope of Earth science, and a radical reconsideration of the place of normative judgments in scientific work.

  3. Cloning of Homo sapiens? No!

    PubMed

    McKinnell, Robert G

    2002-01-01

    Animal cloning by nuclear transplantation was first developed in the northern leopard frog, Rana pipiens. It was soon extended to other amphibian species and within time, to various mammalian species. The production of a cloned sheep (Dolly) from an adult nuclear donor reawakened interest in human cloning. Nuclear transfer for the production of animal clones has served experimental biology well. Nonetheless, the potential burden of developmental hazards, scientists and funds diverted from more needy causes, as well as the potential assault on the concept of family has led the author to oppose human cloning.

  4. Cloning of Homo sapiens? No!

    PubMed

    McKinnell, Robert G

    2002-01-01

    Animal cloning by nuclear transplantation was first developed in the northern leopard frog, Rana pipiens. It was soon extended to other amphibian species and within time, to various mammalian species. The production of a cloned sheep (Dolly) from an adult nuclear donor reawakened interest in human cloning. Nuclear transfer for the production of animal clones has served experimental biology well. Nonetheless, the potential burden of developmental hazards, scientists and funds diverted from more needy causes, as well as the potential assault on the concept of family has led the author to oppose human cloning. PMID:11841468

  5. The evolution of Homo sapiens denisova and Homo sapiens neanderthalensis miRNA targeting genes in the prenatal and postnatal brain

    PubMed Central

    2015-01-01

    Background As the evolution of miRNA genes has been found to be one of the important factors in formation of the modern type of man, we performed a comparative analysis of the evolution of miRNA genes in two archaic hominines, Homo sapiens neanderthalensis and Homo sapiens denisova, and elucidated the expression of their target mRNAs in bain. Results A comparative analysis of the genomes of primates, including species in the genus Homo, identified a group of miRNA genes having fixed substitutions with important implications for the evolution of Homo sapiens neanderthalensis and Homo sapiens denisova. The mRNAs targeted by miRNAs with mutations specific for Homo sapiens denisova exhibited enhanced expression during postnatal brain development in modern humans. By contrast, the expression of mRNAs targeted by miRNAs bearing variations specific for Homo sapiens neanderthalensis was shown to be enhanced in prenatal brain development. Conclusions Our results highlight the importance of changes in miRNA gene sequences in the course of Homo sapiens denisova and Homo sapiens neanderthalensis evolution. The genetic alterations of miRNAs regulating the spatiotemporal expression of multiple genes in the prenatal and postnatal brain may contribute to the progressive evolution of brain function, which is consistent with the observations of fine technical and typological properties of tools and decorative items reported from archaeological Denisovan sites. The data also suggest that differential spatial-temporal regulation of gene products promoted by the subspecies-specific mutations in the miRNA genes might have occurred in the brains of Homo sapiens denisova and Homo sapiens neanderthalensis, potentially contributing to the cultural differences between these two archaic hominines. PMID:26693966

  6. Generalization of category knowledge and dimensional categorization in humans (Homo sapiens) and nonhuman primates (Macaca mulatta).

    PubMed

    Smith, J David; Zakrzewski, Alexandria C; Johnston, Jennifer J R; Roeder, Jessica L; Boomer, Joseph; Ashby, F Gregory; Church, Barbara A

    2015-10-01

    A theoretical framework within neuroscience distinguishes humans' implicit and explicit systems for category learning. We used a perceptual-categorization paradigm to ask whether nonhumans share elements of these systems. Participants learned categories that foster implicit or explicit categorization in humans, because they had a multidimensional, information-integration (II) solution or a unidimensional, rule-based (RB) solution. Then humans and macaques generalized their category knowledge to new, untested regions of the stimulus space. II generalization was impaired, suggesting that II category learning is conditioned and constrained by stimulus generalization to its original, trained stimulus contexts. RB generalization was nearly seamless, suggesting that RB category knowledge in humans and monkeys has properties that grant it some independence from the original, trained stimulus contexts. These findings raise the questions of (a) how closely macaques' dimensional categorization verges on humans' explicit/declarative categorization, and (b) how far macaques' dimensional categorization has advanced beyond that in other vertebrate species. PMID:26167774

  7. Implicit and Explicit Category Learning by Macaques (Macaca mulatta) and Humans (Homo sapiens)

    PubMed Central

    Smith, J. David; Beran, Michael J.; Crossley, Matthew J.; Boomer, Joseph. T.; Ashby, F. Gregory

    2010-01-01

    An influential theoretical perspective differentiates in humans an explicit, rule-based system of category learning from an implicit system that slowly associates different regions of perceptual space with different response outputs. This perspective was extended for the first time to the category learning of nonhuman primates. Humans and macaques learned categories composed of sine-wave gratings that varied across trials in bar width and bar orientation. The categories had either a single-dimensional, rule-based solution or a two-dimensional, information-integration solution. Humans strongly dimensionalized the stimuli and learned the rule-based task far more quickly. Six macaques showed the same performance advantage in the rule-based task. In humans, rule-based category learning is linked to explicit cognition, consciousness, and to declarative reports about the contents of cognition. The present results demonstrate an empirical continuity between human and nonhuman primate cognition, suggesting that nonhuman primates may have some structural components of humans’ capacity for explicit cognition. PMID:20141317

  8. Focusing and shifting attention in human children (Homo sapiens) and chimpanzees (Pan troglodytes).

    PubMed

    Herrmann, Esther; Tomasello, Michael

    2015-08-01

    Humans often must coordinate co-occurring activities, and their flexible skills for doing so would seem to be uniquely powerful. In 2 studies, we compared 4- and 5-year-old children and one of humans' nearest relatives, chimpanzees, in their ability to focus and shift their attention when necessary. The results of Study 1 showed that 4-year-old children and chimpanzees were very similar in their ability to monitor two identical devices and to sequentially switch between the two to collect a reward, and that they were less successful at doing so than 5-year-old children. In Study 2, which required subjects to alternate between two different tasks, one of which had rewards continuously available whereas the other one only occasionally released rewards, no species differences were found. These results suggest that chimpanzees and human children share some fundamental attentional control skills, but that such abilities continue to develop during human ontogeny, resulting in the uniquely human capacity to succeed at complex multitasking.

  9. Perception of emergent configurations in humans (Homo sapiens) and chimpanzees (Pan troglodytes).

    PubMed

    Goto, Kazuhiro; Imura, Tomoko; Tomonaga, Masaki

    2012-04-01

    We examined the perceptions of emergent configurations in humans and chimpanzees using a target-localization task. The stimulus display consisted of a target placed among multiple identical distractors. The target and distractors were presented either solely, within congruent contexts in which salient configurations emerge, or within incongruent contexts in which salient configurations do not emerge. We found that congruent contexts had similar facilitative effects on target localization by humans and chimpanzees, whereas similar disruptive effects emerged when the stimuli were presented within incongruent contexts. When display size was manipulated, targets under the congruent-context condition were localized in a parallel manner, but those under the no-context and incongruent-context conditions were localized in a serial manner by both species. These results suggest that both humans and chimpanzees perceive emergent configurations when targets and distractors are presented within certain congruent contexts and that they process such emergent configurations preattentively.

  10. Temporal coherence for complex signals in budgerigars (Melopsittacus undulatus) and humans (Homo sapiens).

    PubMed

    Neilans, Erikson G; Dent, Micheal L

    2015-05-01

    The auditory scene is filled with an array of overlapping acoustic signals, yet relatively little work has focused on how animals are able to perceptually isolate different sound sources necessary for survival. Much of the previous work on auditory scene analysis has investigated how sequential pure tone stimuli are perceived, but how temporally overlapping complex communication signals are segregated has been largely ignored. In this study, budgerigars and humans were tested using psychophysical procedures to measure their perception of synchronous, asynchronous, and partially overlapping complex signals, including bird calls and human vowels. Segregation thresholds for complex stimuli were significantly lower than those for pure tone stimuli in both humans and birds. Additionally, a species effect was discovered such that relative to humans, budgerigars required significantly less temporal separation between 2 sounds in order to segregate them. Overall, and similar to previous behavioral results investigating temporal coherence, the results from this experiment illustrate that temporal cues are particularly important for auditory scene analysis across multiple species and for both simple and complex acoustic signals. PMID:25822769

  11. Side biases in humans ( Homo sapiens): three ecological studies on hemispheric asymmetries

    NASA Astrophysics Data System (ADS)

    Marzoli, Daniele; Tommasi, Luca

    2009-09-01

    Hemispheric asymmetries and side biases have been studied in humans mostly in laboratory settings, and evidence obtained in naturalistic settings is scarce. We here report the results of three studies on human ear preference observed during social interactions in noisy environments, i.e., discotheques. In the first study, a spontaneous right-ear preference was observed during linguistic exchange between interacting individuals. This lateral bias was confirmed in a quasi-experimental study in which a confederate experimenter evoked an ear-orienting response in bystanders, under the pretext of approaching them with a whispered request. In the last study, subjects showed a greater proneness to meet an experimenter’s request when it was directly addressed to the right rather than the left ear. Our findings are in agreement both with laboratory studies on hemispheric lateralization for language and approach/avoidance behavior in humans and with animal research. The present work is one of the few studies demonstrating the natural expression of hemispheric asymmetries, showing their effect in everyday human behavior.

  12. Processing advantages for consonance: A comparison between rats (Rattus norvegicus) and humans (Homo sapiens).

    PubMed

    Crespo-Bojorque, Paola; Toro, Juan M

    2016-05-01

    Consonance is a salient perceptual feature in harmonic music associated with pleasantness. Besides being deeply rooted in how we experience music, research suggests consonant intervals are more easily processed than dissonant intervals. In the present work we explore from a comparative perspective if such processing advantage extends to more complex tasks such as the detection of abstract rules. We ran experiments on rule learning over consonant and dissonant intervals with nonhuman animals and human participants. Results show differences across species regarding the extent to which they benefit from differences in consonance. Animals learn abstract rules with the same ease independently of whether they are implemented over consonant intervals (Experiment 1), dissonant intervals (Experiment 2), or over a combination of them (Experiment 3). Humans, on the contrary, learn an abstract rule better when it is implemented over consonant (Experiment 4) than over dissonant intervals (Experiment 5). Moreover, their performance improves when there is a mapping between abstract categories defining a rule and consonant and dissonant intervals (Experiments 6 and 7). Results suggest that for humans, consonance might be used as a perceptual anchor for other cognitive processes as to facilitate the detection of abstract patterns. Lacking extensive experience with harmonic stimuli, nonhuman animals tested here do not seem to benefit from a processing advantage for consonant intervals. (PsycINFO Database Record PMID:27078078

  13. Timbre influences chord discrimination in black-capped chickadees (Poecile atricapillus) but not humans (Homo sapiens).

    PubMed

    Hoeschele, Marisa; Cook, Robert G; Guillette, Lauren M; Hahn, Allison H; Sturdy, Christopher B

    2014-11-01

    Timbre is an important attribute of sound both in music and nature. Previously, using an operant conditioning paradigm, we found that black-capped chickadees and humans show similar response patterns in discriminating triadic chords of the same timbre and transferred this discrimination to a novel key center (novel absolute pitch). The current study examined how varying the timbre of the chords influenced discrimination. Using a similar operant conditioning procedure, we trained humans (Experiment 1) and chickadees (Experiments 2 and 3) to discriminate a major chord from 6 other chord types that had semitone deviations from the major chord. The pattern of errors of the 2 species replicated our previous findings. We then tested participants with novel timbres. We found that humans readily transferred their discrimination to novel timbres, suggesting they were attending to triadic pitch relations. The chickadees failed to transfer to novel timbres, suggesting they were using a different strategy to perform the original chord discrimination. We conducted an acoustic analysis examining frequency ranges that are biologically relevant to chickadees. We found that the relative intensity within each chord of the frequencies used in black-capped chickadee song significantly correlated with chickadees' percent response during probe testing. In Experiment 3, we trained a new set of chickadees by including either expanded pitch or timbre training before testing. Although chickadees showed some transfer to novel chords following this expanded training, we found that neither type of expanded training helped the chickadees when probe tested with novel stimuli.

  14. Neanderthal paintings? Production of prototypical human (Homo sapiens) faces shows systematic distortions.

    PubMed

    Carbon, Claus-Christian; Wirth, Benedikt Emanuel

    2014-01-01

    People's sketches of human faces seem to be systematically distorted: the eye position is always higher than in reality. This bias was experimentally analyzed by a series of experiments varying drawing conditions. Participants either drew prototypical faces from memory (studies 1 and 2: free reconstruction; study 3: cued reconstruction) or directly copied average faces (study 4). Participants consistently showed this positioning bias, which is even in accord with facial depictions published in influential research articles by famous face researchers (study 5). We discuss plausible explanations for this reliable and stable bias, which is coincidentally similar to the morphology of Neanderthals.

  15. The evolution and development of cranial form in Homo sapiens

    PubMed Central

    Lieberman, Daniel E.; McBratney, Brandeis M.; Krovitz, Gail

    2002-01-01

    Despite much data, there is no unanimity over how to define Homo sapiens in the fossil record. Here, we examine cranial variation among Pleistocene and recent human fossils by using a model of cranial growth to identify unique derived features (autapomorphies) that reliably distinguish fossils attributed to “anatomically modern” H. sapiens (AMHS) from those attributed to various taxa of “archaic” Homo spp. (AH) and to test hypotheses about the changes in cranial development that underlie the origin of modern human cranial form. In terms of pattern, AMHS crania are uniquely characterized by two general structural autapomorphies: facial retraction and neurocranial globularity. Morphometric analysis of the ontogeny of these autapomorphies indicates that the developmental changes that led to modern human cranial form derive from a combination of shifts in cranial base angle, cranial fossae length and width, and facial length. These morphological changes, some of which may have occurred because of relative size increases in the temporal and possibly the frontal lobes, occur early in ontogeny, and their effects on facial retraction and neurocranial globularity discriminate AMHS from AH crania. The existence of these autapomorphies supports the hypothesis that AMHS is a distinct species from taxa of “archaic” Homo (e.g., Homo neanderthalensis). PMID:11805284

  16. The Easy-to-Hard Effect in Human (Homo sapiens) and Rat (Rattus norvegicus) Auditory Identification

    PubMed Central

    Liu, Estella H.; Mercado, Eduardo; Church, Barbara A.; Orduña, Itzel

    2009-01-01

    Training exercises can improve perceptual sensitivities. We examined whether progressively training humans and rats to perform a difficult auditory identification task led to larger improvements than extensive training with highly similar sounds (the easy-to-hard effect). Practice improved humans’ ability to distinguish sounds regardless of the training regimen. However, progressively trained participants were more accurate and showed more generalization, despite significantly less training with the stimuli that were the most difficult to distinguish. Rats showed less capacity to improve with practice, but still benefited from progressive training. These findings indicate that transitioning from an easier to a more difficult task during training can facilitate, and in some cases may be essential for, auditory perceptual learning. The results are not predicted by an explanation that assumes interaction of generalized excitation and inhibition, but are consistent with a hierarchical account of perceptual learning in which the representational precision required to distinguish stimuli determines the mechanisms engaged during learning. PMID:18489229

  17. Discrimination of holograms and real objects by pigeons (Columba livia) and humans (Homo sapiens).

    PubMed

    Stephan, Claudia; Steurer, Michael M; Aust, Ulrike

    2014-08-01

    The type of stimulus material employed in visual tasks is crucial to all comparative cognition research that involves object recognition. There is considerable controversy about the use of 2-dimensional stimuli and the impact that the lack of the 3rd dimension (i.e., depth) may have on animals' performance in tests for their visual and cognitive abilities. We report evidence of discrimination learning using a completely novel type of stimuli, namely, holograms. Like real objects, holograms provide full 3-dimensional shape information but they also offer many possibilities for systematically modifying the appearance of a stimulus. Hence, they provide a promising means for investigating visual perception and cognition of different species in a comparative way. We trained pigeons and humans to discriminate either between 2 real objects or between holograms of the same 2 objects, and we subsequently tested both species for the transfer of discrimination to the other presentation mode. The lack of any decrements in accuracy suggests that real objects and holograms were perceived as equivalent in both species and shows the general appropriateness of holograms as stimuli in visual tasks. A follow-up experiment involving the presentation of novel views of the training objects and holograms revealed some interspecies differences in rotational invariance, thereby confirming and extending the results of previous studies. Taken together, these results suggest that holograms may not only provide a promising tool for investigating yet unexplored issues, but their use may also lead to novel insights into some crucial aspects of comparative visual perception and categorization.

  18. Taxonomic differences in deciduous upper second molar crown outlines of Homo sapiens, Homo neanderthalensis and Homo erectus.

    PubMed

    Bailey, Shara E; Benazzi, Stefano; Souday, Caroline; Astorino, Claudia; Paul, Kathleen; Hublin, Jean-Jacques

    2014-07-01

    A significant number of Middle to Late Pleistocene sites contain primarily (and sometimes only) deciduous teeth (e.g., Grotta del Cavallo, Mezmaiskaya, Blombos). Not surprisingly, there has been a recent renewed interest in deciduous dental variation, especially in the context of distinguishing Homo neanderthalensis and Homo sapiens. Most studies of the deciduous dentition of fossil hominins have focused on standard metrical variation but morphological (non-metric and morphometric) variation also promises to shed light on long standing taxonomic questions. This study examines the taxonomic significance of the crown outline of the deciduous upper second molar through principal components analysis and linear discriminant analysis. We examine whether or not the crown shape of the upper deciduous second molar separates H. neanderthalensis from H. sapiens and explore whether it can be used to correctly assign individuals to taxa. It builds on previous studies by focusing on crown rather than cervical outline and by including a large sample of geographically diverse recent human populations. Our samples include 17 H. neanderthalensis, five early H. sapiens, and 12 Upper Paleolithic H. sapiens. In addition, we include two Homo erectus specimens in order to evaluate the polarity of crown shape differences observed between H. neanderthalensis and H. sapiens. Our results show that crown outline shape discriminates H. sapiens and H. neanderthalensis quite well, but does not do well at distinguishing H. erectus from H. sapiens. We conclude that the crown outline shape observed in H. sapiens is a primitive retention and that the skewed shape observed in H. neanderthalensis is a derived condition. Finally, we explore the phylogenetic implications of the results for the H. erectus molars. PMID:24703186

  19. Face and eye scanning in gorillas (Gorilla gorilla), orangutans (Pongo abelii), and humans (Homo sapiens): unique eye-viewing patterns in humans among hominids.

    PubMed

    Kano, Fumihiro; Call, Josep; Tomonaga, Masaki

    2012-11-01

    Because the faces and eyes of primates convey a rich array of social information, the way in which primates view faces and eyes reflects species-specific strategies for facial communication. How are humans and closely related species such as great apes similar and different in their viewing patterns for faces and eyes? Following previous studies comparing chimpanzees (Pan troglodytes) with humans (Homo sapiens), this study used the eye-tracking method to directly compare the patterns of face and eye scanning by humans, gorillas (Gorilla gorilla), and orangutans (Pongo abelii). Human and ape participants freely viewed pictures of whole bodies and full faces of conspecifics and allospecifics under the same experimental conditions. All species were strikingly similar in that they viewed predominantly faces and eyes. No particular difference was identified between gorillas and orangutans, and they also did not differ from the chimpanzees tested in previous studies. However, humans were somewhat different from apes, especially with respect to prolonged eye viewing. We also examined how species-specific facial morphologies, such as the male flange of orangutans and the black-white contrast of human eyes, affected viewing patterns. Whereas the male flange of orangutans affected viewing patterns, the color contrast of human eyes did not. Humans showed prolonged eye viewing independently of the eye color of presented faces, indicating that this pattern is internally driven rather than stimulus dependent. Overall, the results show general similarities among the species and also identify unique eye-viewing patterns in humans.

  20. Rethinking the dispersal of Homo sapiens out of Africa.

    PubMed

    Groucutt, Huw S; Petraglia, Michael D; Bailey, Geoff; Scerri, Eleanor M L; Parton, Ash; Clark-Balzan, Laine; Jennings, Richard P; Lewis, Laura; Blinkhorn, James; Drake, Nick A; Breeze, Paul S; Inglis, Robyn H; Devès, Maud H; Meredith-Williams, Matthew; Boivin, Nicole; Thomas, Mark G; Scally, Aylwyn

    2015-01-01

    Current fossil, genetic, and archeological data indicate that Homo sapiens originated in Africa in the late Middle Pleistocene. By the end of the Late Pleistocene, our species was distributed across every continent except Antarctica, setting the foundations for the subsequent demographic and cultural changes of the Holocene. The intervening processes remain intensely debated and a key theme in hominin evolutionary studies. We review archeological, fossil, environmental, and genetic data to evaluate the current state of knowledge on the dispersal of Homo sapiens out of Africa. The emerging picture of the dispersal process suggests dynamic behavioral variability, complex interactions between populations, and an intricate genetic and cultural legacy. This evolutionary and historical complexity challenges simple narratives and suggests that hybrid models and the testing of explicit hypotheses are required to understand the expansion of Homo sapiens into Eurasia. PMID:26267436

  1. Analysis of movement kinematics on analogous spatial learning tasks demonstrates conservation of direction and distance estimation across humans (Homo sapiens) and rats (Rattus norvegicus).

    PubMed

    Köppen, Jenny R; Winter, Shawn S; Loda, Eileah L; Apger, Brianne P; Grimelli, Danielle; Hamilton, Derek A; Wallace, Douglas G

    2013-05-01

    This series of experiments evaluates the nature of the representation that mediates human (Homo sapiens) and rat (Rattus norvegicus) movement characteristics on analogous spatial learning tasks. The results of Experiment 1 demonstrated that self-movement cues were sufficient to guide the performance of human participants during place training and matching-to-place testing tasks adapted to tabletop or manipulatory scale. Experiment 2 investigated the effect of manipulating access to environmental cues during place training on the nature of the representation used to guide performance. Blindfolded human participants appeared to encode the absolute location of the goal, whereas participants with access to environmental cues appeared to encode the relative location of the goal. The results of Experiment 3 demonstrated that human participants with access to environmental cues exhibited a similar response tendency (as observed in Experiment 2) after half as many trials of place training. During Experiment 4, rats exhibited movement characteristics in the water maze that were similar to movement characteristics observed in human participants who were provided access to environmental cues. These observations provide evidence that direction and distance estimation processes mediate performance on spatial tasks that are conserved across humans and rats.

  2. Social and emotional values of sounds influence human (Homo sapiens) and non-human primate (Cercopithecus campbelli) auditory laterality.

    PubMed

    Basile, Muriel; Lemasson, Alban; Blois-Heulin, Catherine

    2009-01-01

    The last decades evidenced auditory laterality in vertebrates, offering new important insights for the understanding of the origin of human language. Factors such as the social (e.g. specificity, familiarity) and emotional value of sounds have been proved to influence hemispheric specialization. However, little is known about the crossed effect of these two factors in animals. In addition, human-animal comparative studies, using the same methodology, are rare. In our study, we adapted the head turn paradigm, a widely used non invasive method, on 8-9-year-old schoolgirls and on adult female Campbell's monkeys, by focusing on head and/or eye orientations in response to sound playbacks. We broadcast communicative signals (monkeys: calls, humans: speech) emitted by familiar individuals presenting distinct degrees of social value (female monkeys: conspecific group members vs heterospecific neighbours, human girls: from the same vs different classroom) and emotional value (monkeys: contact vs threat calls; humans: friendly vs aggressive intonation). We evidenced a crossed-categorical effect of social and emotional values in both species since only "negative" voices from same class/group members elicited a significant auditory laterality (Wilcoxon tests: monkeys, T = 0 p = 0.03; girls: T = 4.5 p = 0.03). Moreover, we found differences between species as a left and right hemisphere preference was found respectively in humans and monkeys. Furthermore while monkeys almost exclusively responded by turning their head, girls sometimes also just moved their eyes. This study supports theories defending differential roles played by the two hemispheres in primates' auditory laterality and evidenced that more systematic species comparisons are needed before raising evolutionary scenario. Moreover, the choice of sound stimuli and behavioural measures in such studies should be the focus of careful attention.

  3. Do You See What I See? A Comparative Investigation of the Delboeuf Illusion in Humans (Homo sapiens), Rhesus Monkeys (Macaca mulatta) and Capuchin Monkeys (Cebus apella)

    PubMed Central

    Parrish, Audrey E.; Brosnan, Sarah F.; Beran, Michael J.

    2015-01-01

    Studying visual illusions is critical to understanding typical visual perception. We investigated whether rhesus monkeys (Macaca mulatta) and capuchin monkeys (Cebus apella) perceived the Delboeuf illusion in a similar manner as human adults (Homo sapiens). To test this, in Experiment 1, we presented monkeys and humans with a relative discrimination task that required subjects to choose the larger of two central dots that were sometimes encircled by concentric rings. As predicted, humans demonstrated evidence of the Delboeuf illusion, overestimating central dots when small rings surrounded them and underestimating the size of central dots when large rings surrounded them. However, monkeys did not show evidence of the illusion. To rule out an alternate explanation, in Experiment 2, we presented all species with an absolute classification task that required them to classify a central dot as ‘small’ or ‘large.’ We presented a range of ring sizes to determine whether the Delboeuf illusion would occur for any dot-to-ring ratios. Here, we found evidence of the Delboeuf illusion in all three species. Humans and monkeys underestimated central dot size to a progressively greater degree with progressively larger rings. The Delboeuf illusion now has been extended to include capuchin monkeys and rhesus monkeys, and through such comparative investigations we can better evaluate hypotheses regarding illusion perception among nonhuman animals. PMID:26322505

  4. Karyotype evolution of giraffes (Giraffa camelopardalis) revealed by cross-species chromosome painting with Chinese muntjac (Muntiacus reevesi) and human (Homo sapiens) paints.

    PubMed

    Huang, L; Nesterenko, A; Nie, W; Wang, J; Su, W; Graphodatsky, A S; Yang, F

    2008-01-01

    Considering the giraffe (Giraffa camelopardalis, GCA, 2n = 30) as a primitive species, its comparative genomic data are critical for our understanding of the karyotype evolution of pecorans. Here, we have established genome-wide chromosomal homologies between giraffe, Chinese muntjac (Muntiacus reevesi, MRE, 2n = 46) and human (Homo sapiens, HSA, 2n = 46) with whole sets of chromosome-specific paints from Chinese muntjac and human, in addition to providing a high-resolution G-banding karyotype of giraffe. Chinese muntjac and human chromosome paints detected 32 and 45 autosomal homologs in the genome of giraffe, respectively. Our results suggest that it would require at least thirteen fissions, six fusions and three intrachromosomal rearrangements to 'transform' the 2n = 44 eutherian ancestral karyotype to the 2n = 58 pecoran ancestral karyotype. During giraffe evolution, some ancestral eutherian syntenies (i.e. association of HSA3/21, 4/8, 7/16, 14/15, 16/19 and two forms of 12/22) have been retained, while several derived syntenies (i.e. associations of human homologous segments 2/1, 2/9, 5/19, 4/12/22, 8/9, and 10/20) have been produced. The reduction of chromosome number in giraffe from the 2n = 58 pecoran ancestral karyotype could be primarily attributed to extensive Robertsonian translocations of ancestral chromosomal segments. More complex chromosomal rearrangements (including tandem fusion, centromere repositioning and pericentric inversion) have happened during the evolution of GCA2 and GCA8.

  5. Karyotype evolution of giraffes (Giraffa camelopardalis) revealed by cross-species chromosome painting with Chinese muntjac (Muntiacus reevesi) and human (Homo sapiens) paints.

    PubMed

    Huang, L; Nesterenko, A; Nie, W; Wang, J; Su, W; Graphodatsky, A S; Yang, F

    2008-01-01

    Considering the giraffe (Giraffa camelopardalis, GCA, 2n = 30) as a primitive species, its comparative genomic data are critical for our understanding of the karyotype evolution of pecorans. Here, we have established genome-wide chromosomal homologies between giraffe, Chinese muntjac (Muntiacus reevesi, MRE, 2n = 46) and human (Homo sapiens, HSA, 2n = 46) with whole sets of chromosome-specific paints from Chinese muntjac and human, in addition to providing a high-resolution G-banding karyotype of giraffe. Chinese muntjac and human chromosome paints detected 32 and 45 autosomal homologs in the genome of giraffe, respectively. Our results suggest that it would require at least thirteen fissions, six fusions and three intrachromosomal rearrangements to 'transform' the 2n = 44 eutherian ancestral karyotype to the 2n = 58 pecoran ancestral karyotype. During giraffe evolution, some ancestral eutherian syntenies (i.e. association of HSA3/21, 4/8, 7/16, 14/15, 16/19 and two forms of 12/22) have been retained, while several derived syntenies (i.e. associations of human homologous segments 2/1, 2/9, 5/19, 4/12/22, 8/9, and 10/20) have been produced. The reduction of chromosome number in giraffe from the 2n = 58 pecoran ancestral karyotype could be primarily attributed to extensive Robertsonian translocations of ancestral chromosomal segments. More complex chromosomal rearrangements (including tandem fusion, centromere repositioning and pericentric inversion) have happened during the evolution of GCA2 and GCA8. PMID:19096208

  6. Mechanistically Distinct Pathways of Divergent Regulatory DNA Creation Contribute to Evolution of Human-Specific Genomic Regulatory Networks Driving Phenotypic Divergence of Homo sapiens.

    PubMed

    Glinsky, Gennadi V

    2016-01-01

    Thousands of candidate human-specific regulatory sequences (HSRS) have been identified, supporting the hypothesis that unique to human phenotypes result from human-specific alterations of genomic regulatory networks. Collectively, a compendium of multiple diverse families of HSRS that are functionally and structurally divergent from Great Apes could be defined as the backbone of human-specific genomic regulatory networks. Here, the conservation patterns analysis of 18,364 candidate HSRS was carried out requiring that 100% of bases must remap during the alignments of human, chimpanzee, and bonobo sequences. A total of 5,535 candidate HSRS were identified that are: (i) highly conserved in Great Apes; (ii) evolved by the exaptation of highly conserved ancestral DNA; (iii) defined by either the acceleration of mutation rates on the human lineage or the functional divergence from non-human primates. The exaptation of highly conserved ancestral DNA pathway seems mechanistically distinct from the evolution of regulatory DNA segments driven by the species-specific expansion of transposable elements. Genome-wide proximity placement analysis of HSRS revealed that a small fraction of topologically associating domains (TADs) contain more than half of HSRS from four distinct families. TADs that are enriched for HSRS and termed rapidly evolving in humans TADs (revTADs) comprise 0.8-10.3% of 3,127 TADs in the hESC genome. RevTADs manifest distinct correlation patterns between placements of human accelerated regions, human-specific transcription factor-binding sites, and recombination rates. There is a significant enrichment within revTAD boundaries of hESC-enhancers, primate-specific CTCF-binding sites, human-specific RNAPII-binding sites, hCONDELs, and H3K4me3 peaks with human-specific enrichment at TSS in prefrontal cortex neurons (P < 0.0001 in all instances). Present analysis supports the idea that phenotypic divergence of Homo sapiens is driven by the evolution of human

  7. Mechanistically Distinct Pathways of Divergent Regulatory DNA Creation Contribute to Evolution of Human-Specific Genomic Regulatory Networks Driving Phenotypic Divergence of Homo sapiens.

    PubMed

    Glinsky, Gennadi V

    2016-09-19

    Thousands of candidate human-specific regulatory sequences (HSRS) have been identified, supporting the hypothesis that unique to human phenotypes result from human-specific alterations of genomic regulatory networks. Collectively, a compendium of multiple diverse families of HSRS that are functionally and structurally divergent from Great Apes could be defined as the backbone of human-specific genomic regulatory networks. Here, the conservation patterns analysis of 18,364 candidate HSRS was carried out requiring that 100% of bases must remap during the alignments of human, chimpanzee, and bonobo sequences. A total of 5,535 candidate HSRS were identified that are: (i) highly conserved in Great Apes; (ii) evolved by the exaptation of highly conserved ancestral DNA; (iii) defined by either the acceleration of mutation rates on the human lineage or the functional divergence from non-human primates. The exaptation of highly conserved ancestral DNA pathway seems mechanistically distinct from the evolution of regulatory DNA segments driven by the species-specific expansion of transposable elements. Genome-wide proximity placement analysis of HSRS revealed that a small fraction of topologically associating domains (TADs) contain more than half of HSRS from four distinct families. TADs that are enriched for HSRS and termed rapidly evolving in humans TADs (revTADs) comprise 0.8-10.3% of 3,127 TADs in the hESC genome. RevTADs manifest distinct correlation patterns between placements of human accelerated regions, human-specific transcription factor-binding sites, and recombination rates. There is a significant enrichment within revTAD boundaries of hESC-enhancers, primate-specific CTCF-binding sites, human-specific RNAPII-binding sites, hCONDELs, and H3K4me3 peaks with human-specific enrichment at TSS in prefrontal cortex neurons (P < 0.0001 in all instances). Present analysis supports the idea that phenotypic divergence of Homo sapiens is driven by the evolution of human

  8. Ecospaces occupied by Homo erectus and Homo sapiens in insular Southeast Asia in the Pleistocene

    NASA Astrophysics Data System (ADS)

    Hertler, Christine; Haupt, Susanne; Volmer, Rebekka; Bruch, Angela

    2014-05-01

    Hominins migrated to the islands of the Sunda Shelf multiple times. At least two immigration events are evident, an early immigration of Homo erectus in the late Early Pleistocene and a second immigration of Homo sapiens during the Late Pleistocene. Regional environments changed considerably in the Pleistocene. Expansion patterns among hominins are at least co-determined by their ecologies and environmental change. We examine these expansion patterns on the basis of habitat reconstructions. Mammalian communities provide a geographically extensive record and permit to assess hominin ecospaces. Although chronological resolution is low, they represent the most complete record of habitat changes associated with hominin expansion patterns. In order to reconstruct and compare hominin ecospaces on a quantitative scale, we set up a reference sample consisting of mammalian communities of 117 national parks in South Asia and Sub-Saharan Africa. The diversity of such communities is assessed by ecological profiling of specialized herbivore taxa. Moreover, datasets on climate and vegetation correlate with the diversity structure of such specialized herbivore communities. Reconstructing the diversity structure of communities at key sites in Pleistocene Southeast Asia permits to infer features of the climatic and vegetation framework associated with different hominin taxa. Our results show that Homo erectus and Homo sapiens did not occupy similar ecospaces. The ecospace of Homo erectus is characterized by comparatively low diversity among frugivorous and folivorous taxa, while obligate grazers are part of the assemblages. Specialized herbivore communities with such a diversity structure occur at present in East Africa, while they are absent in Southeast Asia. In the reference sample, this type of ecospace corresponds to seasonal wetlands. Although Homo sapiens still inhabits this type of environment in Southeast Asia, his ecospace is wider. Homo sapiens is associated with

  9. Crystal structure of Homo sapiens protein LOC79017

    SciTech Connect

    Bae, Euiyoung; Bingman, Craig A.; Aceti, David J.; Phillips, Jr., George N.

    2010-02-08

    LOC79017 (MW 21.0 kDa, residues 1-188) was annotated as a hypothetical protein encoded by Homo sapiens chromosome 7 open reading frame 24. It was selected as a target by the Center for Eukaryotic Structural Genomics (CESG) because it did not share more than 30% sequence identity with any protein for which the three-dimensional structure is known. The biological function of the protein has not been established yet. Parts of LOC79017 were identified as members of uncharacterized Pfam families (residues 1-95 as PB006073 and residues 104-180 as PB031696). BLAST searches revealed homologues of LOC79017 in many eukaryotes, but none of them have been functionally characterized. Here, we report the crystal structure of H. sapiens protein LOC79017 (UniGene code Hs.530024, UniProt code O75223, CESG target number go.35223).

  10. Découverte d'un Homo sapiens archaïque à Oranjemund, NamibieDiscovery of an archaic Homo sapiens in Oranjemund, Namibia.

    NASA Astrophysics Data System (ADS)

    Senut, Brigitte; Pickford, Martin; Braga, José; Marais, Daan; Coppens, Yves

    2000-06-01

    The transition between Homo erectus and Homo sapiens in Africa is still a matter of debate due to the paucity of fossils and to the difficulty of estimating their chronologic age. The discovery of a well preserved skull-cap of archaic Homo sapiens (OMD 1'98) in Namibia on the banks of the Orange River enlarges the distribution of these archaic populations to southwestern Africa.

  11. Frequency-range discriminations: special and general abilities in zebra finches (Taeniopygia guttata) and humans (Homo sapiens).

    PubMed

    Weisman, R; Njegovan, M; Sturdy, C; Phillmore, L; Coyle, J; Mewhort, D

    1998-09-01

    The acoustic frequency ranges in birdsongs and human speech can provide important pitch cues for recognition. Zebra finches and humans were trained to sort contiguous frequencies into 3 or 8 ranges, based on associations between the ranges and reward. The 3-range task was conducted separately in 3 spectral regions. Zebra finches discriminated 3 ranges in the medium and high spectral regions faster than in the low region and discriminated 8 ranges with precision. Humans discriminated 3 ranges in all 3 spectral regions to the same modest standard and acquired only a crude discrimination of the lowest and highest of 8 ranges. The results indicate that songbirds have a special sensitivity to the pitches in conspecific songs and, relative to humans, have a remarkable general ability to sort pitches into ranges.

  12. Frequency-range discriminations: special and general abilities in zebra finches (Taeniopygia guttata) and humans (Homo sapiens).

    PubMed

    Weisman, R; Njegovan, M; Sturdy, C; Phillmore, L; Coyle, J; Mewhort, D

    1998-09-01

    The acoustic frequency ranges in birdsongs and human speech can provide important pitch cues for recognition. Zebra finches and humans were trained to sort contiguous frequencies into 3 or 8 ranges, based on associations between the ranges and reward. The 3-range task was conducted separately in 3 spectral regions. Zebra finches discriminated 3 ranges in the medium and high spectral regions faster than in the low region and discriminated 8 ranges with precision. Humans discriminated 3 ranges in all 3 spectral regions to the same modest standard and acquired only a crude discrimination of the lowest and highest of 8 ranges. The results indicate that songbirds have a special sensitivity to the pitches in conspecific songs and, relative to humans, have a remarkable general ability to sort pitches into ranges. PMID:9770314

  13. The effects of linear perspective on relative size discrimination in chimpanzees (Pan troglodytes) and humans (Homo sapiens).

    PubMed

    Imura, Tomoko; Tomonaga, Masaki; Yagi, Akihiro

    2008-03-01

    In this study, we tested the corridor illusion in three chimpanzees and five humans, applying a relative size discrimination task to assess pictorial depth perception using linear perspective. The subjects were required to choose the physically larger cylinder of two on a background containing drawn linear perspective cues. We manipulated both background and cylinder size in each trial. Our findings suggest that chimpanzees, like humans, exhibit the corridor illusion.

  14. Homo sapiens, Homo neanderthalensis and the Denisova specimen: New insights on their evolutionary histories using whole-genome comparisons

    PubMed Central

    Paixão-Côrtes, Vanessa Rodrigues; Viscardi, Lucas Henrique; Salzano, Francisco Mauro; Hünemeier, Tábita; Bortolini, Maria Cátira

    2012-01-01

    After a brief review of the most recent findings in the study of human evolution, an extensive comparison of the complete genomes of our nearest relative, the chimpanzee (Pan troglodytes), of extant Homo sapiens, archaic Homo neanderthalensis and the Denisova specimen were made. The focus was on non-synonymous mutations, which consequently had an impact on protein levels and these changes were classified according to degree of effect. A total of 10,447 non-synonymous substitutions were found in which the derived allele is fixed or nearly fixed in humans as compared to chimpanzee. Their most frequent location was on chromosome 21. Their presence was then searched in the two archaic genomes. Mutations in 381 genes would imply radical amino acid changes, with a fraction of these related to olfaction and other important physiological processes. Eight new alleles were identified in the Neanderthal and/or Denisova genetic pools. Four others, possibly affecting cognition, occured both in the sapiens and two other archaic genomes. The selective sweep that gave rise to Homo sapiens could, therefore, have initiated before the modern/archaic human divergence. PMID:23413113

  15. Homo sapiens, Homo neanderthalensis and the Denisova specimen: New insights on their evolutionary histories using whole-genome comparisons.

    PubMed

    Paixão-Côrtes, Vanessa Rodrigues; Viscardi, Lucas Henrique; Salzano, Francisco Mauro; Hünemeier, Tábita; Bortolini, Maria Cátira

    2012-12-01

    After a brief review of the most recent findings in the study of human evolution, an extensive comparison of the complete genomes of our nearest relative, the chimpanzee (Pan troglodytes), of extant Homo sapiens, archaic Homo neanderthalensis and the Denisova specimen were made. The focus was on non-synonymous mutations, which consequently had an impact on protein levels and these changes were classified according to degree of effect. A total of 10,447 non-synonymous substitutions were found in which the derived allele is fixed or nearly fixed in humans as compared to chimpanzee. Their most frequent location was on chromosome 21. Their presence was then searched in the two archaic genomes. Mutations in 381 genes would imply radical amino acid changes, with a fraction of these related to olfaction and other important physiological processes. Eight new alleles were identified in the Neanderthal and/or Denisova genetic pools. Four others, possibly affecting cognition, occured both in the sapiens and two other archaic genomes. The selective sweep that gave rise to Homo sapiens could, therefore, have initiated before the modern/archaic human divergence. PMID:23413113

  16. Rules and Resemblance: Their Changing Balance in the Category Learning of Humans (Homo sapiens) and Monkeys (Macaca mulatta)

    PubMed Central

    Couchman, Justin J.; Coutinho, Mariana V. C.; Smith, J. David

    2010-01-01

    In an early dissociation between intentional and incidental category learning, Kemler Nelson (1984) gave participants a categorization task that could be performed by responding either to a single-dimensional rule or to overall family resemblance. Humans learning intentionally deliberately adopted rule-based strategies; humans learning incidentally adopted family-resemblance strategies. The present authors replicated Kemler Nelson’s human experiment and found a similar dissociation. They also extended her paradigm so as to evaluate the balance between rules and family-resemblance in determining the category decisions of rhesus monkeys. Monkeys heavily favored the family-resemblance strategy. Formal models showed that even after many sessions and thousands of trials, they spread attention across all stimulus dimensions rather than focus on a single, criterial dimension that could also produce perfect categorization. PMID:20384398

  17. Can Chimpanzee Infants ("Pan Troglodytes") Form Categorical Representations in the Same Manner as Human Infants ("Homo Sapiens")?

    ERIC Educational Resources Information Center

    Murai, Chizuko; Kosugi, Daisuke; Tomonaga, Masaki; Tanaka, Masayuki; Matsuzawa, Tetsuro; Itakura, Shoji

    2005-01-01

    We directly compared chimpanzee infants and human infants for categorical representations of three global-like categories (mammals, furniture and vehicles), using the familiarization-novelty preference technique. Neither species received any training during the experiments. We used the time that participants spent looking at the stimulus object…

  18. Cashing Out: The Decisional Flexibility of Uncertainty Responses in Rhesus Macaques (Macaca mulatta) and Humans (Homo sapiens)

    PubMed Central

    Zakrzewski, Alexandria C.; Perdue, Bonnie M.; Beran, Michael J.; Church, Barbara A.; Smith, J. David

    2014-01-01

    Researchers are exploring whether animals share with humans something like a metacognitive capacity. Though some results point to human-animal continuities in this domain, they face the dominant criticism that animals’ performances might be associative. A persistent problem is that animal-metacognition paradigms present static environments of risk and reward that may foster inflexible and conditioned responding. Those environments do not challenge animals to show the flexibility in their decision strategies that could indicate an antecedent capacity to metacognition. Accordingly, we tested macaques and humans on an uncertainty-monitoring paradigm in which risk changed dynamically. Participants classified stimuli of different difficulties while also choosing when to use a cashout response to collect the accumulated rewards that would be forfeit on a discrimination error. Macaques and humans flexibly adjusted their decision criteria to achieve appropriate protection against the cost of error that could differ depending on trial difficulty and the number of rewards at risk. In particular, monkeys widened their cashout-response region as their accumulated rewards increased, providing more protection against a more costly error. These findings demonstrate a new continuity between humans’ and animals’ uncertainty systems. They reveal a calibration by macaques of present risk to trial difficulty tolerated. They show that animals’ uncertainty-monitoring and risk-management systems have substantial trial-by-trial flexibility. PMID:25546106

  19. Spatial working memory in immersive virtual reality foraging: path organization, traveling distance and search efficiency in humans (Homo sapiens).

    PubMed

    De Lillo, Carlo; Kirby, Melissa; James, Frances C

    2014-05-01

    Search and serial recall tasks were used in the present study to characterize the factors affecting the ability of humans to keep track of a set of spatial locations while traveling in an immersive virtual reality foraging environment. The first experiment required the exhaustive exploration of a set of locations following a procedure previously used with other primate and non-primate species to assess their sensitivity to the geometric arrangement of foraging sites. The second experiment assessed the dependency of search performance on search organization by requiring the participants to recall specific trajectories throughout the foraging space. In the third experiment, the distance between the foraging sites was manipulated in order to contrast the effects of organization and traveling distance on recall accuracy. The results show that humans benefit from the use of organized search patterns when attempting to monitor their travel though either a clustered "patchy" space or a matrix of locations. Their ability to recall a series of locations is dependent on whether the order in which they are explored conformed or did not conform to specific organization principles. Moreover, the relationship between search efficiency and search organization is not confounded by effects of traveling distance. These results indicate that in humans, organizational factors may play a large role in their ability to forage efficiently. The extent to which such dependency may pertain to other primates and could be accounted for by visual organization processes is discussed on the basis of previous studies focused on perceptual grouping, search, and serial recall in non-human species. PMID:24038208

  20. Spatial working memory in immersive virtual reality foraging: path organization, traveling distance and search efficiency in humans (Homo sapiens).

    PubMed

    De Lillo, Carlo; Kirby, Melissa; James, Frances C

    2014-05-01

    Search and serial recall tasks were used in the present study to characterize the factors affecting the ability of humans to keep track of a set of spatial locations while traveling in an immersive virtual reality foraging environment. The first experiment required the exhaustive exploration of a set of locations following a procedure previously used with other primate and non-primate species to assess their sensitivity to the geometric arrangement of foraging sites. The second experiment assessed the dependency of search performance on search organization by requiring the participants to recall specific trajectories throughout the foraging space. In the third experiment, the distance between the foraging sites was manipulated in order to contrast the effects of organization and traveling distance on recall accuracy. The results show that humans benefit from the use of organized search patterns when attempting to monitor their travel though either a clustered "patchy" space or a matrix of locations. Their ability to recall a series of locations is dependent on whether the order in which they are explored conformed or did not conform to specific organization principles. Moreover, the relationship between search efficiency and search organization is not confounded by effects of traveling distance. These results indicate that in humans, organizational factors may play a large role in their ability to forage efficiently. The extent to which such dependency may pertain to other primates and could be accounted for by visual organization processes is discussed on the basis of previous studies focused on perceptual grouping, search, and serial recall in non-human species.

  1. Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology

    SciTech Connect

    Watson, J.D.; Siniscalco, M.

    1986-01-01

    This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

  2. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific

    SciTech Connect

    Rapacz, J.; Hasler-Rapacz, J.O. ); Chen, L.; Wu, Mingjiuan; Schumaker, V.N. ); Butler-Brunner, E.; Butler, R. )

    1991-02-15

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes.

  3. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific.

    PubMed Central

    Rapacz, J; Chen, L; Butler-Brunner, E; Wu, M J; Hasler-Rapacz, J O; Butler, R; Schumaker, V N

    1991-01-01

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes. PMID:1996341

  4. Identification of the ancestral haplotype for apolipoprotein B suggests an African origin of Homo sapiens sapiens and traces their subsequent migration to Europe and the Pacific.

    PubMed

    Rapacz, J; Chen, L; Butler-Brunner, E; Wu, M J; Hasler-Rapacz, J O; Butler, R; Schumaker, V N

    1991-02-15

    The probable ancestral haplotype for human apolipoprotein B (apoB) has been identified through immunological analysis of chimpanzee and gorilla serum and sequence analysis of their DNA. Moreover, the frequency of this ancestral apoB haplotype among different human populations provides strong support for the African origin of Homo sapiens sapiens and their subsequent migration from Africa to Europe and to the Pacific. The approach used here for the identification of the ancestral human apoB haplotype is likely to be applicable to many other genes. PMID:1996341

  5. Bone strength and athletic ability in hominids: Ardipithecus ramidus to Homo sapiens

    NASA Astrophysics Data System (ADS)

    Lee, S. A.

    2013-03-01

    The ability of the femur to resist bending stresses is determined by its midlength cross-sectional geometry, its length and the elastic properties of the mineral part of the bone. The animal's athletic ability, determined by a ``bone strength index,'' is limited by this femoral bending strength in relation to the loads on the femur. This analysis is applied to the fossil record for Homo sapiens, Homo neanderthalensis, Homo erectus, Homo habilis, Australopithecus afarensis and Ardipithecus ramidus. Evidence that the femoral bone strength index of modern Homo sapiens has weakened over the last 50,000 years is found.

  6. Tissue-Specific Methylation of Long Interspersed Nucleotide Element-1 of Homo Sapiens (L1Hs) During Human Embryogenesis and Roles in Neural Tube Defects.

    PubMed

    Wang, L; Chang, S; Guan, J; Shangguan, S; Lu, X; Wang, Z; Wu, L; Zou, J; Zhao, H; Bao, Y; Qiu, Z; Niu, B; Zhang, T

    2015-01-01

    Epigenetic regulation of long interspersed nucleotide element-1 (LINE-1) retrotransposition events plays crucial roles during early development. Previously we showed that LINE-1 hypomethylation in neuronal tissues is associated with pathogenesis of neural tube defect (NTD). Herein, we further evaluated LINE-1 Homo sapiens (L1Hs) methylation in tissues derived from three germ layers of stillborn NTD fetuses, to define patterns of tissue specific methylation and site-specific hypomethylation at CpG sites within an L1Hs promoter region. Stable, tissue-specific L1Hs methylation patterns throughout three germ layer lineages of the fetus, placenta, and maternal peripheral blood were observed. Samples from maternal peripheral blood exhibited the highest level of L1Hs methylation (64.95%) and that from placenta showed the lowest (26.82%). Between samples from NTDs and controls, decrease in L1Hs methylation was only significant in NTD-affected brain tissue at 7.35%, especially in females (8.98%). L1Hs hypomethylation in NTDs was also associated with a significant increase in expression level of an L1Hs-encoded transcript in females (r = -0.846, p = 0.004). This could be due to genomic DNA instability and alternation in chromatins accessibility resulted from abnormal L1Hs hypomethylation, as showed in this study with HCT-15 cells treated with methylation inhibitor 5-Aza.

  7. The dispersal of Homo sapiens across southern Asia: how early, how often, how complex?

    NASA Astrophysics Data System (ADS)

    Dennell, Robin; Petraglia, Michael D.

    2012-07-01

    The timing and the paths of colonization of southern Asia by Homo sapiens are poorly known, though many population geneticists, paleoanthropologists, and archaeologists have contended that this process began with dispersal from East Africa, and occurred between 60,000 and 40,000 years ago. However, the evidence for this scenario is very weak, particularly the lack of human skeletal evidence between the Levant and Borneo before 40 ka, and other explanations are possible. Here we argue that environmental and archaeological information is increasingly indicating the likelihood that H. sapiens exited Africa much earlier than commonly thought, and may have colonized much of southern Asia well before 60,000 years ago. Additionally, we cannot exclude the possibility that several dispersal events occurred, from both North and East Africa, nor the likelihood that early populations of H. sapiens in southern Asia interbred with indigenous populations of Neanderthals, Denisovans and Homo erectus. The population history of southern Asia during the Upper Pleistocene is likely far more complex than currently envisaged.

  8. Sky Luminaries in the Space Orienting Activity of Homo Sapiens in the Middle Palaeolithic

    NASA Astrophysics Data System (ADS)

    Kaurov, E. N.

    Data describing the beginnings of the space orienting activity of Homo sapiens is analysed and systematized: observation of the Pole and the recognition of Ursa Major were used as the basis of the determination of the points of the compass. Data and results from astronomy, history of astronomy, archaeology and palaeoanthropology were used for the reconstruction of the evolution of the space orienting activity of Homo sapiens.

  9. Bone strength and athletic ability in hominids: Ardipithecus ramidus to Homo sapiens

    NASA Astrophysics Data System (ADS)

    Lee, Scott

    2012-10-01

    A methodology for the evaluation of the athletic ability of animals based on the strength of their femur and their body mass is developed. The ability of the femur to resist bending stresses is determined by its midlength cross-sectional geometry, its length and the elastic properties of the mineral part of the bone. The animal's athletic ability, determined by a ``bone strength index,'' is limited by this femoral bending strength in relation to the loads on the femur. This analysis is applied to the fossil record for Homo sapiens, Homo neanderthalensis, Homo erectus, Homo habilis, Australopithecus afarensis and Ardipithecus ramidus. Evidence that the femoral bone strength index of modern Homo sapiens has weakened over the last 50,000 years is found.

  10. Self-control across species (Columba livia, Homo sapiens, and Rattus norvegicus).

    PubMed

    Tobin, H; Logue, A W

    1994-06-01

    Data from six previous studies of self-control behavior were compared against predictions made by the matching law and by molar maximization. The studies involved pigeons (Columba livia), rats (Rattus norvegicus), and 3-year-old, 5-year-old, and adult humans (Homo sapiens) who had received food as the reinforcer, and adult humans who had received points exchangeable for money as the reinforcer. Neither theory proved to be an accurate or better predictor for all groups. In contrast to the predictions of these theories, self-control was shown to vary according to species, human age group, and reinforcer quality. When the reinforcer was food, the self-control of different species was found to be negatively correlated with metabolic rate; that is, larger species showed greater self-control. These results suggest that allometric scaling may prove useful in describing and predicting species differences in self-control.

  11. Stratigraphic, chronological and behavioural contexts of Pleistocene Homo sapiens from Middle Awash, Ethiopia.

    PubMed

    Clark, J Desmond; Beyene, Yonas; WoldeGabriel, Giday; Hart, William K; Renne, Paul R; Gilbert, Henry; Defleur, Alban; Suwa, Gen; Katoh, Shigehiro; Ludwig, Kenneth R; Boisserie, Jean-Renaud; Asfaw, Berhane; White, Tim D

    2003-06-12

    Clarifying the geographic, environmental and behavioural contexts in which the emergence of anatomically modern Homo sapiens occurred has proved difficult, particularly because Africa lacked adequate geochronological, palaeontological and archaeological evidence. The discovery of anatomically modern Homo sapiens fossils at Herto, Ethiopia, changes this. Here we report on stratigraphically associated Late Middle Pleistocene artefacts and fossils from fluvial and lake margin sandstones of the Upper Herto Member of the Bouri Formation, Middle Awash, Afar Rift, Ethiopia. The fossils and artefacts are dated between 160,000 and 154,000 years ago by precise age determinations using the 40Ar/39Ar method. The archaeological assemblages contain elements of both Acheulean and Middle Stone Age technocomplexes. Associated faunal remains indicate repeated, systematic butchery of hippopotamus carcasses. Contemporary adult and juvenile Homo sapiens fossil crania manifest bone modifications indicative of deliberate mortuary practices. PMID:12802333

  12. Evaluating the transitional mosaic: frameworks of change from Neanderthals to Homo sapiens in eastern Europe

    NASA Astrophysics Data System (ADS)

    Davies, William; White, Dustin; Lewis, Mark; Stringer, Chris

    2015-06-01

    Defining varying spatial and temporal analytical scales is essential before evaluating the responses of late Neanderthals and early Homo sapiens to Abrupt Environmental Transitions (AETs) and environmental disasters for the period 130-25 ka. Recent advances in addressing the population histories and interactions (using both genetic and archaeological evidence) of Neanderthals and H. sapiens have encouraged consideration of more subtle dynamics of archaeological change. Descriptions of change based on methodologies pioneered some 160 years ago are no longer adequate to explain the patterning we now see in the record. New chronological results, using multiple dating methods, allow us to begin to unpick the spatial and temporal scales of change. Isochronic markers (such as specific volcanic eruptions) can be used to create temporal frameworks (lattices), and results from other dating techniques compared against them. A combination of chronological lattices and direct dating of diagnostic artefacts and human fossils permits us, for the first time, to have greater confidence in connecting human (recent hominin) species and their behavioural responses to environmental conditions, and in quantifying scales of change over time and space (time-transgression). The timing of innovations, particularly those in bone, antler and ivory, can be directly quantified and tested, and used to re-evaluate longstanding models of cultural change. This paper also uses these new chronologies to explore the ecologies of late Neanderthals and early H. sapiens: their population densities, mobilities, resources exploited and possible interactions. Environmental productivity estimates are used to generate new questions of potential population densities and mobilities, and thus the sensitivity of these groups to environmental perturbations. Scales and intensities of effect on environments from natural disasters and AETs (notably Heinrich Events and the Campanian Ignimbrite eruption) are defined

  13. Development of the palatal size in Pan troglodytes, Hominids and Homo sapiens.

    PubMed

    Arnold, W H; Zoellner, A; Sebastian, T

    2004-12-01

    As the hard palate plays an important role in speech production it was the aim of this study whether similarities or dissimilarities in palatal size may allow conclusions about the ability to produce speech in the extant investigated species. The palatal size of Pan troglodytes, Homo sapiens, Australopithecus afarensis, Australopithecus africanus, Australopithecus robustus, Australopithecus boisei, Homo erectus, Homo neanderthalensis and Cro-Magnon has been investigated using euclidian distance matrix analysis (EDMA) and thin-plate-spline analysis. The results show that the palatal size of all australopithecine specimens and H. erectus is very similar to that of P toglodytes, whereas the palatal size of H. neanderthalensis more closely resembles that of H. sapiens. Postnatal development of palatal size in P troglodytes is different from that of H. sapiens. In P troglodytes not only the size of the palate changes but also the form. In H. sapiens there is little change in form, but a continuos uniform growth from infantile to adult specimens. From the results we conclude that in all australopithecine samples which have been investigated, the palatal size is similar to that of P troglodytes. Therefore, it is unlikely that austraopithecine individuals were capable of producing vowels and consonants. The palatal size of H. neandethalensis and Cro-Magnon is similar to that of H. sapiens which may indicate the possibility that they were capable of speech production.

  14. Development of the palatal size in Pan troglodytes, Hominids and Homo sapiens.

    PubMed

    Arnold, W H; Zoellner, A; Sebastian, T

    2004-12-01

    As the hard palate plays an important role in speech production it was the aim of this study whether similarities or dissimilarities in palatal size may allow conclusions about the ability to produce speech in the extant investigated species. The palatal size of Pan troglodytes, Homo sapiens, Australopithecus afarensis, Australopithecus africanus, Australopithecus robustus, Australopithecus boisei, Homo erectus, Homo neanderthalensis and Cro-Magnon has been investigated using euclidian distance matrix analysis (EDMA) and thin-plate-spline analysis. The results show that the palatal size of all australopithecine specimens and H. erectus is very similar to that of P toglodytes, whereas the palatal size of H. neanderthalensis more closely resembles that of H. sapiens. Postnatal development of palatal size in P troglodytes is different from that of H. sapiens. In P troglodytes not only the size of the palate changes but also the form. In H. sapiens there is little change in form, but a continuos uniform growth from infantile to adult specimens. From the results we conclude that in all australopithecine samples which have been investigated, the palatal size is similar to that of P troglodytes. Therefore, it is unlikely that austraopithecine individuals were capable of producing vowels and consonants. The palatal size of H. neandethalensis and Cro-Magnon is similar to that of H. sapiens which may indicate the possibility that they were capable of speech production. PMID:15646285

  15. Gracility of the modern Homo sapiens skeleton is the result of decreased biomechanical loading

    PubMed Central

    Ryan, Timothy M.; Shaw, Colin N.

    2015-01-01

    The postcranial skeleton of modern Homo sapiens is relatively gracile compared with other hominoids and earlier hominins. This gracility predisposes contemporary humans to osteoporosis and increased fracture risk. Explanations for this gracility include reduced levels of physical activity, the dissipation of load through enlarged joint surfaces, and selection for systemic physiological characteristics that differentiate modern humans from other primates. This study considered the skeletal remains of four behaviorally diverse recent human populations and a large sample of extant primates to assess variation in trabecular bone structure in the human hip joint. Proximal femur trabecular bone structure was quantified from microCT data for 229 individuals from 31 extant primate taxa and 59 individuals from four distinct archaeological human populations representing sedentary agriculturalists and mobile foragers. Analyses of mass-corrected trabecular bone variables reveal that the forager populations had significantly higher bone volume fraction, thicker trabeculae, and consequently lower relative bone surface area compared with the two agriculturalist groups. There were no significant differences between the agriculturalist and forager populations for trabecular spacing, number, or degree of anisotropy. These results reveal a correspondence between human behavior and bone structure in the proximal femur, indicating that more highly mobile human populations have trabecular bone structure similar to what would be expected for wild nonhuman primates of the same body mass. These results strongly emphasize the importance of physical activity and exercise for bone health and the attenuation of age-related bone loss. PMID:25535352

  16. Life as a Cosmic Phenomenon: 2. the Panspermic Trajectory of Homo Sapiens

    NASA Astrophysics Data System (ADS)

    Tokoro, Gensuke; Wickramasinghe, N. Chandra

    We discuss the origin and evolution of Homo sapiens in a cosmic context, and in relation to the Hoyle-Wickramasinghe theory of panspermia for which there is now overwhelming evidence. It is argued that the first bacteria (archea) incident on the Earth via the agency of comets 3.8-4 billion years ago continued at later times to be augmented by viral genes (DNA, RNA) from space that eventually led to the evolutionary patterns we see in present-day biology. We argue that the current evolutionary status of Homo sapiens as well as its future trajectory is circumscribed by evolutionary processes that were pre-determined on a cosmic scale -- over vast distances and enormous spans of cosmic time. Based on this teleological hypothesis we postulate that two distinct classes of cosmic viruses (cosmic viral genes) are involved in accounting for the facts relating to the evolution of life.

  17. Do primates see the solitaire illusion differently? A comparative assessment of humans (Homo sapiens), chimpanzees (Pan troglodytes), rhesus monkeys (Macaca mulatta), and capuchin monkeys (Cebus apella).

    PubMed

    Agrillo, Christian; Parrish, Audrey E; Beran, Michael J

    2014-11-01

    An important question in comparative psychology is whether human and nonhuman animals share similar principles of perceptual organization. Despite much empirical research, no firm conclusion has been drawn. The Solitaire illusion is a numerosity illusion in humans that occurs when one misperceives the relative number of 2 types of items presented in intermingled sets. To date, no study has investigated whether nonhuman animals perceive the Solitaire illusion as humans do. Here, we compared the perception of the Solitaire illusion in human and nonhuman primates in 3 experiments. We first observed (Experiment 1) the spontaneous behavior of chimpanzees when presented with 2 arrays composed of a different number of preferred and nonpreferred food items. In probe trials, preferred items were presented in the Solitaire pattern in 2 different spatial arrangements (either clustered centrally or distributed on the perimeter). Chimpanzees did not show any misperception of quantity in the Solitaire pattern. Next, humans, chimpanzees, rhesus monkeys, and capuchin monkeys underwent the same testing of relative quantity judgments in a computerized task that also presented the Solitaire illusion (Experiments 2 and 3). Unlike humans, chimpanzees did not appear to perceive the illusion, in agreement with Experiment 1. The performance of rhesus monkeys and capuchin monkeys was also different from that of humans, but was slightly more indicative of a potential Solitaire illusion. On the whole, our results suggest a potential discontinuity in the visual mechanisms underlying the Solitaire illusion between human and nonhuman primates.

  18. Cold Spring Harbor symposia on quantitative biology: Volume 51, Molecular biology of Homo sapiens

    SciTech Connect

    Not Available

    1986-01-01

    Thirteen years marked the time between the discovery of the double helix in 1953 and the elucidation of the genetic code in 1966. A similar interval has now passed since the development by Cohen and Boyer of a simple procedure for the cloning of selective DNA fragments. The scientific advances made possible by the subsequent modification and elaboration of these original cloning procedures now amaze, stimulate, and increasingly often overwhelm us. Facts that until recently were virtually unobtainable now flow forth almost effortlessly. Most excitingly, the frenetic pace of these new discoveries, instead of marking the impending end of a glorious moment of learning, give every indication of opening up scientific frontiers that will take hundreds if not thousands of years to explore thoroughly. This new era of enlightenment is nowhere more apparent than in our newfound ability to study ourselves at the molecular level. This volume is the first of two collections of papers submitted by the contributors to the Cold Spring Harbor symposia on quantitative biology for 1986 - molecular biology of Homo sapiens. Contained in this collection are 80 papers grouped into sessions entitled Human Gene Map, Genetic Diagnosis, Human Evolution, and Drugs Made Off Human Genes.

  19. Direct and indirect reputation formation in nonhuman great apes (Pan paniscus, Pan troglodytes, Gorilla gorilla, Pongo pygmaeus) and human children (Homo sapiens).

    PubMed

    Herrmann, Esther; Keupp, Stefanie; Hare, Brian; Vaish, Amrisha; Tomasello, Michael

    2013-02-01

    Humans make decisions about when and with whom to cooperate based on their reputations. People either learn about others by direct interaction or by observing third-party interactions or gossip. An important question is whether other animal species, especially our closest living relatives, the nonhuman great apes, also form reputations of others. In Study 1, chimpanzees, bonobos, orangutans, and 2.5-year-old human children experienced a nice experimenter who tried to give food/toys to the subject and a mean experimenter who interrupted the food/toy giving. In studies 2 and 3, nonhuman great apes and human children could only passively observe a similar interaction, in which a nice experimenter and a mean experimenter interacted with a third party. Orangutans and 2.5-year-old human children preferred to approach the nice experimenter rather than the mean one after having directly experienced their respective behaviors. Orangutans, chimpanzees, and 2.5-year-old human children also took into account experimenter actions toward third parties in forming reputations. These studies show that the human ability to form direct and indirect reputation judgment is already present in young children and shared with at least some of the other great apes.

  20. Stereology of the Thyroid Gland in Indo-Pacific Bottlenose Dolphin (Tursiops aduncus) in Comparison with Human (Homo sapiens): Quantitative and Functional Implications

    PubMed Central

    Kot, Brian Chin Wing; Lau, Thomas Yue Huen; Cheng, Sammy Chi Him

    2013-01-01

    The mammalian thyroid gland maintains basal metabolism in tissues for optimal function. Determining thyroid volume is important in assessing growth and involution. Volume estimation is also important in stereological studies. Direct measurements of colloid volume and nuclear-to-cytoplasmic ratio of the follicular cells may provide important information about thyroid gland function such as hormone storage and secretion, which helps understand the changes at morphological and functional levels. The present study determined the colloid volume using simple stereological principle and the nuclear-to-cytoplasmic ratio of 4 Indo-Pacific bottlenose dolphins and 2 human thyroid glands. In both dolphin and human thyroid glands, the size of the follicles tended to be quite variable. The distribution of large and small follicles within the thyroid gland was also found to be random in both the dolphin and human thyroid gland; however, the size of follicles appeared to decrease as a function of increasing age in the dolphin thyroid gland. The mean colloid volume of the dolphin thyroid gland and human thyroid gland was 1.22×105 µm3 and 7.02×105 µm3 respectively. The dolphin and human subjects had a significant difference in the mean colloid volume. The mean N/C ratio of the dolphin thyroid follicular epithelia and human follicular epithelia was 0.50 and 0.64 respectively. The dolphin and human subjects had a significant difference in the mean N/C ratio. This information contributes to understanding dolphin thyroid physiology and its structural adaptations to meet the physical demands of the aquatic environment, and aids with ultrasonography and corrective therapy in live subjects. PMID:23690927

  1. Stereology of the thyroid gland in Indo-Pacific bottlenose dolphin (Tursiops aduncus) in comparison with human (Homo sapiens): quantitative and functional implications.

    PubMed

    Kot, Brian Chin Wing; Lau, Thomas Yue Huen; Cheng, Sammy Chi Him

    2013-01-01

    The mammalian thyroid gland maintains basal metabolism in tissues for optimal function. Determining thyroid volume is important in assessing growth and involution. Volume estimation is also important in stereological studies. Direct measurements of colloid volume and nuclear-to-cytoplasmic ratio of the follicular cells may provide important information about thyroid gland function such as hormone storage and secretion, which helps understand the changes at morphological and functional levels. The present study determined the colloid volume using simple stereological principle and the nuclear-to-cytoplasmic ratio of 4 Indo-Pacific bottlenose dolphins and 2 human thyroid glands. In both dolphin and human thyroid glands, the size of the follicles tended to be quite variable. The distribution of large and small follicles within the thyroid gland was also found to be random in both the dolphin and human thyroid gland; however, the size of follicles appeared to decrease as a function of increasing age in the dolphin thyroid gland. The mean colloid volume of the dolphin thyroid gland and human thyroid gland was 1.22×10(5) µm(3) and 7.02×10(5) µm(3) respectively. The dolphin and human subjects had a significant difference in the mean colloid volume. The mean N/C ratio of the dolphin thyroid follicular epithelia and human follicular epithelia was 0.50 and 0.64 respectively. The dolphin and human subjects had a significant difference in the mean N/C ratio. This information contributes to understanding dolphin thyroid physiology and its structural adaptations to meet the physical demands of the aquatic environment, and aids with ultrasonography and corrective therapy in live subjects.

  2. Co-evolution of Mycobacterium tuberculosis and Homo sapiens

    PubMed Central

    Brites, Daniela; Gagneux, Sebastien

    2015-01-01

    The causative agent of human tuberculosis (TB), Mycobacterium tuberculosis, is an obligate pathogen that evolved to exclusively persist in human populations. For M. tuberculosis to transmit from person to person, it has to cause pulmonary disease. Therefore, M. tuberculosis virulence has likely been a significant determinant of the association between M. tuberculosis and humans. Indeed, the evolutionary success of some M. tuberculosis genotypes seems at least partially attributable to their increased virulence. The latter possibly evolved as a consequence of human demographic expansions. If co-evolution occurred, humans would have counteracted to minimize the deleterious effects of M. tuberculosis virulence. The fact that human resistance to infection has a strong genetic basis is a likely consequence of such a counter-response. The genetic architecture underlying human resistance to M. tuberculosis remains largely elusive. However, interactions between human genetic polymorphisms and M. tuberculosis genotypes have been reported. Such interactions are consistent with local adaptation and allow for a better understanding of protective immunity in TB. Future ‘genome-to-genome’ studies, in which locally associated human and M. tuberculosis genotypes are interrogated in conjunction, will help identify new protective antigens for the development of better TB vaccines. PMID:25703549

  3. Transfer between local and global processing levels by pigeons (Columba livia) and humans (Homo sapiens) in exemplar- and rule-based categorization tasks.

    PubMed

    Aust, Ulrike; Braunöder, Elisabeth

    2015-02-01

    The present experiment investigated pigeons' and humans' processing styles-local or global-in an exemplar-based visual categorization task in which category membership of every stimulus had to be learned individually, and in a rule-based task in which category membership was defined by a perceptual rule. Group Intact was trained with the original pictures (providing both intact local and global information), Group Scrambled was trained with scrambled versions of the same pictures (impairing global information), and Group Blurred was trained with blurred versions (impairing local information). Subsequently, all subjects were tested for transfer to the 2 untrained presentation modes. Humans outperformed pigeons regarding learning speed and accuracy as well as transfer performance and showed good learning irrespective of group assignment, whereas the pigeons of Group Blurred needed longer to learn the training tasks than the pigeons of Groups Intact and Scrambled. Also, whereas humans generalized equally well to any novel presentation mode, pigeons' transfer from and to blurred stimuli was impaired. Both species showed faster learning and, for the most part, better transfer in the rule-based than in the exemplar-based task, but there was no evidence of the used processing mode depending on the type of task (exemplar- or rule-based). Whereas pigeons relied on local information throughout, humans did not show a preference for either processing level. Additional tests with grayscale versions of the training stimuli, with versions that were both blurred and scrambled, and with novel instances of the rule-based task confirmed and further extended these findings.

  4. The Arrival of Homo sapiens into the Southern Cone at 14,000 Years Ago

    PubMed Central

    Politis, Gustavo G.; Gutiérrez, María A.; Blasi, Adriana

    2016-01-01

    The Arroyo Seco 2 site contains a rich archaeological record, exceptional for South America, to explain the expansion of Homo sapiens into the Americas and their interaction with extinct Pleistocene mammals. The following paper provides a detailed overview of material remains found in the earliest cultural episodes at this multi-component site, dated between ca. 12,170 14C yrs B.P. (ca. 14,064 cal yrs B.P.) and 11,180 14C yrs B.P. (ca. 13,068 cal yrs B.P.). Evidence of early occupations includes the presence of lithic tools, a concentration of Pleistocene species remains, human-induced fractured animal bones, and a selection of skeletal parts of extinct fauna. The occurrence of hunter-gatherers in the Southern Cone at ca. 14,000 cal yrs B.P. is added to the growing list of American sites that indicate a human occupation earlier than the Clovis dispersal episode, but posterior to the onset of the deglaciation of the Last Glacial Maximum (LGM) in the North America. PMID:27683248

  5. Looking Ahead? Computerized Maze Task Performance by Chimpanzees (Pan troglodytes), Rhesus Monkeys (Macaca mulatta), Capuchin Monkeys (Cebus apella), and Human Children (Homo sapiens)

    PubMed Central

    Beran, Michael J.; Parrish, Audrey E.; Futch, Sara E.; Evans, Theodore A.; Perdue, Bonnie M.

    2015-01-01

    Human and nonhuman primates are not mentally constrained to the present. They can remember the past and – at least to an extent – anticipate the future. Anticipation of the future ranges from long-term prospection such as planning for retirement to more short-term future oriented cognition such as planning a route through a maze. Here we tested a great ape species (chimpanzees), an Old World monkey species (rhesus macaques) a New World monkey species (capuchin monkeys) and human children on a computerized maze task. All subjects had to move a cursor through a maze to reach a goal at the bottom of the screen. For best performance on the task, subjects had to “plan ahead” to the end of the maze to move the cursor in the correct direction, avoid traps, and reverse directions if necessary. Mazes varied in difficulty. Chimpanzees were better than both monkey species, and monkeys showed a particular deficit when moving away from the goal or changing directions was required. Children showed a similar pattern to monkeys regarding the effects of reversals and moves away from the goal, but their overall performance in terms of correct maze completion was similar to the chimpanzees. The results highlight similarities as well as differences in planning across species and the role that inhibitory control may play in future oriented cognition in primates. PMID:25798793

  6. Looking ahead? Computerized maze task performance by chimpanzees (Pan troglodytes), rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and human children (Homo sapiens).

    PubMed

    Beran, Michael J; Parrish, Audrey E; Futch, Sara E; Evans, Theodore A; Perdue, Bonnie M

    2015-05-01

    Human and nonhuman primates are not mentally constrained to the present. They can remember the past and-at least to an extent-anticipate the future. Anticipation of the future ranges from long-term prospection such as planning for retirement to more short-term future-oriented cognition such as planning a route through a maze. Here we tested a great ape species (chimpanzees), an Old World monkey species (rhesus macaques), a New World monkey species (capuchin monkeys), and human children on a computerized maze task. All subjects had to move a cursor through a maze to reach a goal at the bottom of the screen. For best performance on the task, subjects had to "plan ahead" to the end of the maze to move the cursor in the correct direction, avoid traps, and reverse directions if necessary. Mazes varied in difficulty. Chimpanzees were better than both monkey species, and monkeys showed a particular deficit when moving away from the goal or changing directions was required. Children showed a similar pattern to monkeys regarding the effects of reversals and moves away from the goal, but their overall performance in terms of correct maze completion was similar to the chimpanzees. The results highlight similarities as well as differences in planning across species and the role that inhibitory control may play in future-oriented cognition in primates. PMID:25798793

  7. Looking ahead? Computerized maze task performance by chimpanzees (Pan troglodytes), rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and human children (Homo sapiens).

    PubMed

    Beran, Michael J; Parrish, Audrey E; Futch, Sara E; Evans, Theodore A; Perdue, Bonnie M

    2015-05-01

    Human and nonhuman primates are not mentally constrained to the present. They can remember the past and-at least to an extent-anticipate the future. Anticipation of the future ranges from long-term prospection such as planning for retirement to more short-term future-oriented cognition such as planning a route through a maze. Here we tested a great ape species (chimpanzees), an Old World monkey species (rhesus macaques), a New World monkey species (capuchin monkeys), and human children on a computerized maze task. All subjects had to move a cursor through a maze to reach a goal at the bottom of the screen. For best performance on the task, subjects had to "plan ahead" to the end of the maze to move the cursor in the correct direction, avoid traps, and reverse directions if necessary. Mazes varied in difficulty. Chimpanzees were better than both monkey species, and monkeys showed a particular deficit when moving away from the goal or changing directions was required. Children showed a similar pattern to monkeys regarding the effects of reversals and moves away from the goal, but their overall performance in terms of correct maze completion was similar to the chimpanzees. The results highlight similarities as well as differences in planning across species and the role that inhibitory control may play in future-oriented cognition in primates.

  8. Confronting JC virus and Homo sapiens biological signatures.

    PubMed

    Lucchese, Guglielmo

    2013-01-01

    The present report describes the peptide commonality between JC virus (JCV) and the human proteome at the heptamer level. In total, 53 viral heptapeptides occur in functionally important human proteins with potential consequences for host functions and JCV pathogenesis. A paradigmatic example of a crucial peptide match is the SGKTTLA sequence, shared by JCV LT antigen and human nicotinamide/nicotinic acid riboside kinase, an enzyme involved in myelination processes. In general, the JCV-versus-host heptapeptide overlap may result in a competition between viral sequences and identical motifs in host enzymic active sites, adhesive domains, regulatory signaling motifs, etc., thus interfering with essential reactions and posing disadvantages to the cell. Overall, this study provides a starting point for investigating the role of peptide commonality in host-pathogen interactions. PMID:23276955

  9. Transfer of spatial search between environments in human adults and young children (Homo sapiens): implications for representation of local geometry by spatial systems.

    PubMed

    Lew, Adina R; Usherwood, Barrie; Fragkioudaki, Frantzeska; Koukoumi, Varvara; Smith, Shamus P; Austen, Joe M; McGregor, Anthony

    2014-04-01

    Whether animals represent environmental geometry in a global and/or local way has been the subject of recent debate. We applied a transfer of search paradigm between rectangular- and kite-shaped arenas to examine the performance of human adults (using virtual environments) and children of 2.5-3.5 years (using real arenas). Adults showed robust transfer to a congruent corner in a kite-shaped arena, following training in a rectangular-shaped arena in two paradigms modeled on those used with rats and young children respectively. In contrast, the children showed no evidence of transfer of search, despite above chance performance in the rectangular arena, and above chance performance in a study where search occurred in the kite arena only. The pattern of findings suggests global aspects of environmental geometry may be used to re-establish heading, and that the matching of elements of local geometry in new global contexts may be an advanced developmental achievement.

  10. Variability in first Homo: Analysis of the ratio between the skulls KNM-ER 1470 and KNM-ER 1813 based on sexual dimorphism of Homo sapiens.

    PubMed

    Guimarães, S W Ferreira; Lorenzo, C

    2015-10-01

    The study of the skulls KNM-ER 1470 and KNM-ER 1813, considered the first members of the genus Homo, has raised some debates. While some of researchers maintain that there is only one species, another group argues that there are two species. On one hand these two fossils are still taxonomically undetermined, on the other hand they bring up another problem related to the existence of a genus with multiple species since its beginning, according to the last discoveries. In this paper, we have compared the size ratio between these fossils with ratios established in populations of Homo sapiens, in order to know if they fit into the human standard, considering intra-sexual and inter-sexual variation. Results help to establish whether these fossils correspond to different species or their differences could be related to sexual dimorphism within a single species.

  11. Variability in first Homo: Analysis of the ratio between the skulls KNM-ER 1470 and KNM-ER 1813 based on sexual dimorphism of Homo sapiens.

    PubMed

    Guimarães, S W Ferreira; Lorenzo, C

    2015-10-01

    The study of the skulls KNM-ER 1470 and KNM-ER 1813, considered the first members of the genus Homo, has raised some debates. While some of researchers maintain that there is only one species, another group argues that there are two species. On one hand these two fossils are still taxonomically undetermined, on the other hand they bring up another problem related to the existence of a genus with multiple species since its beginning, according to the last discoveries. In this paper, we have compared the size ratio between these fossils with ratios established in populations of Homo sapiens, in order to know if they fit into the human standard, considering intra-sexual and inter-sexual variation. Results help to establish whether these fossils correspond to different species or their differences could be related to sexual dimorphism within a single species. PMID:26092693

  12. Humans (Homo sapiens) judge the emotional content of piglet (Sus scrofa domestica) calls based on simple acoustic parameters, not personality, empathy, nor attitude toward animals.

    PubMed

    Maruščáková, Iva L; Linhart, Pavel; Ratcliffe, Victoria F; Tallet, Céline; Reby, David; Špinka, Marek

    2015-05-01

    The vocal expression of emotion is likely driven by shared physiological principles among species. However, which acoustic features promote decoding of emotional state and how the decoding is affected by their listener's psychology remain poorly understood. Here we tested how acoustic features of piglet vocalizations interact with psychological profiles of human listeners to affect judgments of emotional content of heterospecific vocalizations. We played back 48 piglet call sequences recorded in four different contexts (castration, isolation, reunion, nursing) to 60 listeners. Listeners judged the emotional intensity and valence of the recordings and were further asked to attribute a context of emission from four proposed contexts. Furthermore, listeners completed a series of questionnaires assessing their personality (NEO-FFI personality inventory), empathy [Interpersonal Reactivity Index (IRI)] and attitudes to animals (Animal Attitudes Scale). None of the listeners' psychological traits affected the judgments. On the contrary, acoustic properties of recordings had a substantial effect on ratings. Recordings were rated as more intense with increasing pitch (mean fundamental frequency) and increasing proportion of vocalized sound within each stimulus recording and more negative with increasing pitch and increasing duration of the calls within the recording. More complex acoustic properties (jitter, harmonic-to-noise ratio, and presence of subharmonics) did not seem to affect the judgments. The probability of correct context recognition correlated positively with the assessed emotion intensity for castration and reunion calls, and negatively for nursing calls. In conclusion, listeners judged emotions from pig calls using simple acoustic properties and the perceived emotional intensity might guide the identification of the context.

  13. Pair-bonding, romantic love, and evolution: the curious case of Homo sapiens.

    PubMed

    Fletcher, Garth J O; Simpson, Jeffry A; Campbell, Lorne; Overall, Nickola C

    2015-01-01

    This article evaluates a thesis containing three interconnected propositions. First, romantic love is a "commitment device" for motivating pair-bonding in humans. Second, pair-bonding facilitated the idiosyncratic life history of hominins, helping to provide the massive investment required to rear children. Third, managing long-term pair bonds (along with family relationships) facilitated the evolution of social intelligence and cooperative skills. We evaluate this thesis by integrating evidence from a broad range of scientific disciplines. First, consistent with the claim that romantic love is an evolved commitment device, our review suggests that it is universal; suppresses mate-search mechanisms; has specific behavioral, hormonal, and neuropsychological signatures; and is linked to better health and survival. Second, we consider challenges to this thesis posed by the existence of arranged marriage, polygyny, divorce, and infidelity. Third, we show how the intimate relationship mind seems to be built to regulate and monitor relationships. Fourth, we review comparative evidence concerning links among mating systems, reproductive biology, and brain size. Finally, we discuss evidence regarding the evolutionary timing of shifts to pair-bonding in hominins. We conclude there is interdisciplinary support for the claim that romantic love and pair-bonding, along with alloparenting, played critical roles in the evolution of Homo sapiens.

  14. Pair-bonding, romantic love, and evolution: the curious case of Homo sapiens.

    PubMed

    Fletcher, Garth J O; Simpson, Jeffry A; Campbell, Lorne; Overall, Nickola C

    2015-01-01

    This article evaluates a thesis containing three interconnected propositions. First, romantic love is a "commitment device" for motivating pair-bonding in humans. Second, pair-bonding facilitated the idiosyncratic life history of hominins, helping to provide the massive investment required to rear children. Third, managing long-term pair bonds (along with family relationships) facilitated the evolution of social intelligence and cooperative skills. We evaluate this thesis by integrating evidence from a broad range of scientific disciplines. First, consistent with the claim that romantic love is an evolved commitment device, our review suggests that it is universal; suppresses mate-search mechanisms; has specific behavioral, hormonal, and neuropsychological signatures; and is linked to better health and survival. Second, we consider challenges to this thesis posed by the existence of arranged marriage, polygyny, divorce, and infidelity. Third, we show how the intimate relationship mind seems to be built to regulate and monitor relationships. Fourth, we review comparative evidence concerning links among mating systems, reproductive biology, and brain size. Finally, we discuss evidence regarding the evolutionary timing of shifts to pair-bonding in hominins. We conclude there is interdisciplinary support for the claim that romantic love and pair-bonding, along with alloparenting, played critical roles in the evolution of Homo sapiens. PMID:25910380

  15. Forearm articular proportions and the antebrachial index in Homo sapiens, Australopithecus afarensis and the great apes.

    PubMed

    Williams, Frank L'Engle; Cunningham, Deborah L; Amaral, Lia Q

    2015-12-01

    When hominin bipedality evolved, the forearms were free to adopt nonlocomotor tasks which may have resulted in changes to the articular surfaces of the ulna and the relative lengths of the forearm bones. Similarly, sex differences in forearm proportions may be more likely to emerge in bipeds than in the great apes given the locomotor constraints in Gorilla, Pan and Pongo. To test these assumptions, ulnar articular proportions and the antebrachial index (radius length/ulna length) in Homo sapiens (n=51), Gorilla gorilla (n=88), Pan troglodytes (n=49), Pongo pygmaeus (n=36) and Australopithecus afarensis A.L. 288-1 and A.L. 438-1 are compared. Intercept-adjusted ratios are used to control for size and minimize the effects of allometry. Canonical scores axes show that the proximally broad and elongated trochlear notch with respect to size in H. sapiens and A. afarensis is largely distinct from G. gorilla, P. troglodytes and P. pygmaeus. A cluster analysis of scaled ulnar articular dimensions groups H. sapiens males with A.L. 438-1 ulna length estimates, while one A.L. 288-1 ulna length estimate groups with Pan and another clusters most closely with H. sapiens, G. gorilla and A.L. 438-1. The relatively low antebrachial index characterizing H. sapiens and non-outlier estimates of A.L. 288-1 and A.L. 438-1 differs from those of the great apes. Unique sex differences in H. sapiens suggest a link between bipedality and forearm functional morphology.

  16. Genetic characterization of general transcription factors TFIIF and TFIIB of Homo sapiens sapiens.

    PubMed

    Purrello, M; Di Pietro, C; Rapisarda, A; Mirabile, E; Motta, S; Sichel, G; Grzeschik, K H

    1995-01-01

    Analysis of loci GTF2F1 and GTF2B, encoding Rap 74 (a subunit of TFIIF) and TFIIB, respectively, showed that they are present in a single copy in the human genome and are localized at 19p13.3 and 1p22, respectively. By using as probe a cDNA for Rap 30 (the other subunit of TFIIF), we localized the GTF2F2 locus to 13q14; the same probe also detected a cross-hybridizing sequence at 4q31 whose functional importance remains to be elucidated. These data and those previously published by our group demonstrate that genes coding for class II general transcription factors with reported sequence similarity to bacterial sigma proteins are scattered in different regions of the human genome, with no evidence of clustering. This dispersion and the identification of homologs of both TBP and TFIIB in Archaea suggest an early evolutionary origin of the general transcription apparatus of contemporary eukaryotes.

  17. HS3D, A Dataset of Homo Sapiens Splice Regions, and its Extraction Procedure from a Major Public Database

    NASA Astrophysics Data System (ADS)

    Pollastro, Pasquale; Rampone, Salvatore

    The aim of this work is to describe a cleaning procedure of GenBank data, producing material to train and to assess the prediction accuracy of computational approaches for gene characterization. A procedure (GenBank2HS3D) has been defined, producing a dataset (HS3D - Homo Sapiens Splice Sites Dataset) of Homo Sapiens Splice regions extracted from GenBank (Rel.123 at this time). It selects, from the complete GenBank Primate Division, entries of Human Nuclear DNA according with several assessed criteria; then it extracts exons and introns from these entries (actually 4523 + 3802). Donor and acceptor sites are then extracted as windows of 140 nucleotides around each splice site (3799 + 3799). After discarding windows not including canonical GT-AG junctions (65 + 74), including insufficient data (not enough material for a 140 nucleotide window) (686 + 589), including not AGCT bases (29 + 30), and redundant (218 + 226), the remaining windows (2796 + 2880) are reported in the dataset. Finally, windows of false splice sites are selected by searching canonical GT-AG pairs in not splicing positions (271 937 + 332 296). The false sites in a range +/- 60 from a true splice site are marked as proximal. HS3D, release 1.2 at this time, is available at the Web server of the University of Sannio: http://www.sci.unisannio.it/docenti/rampone/.

  18. Did the loss of endogenous ascorbate propel the evolution of Anthropoidea and Homo sapiens?

    PubMed

    Challem, J J

    1997-05-01

    It has been previously theorized that free-radical reactions led to the first life on Earth, and their ability to randomly cause mutations may have subsequently led to the evolution of life. One of the most efficient free-radical quenchers is ascorbate, which most animals manufacture endogenously. It is generally believed that, approximately 25 million years ago, an ancestor of the Anthropoidea primate suborder, which includes Homo sapiens, lost the ability to produce its own ascorbate, and all descending species inherited this genetic defect. The first of three hypotheses presented here proposes that a genetic defect, caused by either free radicals or a virus, deleted the gene needed by Anthropoidea to manufacture endogenous ascorbate. The second hypothesis proposes that this evolutionary accident permitted large numbers of free radicals to remain metabolically unquenched. The third hypothesis proposes that the presence of these excessive free radicals increased the likelihood of free-radical-induced genetic mutations, and these mutations propelled the evolution of Anthropoidea, leading to Homo sapiens.

  19. Emergence of a Homo sapiens-specific gene family and chromosome 16p11.2 CNV susceptibility.

    PubMed

    Nuttle, Xander; Giannuzzi, Giuliana; Duyzend, Michael H; Schraiber, Joshua G; Narvaiza, Iñigo; Sudmant, Peter H; Penn, Osnat; Chiatante, Giorgia; Malig, Maika; Huddleston, John; Benner, Chris; Camponeschi, Francesca; Ciofi-Baffoni, Simone; Stessman, Holly A F; Marchetto, Maria C N; Denman, Laura; Harshman, Lana; Baker, Carl; Raja, Archana; Penewit, Kelsi; Janke, Nicolette; Tang, W Joyce; Ventura, Mario; Banci, Lucia; Antonacci, Francesca; Akey, Joshua M; Amemiya, Chris T; Gage, Fred H; Reymond, Alexandre; Eichler, Evan E

    2016-08-11

    Genetic differences that specify unique aspects of human evolution have typically been identified by comparative analyses between the genomes of humans and closely related primates, including more recently the genomes of archaic hominins. Not all regions of the genome, however, are equally amenable to such study. Recurrent copy number variation (CNV) at chromosome 16p11.2 accounts for approximately 1% of cases of autism and is mediated by a complex set of segmental duplications, many of which arose recently during human evolution. Here we reconstruct the evolutionary history of the locus and identify bolA family member 2 (BOLA2) as a gene duplicated exclusively in Homo sapiens. We estimate that a 95-kilobase-pair segment containing BOLA2 duplicated across the critical region approximately 282 thousand years ago (ka), one of the latest among a series of genomic changes that dramatically restructured the locus during hominid evolution. All humans examined carried one or more copies of the duplication, which nearly fixed early in the human lineage--a pattern unlikely to have arisen so rapidly in the absence of selection (P < 0.0097). We show that the duplication of BOLA2 led to a novel, human-specific in-frame fusion transcript and that BOLA2 copy number correlates with both RNA expression (r = 0.36) and protein level (r = 0.65), with the greatest expression difference between human and chimpanzee in experimentally derived stem cells. Analyses of 152 patients carrying a chromosome 16p11. rearrangement show that more than 96% of breakpoints occur within the H. sapiens-specific duplication. In summary, the duplicative transposition of BOLA2 at the root of the H. sapiens lineage about 282 ka simultaneously increased copy number of a gene associated with iron homeostasis and predisposed our species to recurrent rearrangements associated with disease. PMID:27487209

  20. Dental size reduction in Indonesian Homo erectus: Implications for the PU-198 premolar and the appearance of Homo sapiens on Java.

    PubMed

    Polanski, Joshua M; Marsh, Hannah E; Maddux, Scott D

    2016-01-01

    The recent recovery of a hominin maxillary third premolar, PU-198, within the faunal collections from Punung Cave (East Java) has led to assertions that Homo sapiens appeared on Java between 143,000 and 115,000 years ago. The taxonomic assignment of PU-198 to H. sapiens was based predominantly on the small size of the specimen, following an analysis which found little to no overlap in premolar size between Homo erectus and terminal Pleistocene/Holocene H. sapiens. Here, we re-evaluate the use of size in the taxonomic assignment of PU-198 in light of 1) new buccolingual and mesiodistal measurements taken on the fossil, 2) comparisons to a larger sample of H. erectus and H. sapiens maxillary third premolars, and 3) evidence of a diachronic trend in post-canine dental size reduction among Javan H. erectus. Our results demonstrate PU-198 to be slightly larger than previously suggested, reveal substantial overlap in premolar size between H. erectus and H. sapiens, and indicate a statistically significant reduction in premolar size between early and late Javan H. erectus. Our findings cast doubt on the assignment of PU-198 to H. sapiens, and accordingly, question the appearance of H. sapiens on Java between 143,000 and 115,000 years ago. PMID:26767959

  1. Dental size reduction in Indonesian Homo erectus: Implications for the PU-198 premolar and the appearance of Homo sapiens on Java.

    PubMed

    Polanski, Joshua M; Marsh, Hannah E; Maddux, Scott D

    2016-01-01

    The recent recovery of a hominin maxillary third premolar, PU-198, within the faunal collections from Punung Cave (East Java) has led to assertions that Homo sapiens appeared on Java between 143,000 and 115,000 years ago. The taxonomic assignment of PU-198 to H. sapiens was based predominantly on the small size of the specimen, following an analysis which found little to no overlap in premolar size between Homo erectus and terminal Pleistocene/Holocene H. sapiens. Here, we re-evaluate the use of size in the taxonomic assignment of PU-198 in light of 1) new buccolingual and mesiodistal measurements taken on the fossil, 2) comparisons to a larger sample of H. erectus and H. sapiens maxillary third premolars, and 3) evidence of a diachronic trend in post-canine dental size reduction among Javan H. erectus. Our results demonstrate PU-198 to be slightly larger than previously suggested, reveal substantial overlap in premolar size between H. erectus and H. sapiens, and indicate a statistically significant reduction in premolar size between early and late Javan H. erectus. Our findings cast doubt on the assignment of PU-198 to H. sapiens, and accordingly, question the appearance of H. sapiens on Java between 143,000 and 115,000 years ago.

  2. Do chimpanzees (Pan troglodytes) and 2-year-old children (Homo sapiens) understand double invisible displacement?

    PubMed

    Collier-Baker, Emma; Suddendorf, Thomas

    2006-05-01

    Chimpanzees (Pan troglodytes) and young children (Homo sapiens) have difficulty with double invisible displacements in which an object is hidden in two nonadjacent boxes in a linear array. Experiment 1 eliminated the possibility that chimpanzees' previous poor performance was due to the hiding direction of the displacement device. As in Call (2001), subjects failed double nonadjacent displacements, showing a tendency to select adjacent boxes. In Experiments 2 and 3, chimpanzees and 24-month-old children were tested on a new adaptation of the task in which four hiding boxes were presented in a diamond-shaped array on a vertical plane. Both species performed above chance on double invisible displacements using this format, suggesting that previous poor performance was due to a response bias or inhibition problem rather than a fundamental limitation in representational capacity.

  3. Dentofacial growth and development in Homo sapiens: evidence from perinatal individuals from Punic Carthage.

    PubMed

    Schwartz, J H

    1982-01-01

    Study of perinatal individuals from 7-4th c. B.C. Punic Carthage and specimens from more recent sources elucidates: 1. variability in the formation of the infraorbital foramen; 2. the nature of, and variability in, the expression of the incisive suture. With regard to the latter, and in conjunction with data on the embryological formation of the upper jaw and dentition, the following generalization appears warranted in Homo sapiens. The incisors and canine may come to erupt in the alveolar bone associated with the premaxillary region. Combination of these data with those on the timing of tooth germ development and their forward migration yields an explanation of the dental anomalies associated with anterior facial cleft and a prediction of when this disorder occurs.

  4. From Homo Sapiens to Homo Cosmicus - Astronautics, Darwinism abd Historical Determinism

    NASA Astrophysics Data System (ADS)

    Tolkowsky, G.

    Since its inception in late-nineteenth century, astronautics has been viewed as a historical outcome of human evolution as well as a future driver thereof. The history of astronautics-related, evolutionary thought reveals a tension between the Darwinian notion of natural selection and that of homocosmic predestination - be it of dialectical materialistic or theological nature. One can detect the influence of this ideological diversity on the American and Soviet space programs.

  5. Object permanence in orangutans (Pongo pygmaeus), chimpanzees (Pan troglodytes), and children (Homo sapiens).

    PubMed

    Call, J

    2001-06-01

    Juvenile and adult orangutans (n = 5; Pongo pygmaeus), chimpanzees (n = 7; Pan troglodytes), and 19- and 26-month-old children (n = 24; Homo sapiens) received visible and invisible displacements. Three containers were presented forming a straight line, and a small box was used to displace a reward under them. Subjects received 3 types of displacement: single (the box visited 1 container), double adjacent (the box visited 2 contiguous containers), and double nonadjacent (the box visited 2 noncontiguous containers). All species performed at comparable levels, solving all problems except the invisible nonadjacent displacements. Visible displacements were easier than invisible, and single were easier than double displacements. In a 2nd experiment, subjects saw the baiting of either 2 adjacent or 2 nonadjacent containers with no displacements. All species selected the empty container more often when the baited containers were nonadjacent than when they were adjacent. It is hypothesized that a response bias and inhibition problem were responsible for the poor performance in nonadjacent displacements.

  6. Normalization of Complete Genome Characteristics: Application to Evolution from Primitive Organisms to Homo sapiens

    PubMed Central

    Sorimachi, Kenji; Okayasu, Teiji; Ohhira, Shuji

    2015-01-01

    Normalized nucleotide and amino acid contents of complete genome sequences can be visualized as radar charts. The shapes of these charts depict the characteristics of an organism’s genome. The normalized values calculated from the genome sequence theoretically exclude experimental errors. Further, because normalization is independent of both target size and kind, this procedure is applicable not only to single genes but also to whole genomes, which consist of a huge number of different genes. In this review, we discuss the applications of the normalization of the nucleotide and predicted amino acid contents of complete genomes to the investigation of genome structure and to evolutionary research from primitive organisms to Homo sapiens. Some of the results could never have been obtained from the analysis of individual nucleotide or amino acid sequences but were revealed only after the normalization of nucleotide and amino acid contents was applied to genome research. The discovery that genome structure was homogeneous was obtained only after normalization methods were applied to the nucleotide or predicted amino acid contents of genome sequences. Normalization procedures are also applicable to evolutionary research. Thus, normalization of the contents of whole genomes is a useful procedure that can help to characterize organisms. PMID:26085808

  7. The mitogenome of a 35,000-year-old Homo sapiens from Europe supports a Palaeolithic back-migration to Africa.

    PubMed

    Hervella, M; Svensson, E M; Alberdi, A; Günther, T; Izagirre, N; Munters, A R; Alonso, S; Ioana, M; Ridiche, F; Soficaru, A; Jakobsson, M; Netea, M G; de-la-Rua, C

    2016-05-19

    After the dispersal of modern humans (Homo sapiens) Out of Africa, hominins with a similar morphology to that of present-day humans initiated the gradual demographic expansion into Eurasia. The mitogenome (33-fold coverage) of the Peştera Muierii 1 individual (PM1) from Romania (35 ky cal BP) we present in this article corresponds fully to Homo sapiens, whilst exhibiting a mosaic of morphological features related to both modern humans and Neandertals. We have identified the PM1 mitogenome as a basal haplogroup U6*, not previously found in any ancient or present-day humans. The derived U6 haplotypes are predominantly found in present-day North-Western African populations. Concomitantly, those found in Europe have been attributed to recent gene-flow from North Africa. The presence of the basal haplogroup U6* in South East Europe (Romania) at 35 ky BP confirms a Eurasian origin of the U6 mitochondrial lineage. Consequently, we propose that the PM1 lineage is an offshoot to South East Europe that can be traced to the Early Upper Paleolithic back migration from Western Asia to North Africa, during which the U6 lineage diversified, until the emergence of the present-day U6 African lineages.

  8. The mitogenome of a 35,000-year-old Homo sapiens from Europe supports a Palaeolithic back-migration to Africa

    PubMed Central

    Hervella, M.; Svensson, E. M.; Alberdi, A.; Günther, T.; Izagirre, N.; Munters, A. R.; Alonso, S.; Ioana, M.; Ridiche, F.; Soficaru, A.; Jakobsson, M.; Netea, M. G.; de-la-Rua, C.

    2016-01-01

    After the dispersal of modern humans (Homo sapiens) Out of Africa, hominins with a similar morphology to that of present-day humans initiated the gradual demographic expansion into Eurasia. The mitogenome (33-fold coverage) of the Peştera Muierii 1 individual (PM1) from Romania (35 ky cal BP) we present in this article corresponds fully to Homo sapiens, whilst exhibiting a mosaic of morphological features related to both modern humans and Neandertals. We have identified the PM1 mitogenome as a basal haplogroup U6*, not previously found in any ancient or present-day humans. The derived U6 haplotypes are predominantly found in present-day North-Western African populations. Concomitantly, those found in Europe have been attributed to recent gene-flow from North Africa. The presence of the basal haplogroup U6* in South East Europe (Romania) at 35 ky BP confirms a Eurasian origin of the U6 mitochondrial lineage. Consequently, we propose that the PM1 lineage is an offshoot to South East Europe that can be traced to the Early Upper Paleolithic back migration from Western Asia to North Africa, during which the U6 lineage diversified, until the emergence of the present-day U6 African lineages. PMID:27195518

  9. The mitogenome of a 35,000-year-old Homo sapiens from Europe supports a Palaeolithic back-migration to Africa.

    PubMed

    Hervella, M; Svensson, E M; Alberdi, A; Günther, T; Izagirre, N; Munters, A R; Alonso, S; Ioana, M; Ridiche, F; Soficaru, A; Jakobsson, M; Netea, M G; de-la-Rua, C

    2016-01-01

    After the dispersal of modern humans (Homo sapiens) Out of Africa, hominins with a similar morphology to that of present-day humans initiated the gradual demographic expansion into Eurasia. The mitogenome (33-fold coverage) of the Peştera Muierii 1 individual (PM1) from Romania (35 ky cal BP) we present in this article corresponds fully to Homo sapiens, whilst exhibiting a mosaic of morphological features related to both modern humans and Neandertals. We have identified the PM1 mitogenome as a basal haplogroup U6*, not previously found in any ancient or present-day humans. The derived U6 haplotypes are predominantly found in present-day North-Western African populations. Concomitantly, those found in Europe have been attributed to recent gene-flow from North Africa. The presence of the basal haplogroup U6* in South East Europe (Romania) at 35 ky BP confirms a Eurasian origin of the U6 mitochondrial lineage. Consequently, we propose that the PM1 lineage is an offshoot to South East Europe that can be traced to the Early Upper Paleolithic back migration from Western Asia to North Africa, during which the U6 lineage diversified, until the emergence of the present-day U6 African lineages. PMID:27195518

  10. Foramen magnum position variation in Pan troglodytes, Plio-Pleistocene hominids, and recent Homo sapiens: implications for recognizing the earliest hominids.

    PubMed

    Ahern, James C M

    2005-07-01

    The anteroposterior position of the foramen magnum distinguishes living Homo sapiens from apes, and has been used as evidence for the hominid status of numerable fossils in the history of human paleontology. During the past decade, foramen magnum position has been cited as evidence of the hominid status of Ardipithecus and Sahelanthropus. Specifically, the basion of Ardpithecus is reported to be inline with the bicarotid chord, while the basion of Sahelanthropus is reported to both touch the biporion chord and intersect the bicarotid chord. In order to assess the effectiveness of anteroposterior foramen magnum position in distinguishing hominids from nonhominid apes, this study examined whether or not the positions of biporion and bicarotid relative to basion sufficiently distinguished Pan troglodytes from recent Homo sapiens and Plio-Pleistocene hominids. The distances from basion to the biporion chord (BSBIP) and from basion to the bicarotid chord (BSBIC) were measured on samples of chimpanzee (n = 69) and recent human (n = 42) crania and a sample of Plio-Pleistocene hominid fossils (n = 8). The data were used to test the hypothesis that BSBIP and BSBIC measurements do not sufficiently distinguish P. troglodytes from hominids. While basion to biporion (BSBIP) does not effectively distinguish P. troglodytes from Plio-Pleistocene hominids and humans when used univariately, basion to bicarotid (BSBIC), when used univariately or bivariately with BSBIP, can be used to test whether or not an unknown specimen is a hominid. These results are used to evaluate the hominid status of Ardipithecus and Sahelanthropus.

  11. The rhizome of Reclinomonas americana, Homo sapiens, Pediculus humanus and Saccharomyces cerevisiae mitochondria

    PubMed Central

    2011-01-01

    Background Mitochondria are thought to have evolved from eubacteria-like endosymbionts; however, the origin of the mitochondrion remains a subject of debate. In this study, we investigated the phenomenon of chimerism in mitochondria to shed light on the origin of these organelles by determining which species played a role in their formation. We used the mitochondria of four distinct organisms, Reclinomonas americana, Homo sapiens, Saccharomyces cerevisiae and multichromosome Pediculus humanus, and attempted to identify the origin of each mitochondrial gene. Results Our results suggest that the origin of mitochondrial genes is not limited to the Rickettsiales and that the creation of these genes did not occur in a single event, but through multiple successive events. Some of these events are very old and were followed by events that are more recent and occurred through the addition of elements originating from current species. The points in time that the elements were added and the parental species of each gene in the mitochondrial genome are different to the individual species. These data constitute strong evidence that mitochondria do not have a single common ancestor but likely have numerous ancestors, including proto-Rickettsiales, proto-Rhizobiales and proto-Alphaproteobacteria, as well as current alphaproteobacterial species. The analysis of the multichromosome P. humanus mitochondrion supports this mechanism. Conclusions The most plausible scenario of the origin of the mitochondrion is that ancestors of Rickettsiales and Rhizobiales merged in a proto-eukaryotic cell approximately one billion years ago. The fusion of the Rickettsiales and Rhizobiales cells was followed by gene loss, genomic rearrangements and the addition of alphaproteobacterial elements through ancient and more recent recombination events. Each gene of each of the four studied mitochondria has a different origin, while in some cases, multichromosomes may allow for enhanced gene exchange

  12. Analytical morphies on mid-sagittal craniograms glabella-opisthocranion of Homo erectus and Homo sapiens neanderthalensis: Fourier parameters and multivariate discriminant analysis.

    PubMed

    Vacca, E; Pesce Delfino, V

    1991-03-01

    The analytical description of complicated morphologies offers the possibility to define patterns of parameters characterizing the investigated groups. These patterns must be considered as morphies useful in performing classification and comparison. Fourier parameters are extremely effective in describing and comparing complex irregular forms and since they are statistically independent we can use them in performing multivariate discriminant analysis. Two groups of mid-sagittal craniograms glabella-opisthocranion of asiatic samples of Homo erectus and of Homo sapiens neanderthalensis were described by means of Fourier harmonic analysis. The discriminatory power of all the obtained parameters (coefficients, amplitudes and phases) was tested. A discriminant function (error % = 0) was obtained using as parameters the first 4 sine/cosine coefficients, the 5th sine, the 6th and the 7th cosine components (11 parameters in all). When the information contained in the coefficient values is being subdivided into the two components of amplitude and phase, the amplitude component is not able to discriminate between the two groups (error % = 25), while the phase values of the first 7 harmonics are able to discriminate them (error % = 0 and distance between centroids = 47).

  13. Field-mapping and petrographic analysis of volcanoes surrounding the Lake Natron Homo sapiens footprint site, northern Tanzania

    NASA Astrophysics Data System (ADS)

    Hewitt, S. M.; Zimmer, B.; Liutkus, C.; Carmichael, S. K.; McGinnis, K.

    2010-12-01

    The Lake Natron Homo sapiens footprint site is located in northern Tanzania along the East African Rift escarpment. The site is positioned south of Lake Natron within an ephemeral channel of the Engare Sero River. The hominid footprints are preserved in a tuff, which originated from one of the volcanic centers surrounding the site. Two large volcanoes in the surrounding region, including the active carbonatite producing Oldoinyo L’engai and the now extinct Kerimasi are possible sources. This area also contains over 30 smaller tuff cones and tuff rings that have been poorly mapped and not analyzed in detail. The site is significant as it is the oldest modern human trackway in East Africa and one of the largest collections of hominid footprints in the world. Determining the source of the footprinted volcanic ash requires detailed field mapping, and both petrographic and geochemical analyses. Extensive field-mapping of the region revealed multiple regional beds that stratigraphically overlay the footprinted layer. Age dating as well as geochemical analysis is being conducted to relate these beds to the footprinted layer. Field-mapping showed that the footprinted tuff is over 35 cm thick, suggesting a large, sustained eruption. The bulk of the tuff cones examined in the field visibly varied in composition to the footprinted tuff and, based on proximity to the footprint site, are too small to produce the requisite volume of ash. Field analysis of samples collected from Oldoinyo L’engai reveal the most similar mineral assemblages to the footprinted layer, and the large volcano provides a source substantial enough to create a thick ash bed 10 km north of the summit. Preliminary research reveals that the footprinted tuff is a phonolite, characterized by silica depletion and the presence of sanidine, augite, and annite with interstitial calcite. XRD analysis of samples collected from Oldoinyo L’engai reveal a nepheline-rich phonolite with zeolites (ie. phillipsite

  14. Terrestrial environmental changes around the Gulf of Aden over the last 210 kyr deduced from the sediment n-alkane record: Implications for the dispersal of Homo sapiens

    NASA Astrophysics Data System (ADS)

    Isaji, Yuta; Kawahata, Hodaka; Ohkouchi, Naohiko; Murayama, Masafumi; Tamaki, Kensaku

    2015-03-01

    We analyzed long-chain (C25-C36) n-alkanes and pollen grains in sediments from the Gulf of Aden covering the last 212 kyr to reconstruct the surrounding terrestrial environment, a critical region for the dispersal of Homo sapiens. Substantial increases in the flux of n-alkanes during 200-185, 120-95, and 70-50 ka were interpreted to indicate enhanced vegetation biomass in the Arabian Peninsula and the northern part of the Horn of Africa or increase in lithogenic material inputs. Periods of enhanced n-alkane flux occurred during or immediately after pluvial episodes, indicating that the increased precipitation may have induced substantially enhanced vegetation biomass, creating favorable conditions for Homo sapiens. Additionally, vegetation may have increased due to moderate precipitation unrecorded by speleothems or in accordance with the lowering of sea level, indicating that the dispersal might have been possible even after the shift to an arid environment indicated by the speleothems.

  15. Middle Stone Age (MSA) site distributions in eastern Africa and their relationship to Quaternary environmental change, refugia and the evolution of Homo sapiens

    NASA Astrophysics Data System (ADS)

    Basell, Laura S.

    2008-12-01

    This paper considers the evolution of Homo sapiens in eastern Africa in relation to refugia and bottlenecks around ˜200 ka BP, at a macro scale. Middle Stone Age (MSA) lithics, site distributions and locations are analysed in relation to palaeovegetation maps of the last glacial/interglacial cycle, which are used as a proxy for earlier climate cycles. A "push and pull" model is then postulated for the spread of Homo sapiens out of refugia in eastern Africa, involving both volcanism (push) and habitat availability (pull). A date within OIS 5 is suggested for this expansion to other parts of the continent, and potentially further afield, contrary to a frequently proposed expansion within OIS 3.

  16. Structural modeling and docking studies of ribose 5-phosphate isomerase from Leishmania major and Homo sapiens: a comparative analysis for Leishmaniasis treatment.

    PubMed

    Capriles, Priscila V S Z; Baptista, Luiz Phillippe R; Guedes, Isabella A; Guimarães, Ana Carolina R; Custódio, Fabio L; Alves-Ferreira, Marcelo; Dardenne, Laurent E

    2015-02-01

    Leishmaniases are caused by protozoa of the genus Leishmania and are considered the second-highest cause of death worldwide by parasitic infection. The drugs available for treatment in humans are becoming ineffective mainly due to parasite resistance; therefore, it is extremely important to develop a new chemotherapy against these parasites. A crucial aspect of drug design development is the identification and characterization of novel molecular targets. In this work, through an in silico comparative analysis between the genomes of Leishmania major and Homo sapiens, the enzyme ribose 5-phosphate isomerase (R5PI) was indicated as a promising molecular target. R5PI is an important enzyme that acts in the pentose phosphate pathway and catalyzes the interconversion of d-ribose-5-phosphate (R5P) and d-ribulose-5-phosphate (5RP). R5PI activity is found in two analogous groups of enzymes called RpiA (found in H. sapiens) and RpiB (found in L. major). Here, we present the first report of the three-dimensional (3D) structures and active sites of RpiB from L. major (LmRpiB) and RpiA from H. sapiens (HsRpiA). Three-dimensional models were constructed by applying a hybrid methodology that combines comparative and ab initio modeling techniques, and the active site was characterized based on docking studies of the substrates R5P (furanose and ring-opened forms) and 5RP. Our comparative analyses show that these proteins are structural analogs and that distinct residues participate in the interconversion of R5P and 5RP. We propose two distinct reaction mechanisms for the reversible isomerization of R5P to 5RP, which is catalyzed by LmRpiB and HsRpiA. We expect that the present results will be important in guiding future molecular modeling studies to develop new drugs that are specially designed to inhibit the parasitic form of the enzyme without significant effects on the human analog.

  17. Comparative in vivo forefoot kinematics of Homo sapiens and Pan paniscus.

    PubMed

    Griffin, Nicole L; D'Août, Kristiaan; Richmond, Brian; Gordon, Adam; Aerts, Peter

    2010-12-01

    The human metatarsophalangeal joints play a key role in weight transmission and propulsion during bipedal gait, but at present, the identification of when a habitual, human-like metatarsi-fulcrimating mechanism first appeared in the fossil record is debated. Part of this debate can be attributed to the absence of certain detailed quantitative data distinguishing human and great ape forefoot form and function. The aim of this study is to quantitatively test previous observations that human metatarsophalangeal joints exhibit greater amounts of dorsal excursion (i.e., dorsiflexion) than those of Pan at the terminal stance phase of terrestrial locomotion. Video recordings were made in order to measure sagittal excursions of the medial metatarsophalangeal joints in habitually shod/unshod adult humans and adult bonobos (Pan paniscus). Results indicate that the human first and second metatarsophalangeal joints usually dorsiflex more than those of bonobos. When timing of maximum excursion of the first metatarsophalangeal joint is coupled with existing plantar pressure data, the unique role of the human forefoot as a key site of leverage and weight transmission is highlighted. These results support hypotheses that significant joint functional differences between great apes and humans during gait underlie taxonomic distinctions in trabecular bone architecture of the forefoot.

  18. Non-molecular-clock-like evolution following viral origins in homo sapiens.

    PubMed

    Mok, Wendy; Seto, Kelly; Stone, Jon

    2007-09-26

    Researchers routinely adopt molecular clock assumptions in conducting sequence analyses to estimate dates for viral origins in humans. We used computational methods to examine the extent to which this practice can result in inaccurate 'retrodiction.' Failing to account for dynamic molecular evolution can affect greatly estimating index case dates, resulting in an overestimated age for the SARS-CoV-human infection, for instance.

  19. Horizontal gene transfer events reshape the global landscape of arm race between viruses and homo sapiens

    PubMed Central

    Chen, Dong-Sheng; Wu, Yi-Quan; Zhang, Wei; Jiang, San-Jie; Chen, Shan-Ze

    2016-01-01

    Horizontal gene transfer (HGT) drives the evolution of recipient organism particularly if it provides a novel function which enhances the fitness or its adaption to the environment. Virus-host co-evolution is attractive for studying co-evolutionary processes, since viruses strictly replicate inside of the host cells and thus their evolution is inexorably tangled with host biology. HGT, as a mechanism of co-evolution between human and viruses, has been widely documented, however, the roles HGT play during the interaction between human and viruses are still in their infancy. In this study, we performed a comprehensive analysis on the genes horizontally transferred between viruses and their corresponding human hosts. Our study suggests that the HGT genes in human are predominantly enriched in immune related GO terms while viral HGT genes are tend to be encoded by viruses which promote the invasion of immune system of hosts. Based on our results, it gives us a hint about the evolution trajectory of HGT events. Overall, our study suggests that the HGT between human and viruses are highly relevant to immune interaction and probably reshaped the arm race between hosts and viruses. PMID:27270140

  20. Co-dispersal of the blood fluke Schistosoma japonicum and Homo sapiens in the Neolithic Age

    PubMed Central

    Yin, Mingbo; Zheng, Hong-Xiang; Su, Jing; Feng, Zheng; McManus, Donald P.; Zhou, Xiao-Nong; Jin, Li; Hu, Wei

    2015-01-01

    The global spread of human infectious diseases is of considerable public health and biomedical interest. Little is known about the relationship between the distribution of ancient parasites and that of their human hosts. Schistosoma japonicum is one of the three major species of schistosome blood flukes causing the disease of schistosomiasis in humans. The parasite is prevalent in East and Southeast Asia, including the People’s Republic of China, the Philippines and Indonesia. We studied the co-expansion of S. japonicum and its human definitive host. Phylogenetic reconstruction based on complete mitochondrial genome sequences showed that S. japonicum radiated from the middle and lower reaches of the Yangtze River to the mountainous areas of China, Japan and Southeast Asia. In addition, the parasite experienced two population expansions during the Neolithic agriculture era, coinciding with human migration and population growth. The data indicate that the advent of rice planting likely played a key role in the spread of schistosomiasis in Asia. Moreover, the presence of different subspecies of Oncomelania hupensis intermediate host snails in different localities in Asia allowed S. japonicum to survive in new rice-planting areas, and concurrently drove the intraspecies divergence of the parasite. PMID:26686813

  1. Horizontal gene transfer events reshape the global landscape of arm race between viruses and homo sapiens.

    PubMed

    Chen, Dong-Sheng; Wu, Yi-Quan; Zhang, Wei; Jiang, San-Jie; Chen, Shan-Ze

    2016-01-01

    Horizontal gene transfer (HGT) drives the evolution of recipient organism particularly if it provides a novel function which enhances the fitness or its adaption to the environment. Virus-host co-evolution is attractive for studying co-evolutionary processes, since viruses strictly replicate inside of the host cells and thus their evolution is inexorably tangled with host biology. HGT, as a mechanism of co-evolution between human and viruses, has been widely documented, however, the roles HGT play during the interaction between human and viruses are still in their infancy. In this study, we performed a comprehensive analysis on the genes horizontally transferred between viruses and their corresponding human hosts. Our study suggests that the HGT genes in human are predominantly enriched in immune related GO terms while viral HGT genes are tend to be encoded by viruses which promote the invasion of immune system of hosts. Based on our results, it gives us a hint about the evolution trajectory of HGT events. Overall, our study suggests that the HGT between human and viruses are highly relevant to immune interaction and probably reshaped the arm race between hosts and viruses. PMID:27270140

  2. Co-dispersal of the blood fluke Schistosoma japonicum and Homo sapiens in the Neolithic Age.

    PubMed

    Yin, Mingbo; Zheng, Hong-Xiang; Su, Jing; Feng, Zheng; McManus, Donald P; Zhou, Xiao-Nong; Jin, Li; Hu, Wei

    2015-01-01

    The global spread of human infectious diseases is of considerable public health and biomedical interest. Little is known about the relationship between the distribution of ancient parasites and that of their human hosts. Schistosoma japonicum is one of the three major species of schistosome blood flukes causing the disease of schistosomiasis in humans. The parasite is prevalent in East and Southeast Asia, including the People's Republic of China, the Philippines and Indonesia. We studied the co-expansion of S. japonicum and its human definitive host. Phylogenetic reconstruction based on complete mitochondrial genome sequences showed that S. japonicum radiated from the middle and lower reaches of the Yangtze River to the mountainous areas of China, Japan and Southeast Asia. In addition, the parasite experienced two population expansions during the Neolithic agriculture era, coinciding with human migration and population growth. The data indicate that the advent of rice planting likely played a key role in the spread of schistosomiasis in Asia. Moreover, the presence of different subspecies of Oncomelania hupensis intermediate host snails in different localities in Asia allowed S. japonicum to survive in new rice-planting areas, and concurrently drove the intraspecies divergence of the parasite. PMID:26686813

  3. Developmental Changes in Morphology of the Middle and Posterior External Cranial Base in Modern Homo sapiens

    PubMed Central

    Dalal, Deepal H.; Smith, Heather F.

    2015-01-01

    The basicranium has been described as phylogenetically informative, developmentally stable, and minimally affected by external factors and consequently plays an important role in cranial size and shape in subadult humans. Here basicranial variation of subadults from several modern human populations was investigated and the impact of genetic relatedness on basicranial morphological similarities was investigated. Three-dimensional landmark data were digitized from subadult basicrania from seven populations. Published molecular data on short tandem repeats were statistically compared to morphological data from three ontogenetic stages. Basicranial and temporal bone morphology both reflect genetic distances in childhood and adolescence (5–18 years), but not in infancy (<5 years). The occipital bone reflects genetic distances only in adolescence (13–18 years). The sphenoid bone does not reflect genetic distances at any ontogenetic stage but was the most diagnostic region evaluated, resulting in high rates of correct classification among populations. These results suggest that the ontogenetic processes driving basicranial development are complex and cannot be succinctly summarized across populations or basicranial regions. However, the fact that certain regions reflect genetic distances suggests that the morphology of these regions may be useful in reconstructing population history in specimens for which direct DNA evidence is unavailable, such as archaeological sites. PMID:26413515

  4. She more than he: gender bias supports the empathic nature of yawn contagion in Homo sapiens

    PubMed Central

    Norscia, Ivan; Demuru, Elisa; Palagi, Elisabetta

    2016-01-01

    Psychological, clinical and neurobiological findings endorse that empathic abilities are more developed in women than in men. Because there is growing evidence that yawn contagion is an empathy-based phenomenon, we expect that the female bias in the empathic abilities reflects on a gender skew in the responsiveness to others’ yawns. We verified this assumption by applying a linear model on a dataset gathered during a 5 year period of naturalistic observations on humans. Gender, age and social bond were included in the analysis as fixed factors. The social bond and the receiver’s gender remained in the best model. The rates of contagion were significantly lower between acquaintances than between friends and family members, and significantly higher in women than in men. These results not only confirm that yawn contagion is sensitive to social closeness, but also that the phenomenon is affected by the same gender bias affecting empathy. The sex skew, also found in other non-human species, fits with the female social roles which are likely to require higher empathic abilities (e.g. parental care, group cohesion maintenance, social mediation). The fact that female influence in social dynamics also relies on face-to-face emotional exchange raises concerns on the negative repercussions of having women’s facial expressions forcibly concealed. PMID:26998318

  5. Structural Exploration and Conformational Transitions in MDM2 upon DHFR Interaction from Homo sapiens: A Computational Outlook for Malignancy via Epigenetic Disruption.

    PubMed

    Banerjee, Arundhati; Ray, Sujay

    2016-01-01

    Structural basis for exploration into MDM2 and MDM2-DHFR interaction plays a vital role in analyzing the obstruction in folate metabolism, nonsynthesis of purines, and further epigenetic regulation in Homo sapiens. Therefore, it leads to suppression of normal cellular behavior and malignancy. This has been earlier documented via yeast two-hybrid assays. So, with a novel outlook, this study explores the molecular level demonstration of the best satisfactory MDM2 model selection after performing manifold modeling techniques. Z-scores and other stereochemical features were estimated for comparison. Further, protein-protein docking was executed with MDM2 and the experimentally validated X-ray crystallographic DHFR. Residual disclosure from the best suited simulated protein complex disclosed 18 side chain and 3 ionic interactions to strongly accommodate MDM2 protein into the pocket-like zone in DHFR due to the positive environment by charged residues. Lysine residues from MDM2 played a predominant role. Moreover, evaluation from varied energy calculations, folding rate, and net area for solvent accessibility implied the active participation of MDM2 with DHFR. Fascinatingly, conformational transitions from coils to helices and β-sheets after interaction with DHFR affirm the conformational strength and firmer interaction of human MDM2-DHFR. Therefore, this probe instigates near-future clinical research and interactive computational investigations with mutations. PMID:27213086

  6. Crystal Structure of the Homo sapiens Kynureninase-3-Hydroxyhippuric Acid Inhibitor Complex: Insights into the Molecular Basis Of Kynureninase Substrate Specificity

    SciTech Connect

    Lima,Santiago; Kumar,Sunil; Gawandi,Vijay; Momany,Cory; Phillips,Robert S.

    2009-02-23

    Homo sapiens kynureninase is a pyridoxal-5'-phosphate dependent enzyme that catalyzes the hydrolytic cleavage of 3-hydroxykynurenine to yield 3-hydroxyanthranilate and L-alanine as part of the tryptophan catabolic pathway leading to the de novo biosynthesis of NAD{sup +}. This pathway results in quinolinate, an excitotoxin that is an NMDA receptor agonist. High levels of quinolinate have been correlated with the etiology of neurodegenerative disorders such as AIDS-related dementia and Alzheimer's disease. We have synthesized a novel kynureninase inhibitor, 3-hydroxyhippurate, cocrystallized it with human kynureninase, and solved the atomic structure. On the basis of an analysis of the complex, we designed a series of His-102, Ser-332, and Asn-333 mutants. The H102W/N333T and H102W/S332G/N333T mutants showed complete reversal of substrate specificity between 3-hydroxykynurenine and L-kynurenine, thus defining the primary residues contributing to substrate specificity in kynureninases.

  7. Structural Exploration and Conformational Transitions in MDM2 upon DHFR Interaction from Homo sapiens: A Computational Outlook for Malignancy via Epigenetic Disruption

    PubMed Central

    Banerjee, Arundhati; Ray, Sujay

    2016-01-01

    Structural basis for exploration into MDM2 and MDM2-DHFR interaction plays a vital role in analyzing the obstruction in folate metabolism, nonsynthesis of purines, and further epigenetic regulation in Homo sapiens. Therefore, it leads to suppression of normal cellular behavior and malignancy. This has been earlier documented via yeast two-hybrid assays. So, with a novel outlook, this study explores the molecular level demonstration of the best satisfactory MDM2 model selection after performing manifold modeling techniques. Z-scores and other stereochemical features were estimated for comparison. Further, protein-protein docking was executed with MDM2 and the experimentally validated X-ray crystallographic DHFR. Residual disclosure from the best suited simulated protein complex disclosed 18 side chain and 3 ionic interactions to strongly accommodate MDM2 protein into the pocket-like zone in DHFR due to the positive environment by charged residues. Lysine residues from MDM2 played a predominant role. Moreover, evaluation from varied energy calculations, folding rate, and net area for solvent accessibility implied the active participation of MDM2 with DHFR. Fascinatingly, conformational transitions from coils to helices and β-sheets after interaction with DHFR affirm the conformational strength and firmer interaction of human MDM2-DHFR. Therefore, this probe instigates near-future clinical research and interactive computational investigations with mutations. PMID:27213086

  8. Evolution and development of brain networks: from Caenorhabditis elegans to Homo sapiens.

    PubMed

    Kaiser, Marcus; Varier, Sreedevi

    2011-01-01

    Neural networks show a progressive increase in complexity during the time course of evolution. From diffuse nerve nets in Cnidaria to modular, hierarchical systems in macaque and humans, there is a gradual shift from simple processes involving a limited amount of tasks and modalities to complex functional and behavioral processing integrating different kinds of information from highly specialized tissue. However, studies in a range of species suggest that fundamental similarities, in spatial and topological features as well as in developmental mechanisms for network formation, are retained across evolution. 'Small-world' topology and highly connected regions (hubs) are prevalent across the evolutionary scale, ensuring efficient processing and resilience to internal (e.g. lesions) and external (e.g. environment) changes. Furthermore, in most species, even the establishment of hubs, long-range connections linking distant components, and a modular organization, relies on similar mechanisms. In conclusion, evolutionary divergence leads to greater complexity while following essential developmental constraints.

  9. Morphometric variability of minicolumns in the striate cortex of Homo sapiens, Macaca mulatta, and Pan troglodytes.

    PubMed

    Casanova, Manuel F; Trippe, Juan; Tillquist, Christopher; Switala, Andrew E

    2009-02-01

    Radially oriented ensembles of neurons and their projections, termed minicolumns, are hypothesized to be the basic microcircuit of mammalian cerebral cortex. Minicolumns can be divided into a core and a peripheral neuropil space compartment. The core of minicolumns is constrained by the migratory path of pyramidal cells and their attendant radially oriented projections. Variation in minicolumnar morphometry and density is observed both within and across species. Using a scale-independent measure of variability in minicolumnar width (V(CW)), we demonstrated a significant increase in V(CW) in layers III-V of striate cortex in humans relative to macaques and chimpanzees. Despite changes in minicolumnar width (CW) across species, their core space (w) remained the same. Given that cellular elements and processes within the peripheral neuropil space of minicolumns are derived from assorted sources, cross-species differences in VCW may result from genetic and epigenetic influences acting primarily on this compartment of the minicolumn.

  10. From Sea Anemone to Homo Sapiens: The Evolution of the p53 Family of Genes

    SciTech Connect

    Levine, Arnold

    2009-09-14

    The human genome contains three transcription factors termed p53, p63 and p73 which are related orthologues. The function of the p53 protein is to respond to a wide variety of stresses which can disrupt the fidelity of DNA replication and cell division in somatic cells of the body. These stress signals, such as DNA damage, increase the mutation rate during DNA duplication and so an active p53 protein responds by eliminating clones of cells with mutations employing apoptosis, senescence or cell cycle arrest. In this way the p53 protein acts as a tumor suppressor preventing the mutations that can lead to cancers. The p63 and p73 proteins act in a similar fashion to protect the germ line cells in females (eggs). In addition the p63 protein plays a central role in the formation of epithelial cell layers and p73 plays a critical role in the formation of several structures in the central nervous system. Based upon their amino acid sequences and structural considerations the oldest organisms that contain an ancestor of the p53/p63/p73 gene are the sea anemone or hydra. The present day representatives of these animals contain a p63/p73 like ancestor gene and the protein functions in germ cells of this animal to enforce the fidelity of DNA replication after exposure to ultraviolet light. Thus the structure and functions of this gene family have been preserved for over one billion years of evolution. Other invertebrates such as the worm, the fly and the clam contain a very similar ancestor gene with a similar set of functions. The withdrawal of a food source from a worm results in the p63/p73 mediated apoptosis of the eggs so that new organisms will not be hatched into a poor environment. A similar response is thought to occur in humans. Thus this ancestor gene ensures the fidelity of the next generation of organisms. The first time a clearly distinct new p53 gene arises is in the cartilaginous fish and in the bony fish a separation of the p

  11. From Sea Anemone to Homo sapiens: The Evolution of the p53 Family of Genes

    SciTech Connect

    Levine, Arnold

    2009-09-14

    The human genome contains three transcription factors termed p53, p63 and p73 which are related orthologues. The function of the p53 protein is to respond to a wide variety of stresses which can disrupt the fidelity of DNA replication and cell division in somatic cells of the body. These stress signals, such as DNA damage, increase the mutation rate during DNA duplication and so an active p53 protein responds by eliminating clones of cells with mutations employing apoptosis, senescence or cell cycle arrest. In this way the p53 protein acts as a tumor suppressor preventing the mutations that can lead to cancers. The p63 and p73 proteins act in a similar fashion to protect the germ line cells in females (eggs). In addition the p63 protein plays a central role in the formation of epithelial cell layers and p73 plays a critical role in the formation of several structures in the central nervous system. Based upon their amino acid sequences and structural considerations the oldest organisms that contain an ancestor of the p53/p63/p73 gene are the sea anemone or hydra. The present day representatives of these animals contain a p63/p73 like ancestor gene and the protein functions in germ cells of this animal to enforce the fidelity of DNA replication after exposure to ultraviolet light. Thus the structure and functions of this gene family have been preserved for over one billion years of evolution. Other invertebrates such as the worm, the fly and the clam contain a very similar ancestor gene with a similar set of functions. The withdrawal of a food source from a worm results in the p63/p73 mediated apoptosis of the eggs so that new organisms will not be hatched into a poor environment. A similar response is thought to occur in humans. Thus this ancestor gene ensures the fidelity of the next generation of organisms. The first time a clearly distinct new p53 gene arises is in the cartilaginous fish and in the bony fish a separation of the p

  12. Comparative mapping of Homo sapiens chromosome 4 (HSA4) and Sus scrofa chromosome 8 (SSC8) using orthologous genes representing different cytogenetic bands as landmarks.

    PubMed

    Jiang, Zhihua; He, Hong; Hamasima, Noriyuki; Suzuki, Hideaki; Verrinder, GibbinsAnnM

    2002-02-01

    The recently published draft sequence of the human genome will provide a basic reference for the comparative mapping of genomes among mammals. In this study, we selected 214 genes with complete coding sequences on Homo sapiens chromosome 4 (HSA4) to search for orthologs and expressed sequence tag (EST) sequences in eight other mammalian species (cattle, pig, sheep, goat, horse, dog, cat, and rabbit). In particular, 46 of these genes were used as landmarks for comparative mapping of HSA4 and Sus scrofa chromosome 8 (SSC8); most of HSA4 is homologous to SSC8, which is of particular interest because of its association with genes affecting the reproductive performance of pigs. As a reference framework, the 46 genes were selected to represent different cytogenetic bands on HSA4. Polymerase chain reaction (PCR) products amplified from pig DNA were directly sequenced and their orthologous status was confirmed by a BLAST search. These 46 genes, plus 11 microsatellite markers for SSC8, were typed against DNA from a pig-mouse radiation hybrid (RH) panel with 110 lines. RHMAP analysis assigned these 57 markers to 3 linkage groups in the porcine genome, 52 to SSC8, 4 to SSC15, and 1 to SSC17. By comparing the order and orientation of orthologous landmark genes on the porcine RH maps with those on the human sequence map, HSA4 was recognized as being split into nine conserved segments with respect to the porcine genome, seven with SSC8, one with SSC15, and one with SSC17. With 41 orthologous gene loci mapped, this report provides the largest functional gene map of SSC8, with 30 of these loci representing new single-gene assignments to SSC8. PMID:11908657

  13. Tracking the displacement of objects: a series of tasks with great apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, and Pongo pygmaeus) and young children (Homo sapiens).

    PubMed

    Barth, Jochen; Call, Josep

    2006-07-01

    The authors administered a series of object displacement tasks to 24 great apes and 24 30-month-old children (Homo sapiens). Objects were placed under 1 or 2 of 3 cups by visible or invisible displacements. The series included 6 tasks: delayed response, inhibition test, A not B, rotations, transpositions, and object permanence. Apes and children solved most tasks performing at comparable levels except in the transposition task, in which apes performed better than children. Ape species performed at comparable levels in all tasks except in single transpositions, in which chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) performed better than gorillas (Gorilla gorilla) and orangutans (Pongo pygmeaus). All species found nonadjacent trials and rotations especially difficult. The number of elements that changed locations, the type of displacement, and having to inhibit predominant reaching responses were factors that negatively affected the subjects' performance.

  14. On the interconnection of stable protein complexes: inter-complex hubs and their conservation in Saccharomyces cerevisiae and Homo sapiens networks.

    PubMed

    Guerra, Concettina

    2015-01-01

    Protein complexes are key molecular entities that perform a variety of essential cellular functions. The connectivity of proteins within a complex has been widely investigated with both experimental and computational techniques. We developed a computational approach to identify and characterise proteins that play a role in interconnecting complexes. We computed a measure of inter-complex centrality, the crossroad index, based on disjoint paths connecting proteins in distinct complexes and identified inter-complex hubs as proteins with a high value of the crossroad index. We applied the approach to a set of stable complexes in Saccharomyces cerevisiae and in Homo sapiens. Just as done for hubs, we evaluated the topological and biological properties of inter-complex hubs addressing the following questions. Do inter-complex hubs tend to be evolutionary conserved? What is the relation between crossroad index and essentiality? We found a good correlation between inter-complex hubs and both evolutionary conservation and essentiality.

  15. Utilization of Boron Compounds for the Modification of Suberoyl Anilide Hydroxamic Acid as Inhibitor of Histone Deacetylase Class II Homo sapiens

    PubMed Central

    Bakri, Ridla; Parikesit, Arli Aditya; Satriyanto, Cipta Prio; Kerami, Djati; Tambunan, Usman Sumo Friend

    2014-01-01

    Histone deacetylase (HDAC) has a critical function in regulating gene expression. The inhibition of HDAC has developed as an interesting anticancer research area that targets biological processes such as cell cycle, apoptosis, and cell differentiation. In this study, an HDAC inhibitor that is available commercially, suberoyl anilide hydroxamic acid (SAHA), has been modified to improve its efficacy and reduce the side effects of the compound. Hydrophobic cap and zinc-binding group of these compounds were substituted with boron-based compounds, whereas the linker region was substituted with p-aminobenzoic acid. The molecular docking analysis resulted in 8 ligands with ΔGbinding value more negative than the standards, SAHA and trichostatin A (TSA). That ligands were analyzed based on the nature of QSAR, pharmacological properties, and ADME-Tox. It is conducted to obtain a potent inhibitor of HDAC class II Homo sapiens. The screening process result gave one best ligand, Nova2 (513246-99-6), which was then further studied by molecular dynamics simulations. PMID:25214833

  16. The critical role played by animal source foods in human (Homo) evolution.

    PubMed

    Milton, Katharine

    2003-11-01

    Wild primates take most of the daily diet from plant sources, eating moderate to small amounts of animal source foods (ASF). Plant materials make up from 87% to >99% of the annual diet of great apes, the closest living relatives of modern humans (Homo sapiens sapiens). Reflecting their close genetic relationship, gut form and nutrient requirements of apes and humans (Hominoidea) are very similar, as is their pattern of digestive kinetics-one predicated on a relatively slow turnover of ingesta. In plant-eating mammals, in contrast to carnivorous mammals, greater body size is associated with lower dietary quality. Turning to ASF as a routine rather than occasional dietary component would have permitted the evolving human lineage to evade the nutritional constraints placed on body size increases in apes. Without routine access to ASF, it is highly unlikely that evolving humans could have achieved their unusually large and complex brain while simultaneously continuing their evolutionary trajectory as large, active and highly social primates. As human evolution progressed, young children in particular, with their rapidly expanding large brain and high metabolic and nutritional demands relative to adults would have benefited from volumetrically concentrated, high quality foods such as meat. Today, many humans, particularly those in high income nations, have a variety of high quality, non-ASF dietary alternatives, but such foods were not generally available to paleolithic human ancestors nor to many people today in low income nations. PMID:14672286

  17. The critical role played by animal source foods in human (Homo) evolution.

    PubMed

    Milton, Katharine

    2003-11-01

    Wild primates take most of the daily diet from plant sources, eating moderate to small amounts of animal source foods (ASF). Plant materials make up from 87% to >99% of the annual diet of great apes, the closest living relatives of modern humans (Homo sapiens sapiens). Reflecting their close genetic relationship, gut form and nutrient requirements of apes and humans (Hominoidea) are very similar, as is their pattern of digestive kinetics-one predicated on a relatively slow turnover of ingesta. In plant-eating mammals, in contrast to carnivorous mammals, greater body size is associated with lower dietary quality. Turning to ASF as a routine rather than occasional dietary component would have permitted the evolving human lineage to evade the nutritional constraints placed on body size increases in apes. Without routine access to ASF, it is highly unlikely that evolving humans could have achieved their unusually large and complex brain while simultaneously continuing their evolutionary trajectory as large, active and highly social primates. As human evolution progressed, young children in particular, with their rapidly expanding large brain and high metabolic and nutritional demands relative to adults would have benefited from volumetrically concentrated, high quality foods such as meat. Today, many humans, particularly those in high income nations, have a variety of high quality, non-ASF dietary alternatives, but such foods were not generally available to paleolithic human ancestors nor to many people today in low income nations.

  18. Describing the hexapeptide identity platform between the influenza A H5N1 and Homo sapiens proteomes.

    PubMed

    Kanduc, Darja

    2010-01-01

    We searched the primary sequence of influenza A H5N1 polyprotein for hexamer amino acid sequences shared with human proteins using the Protein International Resource database and the exact peptide matching analysis program. We find that the viral polyprotein shares numerous hexapeptides with the human proteome. The human proteins involved in the viral overlap are represented by antigens associated with basic cell functions such as proliferation, development, and differentiation. Of special importance, many human proteins that share peptide sequences with influenza A polyprotein are antigens such as reelin, neurexin I-α, myosin-IXa, Bardet-Biedl syndrome 10 protein, Williams syndrome transcription factor, disrupted in schizophrenia 1 protein, amyotrophic lateral sclerosis 2 chromosomal region candidate gene 17 protein, fragile X mental retardation 2 protein, and jouberin. That is, the viral-vs-human overlap involves human proteins that, when altered, have been reported to be potentially associated with multiple neurological disorders that can include autism, epilepsy, obesity, dystonia, ataxia-telangiectasia, amyotrophic lateral sclerosis, sensorineural deafness, sudden infant death syndrome, Charcot-Marie-Tooth disease, and myelination. The present data are discussed as a possible molecular basis for understanding influenza A viral escape from immunosurveillance and for defining anti-influenza immune-therapeutic approaches devoid of collateral adverse events. PMID:20859452

  19. Describing the hexapeptide identity platform between the influenza A H5N1 and Homo sapiens proteomes

    PubMed Central

    Kanduc, Darja

    2010-01-01

    We searched the primary sequence of influenza A H5N1 polyprotein for hexamer amino acid sequences shared with human proteins using the Protein International Resource database and the exact peptide matching analysis program. We find that the viral polyprotein shares numerous hexapeptides with the human proteome. The human proteins involved in the viral overlap are represented by antigens associated with basic cell functions such as proliferation, development, and differentiation. Of special importance, many human proteins that share peptide sequences with influenza A polyprotein are antigens such as reelin, neurexin I-α, myosin-IXa, Bardet–Biedl syndrome 10 protein, Williams syndrome transcription factor, disrupted in schizophrenia 1 protein, amyotrophic lateral sclerosis 2 chromosomal region candidate gene 17 protein, fragile X mental retardation 2 protein, and jouberin. That is, the viral-vs-human overlap involves human proteins that, when altered, have been reported to be potentially associated with multiple neurological disorders that can include autism, epilepsy, obesity, dystonia, ataxia–telangiectasia, amyotrophic lateral sclerosis, sensorineural deafness, sudden infant death syndrome, Charcot-Marie-Tooth disease, and myelination. The present data are discussed as a possible molecular basis for understanding influenza A viral escape from immunosurveillance and for defining anti-influenza immune-therapeutic approaches devoid of collateral adverse events. PMID:20859452

  20. The brain of LB1, Homo floresiensis.

    PubMed

    Falk, Dean; Hildebolt, Charles; Smith, Kirk; Morwood, M J; Sutikna, Thomas; Brown, Peter; Jatmiko; Saptomo, E Wayhu; Brunsden, Barry; Prior, Fred

    2005-04-01

    The brain of Homo floresiensis was assessed by comparing a virtual endocast from the type specimen (LB1) with endocasts from great apes, Homo erectus, Homo sapiens, a human pygmy, a human microcephalic, specimen number Sts 5 (Australopithecus africanus), and specimen number WT 17000 (Paranthropus aethiopicus). Morphometric, allometric, and shape data indicate that LB1 is not a microcephalic or pygmy. LB1's brain/body size ratio scales like that of an australopithecine, but its endocast shape resembles that of Homo erectus. LB1 has derived frontal and temporal lobes and a lunate sulcus in a derived position, which are consistent with capabilities for higher cognitive processing. PMID:15749690

  1. Chemical shift assignments of zinc finger domain of methionine aminopeptidase 1 (MetAP1) from Homo sapiens.

    PubMed

    Rachineni, Kavitha; Arya, Tarun; Singarapu, Kiran Kumar; Addlagatta, Anthony; Bharatam, Jagadeesh

    2015-10-01

    Methionine aminopeptidase Type I (MetAP1) cleaves the initiator methionine from about 70 % of all newly synthesized proteins in almost every living cell. Human MetAP1 is a two domain protein with a zinc finger on the N-terminus and a catalytic domain on the C-terminus. Here, we report the chemical shift assignments of the amino terminal zinc binding domain (ZBD) (1-83 residues) of the human MetAP1 derived by using advanced NMR spectroscopic methods. We were able to assign the chemical shifts of ZBD of MetAP1 nearly complete, which reveal two helical fragments involving residues P44-L49 (α1) and Q59-K82 (α2). The protein structure unfolds upon complex formation with the addition of 2 M excess EDTA, indicated by the appearance of amide resonances in the random coil chemical shift region of (15)NHSQC spectrum.

  2. Comprehensive characterization of evolutionary conserved breakpoints in four New World Monkey karyotypes compared to Chlorocebus aethiops and Homo sapiens.

    PubMed

    Fan, Xiaobo; Supiwong, Weerayuth; Weise, Anja; Mrasek, Kristin; Kosyakova, Nadezda; Tanomtong, Alongkoad; Pinthong, Krit; Trifonov, Vladimir A; Cioffi, Marcelo de Bello; Grothmann, Pierre; Liehr, Thomas; Oliveira, Edivaldo H C de

    2015-11-01

    Comparative cytogenetic analysis in New World Monkeys (NWMs) using human multicolor banding (MCB) probe sets were not previously done. Here we report on an MCB based FISH-banding study complemented with selected locus-specific and heterochromatin specific probes in four NWMs and one Old World Monkey (OWM) species, i.e. in Alouatta caraya (ACA), Callithrix jacchus (CJA), Cebus apella (CAP), Saimiri sciureus (SSC), and Chlorocebus aethiops (CAE), respectively. 107 individual evolutionary conserved breakpoints (ECBs) among those species were identified and compared with those of other species in previous reports. Especially for chromosomal regions being syntenic to human chromosomes 6, 8, 9, 10, 11, 12 and 16 previously cryptic rearrangements could be observed. 50.4% (54/107) NWM-ECBs were colocalized with those of OWMs, 62.6% (62/99) NWM-ECBs were related with those of Hylobates lar (HLA) and 66.3% (71/107) NWM-ECBs corresponded with those known from other mammalians. Furthermore, human fragile sites were aligned with the ECBs found in the five studied species and interestingly 66.3% ECBs colocalized with those fragile sites (FS). Overall, this study presents detailed chromosomal maps of one OWM and four NWM species. This data will be helpful to further investigation on chromosome evolution in NWM and hominoids in general and is prerequisite for correct interpretation of future sequencing based genomic studies in those species.

  3. OSBP-related protein 8 (ORP8) interacts with Homo sapiens sperm associated antigen 5 (SPAG5) and mediates oxysterol interference of HepG2 cell cycle

    SciTech Connect

    Zhong, Wenbin; Zhou, You; Li, Jiwei; Mysore, Raghavendra; Luo, Wei; Li, Shiqian; Chang, Mau-Sun; Olkkonen, Vesa M.; Yan, Daoguang

    2014-04-01

    We earlier identified OSBP-related protein 8 (ORP8) as an endoplasmic reticulum/nuclear envelope oxysterol-binding protein implicated in cellular lipid homeostasis, migration, and organization of the microtubule cytoskeleton. Here, a yeast two-hybrid screen identified Homo sapiens sperm associated antigen 5 (SPAG5)/Astrin as interaction partner of ORP8. The putative interaction was further confirmed by pull-down and co-immunoprecipitation assays. ORP8 did not colocalize with kinetochore-associated SPAG5 in mitotic HepG2 or HuH7 cells, but overexpressed ORP8 was capable of recruiting SPAG5 onto endoplasmic reticulum membranes in interphase cells. In our experiments, 25-hydroxycholesterol (25OHC) retarded the HepG2 cell cycle, causing accumulation in G2/M phase; ORP8 overexpression resulted in the same phenotype. Importantly, ORP8 knock-down dramatically inhibited the oxysterol effect on HepG2 cell cycle, suggesting a mediating role of ORP8. Furthermore, knock-down of SPAG5 significantly reduced the effects of both ORP8 overexpression and 25OHC on the cell cycle, placing SPAG5 downstream of the two cell-cycle interfering factors. Taken together, the present results suggest that ORP8 may via SPAG5 mediate oxysterol interference of the HepG2 cell cycle. - Highlights: • The oxysterol-binding protein ORP8 was found to interact with the mitotic regulator SPAG5/Astrin. • Treatment of HepG2 cells with 25-hydroxycholesterol caused cell cycle retardation in G2/M. • ORP8 overexpression caused a similar G2/M accumulation, and ORP8 knock-down reversed the 25-hydroxycholesterol effect. • Reduction of cellular of SPAG5/Astrin reversed the cell cycle effects of both 25-hydroxycholesterol and ORP8 overexpression. • Our results suggest that ORP8 mediates via SPAG5/Astrin the oxysterol interference of HepG2 cell cycle.

  4. Evolution of the α-Subunit of Na/K-ATPase from Paramecium to Homo sapiens: Invariance of Transmembrane Helix Topology.

    PubMed

    Morrill, Gene A; Kostellow, Adele B; Liu, Lijun; Gupta, Raj K; Askari, Amir

    2016-05-01

    Na/K-ATPase is a key plasma membrane enzyme involved in cell signaling, volume regulation, and maintenance of electrochemical gradients. The α-subunit, central to these functions, belongs to a large family of P-type ATPases. Differences in transmembrane (TM) helix topology, sequence homology, helix-helix contacts, cell signaling, and protein domains of Na/K-ATPase α-subunit were compared in fungi (Beauveria), unicellular organisms (Paramecia), primitive multicellular organisms (Hydra), and vertebrates (Xenopus, Homo sapiens), and correlated with evolution of physiological functions in the α-subunit. All α-subunits are of similar length, with groupings of four and six helices in the N- and C-terminal regions, respectively. Minimal homology was seen for protein domain patterns in Paramecium and Hydra, with high correlation between Hydra and vertebrates. Paramecium α-subunits display extensive disorder, with minimal helix contacts. Increases in helix contacts in Hydra approached vertebrates. Protein motifs known to be associated with membrane lipid rafts and cell signaling reveal significant positional shifts between Paramecium and Hydra vulgaris, indicating that regional membrane fluidity changes occur during evolution. Putative steroid binding sites overlapping TM-3 occurred in all species. Sites associated with G-protein-receptor stimulation occur both in vertebrates and amphibia but not in Hydra or Paramecia. The C-terminus moiety "KETYY," necessary for the Na(+) activation of pump phosphorylation, is not present in unicellular species indicating the absence of classical Na(+)/K(+)-pumps. The basic protein topology evolved earliest, followed by increases in protein domains and ordered helical arrays, correlated with appearance of α-subunit regions known to involve cell signaling, membrane recycling, and ion channel formation. PMID:26961431

  5. Structure of the C-terminal heme-binding domain of THAP domain containing protein 4 from Homo sapiens

    SciTech Connect

    Bianchetti, Christopher M.; Bingman, Craig A.; Phillips, Jr., George N.

    2012-03-15

    The thanatos (the Greek god of death)-associated protein (THAP) domain is a sequence-specific DNA-binding domain that contains a C2-CH (Cys-Xaa{sub 2-4}-Cys-Xaa{sub 35-50}-Cys-Xaa{sub 2}-His) zinc finger that is similar to the DNA domain of the P element transposase from Drosophila. THAP-containing proteins have been observed in the proteome of humans, pigs, cows, chickens, zebrafish, Drosophila, C. elegans, and Xenopus. To date, there are no known THAP domain proteins in plants, yeast, or bacteria. There are 12 identified human THAP domain-containing proteins (THAP0-11). In all human THAP protein, the THAP domain is located at the N-terminus and is {approx}90 residues in length. Although all of the human THAP-containing proteins have a homologous N-terminus, there is extensive variation in both the predicted structure and length of the remaining protein. Even though the exact function of these THAP proteins is not well defined, there is evidence that they play a role in cell proliferation, apoptosis, cell cycle modulation, chromatin modification, and transcriptional regulation. THAP-containing proteins have also been implicated in a number of human disease states including heart disease, neurological defects, and several types of cancers. Human THAP4 is a 577-residue protein of unknown function that is proposed to bind DNA in a sequence-specific manner similar to THAP1 and has been found to be upregulated in response to heat shock. THAP4 is expressed in a relatively uniform manner in a broad range of tissues and appears to be upregulated in lymphoma cells and highly expressed in heart cells. The C-terminal domain of THAP4 (residues 415-577), designated here as cTHAP4, is evolutionarily conserved and is observed in all known THAP4 orthologs. Several single-domain proteins lacking a THAP domain are found in plants and bacteria and show significant levels of homology to cTHAP4. It appears that cTHAP4 belongs to a large class of proteins that have yet to be fully

  6. Gestalt principle use in college students, children with autism, toddlers (Homo sapiens), and cotton top tamarins (Saguinus oedipus).

    PubMed

    Neiworth, Julie J; Whillock, Katherine M; Kim, Seo Hyun; Greenberg, Julia R; Jones, Katherine B; Patel, Anushka R; Steefel-Moore, David L; Shaw, Allyson J; Rupert, Deborah D; Gauer, Jacqueline L; Kudura, Aisha G

    2014-05-01

    The use of Gestalt principles of proximity, similarity, and closure to recognize objects by configural superiority was examined in college students, low- and high-functioning children with autism, toddlers, and adult cotton top tamarin monkeys. At issue was whether the monkeys showed differences from humans in perceptual processing and whether they showed any similarities with clinical or developmental groups. The method required a pointing response to discriminate an odd item in a 4-item visual display. All subjects were trained to a high accuracy to point to the odd item before being tested with graphic stimuli that differentiated feature changes based on configural superiority. The results were that college students and high-functioning children with autism responded faster and more accurately to trials in which the odd item was easily noticed by the use of Gestalt principles and configural superiority. Toddlers also responded more accurately to the Gestalt trials, but without being faster at making the response. Low-functioning children with autism and tamarins showed no advantage to Gestalt trials but exhibited different processing styles. The implications of these findings to track the evolution of human perception and to develop a primate model for the perceptual deficits of autism are discussed.

  7. Cloning, expression, purification, crystallization and X-ray analysis of inositol monophosphatase from Mus musculus and Homo sapiens

    PubMed Central

    Singh, Nisha; Halliday, Amy C.; Knight, Matthew; Lack, Nathan A.; Lowe, Edward; Churchill, Grant C.

    2012-01-01

    Inositol monophosphatase (IMPase) catalyses the hydrolysis of inositol monophosphate to inositol and is crucial in the phosphatidylinositol (PI) signalling pathway. Lithium, which is the drug of choice for bipolar disorder, inhibits IMPase at therapeutically relevant plasma concentrations. Both mouse IMPase 1 (MmIMPase 1) and human IMPase 1 (HsIMPase 1) were cloned into pRSET5a, expressed in Escherichia coli, purified and crystallized using the sitting-drop method. The structures were solved at resolutions of 2.4 and 1.7 Å, respectively. Comparison of MmIMPase 1 and HsIMPase 1 revealed a core r.m.s. deviation of 0.516 Å. PMID:23027737

  8. The solution structure of ZNF593 from Homo sapiens reveals a zinc finger in a predominately unstructured protein

    PubMed Central

    Hayes, Paulette L.; Lytle, Betsy L.; Volkman, Brian F.; Peterson, Francis C.

    2008-01-01

    Here, we report the solution structure of ZNF593, a protein identified in a functional study as a negative modulator of the DNA-binding activity of the Oct-2 transcription factor. ZNF593 contains a classic C2H2 zinc finger domain flanked by about 40 disordered residues on each terminus. Although the protein contains a high degree of intrinsic disorder, the structure of the zinc finger domain was resolved by NMR spectroscopy without a need for N- or C-terminal truncations. The tertiary structure of the zinc finger domain is composed of a β-hairpin that positions the cysteine side chains for zinc coordination, followed by an atypical kinked α-helix containing the two histidine side chain ligands. The structural topology of ZNF593 is similar to a fragment of the double-stranded RNA-binding protein Zfa and the C-terminal zinc finger of MBP-1, a human enhancer binding protein. The structure presented here will provide a guide for future functional studies of how ZNF593 negatively modulates the DNA-binding activity of Oct-2, a POU domain-containing transcription factor. Our work illustrates the unique capacity of NMR spectroscopy for structural analysis of folded domains in a predominantly disordered protein. PMID:18287285

  9. Should autism be considered a canary bird telling that Homo sapiens may be on its way to extinction?

    PubMed Central

    Christophersen, Olav Albert

    2012-01-01

    There has been a dramatic enhancement of the reported incidence of autism in different parts of the world over the last 30 years. This can apparently not be explained only as a result of improved diagnosis and reporting, but may also reflect a real change. The causes of this change are unknown, but if we shall follow T.C. Chamberlin's principle of multiple working hypotheses, we need to take into consideration the possibility that it partly may reflect an enhancement of the average frequency of responsible alleles in large populations. If this hypothesis is correct, it means that the average germline mutation rate must now be much higher in the populations concerned, compared with the natural mutation rate in hominid ancestors before the agricultural and industrial revolutions. This is compatible with the high prevalence of impaired human semen quality in several countries and also with what is known about high levels of total exposure to several different unnatural chemical mutagens, plus some natural ones at unnaturally high levels. Moreover, dietary deficiency conditions that may lead to enhancement of mutation rates are also very widespread, affecting billions of people. However, the natural mutation rate in hominids has been found to be so high that there is apparently no tolerance for further enhancement of the germline mutation rate before the Eigen error threshold will be exceeded and our species will go extinct because of mutational meltdown. This threat, if real, should be considered far more serious than any disease causing the death only of individual patients. It should therefore be considered the first and highest priority of the best biomedical scientists in the world, of research-funding agencies and of all medical doctors to try to stop the express train carrying all humankind as passengers on board before it arrives at the end station of our civilization. PMID:23990819

  10. Toward reduction in animal sacrifice for drugs: molecular modeling of Macaca fascicularis P450 2C20 for virtual screening of Homo sapiens P450 2C8 substrates.

    PubMed

    Rua, Francesco; Di Nardo, Giovanna; Sadeghi, Sheila J; Gilardi, Gianfranco

    2012-01-01

    Macaca fascicularis P450 2C20 shares 92% identity with human cytochrome P450 2C8, which is involved in the metabolism of more than 8% of all prescribed drugs. To date, only paclitaxel and amodiaquine, two substrate markers of the human P450 2C8, have been experimentally confirmed as M. fascicularis P450 2C20 drugs. To bridge the lack of information on the ligands recognized by M. fascicularis P450 2C20, in this study, a three-dimensional homology model of this enzyme was generated on the basis of the available crystal structure of the human homologue P450 2C8 using YASARA. The results indicated that 90.0%, 9.0%, 0.5%, and 0.5% of the residues of the P450 2C20 model were located in the most favorable, allowed, generously allowed, and disallowed regions, respectively. The root-mean-square deviation of the C-alpha superposition of the M. fascicularis P450 2C20 model with the Homo sapiens P450 2C8 was 0.074 Å, indicating a very high similarity of the two structures. Subsequently, the 2C20 model was used for in silico screening of 58 known P450 2C8 substrates and 62 inhibitors. These were also docked in the active site of the crystal structure of the human P450 2C8. The affinity of each compound for the active site of both cytochromes proved to be very similar, meaning that the few key residues that are mutated in the active site of the M. fascicularis P450 do not prevent the P450 2C20 from recognizing the same substrates as the human P450 2C8.

  11. From hominins to humans: how sapiens became behaviourally modern

    PubMed Central

    Sterelny, Kim

    2011-01-01

    This paper contributes to a debate in the palaeoarchaeological community about the major time-lag between the origin of anatomically modern humans and the appearance of typically human cultural behaviour. Why did humans take so long—at least 100 000 years—to become ‘behaviourally modern’? The transition is often explained as a change in the intrinsic cognitive competence of modern humans: often in terms of a new capacity for symbolic thought, or the final perfection of language. These cognitive breakthrough models are not satisfactory, for they fail to explain the uneven palaeoanthropological record of human competence. Many supposed signature capacities appear (and then disappear) before the supposed cognitive breakthrough; many of the signature capacities disappear again after the breakthrough. So, instead of seeing behavioural modernity as a simple reflection of a new kind of mind, this paper presents a niche construction conceptual model of behavioural modernity. Humans became behaviourally modern when they could reliably transmit accumulated informational capital to the next generation, and transmit it with sufficient precision for innovations to be preserved and accumulated. In turn, the reliable accumulation of culture depends on the construction of learning environments, not just intrinsic cognitive machinery. I argue that the model is (i) evolutionarily plausible: the elements of the model can be assembled incrementally, without implausible selective scenarios; (ii) the model coheres with the broad palaeoarchaeological record; (iii) the model is anthropologically and ethnographically plausible; and (iv) the model is testable, though only in coarse, preliminary ways. PMID:21320896

  12. Discovery of Homo sp. tooth associated with a mammalian cave fauna of Late Middle Pleistocene age, northern Thailand.

    PubMed

    Tougard, C; Jaeger, J J

    1998-07-01

    In the context of a Thai-French paleontological project, a single human tooth, a right upper fourth premolar, has been discovered in Northern Thailand among mammalian fossil remains excavated from the "Thum Wiman Nakin" cave. Based on the fauna associated with the human tooth and the Uranium/Thorium datings from the overlying calcite beds, we attribute this site to the Late Middle Pleistocene. The human tooth was compared with teeth of Chinese and Javanese Homo erectus, Homo sapiens neanderthalensis and Homo sapiens sapiens as well as teeth of apes (Orang-utan). The tooth has archaic features of the crown which are similar to Homo erectus. It also has derived features of the root which makes it aligns with Neanderthals and modern humans. Consequently, it has been tentatively attributed to Homo sp. Homo remains have not been previously reported from Thailand, and the specimen described here is therefore the first and oldest fossil human remain from this country.

  13. Origin and evolution of the genus Homo.

    PubMed

    Wood, B

    1992-02-27

    It is remarkable that the taxonomy and phylogenetic relationships of the earliest known representatives of our own genus, Homo, remain obscure. Advances in techniques for absolute dating and reassessments of the fossils themselves have rendered untenable a simple unilineal model of human evolution, in which Homo habilis succeeded the australopithecines and then evolved via H. erectus into H. sapiens-but no clear alternative consensus has yet emerged. PMID:1538759

  14. Geometric variation of the frontal squama in the genus homo: frontal bulging and the origin of modern human morphology.

    PubMed

    Bruner, Emiliano; Athreya, Sheela; de la Cuétara, José Manuel; Marks, Tarah

    2013-02-01

    The majority of studies of frontal bone morphology in paleoanthropology have analyzed the frontal squama and the browridge as a single unit, mixing information from different functional elements. Taking into account that the bulging of the frontal bone is often described as a species-specific trait of Homo sapiens, in this article we analyze variation in the midsagittal profile of the genus Homo, focusing on the frontal squama alone, using landmark-based superimpositions and principal components analysis. Our results demonstrate that anatomically modern humans are definitely separated from extinct human taxa on the basis of frontal bulging. However, there is minor overlap among these groups, indicating that it is necessary to exercise caution when using this trait alone to make taxonomic inferences on individual specimens. Early modern humans do not show differences with recent modern humans, and "transitional" individuals such as Jebel Irhoud 1, Maba, and Florisbad, show modern-like frontal squama morphology. The bulging of the frontal squama in modern humans may represent a structural consequence of more general cranial changes, or it could be a response to changes in the morphology of the underlying prefrontal brain elements. A subtle difference between Neandertals and the Afro-European Middle Pleistocene Homo sample is associated with flattening at bregma in the former group, a result that merits further investigation.

  15. Sarcocystis heydorni, n. sp. (Apicomplexa: Protozoa) with cattle (Bos taurus) and human (Homo sapiens) cycle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cattle (Bos taurus) are intermediate hosts for four species of Sarcocystis, S. cruzi, S. hirsuta, S. hominis, and S. rommeli. Of these four species, mature sarcocysts of S. cruzi are thin-walled (< 1µm) whereas S. hirsuta, S. hominis, and S. rommeli have thick walls (4 µm or more). Here we describe ...

  16. Homo floresiensis: a cladistic analysis.

    PubMed

    Argue, D; Morwood, M J; Sutikna, T; Jatmiko; Saptomo, E W

    2009-11-01

    The announcement of a new species, Homo floresiensis, a primitive hominin that survived until relatively recent times is an enormous challenge to paradigms of human evolution. Until this announcement, the dominant paradigm stipulated that: 1) only more derived hominins had emerged from Africa, and 2) H. sapiens was the only hominin since the demise of Homo erectus and Homo neanderthalensis. Resistance to H. floresiensis has been intense, and debate centers on two sets of competing hypotheses: 1) that it is a primitive hominin, and 2) that it is a modern human, either a pygmoid form or a pathological individual. Despite a range of analytical techniques having been applied to the question, no resolution has been reached. Here, we use cladistic analysis, a tool that has not, until now, been applied to the problem, to establish the phylogenetic position of the species. Our results produce two equally parsimonious phylogenetic trees. The first suggests that H. floresiensis is an early hominin that emerged after Homo rudolfensis (1.86Ma) but before H. habilis (1.66Ma, or after 1.9Ma if the earlier chronology for H. habilis is retained). The second tree indicates H. floresiensis branched after Homo habilis.

  17. Variation in enamel thickness within the genus Homo.

    PubMed

    Smith, Tanya M; Olejniczak, Anthony J; Zermeno, John P; Tafforeau, Paul; Skinner, Matthew M; Hoffmann, Almut; Radovčić, Jakov; Toussaint, Michel; Kruszynski, Robert; Menter, Colin; Moggi-Cecchi, Jacopo; Glasmacher, Ulrich A; Kullmer, Ottmar; Schrenk, Friedemann; Stringer, Chris; Hublin, Jean-Jacques

    2012-03-01

    Recent humans and their fossil relatives are classified as having thick molar enamel, one of very few dental traits that distinguish hominins from living African apes. However, little is known about enamel thickness in the earliest members of the genus Homo, and recent studies of later Homo report considerable intra- and inter-specific variation. In order to assess taxonomic, geographic, and temporal trends in enamel thickness, we applied micro-computed tomographic imaging to 150 fossil Homo teeth spanning two million years. Early Homo postcanine teeth from Africa and Asia show highly variable average and relative enamel thickness (AET and RET) values. Three molars from South Africa exceed Homo AET and RET ranges, resembling the hyper thick Paranthropus condition. Most later Homo groups (archaic European and north African Homo, and fossil and recent Homo sapiens) possess absolutely and relatively thick enamel across the entire dentition. In contrast, Neanderthals show relatively thin enamel in their incisors, canines, premolars, and molars, although incisor AET values are similar to H. sapiens. Comparisons of recent and fossil H. sapiens reveal that dental size reduction has led to a disproportionate decrease in coronal dentine compared with enamel (although both are reduced), leading to relatively thicker enamel in recent humans. General characterizations of hominins as having 'thick enamel' thus oversimplify a surprisingly variable craniodental trait with limited taxonomic utility within a genus. Moreover, estimates of dental attrition rates employed in paleodemographic reconstruction may be biased when this variation is not considered. Additional research is necessary to reconstruct hominin dietary ecology since thick enamel is not a prerequisite for hard-object feeding, and it is present in most later Homo species despite advances in technology and food processing. PMID:22361504

  18. Beyond the Pleistocene: Using Phylogeny and Constraint to Inform the Evolutionary Psychology of Human Mating

    ERIC Educational Resources Information Center

    Eastwick, Paul W.

    2009-01-01

    Evolutionary psychologists explore the adaptive function of traits and behaviors that characterize modern Homo sapiens. However, evolutionary psychologists have yet to incorporate the phylogenetic relationship between modern Homo sapiens and humans' hominid and pongid relatives (both living and extinct) into their theorizing. By considering the…

  19. The advantage of throwing the first stone: how understanding the evolutionary demands of Homo sapiens is helping us understand carpal motion.

    PubMed

    Rohde, Rachel S; Crisco, Joseph J; Wolfe, Scott W

    2010-01-01

    Unlike any other diarthrodial joint in the human body, the "wrist joint" is composed of numerous articulations between eight carpal bones, the distal radius, the distal ulna, and five metacarpal bones. The carpal bones articulate with each other as well as with the distal radius, distal ulna, and the metacarpal bases. Multiple theories explaining intercarpal motion have been proposed; however, controversy exists concerning the degree and direction of motion of the individual carpal bones within the two carpal rows during different planes of motion. Recent investigations have suggested that traditional explanations of carpal bone motion may not entirely account for carpal motion in all planes. Better understanding of the complexities of carpal motion through the use of advanced imaging techniques and simultaneous appreciation of human anatomic and functional evolution have led to the hypothesis that the "dart thrower's motion" of the wrist is uniquely human. Carpal kinematic research and current developments in both orthopaedic surgery and anthropology underscore the importance of the dart thrower's motion in human functional activities and the clinical implications of these concepts for orthopaedic surgery and rehabilitation.

  20. Non-random distribution of homo-repeats: links with biological functions and human diseases

    PubMed Central

    Lobanov, Michail Yu.; Klus, Petr; Sokolovsky, Igor V.; Tartaglia, Gian Gaetano; Galzitskaya, Oxana V.

    2016-01-01

    The biological function of multiple repetitions of single amino acids, or homo-repeats, is largely unknown, but their occurrence in proteins has been associated with more than 20 hereditary diseases. Analysing 122 bacterial and eukaryotic genomes, we observed that the number of proteins containing homo-repeats is significantly larger than expected from theoretical estimates. Analysis of statistical significance indicates that the minimal size of homo-repeats varies with amino acid type and proteome. In an attempt to characterize proteins harbouring long homo-repeats, we found that those containing polar or small amino acids S, P, H, E, D, K, Q and N are enriched in structural disorder as well as protein- and RNA-interactions. We observed that E, S, Q, G, L, P, D, A and H homo-repeats are strongly linked with occurrence in human diseases. Moreover, S, E, P, A, Q, D and T homo-repeats are significantly enriched in neuronal proteins associated with autism and other disorders. We release a webserver for further exploration of homo-repeats occurrence in human pathology at http://bioinfo.protres.ru/hradis/. PMID:27256590

  1. Four subunits that are shared by the three classes of RNA polymerase are functionally interchangeable between Homo sapiens and Saccharomyces cerevisiae.

    PubMed Central

    Shpakovski, G V; Acker, J; Wintzerith, M; Lacroix, J F; Thuriaux, P; Vigneron, M

    1995-01-01

    Four cDNAs encoding human polypeptides hRPB7.0, hRPB7.6, hRPB17, and hRPB14.4 (referred to as Hs10 alpha, Hs10 beta, Hs8, and Hs6, respectively), homologous to the ABC10 alpha, ABC10 beta, ABC14.5, and ABC23 RNA polymerase subunits (referred to as Sc10 alpha, Sc10 beta, Sc8, and Sc6, respectively) of Saccharomyces cerevisiae, were cloned and characterized for their ability to complement defective yeast mutants. Hs10 alpha and the corresponding Sp10 alpha of Schizosaccharomyces pombe can complement an S. cerevisiae mutant (rpc10-delta::HIS3) defective in Sc10 alpha. The peptide sequences are highly conserved in their carboxy-terminal halves, with an invariant motif CX2CX12RCX2CGXR corresponding to a canonical zinc-binding domain. Hs10 beta, Sc10 beta, and the N subunit of archaeal RNA polymerase are homologous. An invariant CX2CGXnCCR motif presumably forms an atypical zinc-binding domain. Hs10 beta, but not the archaeal subunit, complemented an S. cerevisiae mutant (rpb10-delta 1::HIS3) lacking Sc10 beta. Hs8 complemented a yeast mutant (rpb8-delta 1::LYS2) defective in the corresponding Sc8 subunit, although with a strong thermosensitive phenotype. Interspecific complementation also occurred with Hs6 and with the corresponding Dm6 cDNA of Drosophila melanogaster. Hs6 cDNA and the Sp6 cDNA of S. pombe are dosage-dependent suppressors of rpo21-4, a mutation generating a slowly growing yeast defective in the largest subunit of RNA polymerase II. Finally, a doubly chimeric S. cerevisiae strain bearing the Sp6 cDNA and the human Hs10 beta cDNA was also viable. No interspecific complementation was observed for the human hRPB25 (Hs5) homolog of the yeast ABC27 (Sc5) subunit. PMID:7651387

  2. OSL dating of the Aterian levels at Dar es-Soltan I (Rabat, Morocco) and implications for the dispersal of modern Homo sapiens

    NASA Astrophysics Data System (ADS)

    Barton, R. N. E.; Bouzouggar, A.; Collcutt, S. N.; Schwenninger, J.-L.; Clark-Balzan, L.

    2009-09-01

    The Aterian is a distinctive Middle Palaeolithic industry which is very widely spread across North Africa. Its dating and significance have been debated for nearly a century. Renewed interest in the Aterian has arisen because of a recent proposal that its development and spread may be linked to the dispersal of anatomically modern humans. The industry contains technological innovations such as thin bifacially flaked lithic points and pedunculates as well as evidence for personal ornaments and use of red ochre. Such markers as shell beads are believed to be indicative of symbolic behaviour. Dar es-Soltan I on the Atlantic coast of Morocco contains a thick sequence of Aterian deposits that were thought to represent the later stages of development of this industry. New Optically Stimulated Luminescence dates and geomorphological study indicate a much older sequence and so far the earliest yet recorded ages for the Aterian. They suggest an appearance in the Maghreb region during MIS (Marine Isotope Stage) 5.

  3. All great ape species (Gorilla gorilla, Pan paniscus, Pan troglodytes, Pongo abelii) and two-and-a-half-year-old children (Homo sapiens) discriminate appearance from reality.

    PubMed

    Karg, Katja; Schmelz, Martin; Call, Josep; Tomasello, Michael

    2014-11-01

    Nonhuman great apes and human children were tested for an understanding that appearance does not always correspond to reality. Subjects were 29 great apes (bonobos [Pan paniscus], chimpanzees [Pan troglodytes], gorillas [Gorilla gorilla], and orangutans [Pongo abelii]) and 24 2½-year-old children. In our task, we occluded portions of 1 large and 1 small food stick such that the size relations seemed reversed. Subjects could then choose which one they wanted. There was 1 control condition and 2 experimental conditions (administered within subjects). In the control condition subjects saw only the apparent stick sizes, whereas in the 2 experimental conditions they saw the true stick sizes as well (the difference between them being what the subjects saw first: the apparent or the real stick sizes). All great ape species and children successfully identified the bigger stick, despite its smaller appearance, in the experimental conditions, but not in the control. We discuss these results in relation to the understanding of object permanence and conservation, and exclude reversed reward contingency learning as an explanation.

  4. All great ape species (Gorilla gorilla, Pan paniscus, Pan troglodytes, Pongo abelii) and two-and-a-half-year-old children (Homo sapiens) discriminate appearance from reality.

    PubMed

    Karg, Katja; Schmelz, Martin; Call, Josep; Tomasello, Michael

    2014-11-01

    Nonhuman great apes and human children were tested for an understanding that appearance does not always correspond to reality. Subjects were 29 great apes (bonobos [Pan paniscus], chimpanzees [Pan troglodytes], gorillas [Gorilla gorilla], and orangutans [Pongo abelii]) and 24 2½-year-old children. In our task, we occluded portions of 1 large and 1 small food stick such that the size relations seemed reversed. Subjects could then choose which one they wanted. There was 1 control condition and 2 experimental conditions (administered within subjects). In the control condition subjects saw only the apparent stick sizes, whereas in the 2 experimental conditions they saw the true stick sizes as well (the difference between them being what the subjects saw first: the apparent or the real stick sizes). All great ape species and children successfully identified the bigger stick, despite its smaller appearance, in the experimental conditions, but not in the control. We discuss these results in relation to the understanding of object permanence and conservation, and exclude reversed reward contingency learning as an explanation. PMID:25150962

  5. Structural insight with mutational impact on tyrosinase and PKC-β interaction from Homo sapiens: Molecular modeling and docking studies for melanogenesis, albinism and increased risk for melanoma.

    PubMed

    Banerjee, Arundhati; Ray, Sujay

    2016-10-30

    Human tyrosinase, is an important protein for biosynthetic pathway of melanin. It was studied to be phosphorylated and activated by protein kinase-C, β-subunit (PKC-β) through earlier experimentations with in vivo evidences. Documentation documents that mutation in two essentially vital serine residues in C-terminal end of tyrosinase leads to albinism. Due to the deficiency of protective shield like enzyme; melanin, albinos are at an increased peril for melanoma and other skin cancers. So, computational and residue-level insight including a mutational exploration with evolutionary importance into this mechanism lies obligatory for future pathological and therapeutic developments. Therefore, functional tertiary models of the relevant proteins were analyzed after satisfying their stereo-chemical features. Evolutionarily paramount residues for the activation of tyrosinase were perceived via multiple sequence alignment phenomena. Mutant-type tyrosinase protein (S98A and S102A) was thereby modeled, maintaining the wild-type proteins' functionality. Furthermore, this present comparative study discloses the variation in the stable residual participation (for mutant-type and wild-type tyrosinase-PKCβ complex). Mainly, an increased number of polar negatively charged residues from the wild-type tyrosinase participated with PKC-β, predominantly. Fascinatingly supported by evaluation of statistical significances, mutation even led to a destabilizing impact in tyrosinase accompanied by conformational switches with a helix-to-coil transition in the mutated protein. Even the allosteric sites in the protein got poorly hampered upon mutation leading to weaker tendency for binding partners to interact.

  6. Structural insight with mutational impact on tyrosinase and PKC-β interaction from Homo sapiens: Molecular modeling and docking studies for melanogenesis, albinism and increased risk for melanoma.

    PubMed

    Banerjee, Arundhati; Ray, Sujay

    2016-10-30

    Human tyrosinase, is an important protein for biosynthetic pathway of melanin. It was studied to be phosphorylated and activated by protein kinase-C, β-subunit (PKC-β) through earlier experimentations with in vivo evidences. Documentation documents that mutation in two essentially vital serine residues in C-terminal end of tyrosinase leads to albinism. Due to the deficiency of protective shield like enzyme; melanin, albinos are at an increased peril for melanoma and other skin cancers. So, computational and residue-level insight including a mutational exploration with evolutionary importance into this mechanism lies obligatory for future pathological and therapeutic developments. Therefore, functional tertiary models of the relevant proteins were analyzed after satisfying their stereo-chemical features. Evolutionarily paramount residues for the activation of tyrosinase were perceived via multiple sequence alignment phenomena. Mutant-type tyrosinase protein (S98A and S102A) was thereby modeled, maintaining the wild-type proteins' functionality. Furthermore, this present comparative study discloses the variation in the stable residual participation (for mutant-type and wild-type tyrosinase-PKCβ complex). Mainly, an increased number of polar negatively charged residues from the wild-type tyrosinase participated with PKC-β, predominantly. Fascinatingly supported by evaluation of statistical significances, mutation even led to a destabilizing impact in tyrosinase accompanied by conformational switches with a helix-to-coil transition in the mutated protein. Even the allosteric sites in the protein got poorly hampered upon mutation leading to weaker tendency for binding partners to interact. PMID:27450914

  7. The place of Homo floresiensis in human evolution.

    PubMed

    Baab, Karen

    2016-06-20

    Two main evolutionary scenarios have been proposed to explain the presence of the small-bodied and small-brained Homo floresiensis species on the remote Indonesian island of Flores in the Late Pleistocene. According to these two scenarios, H. floresiensis was a dwarfed descendent of H. erectus or a late-surviving remnant of a older lineage, perhaps descended from H. habilis. Each scenario has interesting and important implications for hominin biogeography, body size evolution, brain evolution and morphological convergences. Careful evaluation reveals that only a small number of characters support each of these scenarios uniquely. H. floresiensis exhibits a cranial shape and many cranial characters that appear to be shared derived traits with H. erectus, but postcranial traits are more primitive and resemble those of early Homo or even australopiths. Mandibular and dental traits show a mix of derived and primitive features. Unfortunately, many traits cannot be used to assess these two hypotheses because their distribution in H. erectus, early Homo (e.g., H. habilis), or both is unknown. H. erectus ancestry implies evolutionary convergence on a postcranial configuration similar to australopiths and early Homo, which could be explained by a return to more climbing behaviors. Body size reduction as well as brain size reduction on a scale only rarely documented in mammals would also accompany the origin of H. floresiensis from a H. erectus ancestor. H. habilis ancestry implies parallel evolution of numerous cranial characters, as well as a few dentognathic traits. A pre-H. erectus ancestry also suggests an early migration to Southeast Asia that is as yet undocumented in mainland Asia, but minimal body and brain size reduction. PMID:26829572

  8. Evolution of the Genus Homo

    NASA Astrophysics Data System (ADS)

    Tattersall, Ian; Schwartz, Jeffrey H.

    2009-05-01

    Definition of the genus Homo is almost as fraught as the definition of Homo sapiens. We look at the evidence for “early Homo,” finding little morphological basis for extending our genus to any of the 2.5-1.6-myr-old fossil forms assigned to “early Homo” or Homo habilis/rudolfensis. We also point to heterogeneity among “early African Homo erectus,” and the lack of apomorphies linking these fossils to the Asian Homo erectus group, a cohesive regional clade that shows some internal variation, including brain size increase over time. The first truly cosmopolitan Homo species is Homo heidelbergensis, known from Africa, Europe, and China following 600 kyr ago. One species sympatric with it included the >500-kyr-old Sima de los Huesos fossils from Spain, clearly distinct from Homo heidelbergensis and the oldest hominids assignable to the clade additionally containing Homo neanderthalensis. This clade also shows evidence of brain size expansion with time; but although Homo neanderthalensis had a large brain, it left no unequivocal evidence of the symbolic consciousness that makes our species unique. Homo sapiens clearly originated in Africa, where it existed as a physical entity before it began (also in that continent) to show the first stirrings of symbolism. Most likely, the biological underpinnings of symbolic consciousness were exaptively acquired in the radical developmental reorganization that gave rise to the highly characteristic osteological structure of Homo sapiens, but lay fallow for tens of thousands of years before being “discovered” by a cultural stimulus, plausibly the invention of language.

  9. Evidence of a relational spatial strategy in learning the centre of enclosures in human children (Homo sapiens).

    PubMed

    Tommasi, Luca; Giuliano, Alda

    2014-07-01

    Three- to five-year-old children were trained to localize a sensor hidden underneath the floor, in the centre of a square-shaped enclosure (1.5m×1.5m). Walking over the sensor caused a pleasant music to be played in the environment, thus engaging children in a playful spatial search. Children easily learned to find the centre of the training environment starting from random positions. After training, children were tested in enclosures of different size and/or shape: a larger square-shaped enclosure (3m×3m), a rectangle-shaped enclosure (1.5m×3m), an equilateral triangle-shaped enclosure (side 3m) and an isosceles triangle-shaped enclosure (base 1.5m; sides 3m). Children searched in the central region of the enclosures, their precision varying as a function of the similarity of the testing enclosure's shape to the shape of the training enclosure. This suggests that a relational spatial strategy was used, and that it depended on the encoding of geometrical shape. This result highlights a distinctive role of the geometric centre of enclosed spaces in place learning in children, as already observed in nonhuman species.

  10. Homo floresiensis contextualized: a geometric morphometric comparative analysis of fossil and pathological human samples.

    PubMed

    Baab, Karen L; McNulty, Kieran P; Harvati, Katerina

    2013-01-01

    The origin of hominins found on the remote Indonesian island of Flores remains highly contentious. These specimens may represent a new hominin species, Homo floresiensis, descended from a local population of Homo erectus or from an earlier (pre-H. erectus) migration of a small-bodied and small-brained hominin out of Africa. Alternatively, some workers suggest that some or all of the specimens recovered from Liang Bua are pathological members of a small-bodied modern human population. Pathological conditions proposed to explain their documented anatomical features include microcephaly, myxoedematous endemic hypothyroidism ("cretinism") and Laron syndrome (primary growth hormone insensitivity). This study evaluates evolutionary and pathological hypotheses through comparative analysis of cranial morphology. Geometric morphometric analyses of landmark data show that the sole Flores cranium (LB1) is clearly distinct from healthy modern humans and from those exhibiting hypothyroidism and Laron syndrome. Modern human microcephalic specimens converge, to some extent, on crania of extinct species of Homo. However in the features that distinguish these two groups, LB1 consistently groups with fossil hominins and is most similar to H. erectus. Our study provides further support for recognizing the Flores hominins as a distinct species, H. floresiensis, whose affinities lie with archaic Homo. PMID:23874886

  11. Homo floresiensis Contextualized: A Geometric Morphometric Comparative Analysis of Fossil and Pathological Human Samples

    PubMed Central

    Baab, Karen L.; McNulty, Kieran P.; Harvati, Katerina

    2013-01-01

    The origin of hominins found on the remote Indonesian island of Flores remains highly contentious. These specimens may represent a new hominin species, Homo floresiensis, descended from a local population of Homo erectus or from an earlier (pre-H. erectus) migration of a small-bodied and small-brained hominin out of Africa. Alternatively, some workers suggest that some or all of the specimens recovered from Liang Bua are pathological members of a small-bodied modern human population. Pathological conditions proposed to explain their documented anatomical features include microcephaly, myxoedematous endemic hypothyroidism (“cretinism”) and Laron syndrome (primary growth hormone insensitivity). This study evaluates evolutionary and pathological hypotheses through comparative analysis of cranial morphology. Geometric morphometric analyses of landmark data show that the sole Flores cranium (LB1) is clearly distinct from healthy modern humans and from those exhibiting hypothyroidism and Laron syndrome. Modern human microcephalic specimens converge, to some extent, on crania of extinct species of Homo. However in the features that distinguish these two groups, LB1 consistently groups with fossil hominins and is most similar to H. erectus. Our study provides further support for recognizing the Flores hominins as a distinct species, H. floresiensis, whose affinities lie with archaic Homo. PMID:23874886

  12. Aristotle's "homo mimeticus" as an Educational Paradigm for Human Coexistence

    ERIC Educational Resources Information Center

    Scaramuzzo, Gilberto

    2016-01-01

    In the "Poetics" of Aristotle there is a definition of the human being that perhaps has not yet been well considered in educational theory and practice. This definition calls into question a dynamism that according to Plato was unavoidable for an appropriate understanding of the educational process that turns a human being into a…

  13. Significance of some previously unrecognized apomorphies in the nasal region of Homo neanderthalensis.

    PubMed Central

    Schwartz, J H; Tattersall, I

    1996-01-01

    For many years, the Neanderthals have been recognized as a distinctive extinct hominid group that occupied Europe and western Asia between about 200,000 and 30,000 years ago. It is still debated, however, whether these hominids belong in their own species, Homo neanderthalensis, or represent an extinct variant of Homo sapiens. Our ongoing studies indicate that the Neanderthals differ from modern humans in their skeletal anatomy in more ways than have been recognized up to now. The purpose of this contribution is to describe specializations of the Neanderthal internal nasal region that make them unique not only among hominids but possibly among terrestrial mammals in general as well. These features lend additional weight to the suggestion that Neanderthals are specifically distinct from Homo sapiens. Images Fig. 1 Fig. 2 PMID:8855270

  14. Further morphological evidence on South African earliest Homo lower postcanine dentition: Enamel thickness and enamel dentine junction.

    PubMed

    Pan, Lei; Dumoncel, Jean; de Beer, Frikkie; Hoffman, Jakobus; Thackeray, John Francis; Duployer, Benjamin; Tenailleau, Christophe; Braga, José

    2016-07-01

    The appearance of the earliest members of the genus Homo in South Africa represents a key event in human evolution. Although enamel thickness and enamel dentine junction (EDJ) morphology preserve important information about hominin systematics and dietary adaptation, these features have not been sufficiently studied with regard to early Homo. We used micro-CT to compare enamel thickness and EDJ morphology among the mandibular postcanine dentitions of South African early hominins (N = 30) and extant Homo sapiens (N = 26), with special reference to early members of the genus Homo. We found that South African early Homo shows a similar enamel thickness distribution pattern to modern humans, although three-dimensional average and relative enamel thicknesses do not distinguish australopiths, early Homo, and modern humans particularly well. Based on enamel thickness distributions, our study suggests that a dietary shift occurred between australopiths and the origin of the Homo lineage. We also observed that South African early Homo postcanine EDJ combined primitive traits seen in australopith molars with derived features observed in modern human premolars. Our results confirm that some dental morphological patterns in later Homo actually occurred early in the Homo lineage, and highlight the taxonomic value of premolar EDJ morphology in hominin species.

  15. Hominin interbreeding and the evolution of human variation.

    PubMed

    Ko, Kwang Hyun

    2016-12-01

    Mitochondrial Eve confirms the "out of Africa" theory, but the evidence also supports interbreeding between Homo sapiens and other hominins: Neanderthals, Denisovans, and Homo heidelbergensis. This article explains how interbreeding between early H. sapiens and archaic hominins occurred. The availability of edible insects in East Asia aided the spread of the unaggressive, highly cooperative Neanderthals, who interbred with H. sapiens in Asia, resulting in a higher admixture of Neanderthal DNA in East Asian populations. Geographical variation in degree of interbreeding between H. sapiens and Neanderthals likely contributed to neurological and behavioral differences in modern humans. Similarly, people with Denisovan genetic admixture were better able to dwell in mountainous regions, allowing their genetic legacy to cross the Himalayas and persist in Southeast Asian and Oceanian H. sapiens. In the Sub-Saharan region, unaffected by Denisovan or Neanderthal interbreeding, H. sapiens interbred with H. heidelbergensis, because high humidity militated against fire-making and allowed the survival of these non-fire-making hominins.

  16. What do cranial bones of LB1 tell us about Homo floresiensis?

    PubMed

    Balzeau, Antoine; Charlier, Philippe

    2016-04-01

    Cranial vault thickness (CVT) of Liang Bua 1, the specimen that is proposed to be the holotype of Homo floresiensis, has not yet been described in detail and compared with samples of fossil hominins, anatomically modern humans or microcephalic skulls. In addition, a complete description from a forensic and pathological point of view has not yet been carried out. It is important to evaluate scientifically if features related to CVT bring new information concerning the possible pathological status of LB1, and if it helps to recognize affinities with any hominin species and particularly if the specimen could belong to the species Homo sapiens. Medical examination of the skull based on a micro-CT examination clearly brings to light the presence of a sincipital T (a non-metrical variant of normal anatomy), a scar from an old frontal trauma without any evident functional consequence, and a severe bilateral hyperostosis frontalis interna that may have modified the anterior morphology of the endocranium of LB1. We also show that LB1 displays characteristics, related to the distribution of bone thickness and arrangements of cranial structures, that are plesiomorphic traits for hominins, at least for Homo erectus s.l. relative to Homo neanderthalensis and H. sapiens. All the microcephalic skulls analyzed here share the derived condition of anatomically modern H. sapiens. Cranial vault thickness does not help to clarify the definition of the species H. floresiensis but it also does not support an attribution of LB1 to H. sapiens. We conclude that there is no support for the attribution of LB1 to H. sapiens as there is no evidence of systemic pathology and because it does not have any of the apomorphic traits of our species. PMID:27086053

  17. Post-cranial skeletons of hypothyroid cretins show a similar anatomical mosaic as Homo floresiensis.

    PubMed

    Oxnard, Charles; Obendorf, Peter J; Kefford, Ben J

    2010-01-01

    Human remains, some as recent as 15 thousand years, from Liang Bua (LB) on the Indonesian island of Flores have been attributed to a new species, Homo floresiensis. The definition includes a mosaic of features, some like modern humans (hence derived: genus Homo), some like modern apes and australopithecines (hence primitive: not species sapiens), and some unique (hence new species: floresiensis). Conversely, because only modern humans (H. sapiens) are known in this region in the last 40 thousand years, these individuals have also been suggested to be genetic human dwarfs. Such dwarfs resemble small humans and do not show the mosaic combination of the most complete individuals, LB1 and LB6, so this idea has been largely dismissed. We have previously shown that some features of the cranium of hypothyroid cretins are like those of LB1. Here we examine cretin postcrania to see if they show anatomical mosaics like H. floresiensis. We find that hypothyroid cretins share at least 10 postcranial features with Homo floresiensis and unaffected humans not found in apes (or australopithecines when materials permit). They share with H. floresiensis, modern apes and australopithecines at least 11 postcranial features not found in unaffected humans. They share with H. floresiensis, at least 8 features not found in apes, australopithecines or unaffected humans. Sixteen features can be rendered metrically and multivariate analyses demonstrate that H. floresiensis co-locates with cretins, both being markedly separate from humans and chimpanzees (P<0.001: from analysis of similarity (ANOSIM) over all variables, ANOSIM, global R>0.999). We therefore conclude that LB1 and LB6, at least, are, most likely, endemic cretins from a population of unaffected Homo sapiens. This is consistent with recent hypothyroid endemic cretinism throughout Indonesia, including the nearby island of Bali. PMID:20885948

  18. Post-Cranial Skeletons of Hypothyroid Cretins Show a Similar Anatomical Mosaic as Homo floresiensis

    PubMed Central

    Oxnard, Charles; Obendorf, Peter J.; Kefford, Ben J.

    2010-01-01

    Human remains, some as recent as 15 thousand years, from Liang Bua (LB) on the Indonesian island of Flores have been attributed to a new species, Homo floresiensis. The definition includes a mosaic of features, some like modern humans (hence derived: genus Homo), some like modern apes and australopithecines (hence primitive: not species sapiens), and some unique (hence new species: floresiensis). Conversely, because only modern humans (H. sapiens) are known in this region in the last 40 thousand years, these individuals have also been suggested to be genetic human dwarfs. Such dwarfs resemble small humans and do not show the mosaic combination of the most complete individuals, LB1 and LB6, so this idea has been largely dismissed. We have previously shown that some features of the cranium of hypothyroid cretins are like those of LB1. Here we examine cretin postcrania to see if they show anatomical mosaics like H. floresiensis. We find that hypothyroid cretins share at least 10 postcranial features with Homo floresiensis and unaffected humans not found in apes (or australopithecines when materials permit). They share with H. floresiensis, modern apes and australopithecines at least 11 postcranial features not found in unaffected humans. They share with H. floresiensis, at least 8 features not found in apes, australopithecines or unaffected humans. Sixteen features can be rendered metrically and multivariate analyses demonstrate that H. floresiensis co-locates with cretins, both being markedly separate from humans and chimpanzees (P<0.001: from analysis of similarity (ANOSIM) over all variables, ANOSIM, global R>0.999). We therefore conclude that LB1 and LB6, at least, are, most likely, endemic cretins from a population of unaffected Homo sapiens. This is consistent with recent hypothyroid endemic cretinism throughout Indonesia, including the nearby island of Bali. PMID:20885948

  19. Post-cranial skeletons of hypothyroid cretins show a similar anatomical mosaic as Homo floresiensis.

    PubMed

    Oxnard, Charles; Obendorf, Peter J; Kefford, Ben J

    2010-09-27

    Human remains, some as recent as 15 thousand years, from Liang Bua (LB) on the Indonesian island of Flores have been attributed to a new species, Homo floresiensis. The definition includes a mosaic of features, some like modern humans (hence derived: genus Homo), some like modern apes and australopithecines (hence primitive: not species sapiens), and some unique (hence new species: floresiensis). Conversely, because only modern humans (H. sapiens) are known in this region in the last 40 thousand years, these individuals have also been suggested to be genetic human dwarfs. Such dwarfs resemble small humans and do not show the mosaic combination of the most complete individuals, LB1 and LB6, so this idea has been largely dismissed. We have previously shown that some features of the cranium of hypothyroid cretins are like those of LB1. Here we examine cretin postcrania to see if they show anatomical mosaics like H. floresiensis. We find that hypothyroid cretins share at least 10 postcranial features with Homo floresiensis and unaffected humans not found in apes (or australopithecines when materials permit). They share with H. floresiensis, modern apes and australopithecines at least 11 postcranial features not found in unaffected humans. They share with H. floresiensis, at least 8 features not found in apes, australopithecines or unaffected humans. Sixteen features can be rendered metrically and multivariate analyses demonstrate that H. floresiensis co-locates with cretins, both being markedly separate from humans and chimpanzees (P<0.001: from analysis of similarity (ANOSIM) over all variables, ANOSIM, global R>0.999). We therefore conclude that LB1 and LB6, at least, are, most likely, endemic cretins from a population of unaffected Homo sapiens. This is consistent with recent hypothyroid endemic cretinism throughout Indonesia, including the nearby island of Bali.

  20. Geometric properties and comparative biomechanics of Homo floresiensis mandibles.

    PubMed

    Daegling, David J; Patel, Biren A; Jungers, William L

    2014-03-01

    The hypodigm of Homo floresiensis from the cave of Liang Bua on Flores Island in the archipelago of Indonesia includes two mandibles (LB1/2 and LB6/1). The morphology of their symphyses and corpora has been described as sharing similarities with both australopiths and early Homo despite their Late Pleistocene age. Although detailed morphological comparisons of these mandibles with those of modern and fossil hominin taxa have been made, a functional analysis in the context of masticatory biomechanics has yet to be performed. Utilizing data on cortical bone geometry from computed tomography scans, we compare the mechanical attributes of the LB1 and LB6 mandibles with samples of modern Homo, Pan, Pongo, and Gorilla, as well as fossil samples of Paranthropus robustus, Australopithecus africanus and South African early Homo. Structural stiffness measures were derived from the geometric data to provide relative measures of mandibular corpus strength under hypothesized masticatory loading regimes. These mechanical variables were evaluated relative to bone area, mandibular length and estimates of body size to assess their functional affinities and to test the hypothesis that the Liang Bua mandibles can be described as scaled-down variants of either early hominins or modern humans. Relative to modern hominoids, the H. floresiensis material appears to be relatively strong in terms of rigidity in torsion and transverse bending, but is relatively weak under parasagittal bending. Thus, they are 'robust' relative to modern humans (and comparable with australopiths) under some loads but not others. Neither LB1 nor LB6 can be described simply as 'miniaturized' versions of modern human jaws since mandible length is more or less equivalent in Homo sapiens and H. floresiensis. The mechanical attributes of the Liang Bua mandibles are consistent with previous inferences that masticatory loads were reduced relative to australopiths but remained elevated relative to modern Homo.

  1. Geometric properties and comparative biomechanics of Homo floresiensis mandibles.

    PubMed

    Daegling, David J; Patel, Biren A; Jungers, William L

    2014-03-01

    The hypodigm of Homo floresiensis from the cave of Liang Bua on Flores Island in the archipelago of Indonesia includes two mandibles (LB1/2 and LB6/1). The morphology of their symphyses and corpora has been described as sharing similarities with both australopiths and early Homo despite their Late Pleistocene age. Although detailed morphological comparisons of these mandibles with those of modern and fossil hominin taxa have been made, a functional analysis in the context of masticatory biomechanics has yet to be performed. Utilizing data on cortical bone geometry from computed tomography scans, we compare the mechanical attributes of the LB1 and LB6 mandibles with samples of modern Homo, Pan, Pongo, and Gorilla, as well as fossil samples of Paranthropus robustus, Australopithecus africanus and South African early Homo. Structural stiffness measures were derived from the geometric data to provide relative measures of mandibular corpus strength under hypothesized masticatory loading regimes. These mechanical variables were evaluated relative to bone area, mandibular length and estimates of body size to assess their functional affinities and to test the hypothesis that the Liang Bua mandibles can be described as scaled-down variants of either early hominins or modern humans. Relative to modern hominoids, the H. floresiensis material appears to be relatively strong in terms of rigidity in torsion and transverse bending, but is relatively weak under parasagittal bending. Thus, they are 'robust' relative to modern humans (and comparable with australopiths) under some loads but not others. Neither LB1 nor LB6 can be described simply as 'miniaturized' versions of modern human jaws since mandible length is more or less equivalent in Homo sapiens and H. floresiensis. The mechanical attributes of the Liang Bua mandibles are consistent with previous inferences that masticatory loads were reduced relative to australopiths but remained elevated relative to modern Homo. PMID

  2. Human evolution.

    PubMed

    Wood, B

    1996-12-01

    The common ancestor of modern humans and the great apes is estimated to have lived between 5 and 8 Myrs ago, but the earliest evidence in the human, or hominid, fossil record is Ardipithecus ramidus, from a 4.5 Myr Ethiopian site. This genus was succeeded by Australopithecus, within which four species are presently recognised. All combine a relatively primitive postcranial skeleton, a dentition with expanded chewing teeth and a small brain. The most primitive species in our own genus, Homo habilis and Homo rudolfensis, are little advanced over the australopithecines and with hindsight their inclusion in Homo may not be appropriate. The first species to share a substantial number of features with later Homo is Homo ergaster, or 'early African Homo erectus', which appears in the fossil record around 2.0 Myr. Outside Africa, fossil hominids appear as Homo erectus-like hominids, in mainland Asia and in Indonesia close to 2 Myr ago; the earliest good evidence of 'archaic Homo' in Europe is dated at between 600-700 Kyr before the present. Anatomically modern human, or Homo sapiens, fossils are seen first in the fossil record in Africa around 150 Kyr ago. Taken together with molecular evidence on the extent of DNA variation, this suggests that the transition from 'archaic' to 'modern' Homo may have taken place in Africa. PMID:8976151

  3. Human evolution.

    PubMed

    Wood, B

    1996-12-01

    The common ancestor of modern humans and the great apes is estimated to have lived between 5 and 8 Myrs ago, but the earliest evidence in the human, or hominid, fossil record is Ardipithecus ramidus, from a 4.5 Myr Ethiopian site. This genus was succeeded by Australopithecus, within which four species are presently recognised. All combine a relatively primitive postcranial skeleton, a dentition with expanded chewing teeth and a small brain. The most primitive species in our own genus, Homo habilis and Homo rudolfensis, are little advanced over the australopithecines and with hindsight their inclusion in Homo may not be appropriate. The first species to share a substantial number of features with later Homo is Homo ergaster, or 'early African Homo erectus', which appears in the fossil record around 2.0 Myr. Outside Africa, fossil hominids appear as Homo erectus-like hominids, in mainland Asia and in Indonesia close to 2 Myr ago; the earliest good evidence of 'archaic Homo' in Europe is dated at between 600-700 Kyr before the present. Anatomically modern human, or Homo sapiens, fossils are seen first in the fossil record in Africa around 150 Kyr ago. Taken together with molecular evidence on the extent of DNA variation, this suggests that the transition from 'archaic' to 'modern' Homo may have taken place in Africa.

  4. Craniometric ratios of microcephaly and LB1, Homo floresiensis, using MRI and endocasts

    PubMed Central

    Vannucci, Robert C.; Barron, Todd F.; Holloway, Ralph L.

    2011-01-01

    The designation of Homo floresiensis as a new species derived from an ancient population is controversial, because the type specimen, LB1, might represent a pathological microcephalic modern Homo sapiens. Accordingly, two specific craniometric ratios (relative frontal breadth and cerebellar protrusion) were ascertained in 21 microcephalic infants and children by using MRI. Data on 118 age-equivalent control (normocephalic) subjects were collected for comparative purposes. In addition, the same craniometric ratios were determined on the endocasts of 10 microcephalic individuals, 79 normal controls (anatomically modern humans), and 17 Homo erectus specimens. These ratios were then compared with those of two LB1 endocasts. The findings showed that the calculated cerebral/cerebellar ratios of the LB1 endocast [Falk D, et al. (2007) Proc Natl Acad Sci USA 104:2513–2518] fall outside the range of living normocephalic individuals. The ratios derived from two LB1 endocasts also fall largely outside the range of modern normal human and H. erectus endocasts and within the range of microcephalic endocasts. The findings support but do not prove the contention that LB1 represents a pathological microcephalic Homo sapiens rather than a new species, (i.e., H. floresiensis). PMID:21825126

  5. Evolution of M1 crown size and cusp proportions in the genus Homo

    PubMed Central

    Quam, Rolf; Bailey, Shara; Wood, Bernard

    2009-01-01

    Previous research into tooth crown dimensions and cusp proportions has proved to be a useful way to identify taxonomic differences in Pliocene and Pleistocene fossil hominins. The present study has identified changes in both M1 crown size and cusp proportions within the genus Homo, with M1 overall crown size reduction apparently occurring in two main stages. The first stage (a reduction of ca. 17%) is associated with the emergence of Homo ergaster and Homo erectus sensu stricto. The second stage (a reduction of ca. 10%) occurs in Homo sapiens, but the reduced modern human M1 tooth crown size was only attained in Upper Paleolithic times. The absolute sizes of the individual cusps are highly positively correlated with overall crown size and dental reduction produces a reduction in the absolute size of each of the cusps. Most of the individual cusps scale isometrically with crown size, but the paracone shows a negative allometric relationship, indicating that the reduction in paracone size is less than in the other M1 cusps. Thus, the phylogenetically oldest cusp in the upper molars also seems to be the most stable cusp (at least in the M1). The most striking change in M1 cusp proportions is a change in the relative size of the areas of the paracone and metacone. The combination of a small relative paracone and a large relative metacone generally characterizes specimens attributed to early Homo, and the presence of this character state in Australopithecus andParanthropus suggests it may represent the primitive condition for the later part of the hominin clade. In contrast, nearly all later Homo taxa, with the exception of Homo antecessor, show the opposite condition (i.e. a relatively large paracone and a relatively small metacone). This change in the relationship between the relative sizes of the paracone and metacone is related to an isometric reduction of the absolute size of the metacone. This metacone reduction occurs in the context of relative stability in the

  6. Evolution of M1 crown size and cusp proportions in the genus Homo.

    PubMed

    Quam, Rolf; Bailey, Shara; Wood, Bernard

    2009-05-01

    Previous research into tooth crown dimensions and cusp proportions has proved to be a useful way to identify taxonomic differences in Pliocene and Pleistocene fossil hominins. The present study has identified changes in both M(1) crown size and cusp proportions within the genus Homo, with M(1) overall crown size reduction apparently occurring in two main stages. The first stage (a reduction of ca. 17%) is associated with the emergence of Homo ergaster and Homo erectus sensu stricto. The second stage (a reduction of ca. 10%) occurs in Homo sapiens, but the reduced modern human M(1) tooth crown size was only attained in Upper Paleolithic times. The absolute sizes of the individual cusps are highly positively correlated with overall crown size and dental reduction produces a reduction in the absolute size of each of the cusps. Most of the individual cusps scale isometrically with crown size, but the paracone shows a negative allometric relationship, indicating that the reduction in paracone size is less than in the other M(1) cusps. Thus, the phylogenetically oldest cusp in the upper molars also seems to be the most stable cusp (at least in the M(1)). The most striking change in M(1) cusp proportions is a change in the relative size of the areas of the paracone and metacone. The combination of a small relative paracone and a large relative metacone generally characterizes specimens attributed to early Homo, and the presence of this character state in Australopithecus and Paranthropus suggests it may represent the primitive condition for the later part of the hominin clade. In contrast, nearly all later Homo taxa, with the exception of Homo antecessor, show the opposite condition (i.e. a relatively large paracone and a relatively small metacone). This change in the relationship between the relative sizes of the paracone and metacone is related to an isometric reduction of the absolute size of the metacone. This metacone reduction occurs in the context of relative

  7. Brain size of Homo floresiensis and its evolutionary implications.

    PubMed

    Kubo, Daisuke; Kono, Reiko T; Kaifu, Yousuke

    2013-06-01

    The extremely small endocranial volume (ECV) of LB1, the type specimen of Homo floresiensis, poses a challenge in our understanding of human brain evolution. Some researchers hypothesize dramatic dwarfing of relative brain size from Homo erectus presumably without significant decrease in intellectual function, whereas others expect a lesser degree of brain diminution from a more primitive, small-brained form of hominin currently undocumented in eastern Asia. However, inconsistency in the published ECVs for LB1 (380-430 cc), unclear human intraspecific brain-body size scaling and other uncertainties have hampered elaborative modelling of its brain size reduction. In this study, we accurately determine the ECV of LB1 using high-resolution micro-CT scan. The ECV of LB1 thus measured, 426 cc, is larger than the commonly cited figure in previous studies (400 cc). Coupled with brain-body size correlation in Homo sapiens calculated based on a sample from 20 worldwide modern human populations, we construct new models of the brain size reduction in the evolution of H. floresiensis. The results show a more significant contribution of scaling effect than previously claimed. PMID:23595271

  8. A "g" beyond "Homo Sapiens"? Some Hints and Suggestions

    ERIC Educational Resources Information Center

    Lee, James J.

    2007-01-01

    This article proposes that a complete account of cognitive evolution may have to accommodate a domain-general source of variance in mental abilities accounting for differences among primate taxa. Deaner, van Schaik, and Johnson [Deaner, R.O., van Schaik, C.P. and Johnson, V.E. (2006). Do some taxa have better domain-general cognition than others?…

  9. [The Paderborn calvaria--a diluvial Homo sapiens].

    PubMed

    Henke, W; Protsch, R R

    1978-02-01

    In the following work a morphognostic and morphometric analysis of a diluvial calvaria from Sande/Paderborn in Westfalia is presented. Besides the above, absolute dating by two methods (Radiocarbon- and Amino-acid-dating) was applied. The morphological comparison shows strong affinities to comparative material from the Upper Pleistocene like Cro-Magnon. The absolute dates support this morphological analysis. Both findings--morphological analysis and absolute dating--were done in separate analyses and will be documented separately in the following article.

  10. [The Paderborn calvaria--a diluvial Homo sapiens].

    PubMed

    Henke, W; Protsch, R R

    1978-02-01

    In the following work a morphognostic and morphometric analysis of a diluvial calvaria from Sande/Paderborn in Westfalia is presented. Besides the above, absolute dating by two methods (Radiocarbon- and Amino-acid-dating) was applied. The morphological comparison shows strong affinities to comparative material from the Upper Pleistocene like Cro-Magnon. The absolute dates support this morphological analysis. Both findings--morphological analysis and absolute dating--were done in separate analyses and will be documented separately in the following article. PMID:414655

  11. Beyond the pleistocene: using phylogeny and constraint to inform the evolutionary psychology of human mating.

    PubMed

    Eastwick, Paul W

    2009-09-01

    Evolutionary psychologists explore the adaptive function of traits and behaviors that characterize modern Homo sapiens. However, evolutionary psychologists have yet to incorporate the phylogenetic relationship between modern Homo sapiens and humans' hominid and pongid relatives (both living and extinct) into their theorizing. By considering the specific timing of evolutionary events and the role of evolutionary constraint, researchers using the phylogenetic approach can generate new predictions regarding mating phenomena and derive new explanations for existing evolutionary psychological findings. Especially useful is the concept of the adaptive workaround-an adaptation that manages the maladaptive elements of a pre-existing evolutionary constraint. The current review organizes 7 features of human mating into their phylogenetic context and presents evidence that 2 adaptive workarounds played a critical role as Homo sapiens's mating psychology evolved. These adaptive workarounds function in part to mute or refocus the effects of older, previously evolved adaptations and highlight the layered nature of humans' mating psychology.

  12. The minerals and the light: Mineralogy and astronomy in the history of the homo sapiens sapiens

    NASA Astrophysics Data System (ADS)

    Giovanna Giovine, Laura

    2016-04-01

    Since the end of the '90s, when the concept of competence was introduced in the education world, the debate on teaching assessment of competences is going on in the Italian school system. Nonetheless, first cycle and second cycle State Exams and national tests (INVALSI), yet have a focus on knowledge and skills. In the education field competence is defined as the capability to face requests and complex tasks effectively, using knowledge and skills acquired by study, research, observation and experience. The proposal formulated here is directed to turn disciplinary knowledge and skills to personal competences through educational and unitary teaching, in order to overcome the discontinuities between Primary school - Secondary school - Universities - the world of work. The ultimate goal is to preserve throughout the didactic course of teaching the wholeness and unitarily of personal competence of the student, who uses acquired disciplinary knowledge and skills in a personal fashion, neither mnemonic nor mechanical. The course of study may begin in the first class of lower secondary school and go on up to the fifth class of upper secondary school, with didactic laboratorial strategies and teaching strategies for competences, involving multiple disciplines. The recipients are the classes where a greater difficulty for students to integrate into the life of the School is registered, or the learned input-skills are of low or inadequate level, possibly with the presence of students with Special Educational Needs. In involved classes the collaboration and sharing of all teachers of the Class Council has been requested, in order to build an educational unitary course, centered on the concept of competence. Contents of the course: • The materials of the solid earth: minerals (physical and chemical properties, classification) • Percentages, graphics, angles, geometric solids, symmetry • Measurement units, speed and acceleration, mass and weight, pressure, energy, heat, temperature, density • States of matter: solid state and liquid state • The periodic table of elements, atoms and molecules • Mixtures Introduction to the course: • History informs sciences: newspapers and books dating back to the First World War are read in the classroom, mineral resources used in everyday life and the their mining locations, in cooperation with Geohistory and Italian teachers. • Discussion groups and "questioning" by the test "Is it useful to study the Mineralogy?" and input test with open-ended questions. • Experiments in the laboratory shared with Physics teacher: we observe a mineral (recognition, classification, chemical composition) • Theoretical lesson: natural sciences, physics and chemistry, with the support of the textbook and using material found by students in the Internet • Visit to the local museum with the teacher of Geometric Design or Art History or Technology or Geohistory • Brainstorming and project with support of LIM to view video-on lab and specific software • Experiments in the laboratory shared with the teacher of Mathematics: growing crystals (shape and symmetry, recognition and classification, chemical composition and structure of atoms) • Final report on experiments, possibly with research hypotheses.

  13. Skulls and Human Evolution: The Use of Casts of Anthropoid Skulls in Teaching Concepts of Human Evolution.

    ERIC Educational Resources Information Center

    Gipps, John

    1991-01-01

    Proposes the use of a series of 11 casts of fossil skulls as a method of teaching about the theory of human evolution. Students explore the questions of which skulls are "human" and which came first in Homo Sapien development, large brain or upright stance. (MDH)

  14. Human CCT4 and CCT5 Chaperonin Subunits Expressed in Escherichia coli Form Biologically Active Homo-oligomers*

    PubMed Central

    Sergeeva, Oksana A.; Chen, Bo; Haase-Pettingell, Cameron; Ludtke, Steven J.; Chiu, Wah; King, Jonathan A.

    2013-01-01

    Chaperonins are a family of chaperones that encapsulate their substrates and assist their folding in an ATP-dependent manner. The ubiquitous eukaryotic chaperonin, TCP-1 ring complex (TRiC), is a hetero-oligomeric complex composed of two rings, each formed from eight different CCT (chaperonin containing TCP-1) subunits. Each CCT subunit may have distinct substrate recognition and ATP hydrolysis properties. We have expressed each human CCT subunit individually in Escherichia coli to investigate whether they form chaperonin-like double ring complexes. CCT4 and CCT5, but not the other six CCT subunits, formed high molecular weight complexes within the E. coli cells that sedimented about 20S in sucrose gradients. When CCT4 and CCT5 were purified, they were both organized as two back-to-back rings of eight subunits each, as seen by negative stain and cryo-electron microscopy. This morphology is consistent with that of the hetero-oligomeric double-ring TRiC purified from bovine testes and HeLa cells. Both CCT4 and CCT5 homo-oligomers hydrolyzed ATP at a rate similar to human TRiC and were active as assayed by luciferase refolding and human γD-crystallin aggregation suppression and refolding. Thus, both CCT4 and CCT5 homo-oligomers have the property of forming 8-fold double rings absent the other subunits, and these complexes carry out chaperonin reactions without other partner subunits. PMID:23612981

  15. Dental evidence for ontogenetic differences between modern humans and Neanderthals.

    PubMed

    Smith, Tanya M; Tafforeau, Paul; Reid, Donald J; Pouech, Joane; Lazzari, Vincent; Zermeno, John P; Guatelli-Steinberg, Debbie; Olejniczak, Anthony J; Hoffman, Almut; Radovcic, Jakov; Makaremi, Masrour; Toussaint, Michel; Stringer, Chris; Hublin, Jean-Jacques

    2010-12-01

    Humans have an unusual life history, with an early weaning age, long childhood, late first reproduction, short interbirth intervals, and long lifespan. In contrast, great apes wean later, reproduce earlier, and have longer intervals between births. Despite 80 y of speculation, the origins of these developmental patterns in Homo sapiens remain unknown. Because they record daily growth during formation, teeth provide important insights, revealing that australopithecines and early Homo had more rapid ontogenies than recent humans. Dental development in later Homo species has been intensely debated, most notably the issue of whether Neanderthals and H. sapiens differ. Here we apply synchrotron virtual histology to a geographically and temporally diverse sample of Middle Paleolithic juveniles, including Neanderthals, to assess tooth formation and calculate age at death from dental microstructure. We find that most Neanderthal tooth crowns grew more rapidly than modern human teeth, resulting in significantly faster dental maturation. In contrast, Middle Paleolithic H. sapiens juveniles show greater similarity to recent humans. These findings are consistent with recent cranial and molecular evidence for subtle developmental differences between Neanderthals and H. sapiens. When compared with earlier hominin taxa, both Neanderthals and H. sapiens have extended the duration of dental development. This period of dental immaturity is particularly prolonged in modern humans. PMID:21078988

  16. Dental evidence for ontogenetic differences between modern humans and Neanderthals.

    PubMed

    Smith, Tanya M; Tafforeau, Paul; Reid, Donald J; Pouech, Joane; Lazzari, Vincent; Zermeno, John P; Guatelli-Steinberg, Debbie; Olejniczak, Anthony J; Hoffman, Almut; Radovcic, Jakov; Makaremi, Masrour; Toussaint, Michel; Stringer, Chris; Hublin, Jean-Jacques

    2010-12-01

    Humans have an unusual life history, with an early weaning age, long childhood, late first reproduction, short interbirth intervals, and long lifespan. In contrast, great apes wean later, reproduce earlier, and have longer intervals between births. Despite 80 y of speculation, the origins of these developmental patterns in Homo sapiens remain unknown. Because they record daily growth during formation, teeth provide important insights, revealing that australopithecines and early Homo had more rapid ontogenies than recent humans. Dental development in later Homo species has been intensely debated, most notably the issue of whether Neanderthals and H. sapiens differ. Here we apply synchrotron virtual histology to a geographically and temporally diverse sample of Middle Paleolithic juveniles, including Neanderthals, to assess tooth formation and calculate age at death from dental microstructure. We find that most Neanderthal tooth crowns grew more rapidly than modern human teeth, resulting in significantly faster dental maturation. In contrast, Middle Paleolithic H. sapiens juveniles show greater similarity to recent humans. These findings are consistent with recent cranial and molecular evidence for subtle developmental differences between Neanderthals and H. sapiens. When compared with earlier hominin taxa, both Neanderthals and H. sapiens have extended the duration of dental development. This period of dental immaturity is particularly prolonged in modern humans.

  17. The dual origin of modern humanity.

    PubMed

    Tattersall, Ian

    2004-01-01

    Living Homo sapiens can define itself using both behavioral and anatomical uniquenesses. But is this possible when looking backward? Using a strict morphological definition, Homo sapiens can probably be traced back in the fossil record to about 150 kyr ago, which fits well with molecular estimates for the ancestor of all living human populations. However, activities reliably indicating established symbolic cognition can be recognized in the archaeological record only back to under 100 kyr ago. Since it is probable that the potential for symbolic cognition was born in the genetic/structural alterations that also gave rise to the distinctive morphological entity Homo sapiens, it appears that the expression of the human symbolic cognitive potential had to await, for many millennia, the >discovery< of that potential through a cultural rather than a biological stimulus. Most plausibly, this stimulus was the invention of language. Modern human symbolic cognition is not an extrapolation of pre-existing evolutionary trends, suggesting that Homo sapiens is not biologically >fine-tuned< for any specific behavior patterns.

  18. Reconstructed Homo habilis type OH 7 suggests deep-rooted species diversity in early Homo.

    PubMed

    Spoor, Fred; Gunz, Philipp; Neubauer, Simon; Stelzer, Stefanie; Scott, Nadia; Kwekason, Amandus; Dean, M Christopher

    2015-03-01

    Besides Homo erectus (sensu lato), the eastern African fossil record of early Homo has been interpreted as representing either a single variable species, Homo habilis, or two species. In the latter case, however, there is no consensus over the respective groupings, and which of the two includes OH 7, the 1.8-million-year-old H. habilis holotype. This partial skull and hand from Olduvai Gorge remains pivotal to evaluating the early evolution of the Homo lineage, and by priority names one or other of the two taxa. However, the distorted preservation of the diagnostically important OH 7 mandible has hindered attempts to compare this specimen with other fossils. Here we present a virtual reconstruction of the OH 7 mandible, and compare it to other early Homo fossils. The reconstructed mandible is remarkably primitive, with a long and narrow dental arcade more similar to Australopithecus afarensis than to the derived parabolic arcades of Homo sapiens or H. erectus. We find that this shape variability is not consistent with a single species of early Homo. Importantly, the jaw morphology of OH 7 is incompatible with fossils assigned to Homo rudolfensis and with the A.L. 666-1 Homo maxilla. The latter is morphologically more derived than OH 7 but 500,000 years older, suggesting that the H. habilis lineage originated before 2.3 million years ago, thus marking deep-rooted species diversity in the genus Homo. We also reconstructed the parietal bones of OH 7 and estimated its endocranial volume. At between 729 and 824 ml it is larger than any previously published value, and emphasizes the near-complete overlap in brain size among species of early Homo. Our results clarify the H. habilis hypodigm, but raise questions about its phylogenetic relationships. Differences between species of early Homo appear to be characterized more by gnathic diversity than by differences in brain size, which was highly variable within all taxa. PMID:25739632

  19. Thickened cranial vault and parasagittal keeling: correlated traits and autapomorphies of Homo erectus?

    PubMed

    Balzeau, Antoine

    2013-06-01

    Homo erectus sensu lato (s.l.) is a key species in the hominin fossil record for the study of human evolution, being one of the first species discovered and perhaps the most documented, but also because of its long temporal range and having dispersed out of Africa earlier than any other human species. Here I test two proposed autapomorphic traits of H. erectus, namely the increased thickness of the upper cranial vault and parasagittal keeling. The definition of these two anatomical features and their expression and variation among hominids are discussed. The results of this study indicate that the upper vault in Asian H. erectus is not absolutely thicker compared with fossil anatomically modern Homo sapiens, whereas Broken Hill and Petralona have values above the range of variation of H. erectus. Moreover, this anatomical region in Asian H. erectus is not significantly thicker compared with Pan paniscus. In addition, these results demonstrate that cranial vault thickness should not be used to make hypotheses regarding sexual attribution of fossil hominin specimens. I also show that the relation between relief on the external surface of the upper vault, parasagittal keeling and bregmatic eminence, and bone thickness is complex. In this context, the autapomorphic status of the two analysed traits in H. erectus may be rejected. Nevertheless, different patterns in the distribution of bone thickness on the upper vault were identified. Some individual variations are visible, but specificities are observable in samples of different species. The pattern of bone thickness distribution observed in Asian H. erectus, P. paniscus, possibly australopiths, and early Homo or Homo ergaster/erectus appears to be shared by these different species and would be a plesiomorphic trait among hominids. In contrast, two apomorphic states for this feature were identified for Neandertals and H. sapiens. PMID:23541383

  20. Filling the gap. Human cranial remains from Gombore II (Melka Kunture, Ethiopia; ca. 850 ka) and the origin of Homo heidelbergensis.

    PubMed

    Profico, Antonio; Di Vincenzo, Fabio; Gagliardi, Lorenza; Piperno, Marcello; Manzi, Giorgio

    2016-06-20

    African archaic humans dated to around 1,0 Ma share morphological affinities with Homo ergaster and appear distinct in cranio-dental morphology from those of the Middle Pleistocene that are referred to Homo heidelbergensis. This observation suggests a taxonomic and phylogenetic discontinuity in Africa that ranges across the Matuyama/Brunhes reversal (780 ka). Yet, the fossil record between roughly 900 and 600 ka is notoriously poor. In this context, the Early Stone Age site of Gombore II, in the Melka Kunture formation (Upper Awash, Ethiopia), provides a privileged case-study. In the Acheulean layer of Gombore II, somewhat more recent than 875 ±10 ka, two large cranial fragments were discovered in 1973 and 1975 respectively: a partial left parietal (Melka Kunture 1) and a right portion of the frontal bone (Melka Kunture 2), which probably belonged to the same cranium. We present here the first detailed description and computer-assisted reconstruction of the morphology of the cranial vault pertaining to these fossil fragments. Our analysis suggest that the human fossil specimen from Gombore II fills a phenetic gap between Homo ergaster and Homo heidelbergensis. This appears in agreement with the chronology of such a partial cranial vault, which therefore represents at present one of the best available candidates (if any) for the origin of Homo heidelbergensis in Africa.

  1. Filling the gap. Human cranial remains from Gombore II (Melka Kunture, Ethiopia; ca. 850 ka) and the origin of Homo heidelbergensis.

    PubMed

    Profico, Antonio; Di Vincenzo, Fabio; Gagliardi, Lorenza; Piperno, Marcello; Manzi, Giorgio

    2016-06-20

    African archaic humans dated to around 1,0 Ma share morphological affinities with Homo ergaster and appear distinct in cranio-dental morphology from those of the Middle Pleistocene that are referred to Homo heidelbergensis. This observation suggests a taxonomic and phylogenetic discontinuity in Africa that ranges across the Matuyama/Brunhes reversal (780 ka). Yet, the fossil record between roughly 900 and 600 ka is notoriously poor. In this context, the Early Stone Age site of Gombore II, in the Melka Kunture formation (Upper Awash, Ethiopia), provides a privileged case-study. In the Acheulean layer of Gombore II, somewhat more recent than 875 ±10 ka, two large cranial fragments were discovered in 1973 and 1975 respectively: a partial left parietal (Melka Kunture 1) and a right portion of the frontal bone (Melka Kunture 2), which probably belonged to the same cranium. We present here the first detailed description and computer-assisted reconstruction of the morphology of the cranial vault pertaining to these fossil fragments. Our analysis suggest that the human fossil specimen from Gombore II fills a phenetic gap between Homo ergaster and Homo heidelbergensis. This appears in agreement with the chronology of such a partial cranial vault, which therefore represents at present one of the best available candidates (if any) for the origin of Homo heidelbergensis in Africa. PMID:26583275

  2. [The technological character of the human being].

    PubMed

    Del Barco Collazos, José Luis

    2009-01-01

    Technique is not accidental, but essential, to human being. It is the homo sapiens sapiens way of life. There is neither pretechnological human life nor a historic period without it. Human being is making tools and instruments since the very moment he is on earth. And so will he go on. Plough, airship and future apparatus are stages of the technical progress. The enormous human aptitude for making is due to the connexion between brain and hands. Technique ought be neither venerated nor feared but ruled. PMID:19507914

  3. [The technological character of the human being].

    PubMed

    Del Barco Collazos, José Luis

    2009-01-01

    Technique is not accidental, but essential, to human being. It is the homo sapiens sapiens way of life. There is neither pretechnological human life nor a historic period without it. Human being is making tools and instruments since the very moment he is on earth. And so will he go on. Plough, airship and future apparatus are stages of the technical progress. The enormous human aptitude for making is due to the connexion between brain and hands. Technique ought be neither venerated nor feared but ruled.

  4. Modern human origins: progress and prospects.

    PubMed Central

    Stringer, Chris

    2002-01-01

    The question of the mode of origin of modern humans (Homo sapiens) has dominated palaeoanthropological debate over the last decade. This review discusses the main models proposed to explain modern human origins, and examines relevant fossil evidence from Eurasia, Africa and Australasia. Archaeological and genetic data are also discussed, as well as problems with the concept of 'modernity' itself. It is concluded that a recent African origin can be supported for H. sapiens, morphologically, behaviourally and genetically, but that more evidence will be needed, both from Africa and elsewhere, before an absolute African origin for our species and its behavioural characteristics can be established and explained. PMID:12028792

  5. Novel Nor-Homo- and Spiro-Oxetan- Steroids Target the Human Androgen Receptor and Act as Antiandrogens.

    PubMed

    Thiele, Marie; Rabe, Sebastian; Hessenkemper, Wiebke; Roell, Daniela; Bartsch, Sophie; Kraft, Florian; Abraham, Tsion E; Houtsmuller, Adriaan B; van Royen, Martin E; Giannis, Athanassios; Baniahmad, Aria

    2014-06-01

    The prostate adenocarcinoma is the cancer with the highest incidence for men in Western countries. Targeting the androgen receptor (AR) by antagonists is used as hormone therapy for prostate cancer (PCa), however, eventually therapy resistance occurs in most patients. In most of these cancer the AR signaling is active and thus AR remains an important drug target. Since many years we are characterizing novel chemical structural platforms to provide a broader possibility for compounds that bind to and act as AR antagonists. Here, we describe the chemical synthesis of a battery of novel steroidal derivatives as nor-homo-, spiro-oxolan- and spiro-oxetan- steroids. They modulate the transcriptional activity of the human AR. As AR antagonists, the spiro-oxetan- steroid derivatives seem to be the most potent steroid derivatives. They inhibit the transcriptional activity of both wild-type AR as well as the AR mutant T877A. In line with this, these compounds bind to the human AR and inhibit the proliferation of the human androgen-dependent growing PCa cell line LNCaP. Interestingly, the castration-resistant AR expressing human PC3-AR cells are also growth inhibited. On mechanistic level, fluorescence resonance energy transfer (FRET) assays with living cells indicate that the androgen-induced N/C terminal interaction of the AR is inhibited by the investigated compounds. Using fluorescence recovery after photobleaching (FRAP) assays in living cells suggest a higher mobility of the AR in the cell nuclei in the presence of spiro-oxetan- steroidal antagonists. Together, these findings suggest that spiro-oxetan- steroids are very useful as a chemical platform for novel AR antagonists.

  6. Homo erectus in Salkhit, Mongolia?

    PubMed

    Lee, Sang-Hee

    2015-08-01

    In 2006, a skullcap was discovered in Salkhit, Mongolia. The Salkhit skullcap has a mostly complete frontal, two partially complete parietals, and nasals. No chronometric dating has been published yet, and suggested dates range from early Middle Pleistocene to terminal Late Pleistocene. While no chronometric date has been published, the presence of archaic features has led to a potential affiliation with archaic hominin species. If it is indeed Homo erectus or archaic Homo sapiens, Salkhit implies a much earlier spread of hominins farther north and inland Asia than previously thought. In this paper, the nature of the archaic features in Salkhit is investigated. The Salkhit skullcap morphology and metrics were compared with Middle and Late Pleistocene hominin fossils from northeast Asia: Zhoukoudian Locality 1, Dali, and Zhoukoudian Upper Cave. Results show an interesting pattern: on one hand, the archaic features that Salkhit shares with the Zhoukoudian Locality 1 sample also are shared with other later hominins; on the other hand, Salkhit is different from the Middle Pleistocene materials in the same way later hominins differ from the Middle Pleistocene sample, in having a broader frontal and thinner supraorbital region. This may reflect encephalization and gracilization, a modernization trend found in many places. It is concluded that the archaic features observed in Salkhit are regionally predominant features rather than diagnostic features of an archaic species. PMID:25813423

  7. The Human Story: From Hominids to Homo Intelligens. A Curriculum Map for 5th Grade.

    ERIC Educational Resources Information Center

    Fluellen, Jerry E., Jr.

    A curriculum map for a year-long, fifth-grade, multidisciplinary project takes a performance view of understanding from Harvard University Project Zero's Research Center. Throughout the project and in each assessment of understanding, learners show what they know about human evolution. This guide to deep disciplinary understanding of the big idea…

  8. Hominin interbreeding and the evolution of human variation.

    PubMed

    Ko, Kwang Hyun

    2016-12-01

    Mitochondrial Eve confirms the "out of Africa" theory, but the evidence also supports interbreeding between Homo sapiens and other hominins: Neanderthals, Denisovans, and Homo heidelbergensis. This article explains how interbreeding between early H. sapiens and archaic hominins occurred. The availability of edible insects in East Asia aided the spread of the unaggressive, highly cooperative Neanderthals, who interbred with H. sapiens in Asia, resulting in a higher admixture of Neanderthal DNA in East Asian populations. Geographical variation in degree of interbreeding between H. sapiens and Neanderthals likely contributed to neurological and behavioral differences in modern humans. Similarly, people with Denisovan genetic admixture were better able to dwell in mountainous regions, allowing their genetic legacy to cross the Himalayas and persist in Southeast Asian and Oceanian H. sapiens. In the Sub-Saharan region, unaffected by Denisovan or Neanderthal interbreeding, H. sapiens interbred with H. heidelbergensis, because high humidity militated against fire-making and allowed the survival of these non-fire-making hominins. PMID:27429943

  9. Comparison of cranial ontogenetic trajectories among great apes and humans.

    PubMed

    Mitteroecker, Philipp; Gunz, Philipp; Bernhard, Markus; Schaefer, Katrin; Bookstein, Fred L

    2004-06-01

    Molecular data suggest that humans are more closely related to chimpanzees than either is to the gorillas, yet one finds the closest similarity in craniofacial morphology to be among the great apes to the exclusion of humans. To clarify how and when these differences arise in ontogeny, we studied ontogenetic trajectories for Homo sapiens, Pan paniscus, Pan troglodytes, Gorilla gorilla and Pongo pygmaeus. A total of 96 traditional three-dimensional landmarks and semilandmarks on the face and cranial base were collected on 268 adult and sub-adult crania for a geometric morphometric analysis. The ontogenetic trajectories are compared by various techniques, including a new method, relative warps in size-shape space. We find that adult Homo sapiens specimens are clearly separated from the great apes in shape space and size-shape space. Around birth, Homo sapiens infants are already markedly different from the great apes, which overlap at this age but diverge among themselves postnatally. The results suggest that the small genetic differences between Homo and Pan affect early human ontogeny to induce the distinct adult human craniofacial morphology. Pure heterochrony does not sufficiently explain the human craniofacial morphology nor the differences among the African apes.

  10. The four canonical tpr subunits of human APC/C form related homo-dimeric structures and stack in parallel to form a TPR suprahelix.

    PubMed

    Zhang, Ziguo; Chang, Leifu; Yang, Jing; Conin, Nora; Kulkarni, Kiran; Barford, David

    2013-11-15

    The anaphase-promoting complex or cyclosome (APC/C) is a large E3 RING-cullin ubiquitin ligase composed of between 14 and 15 individual proteins. A striking feature of the APC/C is that only four proteins are involved in directly recognizing target proteins and catalyzing the assembly of a polyubiquitin chain. All other subunits, which account for >80% of the mass of the APC/C, provide scaffolding functions. A major proportion of these scaffolding subunits are structurally related. In metazoans, there are four canonical tetratricopeptide repeat (TPR) proteins that form homo-dimers (Apc3/Cdc27, Apc6/Cdc16, Apc7 and Apc8/Cdc23). Here, we describe the crystal structure of the N-terminal homo-dimerization domain of Schizosaccharomyces pombe Cdc23 (Cdc23(Nterm)). Cdc23(Nterm) is composed of seven contiguous TPR motifs that self-associate through a related mechanism to those of Cdc16 and Cdc27. Using the Cdc23(Nterm) structure, we generated a model of full-length Cdc23. The resultant "V"-shaped molecule docks into the Cdc23-assigned density of the human APC/C structure determined using negative stain electron microscopy (EM). Based on sequence conservation, we propose that Apc7 forms a homo-dimeric structure equivalent to those of Cdc16, Cdc23 and Cdc27. The model is consistent with the Apc7-assigned density of the human APC/C EM structure. The four canonical homo-dimeric TPR proteins of human APC/C stack in parallel on one side of the complex. Remarkably, the uniform relative packing of neighboring TPR proteins generates a novel left-handed suprahelical TPR assembly. This finding has implications for understanding the assembly of other TPR-containing multimeric complexes.

  11. The Four Canonical TPR Subunits of Human APC/C Form Related Homo-Dimeric Structures and Stack in Parallel to Form a TPR Suprahelix☆

    PubMed Central

    Zhang, Ziguo; Chang, Leifu; Yang, Jing; Conin, Nora; Kulkarni, Kiran; Barford, David

    2013-01-01

    The anaphase-promoting complex or cyclosome (APC/C) is a large E3 RING-cullin ubiquitin ligase composed of between 14 and 15 individual proteins. A striking feature of the APC/C is that only four proteins are involved in directly recognizing target proteins and catalyzing the assembly of a polyubiquitin chain. All other subunits, which account for > 80% of the mass of the APC/C, provide scaffolding functions. A major proportion of these scaffolding subunits are structurally related. In metazoans, there are four canonical tetratricopeptide repeat (TPR) proteins that form homo-dimers (Apc3/Cdc27, Apc6/Cdc16, Apc7 and Apc8/Cdc23). Here, we describe the crystal structure of the N-terminal homo-dimerization domain of Schizosaccharomyces pombe Cdc23 (Cdc23Nterm). Cdc23Nterm is composed of seven contiguous TPR motifs that self-associate through a related mechanism to those of Cdc16 and Cdc27. Using the Cdc23Nterm structure, we generated a model of full-length Cdc23. The resultant “V”-shaped molecule docks into the Cdc23-assigned density of the human APC/C structure determined using negative stain electron microscopy (EM). Based on sequence conservation, we propose that Apc7 forms a homo-dimeric structure equivalent to those of Cdc16, Cdc23 and Cdc27. The model is consistent with the Apc7-assigned density of the human APC/C EM structure. The four canonical homo-dimeric TPR proteins of human APC/C stack in parallel on one side of the complex. Remarkably, the uniform relative packing of neighboring TPR proteins generates a novel left-handed suprahelical TPR assembly. This finding has implications for understanding the assembly of other TPR-containing multimeric complexes. PMID:23583778

  12. Human orexin/hypocretin receptors form constitutive homo- and heteromeric complexes with each other and with human CB{sub 1} cannabinoid receptors

    SciTech Connect

    Jäntti, Maria H.; Mandrika, Ilona; Kukkonen, Jyrki P.

    2014-03-07

    Highlights: • OX{sub 1} and OX{sub 2} orexin and CB{sub 1} cannabinoid receptor dimerization was investigated. • Bioluminescence resonance energy transfer method was used. • All receptors readily formed constitutive homo- and heteromeric complexes. - Abstract: Human OX{sub 1} orexin receptors have been shown to homodimerize and they have also been suggested to heterodimerize with CB{sub 1} cannabinoid receptors. The latter has been suggested to be important for orexin receptor responses and trafficking. In this study, we wanted to assess the ability of the other combinations of receptors to also form similar complexes. Vectors for expression of human OX{sub 1}, OX{sub 2} and CB{sub 1} receptors, C-terminally fused with either Renilla luciferase or GFP{sup 2} green fluorescent protein variant, were generated. The constructs were transiently expressed in Chinese hamster ovary cells, and constitutive dimerization between the receptors was assessed by bioluminescence energy transfer (BRET). Orexin receptor subtypes readily formed homo- and hetero(di)mers, as suggested by significant BRET signals. CB{sub 1} receptors formed homodimers, and they also heterodimerized with both orexin receptors. Interestingly, BRET efficiency was higher for homodimers than for almost all heterodimers. This is likely to be due to the geometry of the interaction; the putatively symmetric dimers may place the C-termini in a more suitable orientation in homomers. Fusion of luciferase to an orexin receptor and GFP{sup 2} to CB{sub 1} produced more effective BRET than the opposite fusions, also suggesting differences in geometry. Similar was seen for the OX{sub 1}–OX{sub 2} interaction. In conclusion, orexin receptors have a significant propensity to make homo- and heterodi-/oligomeric complexes. However, it is unclear whether this affects their signaling. As orexin receptors efficiently signal via endocannabinoid production to CB{sub 1} receptors, dimerization could be an effective way

  13. A bivariate approach to the widening of the frontal lobes in the genus Homo.

    PubMed

    Bruner, Emiliano; Holloway, Ralph L

    2010-02-01

    Within the genus Homo, the most encephalized taxa (Neandertals and modern humans) show relatively wider frontal lobes than either Homo erectus or australopithecines. The present analysis considers whether these changes are associated with a single size-based or allometric pattern (positive allometry of the width of the anterior endocranial fossa) or with a more specific and non-allometric pattern. The relationship between hemispheric length, maximum endocranial width, and frontal width at Broca's area was investigated in extant and extinct humans. Our results do not support positive allometry for the frontal lobe's width in relation to the main endocranial diameters within modern humans (Homo sapiens). Also, the correlation between frontal width and hemispheric length is lower than the correlation between frontal width and parieto-temporal width. When compared with the australopithecines, the genus Homo could have experienced a non-allometric widening of the brain at the temporo-parietal areas, which is most evident in Neandertals. Modern humans and Neandertals also display a non-allometric widening of the anterior endocranial fossa at the Broca's cap when compared with early hominids, again more prominent in the latter group. Taking into account the contrast between the intra-specific patterns and the between-species differences, the relative widening of the anterior fossa can be interpreted as a definite evolutionary character instead of a passive consequence of brain size increase. This expansion is most likely associated with correspondent increments of the underlying neural mass, or at least with a geometrical reallocation of the frontal cortical volumes. Although different structural changes of the cranial architecture can be related to such variations, the widening of the frontal areas is nonetheless particularly interesting when some neural functions (like language or working memory, decision processing, etc.) and related fronto-parietal cortico

  14. A bivariate approach to the widening of the frontal lobes in the genus Homo.

    PubMed

    Bruner, Emiliano; Holloway, Ralph L

    2010-02-01

    Within the genus Homo, the most encephalized taxa (Neandertals and modern humans) show relatively wider frontal lobes than either Homo erectus or australopithecines. The present analysis considers whether these changes are associated with a single size-based or allometric pattern (positive allometry of the width of the anterior endocranial fossa) or with a more specific and non-allometric pattern. The relationship between hemispheric length, maximum endocranial width, and frontal width at Broca's area was investigated in extant and extinct humans. Our results do not support positive allometry for the frontal lobe's width in relation to the main endocranial diameters within modern humans (Homo sapiens). Also, the correlation between frontal width and hemispheric length is lower than the correlation between frontal width and parieto-temporal width. When compared with the australopithecines, the genus Homo could have experienced a non-allometric widening of the brain at the temporo-parietal areas, which is most evident in Neandertals. Modern humans and Neandertals also display a non-allometric widening of the anterior endocranial fossa at the Broca's cap when compared with early hominids, again more prominent in the latter group. Taking into account the contrast between the intra-specific patterns and the between-species differences, the relative widening of the anterior fossa can be interpreted as a definite evolutionary character instead of a passive consequence of brain size increase. This expansion is most likely associated with correspondent increments of the underlying neural mass, or at least with a geometrical reallocation of the frontal cortical volumes. Although different structural changes of the cranial architecture can be related to such variations, the widening of the frontal areas is nonetheless particularly interesting when some neural functions (like language or working memory, decision processing, etc.) and related fronto-parietal cortico

  15. In search of Homo economicus.

    PubMed

    Yamagishi, Toshio; Li, Yang; Takagishi, Haruto; Matsumoto, Yoshie; Kiyonari, Toko

    2014-09-01

    Homo economicus, a model for humans in neoclassical economics, is a rational maximizer of self-interest. However, many social scientists regard such a person as a mere imaginary creature. We found that 31 of 446 residents of relatively wealthy Tokyo suburbs met the behavioral definition of Homo economicus. In several rounds of economic games, participants whose behavior was consistent with this model always apportioned the money endowed by the experimenter to themselves, leaving no share for their partners. These participants had high IQs and a deliberative decision style. An additional 39 participants showed a similar disregard for other people's welfare, although they were slightly more altruistic than those in the Homo economicus group. The psychological composition of these quasi-Homo economicus participants was distinct from that of participants in the Homo economicus group. Although participants in the latter group behaved selfishly on the basis of rational calculations, those in the former group made selfish choices impulsively. The implications of these findings concerning the two types of extreme noncooperators are discussed.

  16. Morphological variation in Homo erectus and the origins of developmental plasticity.

    PubMed

    Antón, Susan C; Taboada, Hannah G; Middleton, Emily R; Rainwater, Christopher W; Taylor, Andrea B; Turner, Trudy R; Turnquist, Jean E; Weinstein, Karen J; Williams, Scott A

    2016-07-01

    Homo erectus was the first hominin to exhibit extensive range expansion. This extraordinary departure from Africa, especially into more temperate climates of Eurasia, has been variously related to technological, energetic and foraging shifts. The temporal and regional anatomical variation in H. erectus suggests that a high level of developmental plasticity, a key factor in the ability of H. sapiens to occupy a variety of habitats, may also have been present in H. erectus. Developmental plasticity, the ability to modify development in response to environmental conditions, results in differences in size, shape and dimorphism across populations that relate in part to levels of resource sufficiency and extrinsic mortality. These differences predict not only regional variations but also overall smaller adult sizes and lower levels of dimorphism in instances of resource scarcity and high predator load. We consider the metric variation in 35 human and non-human primate 'populations' from known environmental contexts and 14 time- and space-restricted paleodemes of H. erectus and other fossil Homo Human and non-human primates exhibit more similar patterns of variation than expected, with plasticity evident, but in differing patterns by sex across populations. The fossil samples show less evidence of variation than expected, although H. erectus varies more than Neandertals.This article is part of the themed issue 'Major transitions in human evolution'. PMID:27298467

  17. Small-Bodied Humans from Palau, Micronesia

    PubMed Central

    Berger, Lee R.; Churchill, Steven E.; De Klerk, Bonita; Quinn, Rhonda L.

    2008-01-01

    Newly discovered fossil assemblages of small bodied Homo sapiens from Palau, Micronesia possess characters thought to be taxonomically primitive for the genus Homo. Background Recent surface collection and test excavation in limestone caves in the rock islands of Palau, Micronesia, has produced a sizeable sample of human skeletal remains dating roughly between 940-2890 cal ybp. Principle Findings Preliminary analysis indicates that this material is important for two reasons. First, individuals from the older time horizons are small in body size even relative to “pygmoid” populations from Southeast Asia and Indonesia, and thus may represent a marked case of human insular dwarfism. Second, while possessing a number of derived features that align them with Homo sapiens, the human remains from Palau also exhibit several skeletal traits that are considered to be primitive for the genus Homo. Significance These features may be previously unrecognized developmental correlates of small body size and, if so, they may have important implications for interpreting the taxonomic affinities of fossil specimens of Homo. PMID:18347737

  18. A tentative framework for the acquisition of language and modern human cognition.

    PubMed

    Tattersall, Ian

    2016-06-20

    Modern human beings process information symbolically, rearranging mental symbols to envision multiple potential realities. They also express the ideas they form using structured articulate language. No other living creature does either of these things. Yet it is evident that we are descended from a non-symbolic and non-linguistic ancestor. How did this astonishing transformation occur? Scrutiny of the fossil and archaeological records reveals that the transition to symbolic reasoning happened very late in hominid history - indeed, within the tenure of anatomically recognizable Homo sapiens. It was evidently not simply a passive result of the increase in brain size that typified multiple lineages of the genus Homo over the Pleistocene. Instead, a brain exaptively capable of complex symbolic manipulation and language acquisition was acquired in the major developmental reorganization that gave rise to the anatomically distinctive species Homo sapiens. The new capacity it conferred was later recruited through the action of a cultural stimulus, most plausibly the spontaneous invention of language.

  19. Paleoneurology of two new neandertal occipitals from El Sidrón (asturias, Spain) in the context of homo endocranial evolution.

    PubMed

    Peña-Melián, Angel; Rosas, Antonio; García-Tabernero, Antonio; Bastir, Markus; De La Rasilla, Marco

    2011-08-01

    The endocranial surface description and comparative analyses of two new neandertal occipital fragments (labelled SD-1149 and SD-370a) from the El Sidrón site (Asturias, Spain) reveal new aspects of neandertal brain morphological asymmetries. The dural sinus drainage pattern, as observed on the sagittal-transverse system, as well as the cerebral occipito-petalias, point out a slightly differential configuration of the neandertal brain when compared to other Homo species, especially H. sapiens. The neandertal dural sinus drainage pattern is organized in a more asymmetric mode, in such a way that the superior sagittal sinus (SSS) drains either to the right or to the left transverse sinuses, but in no case in a confluent mode (i.e. simultaneous continuation of SSS with both right (RTS) and left (LTS) transverse sinuses). Besides, the superior sagittal sinus shows an accentuated deviation from of the mid-sagittal plane in its way to the RTS in 35% of neandertals. This condition, which increases the asymmetry of the system, is almost nonexistent neither in the analyzed Homo fossil species sample nor in that of anatomically modern humans. Regarding the cerebral occipito-petalias, neandertals manifest one of the lowest percentages of left petalia of the Homo sample (including modern H. sapiens). As left occipito-petalia is the predominant pattern in hominins, it seems as if neandertals would have developed a different pattern of brain hemispheres asymmetry. Finally, the relief and position of the the cerebral sulci and gyri impressions observed in the El Sidrón occipital specimens look similar to those observed in modern H. sapiens.

  20. More on the Liang Bua finds and modern human cretins.

    PubMed

    Oxnard, Charles; Obendorf, Peter J; Kefford, Ben J; Dennison, John

    2012-12-01

    Brown (2012: LB1 and LB6 Homo floresiensis are not modern human (Homo sapiens) cretins, Journal of Human Evolution) makes errors of fact, omission and interpretation. Brown's comments refer, among others, to (1) delayed growth and development indicated by unfused epiphyses, (2) postcranial limb proportions: limbs to trunk, between limbs, and within limbs, (3) postcranial bone torsions and angles, (4) postcranial robusticity, real and apparent, (5) skull features, and (6) cretinism on Flores. In each of these areas, much information about cretins is incorrect and much information (Oxnard et al., 2010) comparing the Liang Bua remains with cretins is ignored. PMID:23107933

  1. The many mysteries of Homo naledi.

    PubMed

    Stringer, Chris

    2015-01-01

    More than 1500 fossils from the Rising Star cave system in South Africa have been assigned to a new human species, Homo naledi, which displays a unique combination of primitive and derived traits throughout the skeleton.

  2. The many mysteries of Homo naledi

    PubMed Central

    2015-01-01

    More than 1500 fossils from the Rising Star cave system in South Africa have been assigned to a new human species, Homo naledi, which displays a unique combination of primitive and derived traits throughout the skeleton. PMID:26354290

  3. The foot of Homo naledi.

    PubMed

    Harcourt-Smith, W E H; Throckmorton, Z; Congdon, K A; Zipfel, B; Deane, A S; Drapeau, M S M; Churchill, S E; Berger, L R; DeSilva, J M

    2015-01-01

    Modern humans are characterized by a highly specialized foot that reflects our obligate bipedalism. Our understanding of hominin foot evolution is, although, hindered by a paucity of well-associated remains. Here we describe the foot of Homo naledi from Dinaledi Chamber, South Africa, using 107 pedal elements, including one nearly-complete adult foot. The H. naledi foot is predominantly modern human-like in morphology and inferred function, with an adducted hallux, an elongated tarsus, and derived ankle and calcaneocuboid joints. In combination, these features indicate a foot well adapted for striding bipedalism. However, the H. naledi foot differs from modern humans in having more curved proximal pedal phalanges, and features suggestive of a reduced medial longitudinal arch. Within the context of primitive features found elsewhere in the skeleton, these findings suggest a unique locomotor repertoire for H. naledi, thus providing further evidence of locomotor diversity within both the hominin clade and the genus Homo. PMID:26439101

  4. The foot of Homo naledi.

    PubMed

    Harcourt-Smith, W E H; Throckmorton, Z; Congdon, K A; Zipfel, B; Deane, A S; Drapeau, M S M; Churchill, S E; Berger, L R; DeSilva, J M

    2015-10-06

    Modern humans are characterized by a highly specialized foot that reflects our obligate bipedalism. Our understanding of hominin foot evolution is, although, hindered by a paucity of well-associated remains. Here we describe the foot of Homo naledi from Dinaledi Chamber, South Africa, using 107 pedal elements, including one nearly-complete adult foot. The H. naledi foot is predominantly modern human-like in morphology and inferred function, with an adducted hallux, an elongated tarsus, and derived ankle and calcaneocuboid joints. In combination, these features indicate a foot well adapted for striding bipedalism. However, the H. naledi foot differs from modern humans in having more curved proximal pedal phalanges, and features suggestive of a reduced medial longitudinal arch. Within the context of primitive features found elsewhere in the skeleton, these findings suggest a unique locomotor repertoire for H. naledi, thus providing further evidence of locomotor diversity within both the hominin clade and the genus Homo.

  5. The foot of Homo naledi

    PubMed Central

    Harcourt-Smith, W. E. H.; Throckmorton, Z.; Congdon, K. A.; Zipfel, B.; Deane, A. S.; Drapeau, M. S. M.; Churchill, S. E.; Berger, L. R.; DeSilva, J. M.

    2015-01-01

    Modern humans are characterized by a highly specialized foot that reflects our obligate bipedalism. Our understanding of hominin foot evolution is, although, hindered by a paucity of well-associated remains. Here we describe the foot of Homo naledi from Dinaledi Chamber, South Africa, using 107 pedal elements, including one nearly-complete adult foot. The H. naledi foot is predominantly modern human-like in morphology and inferred function, with an adducted hallux, an elongated tarsus, and derived ankle and calcaneocuboid joints. In combination, these features indicate a foot well adapted for striding bipedalism. However, the H. naledi foot differs from modern humans in having more curved proximal pedal phalanges, and features suggestive of a reduced medial longitudinal arch. Within the context of primitive features found elsewhere in the skeleton, these findings suggest a unique locomotor repertoire for H. naledi, thus providing further evidence of locomotor diversity within both the hominin clade and the genus Homo. PMID:26439101

  6. Gamma-ray spectrometric dating of late Homo erectus skulls from Ngandong and Sambungmacan, Central Java, Indonesia.

    PubMed

    Yokoyama, Yuji; Falguères, Christophe; Sémah, François; Jacob, Teuku; Grün, Rainer

    2008-08-01

    Hominid fossils from Ngandong and Sambungmacan, Central Java, Indonesia, are considered to be the most anatomically derived and youngest representatives of Homo erectus. Nondestructive gamma-ray spectrometric dating of three of these Homo erectus skulls showed that all samples underwent uranium leaching. Nevertheless, we could establish minimum age estimates of around 40ka, with an upper age limit of around 60 to 70ka. This means that the Homo erectus of Java very likely survived the Toba eruption and may have been contemporaneous with the earliest Homo sapiens in Southeast Asia and Australasia.

  7. FOXP3 is a homo-oligomer and a component of a supramolecular regulatory complex disabled in the human XLAAD/IPEX autoimmune disease.

    PubMed

    Li, Bin; Samanta, Arabinda; Song, Xiaomin; Iacono, Kathryn T; Brennan, Patrick; Chatila, Talal A; Roncador, Giovanna; Banham, Alison H; Riley, James L; Wang, Qiang; Shen, Yuan; Saouaf, Sandra J; Greene, Mark I

    2007-07-01

    We have found that FOXP3 is an oligomeric component of a large supramolecular complex. Certain FOXP3 mutants with single amino acid deletions in the leucine zipper domain of FOXP3 are associated with the X-linked autoimmunity-allergic dysregulation (XLAAD) and immunodysregulation, polyendocrinopathy and enteropathy, X-linked (IPEX) syndrome in humans. We report that the single amino acid deletion found in human XLAAD/IPEX patients within the leucine zipper domain of FOXP3 does not disrupt its ability to join the larger protein complex, but eliminates FOXP3 homo-oligomerization as well as heteromerization with FOXP1. We found that the zinc finger-leucine zipper domain region of FOXP3 is sufficient to mediate both homodimerization and homotetramerization. However, the same domain region from XLAAD/IPEX FOXP3 containing an E251 deletion prevents oligomerizaton and the protein remains monomeric. We also found that wild-type FOXP3 directly binds to the human IL-2 promoter, but the E251 deletion in FOXP3 in XLAAD/IPEX patient's T cells disrupts its association with the IL-2 promoter in vivo and in vitro, and limits repression of IL-2 transcription after T-cell activation. Our results suggest that compromising FOXP3 homo-oligomerization and hetero-oligomerization with the FOXP1 protein impairs DNA-binding properties leading to distinct biochemical phenotypes in humans with the XLAAD/IPEX autoimmune syndrome. This study explains some features of the pathogenesis of a disease syndrome that arises as a consequence of specific assembly failure of a transcriptional repressor due to certain mutations within the FOXP3 leucine zipper. PMID:17586580

  8. 24- and 26-homo-1,25-dihydroxyvitamin D/sub 3/: preferential activity in inducing differentiation of human leukemia cells HL-60 in vitro inducing differentiation of human leukemia cells HL-60 in vitro

    SciTech Connect

    Ostrem, V.K.; Tanaka, Y.; Prahl, J.; DeLuca, H.F.; Ikekawa, N.

    1987-05-01

    1,25-Dihydroxyvitamin D/sub 3/, the hormonal form of vitamin D/sub 3/, promotes the differentiation of HL-60 human promyelocytic leukemia cells into monocytes. Differentiation changes include the induction of phagocytosis, the initiation of nitroblue tetrazolium-reducing activity, and the appearance of nonspecific acid esterase. The authors have found that the 24-homo- and 26-homo-1,25-dihydroxyvitamin D/sub 3/ and their ..delta../sup 22/ analogues are 10-fold more potent than 1,25-dihydroxyvitamin D/sub 3/ in inducing differentiation of HL-60 cells in vitro. In vivo, these analogues show activity similar to 1,25-dihydroxy-vitamin D/sub 3/ in stimulating intestinal calcium transport in vitamin D-deficient rats. The 24-homoanalogues are significantly less active, whereas the 26-homo derivatives are more active than the natural hormone in mobilizing calcium from bone. This unusual activity pattern cannot be explained on the basis of the affinity of these analogues for the 1,25-dihydroxy-vitamin D/sub 3/ intracellular receptor: both 24-homo- and 26-homo-1,25-dihydroxyvitamin D/sub 3/ have the same effectiveness as 1,25-dihydroxyvitamin D/sub 3/ in displacing the tritiated hormone from its receptor in rat intestine of HL-60 cells. These analogues of 1,25-dihydroxyvitamin D/sub 3/ may be of some interest as possible therapeutic substances, or as tools in understanding the action of 1,25-dihydroxyvitamin D/sub 3/ in inducing differentiation.

  9. Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa.

    PubMed

    Berger, Lee R; Hawks, John; de Ruiter, Darryl J; Churchill, Steven E; Schmid, Peter; Delezene, Lucas K; Kivell, Tracy L; Garvin, Heather M; Williams, Scott A; DeSilva, Jeremy M; Skinner, Matthew M; Musiba, Charles M; Cameron, Noel; Holliday, Trenton W; Harcourt-Smith, William; Ackermann, Rebecca R; Bastir, Markus; Bogin, Barry; Bolter, Debra; Brophy, Juliet; Cofran, Zachary D; Congdon, Kimberly A; Deane, Andrew S; Dembo, Mana; Drapeau, Michelle; Elliott, Marina C; Feuerriegel, Elen M; Garcia-Martinez, Daniel; Green, David J; Gurtov, Alia; Irish, Joel D; Kruger, Ashley; Laird, Myra F; Marchi, Damiano; Meyer, Marc R; Nalla, Shahed; Negash, Enquye W; Orr, Caley M; Radovcic, Davorka; Schroeder, Lauren; Scott, Jill E; Throckmorton, Zachary; Tocheri, Matthew W; VanSickle, Caroline; Walker, Christopher S; Wei, Pianpian; Zipfel, Bernhard

    2015-01-01

    Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.

  10. Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa.

    PubMed

    Berger, Lee R; Hawks, John; de Ruiter, Darryl J; Churchill, Steven E; Schmid, Peter; Delezene, Lucas K; Kivell, Tracy L; Garvin, Heather M; Williams, Scott A; DeSilva, Jeremy M; Skinner, Matthew M; Musiba, Charles M; Cameron, Noel; Holliday, Trenton W; Harcourt-Smith, William; Ackermann, Rebecca R; Bastir, Markus; Bogin, Barry; Bolter, Debra; Brophy, Juliet; Cofran, Zachary D; Congdon, Kimberly A; Deane, Andrew S; Dembo, Mana; Drapeau, Michelle; Elliott, Marina C; Feuerriegel, Elen M; Garcia-Martinez, Daniel; Green, David J; Gurtov, Alia; Irish, Joel D; Kruger, Ashley; Laird, Myra F; Marchi, Damiano; Meyer, Marc R; Nalla, Shahed; Negash, Enquye W; Orr, Caley M; Radovcic, Davorka; Schroeder, Lauren; Scott, Jill E; Throckmorton, Zachary; Tocheri, Matthew W; VanSickle, Caroline; Walker, Christopher S; Wei, Pianpian; Zipfel, Bernhard

    2015-01-01

    Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa. PMID:26354291

  11. The first archaic Homo from Taiwan

    PubMed Central

    Chang, Chun-Hsiang; Kaifu, Yousuke; Takai, Masanaru; Kono, Reiko T.; Grün, Rainer; Matsu’ura, Shuji; Kinsley, Les; Lin, Liang-Kong

    2015-01-01

    Recent studies of an increasing number of hominin fossils highlight regional and chronological diversities of archaic Homo in the Pleistocene of eastern Asia. However, such a realization is still based on limited geographical occurrences mainly from Indonesia, China and Russian Altai. Here we describe a newly discovered archaic Homo mandible from Taiwan (Penghu 1), which further increases the diversity of Pleistocene Asian hominins. Penghu 1 revealed an unexpectedly late survival (younger than 450 but most likely 190–10 thousand years ago) of robust, apparently primitive dentognathic morphology in the periphery of the continent, which is unknown among the penecontemporaneous fossil records from other regions of Asia except for the mid-Middle Pleistocene Homo from Hexian, Eastern China. Such patterns of geographic trait distribution cannot be simply explained by clinal geographic variation of Homo erectus between northern China and Java, and suggests survival of multiple evolutionary lineages among archaic hominins before the arrival of modern humans in the region. PMID:25625212

  12. The first archaic Homo from Taiwan.

    PubMed

    Chang, Chun-Hsiang; Kaifu, Yousuke; Takai, Masanaru; Kono, Reiko T; Grün, Rainer; Matsu'ura, Shuji; Kinsley, Les; Lin, Liang-Kong

    2015-01-01

    Recent studies of an increasing number of hominin fossils highlight regional and chronological diversities of archaic Homo in the Pleistocene of eastern Asia. However, such a realization is still based on limited geographical occurrences mainly from Indonesia, China and Russian Altai. Here we describe a newly discovered archaic Homo mandible from Taiwan (Penghu 1), which further increases the diversity of Pleistocene Asian hominins. Penghu 1 revealed an unexpectedly late survival (younger than 450 but most likely 190-10 thousand years ago) of robust, apparently primitive dentognathic morphology in the periphery of the continent, which is unknown among the penecontemporaneous fossil records from other regions of Asia except for the mid-Middle Pleistocene Homo from Hexian, Eastern China. Such patterns of geographic trait distribution cannot be simply explained by clinal geographic variation of Homo erectus between northern China and Java, and suggests survival of multiple evolutionary lineages among archaic hominins before the arrival of modern humans in the region. PMID:25625212

  13. Early stone technology on Flores and its implications for Homo floresiensis.

    PubMed

    Brumm, Adam; Aziz, Fachroel; van den Bergh, Gert D; Morwood, Michael J; Moore, Mark W; Kurniawan, Iwan; Hobbs, Douglas R; Fullagar, Richard

    2006-06-01

    In the Soa Basin of central Flores, eastern Indonesia, stratified archaeological sites, including Mata Menge, Boa Lesa and Kobatuwa (Fig. 1), contain stone artefacts associated with the fossilized remains of Stegodon florensis, Komodo dragon, rat and various other taxa. These sites have been dated to 840-700 kyr bp (thousand years before present). The authenticity of the Soa Basin artefacts and their provenance have been demonstrated by previous work, but to quell lingering doubts, here we describe the context, attributes and production modes of 507 artefacts excavated at Mata Menge. We also note specific similarities, and apparent technological continuity, between the Mata Menge stone artefacts and those excavated from Late Pleistocene levels at Liang Bua cave, 50 km to the west. The latter artefacts, dated to between 95-74 and 12 kyr ago, are associated with the remains of a dwarfed descendent of S. florensis, Komodo dragon, rat and a small-bodied hominin species, Homo floresiensis, which had a brain size of about 400 cubic centimetres. The Mata Menge evidence negates claims that stone artefacts associated with H. floresiensis are so complex that they must have been made by modern humans (Homo sapiens).

  14. Early stone technology on Flores and its implications for Homo floresiensis.

    PubMed

    Brumm, Adam; Aziz, Fachroel; van den Bergh, Gert D; Morwood, Michael J; Moore, Mark W; Kurniawan, Iwan; Hobbs, Douglas R; Fullagar, Richard

    2006-06-01

    In the Soa Basin of central Flores, eastern Indonesia, stratified archaeological sites, including Mata Menge, Boa Lesa and Kobatuwa (Fig. 1), contain stone artefacts associated with the fossilized remains of Stegodon florensis, Komodo dragon, rat and various other taxa. These sites have been dated to 840-700 kyr bp (thousand years before present). The authenticity of the Soa Basin artefacts and their provenance have been demonstrated by previous work, but to quell lingering doubts, here we describe the context, attributes and production modes of 507 artefacts excavated at Mata Menge. We also note specific similarities, and apparent technological continuity, between the Mata Menge stone artefacts and those excavated from Late Pleistocene levels at Liang Bua cave, 50 km to the west. The latter artefacts, dated to between 95-74 and 12 kyr ago, are associated with the remains of a dwarfed descendent of S. florensis, Komodo dragon, rat and a small-bodied hominin species, Homo floresiensis, which had a brain size of about 400 cubic centimetres. The Mata Menge evidence negates claims that stone artefacts associated with H. floresiensis are so complex that they must have been made by modern humans (Homo sapiens). PMID:16738657

  15. Homo- and hetero-dimerization of human UDP-glucuronosyltransferase 2B7 (UGT2B7) wild type and its allelic variants affect zidovudine glucuronidation activity.

    PubMed

    Yuan, Lingmin; Qian, Sainan; Xiao, Yongsheng; Sun, Hongying; Zeng, Su

    2015-05-01

    Most human UDP-glucuronosyltransferase (UGT; EC 2.4.1.17) genes contain non-synonymous single nucleotide polymorphisms (nsSNPs) which cause amino acid substitutions. Allelic variants caused by nsSNPs may exhibit absent or reduced enzyme activity. UGT2B7 is one of the most important UGTs that glucuronidates abundant endobiotics and xenobiotics, such as estriol, morphine, and anticancer drugs. Three nsSNPs, UGT2B7*71S (211G>T), UGT2B7*2 (802C>T) and UGT2B7*5 (1192G>A) are observed in the UGT2B7 gene, and they code for allozymes UGT2B7*71S (A71S), UGT2B7*2 (H268Y), and UGT2B7*5 (D398N). UGT2B7 has been observed to form oligomers that affect its enzymatic activity and in this study, we investigated protein-protein interactions among UGT2B7 allozymes wild type (WT), A71S, H268Y and D398N, by performing a systematic quantitative fluorescence resonance energy transfer (FRET) analysis in combination with co-immunoprecipitation assay. Quantitative FRET analysis revealed that UGT2B7 allozymes formed homo- and hetero-dimers and showed distinct features in donor-acceptor distances. Both codon 71 and codon 268 in the N-terminal domain were involved in the dimeric interaction. Co-immunoprecipitation experiments also proved that UGT2B7 allozymes formed stable dimers. The glucuronidation activities of homo- and hetero-dimers were further tested with zidovudine as the substrate. An increase in activity was observed when WT hetero-dimerized with A71S compared with homo-dimers, while both H268Y and D398N impaired the activity of WT and A71S by forming hetero-dimers. In addition, zidovudine glucuronidation activity is associated with FRET distance. These findings provide insights into the consequences of amino acid substitution in UGT2B7 on zidovudine glucuronidation and the association between protein-protein interaction and glucuronidation activity. PMID:25770680

  16. Homo-trimeric Structure of the Type IVb Minor Pilin CofB Suggests Mechanism of CFA/III Pilus Assembly in Human Enterotoxigenic Escherichia coli.

    PubMed

    Kawahara, Kazuki; Oki, Hiroya; Fukakusa, Shunsuke; Yoshida, Takuya; Imai, Tomoya; Maruno, Takahiro; Kobayashi, Yuji; Motooka, Daisuke; Iida, Tetsuya; Ohkubo, Tadayasu; Nakamura, Shota

    2016-03-27

    In gram-negative bacteria, the assembly of type IV pilus (T4P) and the evolutionally related pseudopilus of type II secretion system involves specialized structural proteins called pilins and pseudopilins, respectively, and is dynamically regulated to promote bacterial pathogenesis. Previous studies have suggested that a structural "tip"-like hetero-complex formed through the interaction of at least three minor (pseudo) pilins plays an important role in this process, while some members of the pathogenic type IVb subfamily are known to have only one such minor pilin subunit whose function is still unknown. Here, we determined the crystal structure of the type IVb minor pilin CofB of colonization factor antigen/III from human enterotoxigenic Escherichia coli at 1.88-Å resolution. The crystal structure, in conjunction with physicochemical analysis in solution, reveals a symmetrical homo-trimeric arrangement distinct from the hetero-complexes of minor (pseudo) pilins observed in other T4P and type II secretion systems. Each CofB monomer adopts a unique three-domain architecture, in which the C-terminal β-sheet-rich lectin domain can effectively initiate trimer association of its pilin-like N-terminal domain through extensive hydrophobic interactions followed by domain swapping at the central hinge-like domain. Deletion of cofB produces a phenotype with no detectable pili formation on the cell surface, while molecular modeling indicates that the characteristic homo-trimeric structure of CofB is well situated at the pilus tip of colonization factor antigen/III formed by the major pilin CofA, suggesting a role for the minor pilin in the efficient initiation of T4P assembly. PMID:26876601

  17. Homo-trimeric Structure of the Type IVb Minor Pilin CofB Suggests Mechanism of CFA/III Pilus Assembly in Human Enterotoxigenic Escherichia coli.

    PubMed

    Kawahara, Kazuki; Oki, Hiroya; Fukakusa, Shunsuke; Yoshida, Takuya; Imai, Tomoya; Maruno, Takahiro; Kobayashi, Yuji; Motooka, Daisuke; Iida, Tetsuya; Ohkubo, Tadayasu; Nakamura, Shota

    2016-03-27

    In gram-negative bacteria, the assembly of type IV pilus (T4P) and the evolutionally related pseudopilus of type II secretion system involves specialized structural proteins called pilins and pseudopilins, respectively, and is dynamically regulated to promote bacterial pathogenesis. Previous studies have suggested that a structural "tip"-like hetero-complex formed through the interaction of at least three minor (pseudo) pilins plays an important role in this process, while some members of the pathogenic type IVb subfamily are known to have only one such minor pilin subunit whose function is still unknown. Here, we determined the crystal structure of the type IVb minor pilin CofB of colonization factor antigen/III from human enterotoxigenic Escherichia coli at 1.88-Å resolution. The crystal structure, in conjunction with physicochemical analysis in solution, reveals a symmetrical homo-trimeric arrangement distinct from the hetero-complexes of minor (pseudo) pilins observed in other T4P and type II secretion systems. Each CofB monomer adopts a unique three-domain architecture, in which the C-terminal β-sheet-rich lectin domain can effectively initiate trimer association of its pilin-like N-terminal domain through extensive hydrophobic interactions followed by domain swapping at the central hinge-like domain. Deletion of cofB produces a phenotype with no detectable pili formation on the cell surface, while molecular modeling indicates that the characteristic homo-trimeric structure of CofB is well situated at the pilus tip of colonization factor antigen/III formed by the major pilin CofA, suggesting a role for the minor pilin in the efficient initiation of T4P assembly.

  18. Tempo and mode in human evolution.

    PubMed Central

    McHenry, H M

    1994-01-01

    The quickening pace of paleontological discovery is matched by rapid developments in geochronology. These new data show that the pattern of morphological change in the hominid lineage was mosaic. Adaptations essential to bipedalism appeared early, but some locomotor features changed much later. Relative to the highly derived postcrania of the earliest hominids, the craniodental complex was quite primitive (i.e., like the reconstructed last common ancestor with the African great apes). The pattern of craniodental change among successively younger species of Hominidae implies extensive parallel evolution between at least two lineages in features related to mastication. Relative brain size increased slightly among successively younger species of Australopithecus, expanded significantly with the appearance of Homo, but within early Homo remained at about half the size of Homo sapiens for almost a million years. Many apparent trends in human evolution may actually be due to the accumulation of relatively rapid shifts in successive species. PMID:8041697

  19. Recent origin of low trabecular bone density in modern humans.

    PubMed

    Chirchir, Habiba; Kivell, Tracy L; Ruff, Christopher B; Hublin, Jean-Jacques; Carlson, Kristian J; Zipfel, Bernhard; Richmond, Brian G

    2015-01-13

    Humans are unique, compared with our closest living relatives (chimpanzees) and early fossil hominins, in having an enlarged body size and lower limb joint surfaces in combination with a relatively gracile skeleton (i.e., lower bone mass for our body size). Some analyses have observed that in at least a few anatomical regions modern humans today appear to have relatively low trabecular density, but little is known about how that density varies throughout the human skeleton and across species or how and when the present trabecular patterns emerged over the course of human evolution. Here, we test the hypotheses that (i) recent modern humans have low trabecular density throughout the upper and lower limbs compared with other primate taxa and (ii) the reduction in trabecular density first occurred in early Homo erectus, consistent with the shift toward a modern human locomotor anatomy, or more recently in concert with diaphyseal gracilization in Holocene humans. We used peripheral quantitative CT and microtomography to measure trabecular bone of limb epiphyses (long bone articular ends) in modern humans and chimpanzees and in fossil hominins attributed to Australopithecus africanus, Paranthropus robustus/early Homo from Swartkrans, Homo neanderthalensis, and early Homo sapiens. Results show that only recent modern humans have low trabecular density throughout the limb joints. Extinct hominins, including pre-Holocene Homo sapiens, retain the high levels seen in nonhuman primates. Thus, the low trabecular density of the recent modern human skeleton evolved late in our evolutionary history, potentially resulting from increased sedentism and reliance on technological and cultural innovations. PMID:25535354

  20. Recent origin of low trabecular bone density in modern humans.

    PubMed

    Chirchir, Habiba; Kivell, Tracy L; Ruff, Christopher B; Hublin, Jean-Jacques; Carlson, Kristian J; Zipfel, Bernhard; Richmond, Brian G

    2015-01-13

    Humans are unique, compared with our closest living relatives (chimpanzees) and early fossil hominins, in having an enlarged body size and lower limb joint surfaces in combination with a relatively gracile skeleton (i.e., lower bone mass for our body size). Some analyses have observed that in at least a few anatomical regions modern humans today appear to have relatively low trabecular density, but little is known about how that density varies throughout the human skeleton and across species or how and when the present trabecular patterns emerged over the course of human evolution. Here, we test the hypotheses that (i) recent modern humans have low trabecular density throughout the upper and lower limbs compared with other primate taxa and (ii) the reduction in trabecular density first occurred in early Homo erectus, consistent with the shift toward a modern human locomotor anatomy, or more recently in concert with diaphyseal gracilization in Holocene humans. We used peripheral quantitative CT and microtomography to measure trabecular bone of limb epiphyses (long bone articular ends) in modern humans and chimpanzees and in fossil hominins attributed to Australopithecus africanus, Paranthropus robustus/early Homo from Swartkrans, Homo neanderthalensis, and early Homo sapiens. Results show that only recent modern humans have low trabecular density throughout the limb joints. Extinct hominins, including pre-Holocene Homo sapiens, retain the high levels seen in nonhuman primates. Thus, the low trabecular density of the recent modern human skeleton evolved late in our evolutionary history, potentially resulting from increased sedentism and reliance on technological and cultural innovations.

  1. Recent origin of low trabecular bone density in modern humans

    PubMed Central

    Chirchir, Habiba; Kivell, Tracy L.; Ruff, Christopher B.; Hublin, Jean-Jacques; Carlson, Kristian J.; Zipfel, Bernhard; Richmond, Brian G.

    2015-01-01

    Humans are unique, compared with our closest living relatives (chimpanzees) and early fossil hominins, in having an enlarged body size and lower limb joint surfaces in combination with a relatively gracile skeleton (i.e., lower bone mass for our body size). Some analyses have observed that in at least a few anatomical regions modern humans today appear to have relatively low trabecular density, but little is known about how that density varies throughout the human skeleton and across species or how and when the present trabecular patterns emerged over the course of human evolution. Here, we test the hypotheses that (i) recent modern humans have low trabecular density throughout the upper and lower limbs compared with other primate taxa and (ii) the reduction in trabecular density first occurred in early Homo erectus, consistent with the shift toward a modern human locomotor anatomy, or more recently in concert with diaphyseal gracilization in Holocene humans. We used peripheral quantitative CT and microtomography to measure trabecular bone of limb epiphyses (long bone articular ends) in modern humans and chimpanzees and in fossil hominins attributed to Australopithecus africanus, Paranthropus robustus/early Homo from Swartkrans, Homo neanderthalensis, and early Homo sapiens. Results show that only recent modern humans have low trabecular density throughout the limb joints. Extinct hominins, including pre-Holocene Homo sapiens, retain the high levels seen in nonhuman primates. Thus, the low trabecular density of the recent modern human skeleton evolved late in our evolutionary history, potentially resulting from increased sedentism and reliance on technological and cultural innovations. PMID:25535354

  2. Frequency-dependent performance and handedness in professional baseball players (Homo sapiens).

    PubMed

    Clotfelter, Ethan D

    2008-02-01

    I used data on handedness and pitching and hitting performance in annual cohorts of professional baseball players (1957-2005) to test the hypothesis that handedness among pitchers was subject to negative frequency-dependent selection. As predicted by this hypothesis, right-handed pitchers were more successful (i.e., opposing batters hit more poorly against them) when they were relatively rare in the population. Contrary to the predictions of this hypothesis, however, left-handed pitchers were more successful when they were relatively common. Both right- and left-handed batters performed better in years dominated by right-handed pitchers, despite the fact that right-handed batters perform relatively poorly against right-handed pitchers. I suggest that batters form cognitive representations based on pitcher handedness, and that these representations are strengthened by repeated exposure or priming. When the pitcher handedness polymorphism is more balanced (e.g., 67% right-handed, 33% left-handed), these cognitive representations are less effective, which leads to decreased batting averages and improved performance by all pitchers. Furthermore, these cognitive representations are likely to be more critical to the success of right-handed hitters, who have reduced visuomotor skills relative to left-handed hitters. PMID:18298283

  3. Finding genes on the X chromosome by which homo may have become sapiens

    SciTech Connect

    Turner, G.

    1996-06-01

    The map of the X chromosome is now littered, from one telomere to the other, with genes for mental handicap, alone or in combination with other features. In this issue of the journal, report such an entity from the Scottish Highlands, which they give the catchy title of {open_quotes}PPM-X syndrome,{close_quotes} denoting the association of pyramidal tract signs, psychosis, and macroorchidism with mental handicap (XLMR). They have localized this to Xq28 and discuss other genes in the same area, which include L1CAM (associated with MASA [mental retardation, aphasia, shuffling gait, and adducted thumbs] and X-linked hydrocephalus) and two genes for nonspecific XLMR-MRX3 and MRX25. It is also the localization of the gene for G6PD deficiency, which, in earlier studies, had demonstrated linkage to bipolar affective disorders, although this has been questioned in more recent studies. There may well be other families with this pattern of abnormalities who have remained undescribed because depression is so often not diagnosed in those with moderate mental handicap. The occurrence, in this family, of mental handicap with a bipolar disorder may be the chance association of two common disorders, or it may a significant association; at this stage, one cannot judge. 8 refs.

  4. CRYPTOSPORIDIUM HOMINIS N. SP (APICOMPLEXA : CRYPTOSPORIDIIDAE) FROM HOMO SAPIENS. (R826138)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  5. Frequency-dependent performance and handedness in professional baseball players (Homo sapiens).

    PubMed

    Clotfelter, Ethan D

    2008-02-01

    I used data on handedness and pitching and hitting performance in annual cohorts of professional baseball players (1957-2005) to test the hypothesis that handedness among pitchers was subject to negative frequency-dependent selection. As predicted by this hypothesis, right-handed pitchers were more successful (i.e., opposing batters hit more poorly against them) when they were relatively rare in the population. Contrary to the predictions of this hypothesis, however, left-handed pitchers were more successful when they were relatively common. Both right- and left-handed batters performed better in years dominated by right-handed pitchers, despite the fact that right-handed batters perform relatively poorly against right-handed pitchers. I suggest that batters form cognitive representations based on pitcher handedness, and that these representations are strengthened by repeated exposure or priming. When the pitcher handedness polymorphism is more balanced (e.g., 67% right-handed, 33% left-handed), these cognitive representations are less effective, which leads to decreased batting averages and improved performance by all pitchers. Furthermore, these cognitive representations are likely to be more critical to the success of right-handed hitters, who have reduced visuomotor skills relative to left-handed hitters.

  6. African Homo erectus: Old radiometric ages and young Oldowan assemblages in the middle Awash Valley, Ethiopia

    SciTech Connect

    Clark, J.D.; White, T.D.; Selassie, Y.H. ); Heinzelin, J. de ); Schick, K.D. ); Hart, W.K. ); WoldeGabriel, G. ); Walter, R.C. ); Suwa, G. ); Asfaw, B. )

    1994-06-24

    Fossils and artifacts recovered from the middle Awash Valley of Ethiopia's Afar depression sample the Middle Pleistocene transition from Homo erectus to Homo sapiens. Ar/Ar ages, biostratigraphy, and tephrachronology from this area indicate that the Pleistocene Bodo hominid cranium and newer specimens are approximately 0.6 million years old. Only Oldowan chopper and flake assemblages are present in the lower stratigraphic units but Acheulean bifacial artifacts are consistently prevalent and widespread in directly overlying deposits. This technological transition is related to a shift in sedimentary regime, supporting the hypothesis that Middle Pleistocene Oldowan assemblages represent a behavioral facies of the Acheulean industrial complex.

  7. The hand of Homo naledi.

    PubMed

    Kivell, Tracy L; Deane, Andrew S; Tocheri, Matthew W; Orr, Caley M; Schmid, Peter; Hawks, John; Berger, Lee R; Churchill, Steven E

    2015-01-01

    A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi. PMID:26441219

  8. The hand of Homo naledi

    PubMed Central

    Kivell, Tracy L.; Deane, Andrew S.; Tocheri, Matthew W.; Orr, Caley M.; Schmid, Peter; Hawks, John; Berger, Lee R.; Churchill, Steven E.

    2015-01-01

    A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi. PMID:26441219

  9. The hand of Homo naledi.

    PubMed

    Kivell, Tracy L; Deane, Andrew S; Tocheri, Matthew W; Orr, Caley M; Schmid, Peter; Hawks, John; Berger, Lee R; Churchill, Steven E

    2015-10-06

    A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi.

  10. Evolved developmental homeostasis disturbed in LB1 from Flores, Indonesia, denotes Down syndrome and not diagnostic traits of the invalid species Homo floresiensis.

    PubMed

    Henneberg, Maciej; Eckhardt, Robert B; Chavanaves, Sakdapong; Hsü, Kenneth J

    2014-08-19

    Human skeletons from Liang Bua Cave, Flores, Indonesia, are coeval with only Homo sapiens populations worldwide and no other previously known hominins. We report here for the first time to our knowledge the occipitofrontal circumference of specimen LB1. This datum makes it possible to link the 430-mL endocranial volume of LB1 reported by us previously, later confirmed independently by other investigators, not only with other human skeletal samples past and present but also with a large body of clinical data routinely collected on patients with developmental disorders. Our analyses show that the brain size of LB1 is in the range predicted for an individual with Down syndrome (DS) in a normal small-bodied population from the geographic region that includes Flores. Among additional diagnostic signs of DS and other skeletal dysplasiae are abnormally short femora combined with disproportionate flat feet. Liang Bua Cave femora, known only for LB1, match interlimb proportions for DS. Predictions based on corrected LB1 femur lengths show a stature normal for other H. sapiens populations in the region. PMID:25092311

  11. Evolved developmental homeostasis disturbed in LB1 from Flores, Indonesia, denotes Down syndrome and not diagnostic traits of the invalid species Homo floresiensis

    NASA Astrophysics Data System (ADS)

    Henneberg, Maciej; Eckhardt, Robert B.; Chavanaves, Sakdapong; Hsü, Kenneth J.

    2014-08-01

    Human skeletons from Liang Bua Cave, Flores, Indonesia, are coeval with only Homo sapiens populations worldwide and no other previously known hominins. We report here for the first time to our knowledge the occipitofrontal circumference of specimen LB1. This datum makes it possible to link the 430-mL endocranial volume of LB1 reported by us previously, later confirmed independently by other investigators, not only with other human skeletal samples past and present but also with a large body of clinical data routinely collected on patients with developmental disorders. Our analyses show that the brain size of LB1 is in the range predicted for an individual with Down syndrome (DS) in a normal small-bodied population from the geographic region that includes Flores. Among additional diagnostic signs of DS and other skeletal dysplasiae are abnormally short femora combined with disproportionate flat feet. Liang Bua Cave femora, known only for LB1, match interlimb proportions for DS. Predictions based on corrected LB1 femur lengths show a stature normal for other H. sapiens populations in the region.

  12. Evolved developmental homeostasis disturbed in LB1 from Flores, Indonesia, denotes Down syndrome and not diagnostic traits of the invalid species Homo floresiensis

    PubMed Central

    Henneberg, Maciej; Eckhardt, Robert B.; Chavanaves, Sakdapong; Hsü, Kenneth J.

    2014-01-01

    Human skeletons from Liang Bua Cave, Flores, Indonesia, are coeval with only Homo sapiens populations worldwide and no other previously known hominins. We report here for the first time to our knowledge the occipitofrontal circumference of specimen LB1. This datum makes it possible to link the 430-mL endocranial volume of LB1 reported by us previously, later confirmed independently by other investigators, not only with other human skeletal samples past and present but also with a large body of clinical data routinely collected on patients with developmental disorders. Our analyses show that the brain size of LB1 is in the range predicted for an individual with Down syndrome (DS) in a normal small-bodied population from the geographic region that includes Flores. Among additional diagnostic signs of DS and other skeletal dysplasiae are abnormally short femora combined with disproportionate flat feet. Liang Bua Cave femora, known only for LB1, match interlimb proportions for DS. Predictions based on corrected LB1 femur lengths show a stature normal for other H. sapiens populations in the region. PMID:25092311

  13. Rift Valley lake fish and shellfish provided brain-specific nutrition for early Homo.

    PubMed

    Broadhurst, C L; Cunnane, S C; Crawford, M A

    1998-01-01

    An abundant, balanced dietary intake of long-chain polyunsaturated fatty acids is an absolute requirement for sustaining the very rapid expansion of the hominid cerebral cortex during the last one to two million years. The brain contains 600 g lipid/kg, with a long-chain polyunsaturated fatty acid profile containing approximately equal proportions of arachidonic acid and docosahexaenoic acid. Long-chain polyunsaturated fatty acid deficiency at any stage of fetal and/or infant development can result in irreversible failure to accomplish specific components of brain growth. For the past fifteen million years, the East African Rift Valley has been a unique geological environment which contains many enormous freshwater lakes. Paleoanthropological evidence clearly indicates that hominids evolved in East Africa, and that early Homo inhabited the Rift Valley lake shores. Although earlier hominid species migrated to Eurasia, modern Homo sapiens is believed to have originated in Africa between 100 and 200 thousand years ago, and subsequently migrated throughout the world. A shift in the hominid resource base towards more high-quality foods occurred approximately two million years ago; this was accompanied by an increase in relative brain size and a shift towards modern patterns of fetal and infant development. There is evidence for both meat and fish scavenging, although sophisticated tool industries and organized hunting had not yet developed. The earliest occurrences of modern H. sapiens and sophisticated tool technology are associated with aquatic resource bases. Tropical freshwater fish and shellfish have long-chain polyunsaturated lipid ratios more similar to that of the human brain than any other food source known. Consistent consumption of lacustrine foods could have provided a means of initiating and sustaining cerebral cortex growth without an attendant increase in body mass. A modest intake of fish and shellfish (6-12% total dietary energy intake) can provide more

  14. Paleoanthropology: Homo erectus and the limits of a paleontological species.

    PubMed

    Hublin, Jean-Jacques

    2014-01-20

    The bushy nature of the human evolutionary tree in the past 3 million years is widely accepted. Yet, a spectacular new fossil of early Homo has prompted some paleoanthropologists to prune our family tree. PMID:24456983

  15. The Ethics of Using Transgenic Non-Human Primates to Study What Makes Us Human

    PubMed Central

    Coors, Marilyn E.; Glover, Jacqueline J.; Juengst, Eric T.; Sikela, James M.

    2010-01-01

    An ongoing flood of comparative genomic data is identifying human lineage specific (HLS) sequences of unknown function, and there is strong interest in investigating their functional effects. Transgenic apes, our closest evolutionary relative, have the highest potential to express HLS sequences as they are expressed in Homo sapiens and likewise experience harm from such transgenic research. These harms render the conduct of this research ethically unacceptable in apes, justifying regulatory barriers between these species and all other non-human primates for transgenic research. PMID:20717156

  16. Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa

    PubMed Central

    Berger, Lee R; Hawks, John; de Ruiter, Darryl J; Churchill, Steven E; Schmid, Peter; Delezene, Lucas K; Kivell, Tracy L; Garvin, Heather M; Williams, Scott A; DeSilva, Jeremy M; Skinner, Matthew M; Musiba, Charles M; Cameron, Noel; Holliday, Trenton W; Harcourt-Smith, William; Ackermann, Rebecca R; Bastir, Markus; Bogin, Barry; Bolter, Debra; Brophy, Juliet; Cofran, Zachary D; Congdon, Kimberly A; Deane, Andrew S; Dembo, Mana; Drapeau, Michelle; Elliott, Marina C; Feuerriegel, Elen M; Garcia-Martinez, Daniel; Green, David J; Gurtov, Alia; Irish, Joel D; Kruger, Ashley; Laird, Myra F; Marchi, Damiano; Meyer, Marc R; Nalla, Shahed; Negash, Enquye W; Orr, Caley M; Radovcic, Davorka; Schroeder, Lauren; Scott, Jill E; Throckmorton, Zachary; Tocheri, Matthew W; VanSickle, Caroline; Walker, Christopher S; Wei, Pianpian; Zipfel, Bernhard

    2015-01-01

    Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa. DOI: http://dx.doi.org/10.7554/eLife.09560.001 PMID:26354291

  17. The evolutionary relationships and age of Homo naledi: An assessment using dated Bayesian phylogenetic methods.

    PubMed

    Dembo, Mana; Radovčić, Davorka; Garvin, Heather M; Laird, Myra F; Schroeder, Lauren; Scott, Jill E; Brophy, Juliet; Ackermann, Rebecca R; Musiba, Chares M; de Ruiter, Darryl J; Mooers, Arne Ø; Collard, Mark

    2016-08-01

    Homo naledi is a recently discovered species of fossil hominin from South Africa. A considerable amount is already known about H. naledi but some important questions remain unanswered. Here we report a study that addressed two of them: "Where does H. naledi fit in the hominin evolutionary tree?" and "How old is it?" We used a large supermatrix of craniodental characters for both early and late hominin species and Bayesian phylogenetic techniques to carry out three analyses. First, we performed a dated Bayesian analysis to generate estimates of the evolutionary relationships of fossil hominins including H. naledi. Then we employed Bayes factor tests to compare the strength of support for hypotheses about the relationships of H. naledi suggested by the best-estimate trees. Lastly, we carried out a resampling analysis to assess the accuracy of the age estimate for H. naledi yielded by the dated Bayesian analysis. The analyses strongly supported the hypothesis that H. naledi forms a clade with the other Homo species and Australopithecus sediba. The analyses were more ambiguous regarding the position of H. naledi within the (Homo, Au. sediba) clade. A number of hypotheses were rejected, but several others were not. Based on the available craniodental data, Homo antecessor, Asian Homo erectus, Homo habilis, Homo floresiensis, Homo sapiens, and Au. sediba could all be the sister taxon of H. naledi. According to the dated Bayesian analysis, the most likely age for H. naledi is 912 ka. This age estimate was supported by the resampling analysis. Our findings have a number of implications. Most notably, they support the assignment of the new specimens to Homo, cast doubt on the claim that H. naledi is simply a variant of H. erectus, and suggest H. naledi is younger than has been previously proposed.

  18. The evolutionary relationships and age of Homo naledi: An assessment using dated Bayesian phylogenetic methods.

    PubMed

    Dembo, Mana; Radovčić, Davorka; Garvin, Heather M; Laird, Myra F; Schroeder, Lauren; Scott, Jill E; Brophy, Juliet; Ackermann, Rebecca R; Musiba, Chares M; de Ruiter, Darryl J; Mooers, Arne Ø; Collard, Mark

    2016-08-01

    Homo naledi is a recently discovered species of fossil hominin from South Africa. A considerable amount is already known about H. naledi but some important questions remain unanswered. Here we report a study that addressed two of them: "Where does H. naledi fit in the hominin evolutionary tree?" and "How old is it?" We used a large supermatrix of craniodental characters for both early and late hominin species and Bayesian phylogenetic techniques to carry out three analyses. First, we performed a dated Bayesian analysis to generate estimates of the evolutionary relationships of fossil hominins including H. naledi. Then we employed Bayes factor tests to compare the strength of support for hypotheses about the relationships of H. naledi suggested by the best-estimate trees. Lastly, we carried out a resampling analysis to assess the accuracy of the age estimate for H. naledi yielded by the dated Bayesian analysis. The analyses strongly supported the hypothesis that H. naledi forms a clade with the other Homo species and Australopithecus sediba. The analyses were more ambiguous regarding the position of H. naledi within the (Homo, Au. sediba) clade. A number of hypotheses were rejected, but several others were not. Based on the available craniodental data, Homo antecessor, Asian Homo erectus, Homo habilis, Homo floresiensis, Homo sapiens, and Au. sediba could all be the sister taxon of H. naledi. According to the dated Bayesian analysis, the most likely age for H. naledi is 912 ka. This age estimate was supported by the resampling analysis. Our findings have a number of implications. Most notably, they support the assignment of the new specimens to Homo, cast doubt on the claim that H. naledi is simply a variant of H. erectus, and suggest H. naledi is younger than has been previously proposed. PMID:27457542

  19. The earliest unequivocally modern humans in southern China.

    PubMed

    Liu, Wu; Martinón-Torres, María; Cai, Yan-jun; Xing, Song; Tong, Hao-wen; Pei, Shu-wen; Sier, Mark Jan; Wu, Xiao-hong; Edwards, R Lawrence; Cheng, Hai; Li, Yi-yuan; Yang, Xiong-xin; de Castro, José María Bermúdez; Wu, Xiu-jie

    2015-10-29

    The hominin record from southern Asia for the early Late Pleistocene epoch is scarce. Well-dated and well-preserved fossils older than ∼45,000 years that can be unequivocally attributed to Homo sapiens are lacking. Here we present evidence from the newly excavated Fuyan Cave in Daoxian (southern China). This site has provided 47 human teeth dated to more than 80,000 years old, and with an inferred maximum age of 120,000 years. The morphological and metric assessment of this sample supports its unequivocal assignment to H. sapiens. The Daoxian sample is more derived than any other anatomically modern humans, resembling middle-to-late Late Pleistocene specimens and even contemporary humans. Our study shows that fully modern morphologies were present in southern China 30,000-70,000 years earlier than in the Levant and Europe. Our data fill a chronological and geographical gap that is relevant for understanding when H. sapiens first appeared in southern Asia. The Daoxian teeth also support the hypothesis that during the same period, southern China was inhabited by more derived populations than central and northern China. This evidence is important for the study of dispersal routes of modern humans. Finally, our results are relevant to exploring the reasons for the relatively late entry of H. sapiens into Europe. Some studies have investigated how the competition with H. sapiens may have caused Neanderthals' extinction (see ref. 8 and references therein). Notably, although fully modern humans were already present in southern China at least as early as ∼80,000 years ago, there is no evidence that they entered Europe before ∼45,000 years ago. This could indicate that H. neanderthalensis was indeed an additional ecological barrier for modern humans, who could only enter Europe when the demise of Neanderthals had already started.

  20. The earliest unequivocally modern humans in southern China.

    PubMed

    Liu, Wu; Martinón-Torres, María; Cai, Yan-jun; Xing, Song; Tong, Hao-wen; Pei, Shu-wen; Sier, Mark Jan; Wu, Xiao-hong; Edwards, R Lawrence; Cheng, Hai; Li, Yi-yuan; Yang, Xiong-xin; de Castro, José María Bermúdez; Wu, Xiu-jie

    2015-10-29

    The hominin record from southern Asia for the early Late Pleistocene epoch is scarce. Well-dated and well-preserved fossils older than ∼45,000 years that can be unequivocally attributed to Homo sapiens are lacking. Here we present evidence from the newly excavated Fuyan Cave in Daoxian (southern China). This site has provided 47 human teeth dated to more than 80,000 years old, and with an inferred maximum age of 120,000 years. The morphological and metric assessment of this sample supports its unequivocal assignment to H. sapiens. The Daoxian sample is more derived than any other anatomically modern humans, resembling middle-to-late Late Pleistocene specimens and even contemporary humans. Our study shows that fully modern morphologies were present in southern China 30,000-70,000 years earlier than in the Levant and Europe. Our data fill a chronological and geographical gap that is relevant for understanding when H. sapiens first appeared in southern Asia. The Daoxian teeth also support the hypothesis that during the same period, southern China was inhabited by more derived populations than central and northern China. This evidence is important for the study of dispersal routes of modern humans. Finally, our results are relevant to exploring the reasons for the relatively late entry of H. sapiens into Europe. Some studies have investigated how the competition with H. sapiens may have caused Neanderthals' extinction (see ref. 8 and references therein). Notably, although fully modern humans were already present in southern China at least as early as ∼80,000 years ago, there is no evidence that they entered Europe before ∼45,000 years ago. This could indicate that H. neanderthalensis was indeed an additional ecological barrier for modern humans, who could only enter Europe when the demise of Neanderthals had already started. PMID:26466566

  1. [Mutation process in the protein-coding genes of human mitochondrial genome in context of evolution of the genus].

    PubMed

    Maliarchuk, B A

    2013-01-01

    The human mitochondrial genome, although it has a small size, is characterized by high level of variation, non-uniformly distributed in groups of nucleotide positions that differ in the degree of variability. Considering the mutation process in human mtDNA relative to the mitochondrial genomes of the genus Homo-neandertals, denisova hominin and other primate species, it appears that more than half (56.5%) variable positions in the human mtDNA protein-coding genes are characterized by back (reverse) mutations to the pre-H. sapiens state of mitochondrial genome. It has been found that hypervariable nucleotide positions show a minimal proportion of specific to H. sapiens mutations, and, conversely, a high proportion of mutations (both nucleotide and amino acid substitutions), leading to the loss of Homo-specific variants of polymorphisms. Most often, polymorphisms specific to H. sapiens arise in result of single forward mutations and disappear mainly due to multiple back mutations, including those in the mutational "hotspots". PMID:25509854

  2. Endurance running and the evolution of Homo.

    PubMed

    Bramble, Dennis M; Lieberman, Daniel E

    2004-11-18

    Striding bipedalism is a key derived behaviour of hominids that possibly originated soon after the divergence of the chimpanzee and human lineages. Although bipedal gaits include walking and running, running is generally considered to have played no major role in human evolution because humans, like apes, are poor sprinters compared to most quadrupeds. Here we assess how well humans perform at sustained long-distance running, and review the physiological and anatomical bases of endurance running capabilities in humans and other mammals. Judged by several criteria, humans perform remarkably well at endurance running, thanks to a diverse array of features, many of which leave traces in the skeleton. The fossil evidence of these features suggests that endurance running is a derived capability of the genus Homo, originating about 2 million years ago, and may have been instrumental in the evolution of the human body form.

  3. Endurance running and the evolution of Homo.

    PubMed

    Bramble, Dennis M; Lieberman, Daniel E

    2004-11-18

    Striding bipedalism is a key derived behaviour of hominids that possibly originated soon after the divergence of the chimpanzee and human lineages. Although bipedal gaits include walking and running, running is generally considered to have played no major role in human evolution because humans, like apes, are poor sprinters compared to most quadrupeds. Here we assess how well humans perform at sustained long-distance running, and review the physiological and anatomical bases of endurance running capabilities in humans and other mammals. Judged by several criteria, humans perform remarkably well at endurance running, thanks to a diverse array of features, many of which leave traces in the skeleton. The fossil evidence of these features suggests that endurance running is a derived capability of the genus Homo, originating about 2 million years ago, and may have been instrumental in the evolution of the human body form. PMID:15549097

  4. Cladistic analysis of early Homo crania from Swartkrans and Sterkfontein, South Africa.

    PubMed

    Smith, Heather F; Grine, Frederick E

    2008-05-01

    The phylogenetic relationships of early Pleistocene Homo crania from the South African sites of Swartkrans and Sterkfontein were investigated through cladistic analyses of 99 morphological characters. The Swartkrans Member 1 specimen SK 847 and the Stw 53 cranium from Sterkfontein Member 5A were treated as separate operational taxonomic units (OTUs), distinct from the three species of early Homo-H. erectus, H. habilis, and H. rudolfensis-that are recognized from the Plio-Pleistocene deposits of East Africa. The cladistic analyses differed in the treatment of the South African OTUs (separate Swartkrans and Sterkfontein OTUs vs. a single Swartkrans+Sterkfontein OTU). PAUP 4.0 was used to construct cladograms and address hypotheses about relationships. In the analysis that treated the South African specimens as a single OTU, the position of that OTU was stable as a separate branch on the Homo clade between H. rudolfensis and [H. habilis+(H. erectus+H. sapiens)]. When SK 847 and Stw 53 were treated as separate OTUs, the majority of most parsimonious trees indicated that they were positioned in similar positions as the combined South African Homo OTU; that is, as separate branches between H. rudolfensis and [H. habilis+(H. erectus+H. sapiens)], with the Swartkrans OTU generally occupying a more derived position. The position of the Sterkfontein OTU was more stable than that of the Swartkrans OTU, which was found in several other positions among the minimum length trees. Running the analyses with only those characters preserved by SK 847 and Stw 53 resulted in similar topologies for minimum length trees, although the positions of Stw 53, SK 847, and H. habilis exchanged places in some trees. In no case was an exclusive sister relationship between either South African OTU and a particular species of Homo supported statistically. Both South African OTUs differ from H. habilis in the fewest number of cladistic characters.

  5. Spinal cord evolution in early Homo.

    PubMed

    Meyer, Marc R; Haeusler, Martin

    2015-11-01

    The discovery at Nariokotome of the Homo erectus skeleton KNM-WT 15000, with a narrow spinal canal, seemed to show that this relatively large-brained hominin retained the primitive spinal cord size of African apes and that brain size expansion preceded postcranial neurological evolution. Here we compare the size and shape of the KNM-WT 15000 spinal canal with modern and fossil taxa including H. erectus from Dmanisi, Homo antecessor, the European middle Pleistocene hominins from Sima de los Huesos, and Pan troglodytes. In terms of shape and absolute and relative size of the spinal canal, we find all of the Dmanisi and most of the vertebrae of KNM-WT 15000 are within the human range of variation except for the C7, T2, and T3 of KNM-WT 15000, which are constricted, suggesting spinal stenosis. While additional fossils might definitively indicate whether H. erectus had evolved a human-like enlarged spinal canal, the evidence from the Dmanisi spinal canal and the unaffected levels of KNM-WT 15000 show that unlike Australopithecus, H. erectus had a spinal canal size and shape equivalent to that of modern humans. Subadult status is unlikely to affect our results, as spinal canal growth is complete in both individuals. We contest the notion that vertebrae yield information about respiratory control or language evolution, but suggest that, like H. antecessor and European middle Pleistocene hominins from Sima de los Huesos, early Homo possessed a postcranial neurological endowment roughly commensurate to modern humans, with implications for neurological, structural, and vascular improvements over Pan and Australopithecus. PMID:26553817

  6. Energetic consequences of being a Homo erectus female.

    PubMed

    Aiello, Leslie C; Key, Cathy

    2002-01-01

    Body size is one of the most important characteristics of any animal because it affects a range of behavioral, ecological, and physiological traits including energy requirements, choice of food, reproductive strategies, predation risk, range size, and locomotor style. This article focuses on the implications of being large bodied for Homo erectus females, estimated to have been over 50% heavier than average australopithecine females. The energy requirements of these hominins are modeled using data on activity patterns, body mass, and life history from living primates. Particular attention is given to the inferred energetic costs of reproduction for Homo erectus females based on chimpanzee and human reproductive scheduling. Daily energy requirements during gestation and lactation would have been significantly higher for Homo erectus females, as would total energetic cost per offspring if the australopithecines and Homo erectus had similar reproductive schedules (gestation and lactation lengths and interbirth intervals). Shortening the interbirth interval could considerably reduce the costs per offspring to Homo erectus and have the added advantage of increasing reproductive output. The mother would, however, incur additional daily costs of caring for the dependent offspring. If Homo erectus females adopted this reproductive strategy, it would necessarily imply a revolution in the way in which females obtained and utilized energy to support their increased energetic requirements. This transformation is likely to have occurred on several levels involving cooperative economic division of labor, locomotor energetics, menopause, organ size, and other physiological mechanisms for reducing the energetic load on females. PMID:12203811

  7. Energetic consequences of being a Homo erectus female.

    PubMed

    Aiello, Leslie C; Key, Cathy

    2002-01-01

    Body size is one of the most important characteristics of any animal because it affects a range of behavioral, ecological, and physiological traits including energy requirements, choice of food, reproductive strategies, predation risk, range size, and locomotor style. This article focuses on the implications of being large bodied for Homo erectus females, estimated to have been over 50% heavier than average australopithecine females. The energy requirements of these hominins are modeled using data on activity patterns, body mass, and life history from living primates. Particular attention is given to the inferred energetic costs of reproduction for Homo erectus females based on chimpanzee and human reproductive scheduling. Daily energy requirements during gestation and lactation would have been significantly higher for Homo erectus females, as would total energetic cost per offspring if the australopithecines and Homo erectus had similar reproductive schedules (gestation and lactation lengths and interbirth intervals). Shortening the interbirth interval could considerably reduce the costs per offspring to Homo erectus and have the added advantage of increasing reproductive output. The mother would, however, incur additional daily costs of caring for the dependent offspring. If Homo erectus females adopted this reproductive strategy, it would necessarily imply a revolution in the way in which females obtained and utilized energy to support their increased energetic requirements. This transformation is likely to have occurred on several levels involving cooperative economic division of labor, locomotor energetics, menopause, organ size, and other physiological mechanisms for reducing the energetic load on females.

  8. A re-examination of the human fossil specimen from Bački Petrovac (Serbia).

    PubMed

    Radović, Predrag; Lindal, Joshua Allan; Roksandic, Mirjana

    2014-08-01

    A fragmented human calotte was discovered during the early 1950s near Bački Petrovac (Serbia), in association with Palaeolithic stone tools. After its initial publication, the fossil specimen remained largely unknown outside of the Serbian academe and no detailed comparative study has ever been carried out. Since the whereabouts of the fossil itself are currently unknown, and given its potential significance for the Pleistocene human evolution, we re-examine the data published by Živanović (1966, 1975). Using the original measurements, mostly taken on the frontal bone, and a wide comparative sample of 68 fossil specimens, the fossil was compared and analyzed by statistical multivariate methods. We also conducted a visual examination of the morphology based on the available photographic material. Our analysis reveals phenetic similarity with Middle Pleistocene archaic Homo from Africa and anatomically modern Homo sapiens. However, the absence of primitive cranial traits in Bački Petrovac indicates a clear modern Homo sapiens designation. Although lost at the moment, there is a chance for the re-discovery of the fossil in the years to come. This would give us an opportunity to acquire absolute dates and to study the specimen in a more detailed manner.

  9. Human origins: Out of Africa

    PubMed Central

    Tattersall, Ian

    2009-01-01

    Our species, Homo sapiens, is highly autapomorphic (uniquely derived) among hominids in the structure of its skull and postcranial skeleton. It is also sharply distinguished from other organisms by its unique symbolic mode of cognition. The fossil and archaeological records combine to show fairly clearly that our physical and cognitive attributes both first appeared in Africa, but at different times. Essentially modern bony conformation was established in that continent by the 200–150 Ka range (a dating in good agreement with dates for the origin of H. sapiens derived from modern molecular diversity). The event concerned was apparently short-term because it is essentially unanticipated in the fossil record. In contrast, the first convincing stirrings of symbolic behavior are not currently detectable until (possibly well) after 100 Ka. The radical reorganization of gene expression that underwrote the distinctive physical appearance of H. sapiens was probably also responsible for the neural substrate that permits symbolic cognition. This exaptively acquired potential lay unexploited until it was “discovered” via a cultural stimulus, plausibly the invention of language. Modern humans appear to have definitively exited Africa to populate the rest of the globe only after both their physical and cognitive peculiarities had been acquired within that continent. PMID:19805256

  10. 78 FR 12330 - Determination of Regulatory Review Period for Purposes of Patent Extension; SAPIEN TRANSCATHETER...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-22

    ... Patent Extension; SAPIEN TRANSCATHETER HEART VALVE AGENCY: Food and Drug Administration, HHS. ACTION... SAPIEN TRANSCATHETER HEART VALVE and is publishing this notice of that determination as required by law... device, SAPIEN TRANSCATHETER HEART VALVE. SAPIEN TRANSCATHETER HEART VALVE is indicated for...

  11. Homo erectus at Trinil on Java used shells for tool production and engraving.

    PubMed

    Joordens, Josephine C A; d'Errico, Francesco; Wesselingh, Frank P; Munro, Stephen; de Vos, John; Wallinga, Jakob; Ankjærgaard, Christina; Reimann, Tony; Wijbrans, Jan R; Kuiper, Klaudia F; Mücher, Herman J; Coqueugniot, Hélène; Prié, Vincent; Joosten, Ineke; van Os, Bertil; Schulp, Anne S; Panuel, Michel; van der Haas, Victoria; Lustenhouwer, Wim; Reijmer, John J G; Roebroeks, Wil

    2015-02-12

    The manufacture of geometric engravings is generally interpreted as indicative of modern cognition and behaviour. Key questions in the debate on the origin of such behaviour are whether this innovation is restricted to Homo sapiens, and whether it has a uniquely African origin. Here we report on a fossil freshwater shell assemblage from the Hauptknochenschicht ('main bone layer') of Trinil (Java, Indonesia), the type locality of Homo erectus discovered by Eugène Dubois in 1891 (refs 2 and 3). In the Dubois collection (in the Naturalis museum, Leiden, The Netherlands) we found evidence for freshwater shellfish consumption by hominins, one unambiguous shell tool, and a shell with a geometric engraving. We dated sediment contained in the shells with (40)Ar/(39)Ar and luminescence dating methods, obtaining a maximum age of 0.54 ± 0.10 million years and a minimum age of 0.43 ± 0.05 million years. This implies that the Trinil Hauptknochenschicht is younger than previously estimated. Together, our data indicate that the engraving was made by Homo erectus, and that it is considerably older than the oldest geometric engravings described so far. Although it is at present not possible to assess the function or meaning of the engraved shell, this discovery suggests that engraving abstract patterns was in the realm of Asian Homo erectus cognition and neuromotor control. PMID:25470048

  12. Homo erectus at Trinil on Java used shells for tool production and engraving.

    PubMed

    Joordens, Josephine C A; d'Errico, Francesco; Wesselingh, Frank P; Munro, Stephen; de Vos, John; Wallinga, Jakob; Ankjærgaard, Christina; Reimann, Tony; Wijbrans, Jan R; Kuiper, Klaudia F; Mücher, Herman J; Coqueugniot, Hélène; Prié, Vincent; Joosten, Ineke; van Os, Bertil; Schulp, Anne S; Panuel, Michel; van der Haas, Victoria; Lustenhouwer, Wim; Reijmer, John J G; Roebroeks, Wil

    2015-02-12

    The manufacture of geometric engravings is generally interpreted as indicative of modern cognition and behaviour. Key questions in the debate on the origin of such behaviour are whether this innovation is restricted to Homo sapiens, and whether it has a uniquely African origin. Here we report on a fossil freshwater shell assemblage from the Hauptknochenschicht ('main bone layer') of Trinil (Java, Indonesia), the type locality of Homo erectus discovered by Eugène Dubois in 1891 (refs 2 and 3). In the Dubois collection (in the Naturalis museum, Leiden, The Netherlands) we found evidence for freshwater shellfish consumption by hominins, one unambiguous shell tool, and a shell with a geometric engraving. We dated sediment contained in the shells with (40)Ar/(39)Ar and luminescence dating methods, obtaining a maximum age of 0.54 ± 0.10 million years and a minimum age of 0.43 ± 0.05 million years. This implies that the Trinil Hauptknochenschicht is younger than previously estimated. Together, our data indicate that the engraving was made by Homo erectus, and that it is considerably older than the oldest geometric engravings described so far. Although it is at present not possible to assess the function or meaning of the engraved shell, this discovery suggests that engraving abstract patterns was in the realm of Asian Homo erectus cognition and neuromotor control.

  13. Transcranial sonography: a technique for the study of the temporal lobes of the human and non-human primate brain.

    PubMed

    Ruggiero, Marco; Magherini, Stefano; Fiore, Maria Giulia; Chiarelli, Brunetto; Morucci, Gabriele; Branca, Jacopo Junio Valerio; Gulisano, Massimo; Pacini, Stefania

    2013-01-01

    We developed a modified transcranial sonography technique to study the morphology of the temporal lobe, a brain region involved in language, memory and social functions in humans that can be visualized in correspondence of the acoustic window of the temporal squama. Previous studies raise the possibility that a unique derived feature of Homo sapiens is a relatively larger temporal lobe compared to those of other hominins and apes. Such a brain reorganization might have contributed to the evolution of various "higher" cognitive functions of Homo sapiens, including language. Hence, the importance of further comparative analyses of the temporal region. With the technique that we developed we were able to study the meninges, the subarachnoidal space and the cortex of the human temporal lobe. The spatial resolution and the ability to visualize structures of 200-300 microm size led us to hypothesize that the linear structures parallel to the subarachnoidal space might be referred to the neuronal layers of the cortex. The low cost, simplicity and safety of the procedure suggest that this technique may have a significant potential in the comparative study of the primate temporal lobe. Furthermore, the procedure described here can also be used for the study of vascularization of the meninges, in order to better understand the evolutionary relationships between the neurocranial shape and the middle meningeal vessels in living and fossil human species.

  14. From Australopithecus to Homo: the transition that wasn't.

    PubMed

    Kimbel, William H; Villmoare, Brian

    2016-07-01

    Although the transition from Australopithecus to Homo is usually thought of as a momentous transformation, the fossil record bearing on the origin and earliest evolution of Homo is virtually undocumented. As a result, the poles of the transition are frequently attached to taxa (e.g. A. afarensis, at ca 3.0 Ma versus H. habilis or H. erectus, at ca 2.0-1.7 Ma) in which substantial adaptive differences have accumulated over significant spans of independent evolution. Such comparisons, in which temporally remote and adaptively divergent species are used to identify a 'transition', lend credence to the idea that genera should be conceived at once as monophyletic clades and adaptively unified grades. However, when the problem is recast in terms of lineages, rather than taxa per se, the adaptive criterion becomes a problem of subjectively privileging 'key' characteristics from what is typically a stepwise pattern of acquisition of novel characters beginning in the basal representatives of a clade. This is the pattern inferred for species usually included in early Homo, including H. erectus, which has often been cast in the role as earliest humanlike hominin. A fresh look at brain size, hand morphology and earliest technology suggests that a number of key Homo attributes may already be present in generalized species of Australopithecus, and that adaptive distinctions in Homo are simply amplifications or extensions of ancient hominin trends.This article is part of the themed issue 'Major transitions in human evolution'. PMID:27298460

  15. The Path of Human Evolution

    NASA Astrophysics Data System (ADS)

    Feibel, C. S.

    2004-12-01

    A complex series of evolutionary steps, contingent upon a dynamic environmental context and a long biological heritage, have led to the ascent of Homo sapiens as a dominant component of the modern biosphere. In a field where missing links still abound and new discoveries regularly overturn theoretical paradigms, our understanding of the path of human evolution has made tremendous advances in recent years. Two major trends characterize the development of the hominin clade subsequent to its origins with the advent of upright bipedalism in the Late Miocene of Africa. One is a diversification into two prominent morphological branches, each with a series of 'twigs' representing evolutionary experimentation at the species or subspecies level. The second important trend, which in its earliest manifestations cannot clearly be ascribed to one or the other branch, is the behavioral complexity of an increasing reliance on technology to expand upon limited inherent morphological specializations and to buffer the organism from its environment. This technological dependence is directly associated with the expansion of hominin range outside Africa by the genus Homo, and is accelerated in the sole extant form Homo sapiens through the last 100 Ka. There are interesting correlates between the evolutionary and behavioral patterns seen in the hominin clade and environmental dynamics of the Neogene. In particular, the tempo of morphological and behavioral innovation may be tracking major events in Neogene climatic development as well as reflecting intervals of variability or stability. Major improvements in analytical techniques, coupled with important new collections and a growing body of contextual data are now making possible the integration of global, regional and local environmental archives with an improved biological understanding of the hominin clade to address questions of coincidence and causality.

  16. The Homo floresiensis cranium (LB1): Size, scaling, and early Homo affinities

    PubMed Central

    Gordon, Adam D.; Nevell, Lisa; Wood, Bernard

    2008-01-01

    The skeletal remains of a diminutive small-brained hominin found in Late Pleistocene cave deposits on the island of Flores, Indonesia were assigned to a new species, Homo floresiensis [Brown P, et al. (2004) A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia. Nature 431: 1055–1061]. A dramatically different interpretation is that this material belongs not to a novel hominin taxon but to a population of small-bodied modern humans affected, or unaffected, by microcephaly. The debate has primarily focused on the size and shape of the endocranial cavity of the type specimen, LB1, with less attention being paid to the morphological evidence provided by the rest of the LB1 cranium and postcranium, and no study thus far has addressed the problem of how scaling would affect shape comparisons between a diminutive cranium like LB1 and the much larger crania of modern humans. We show that whether or not the effects of its small cranial size are accounted for, the external cranial morphology of the LB1 cranium cannot be accommodated within a large global sample of normal modern human crania. Instead, the shape of LB1, which is shown by multivariate analysis to differ significantly from that of modern humans, is similar to that of Homo erectus sensu lato, and, to a lesser extent, Homo habilis. Our results are consistent with hypotheses that suggest the Liang Bua specimens represent a diminutive population closely related to either early H. erectus s. l. from East Africa and/or Dmanisi or to H. habilis. PMID:18356300

  17. Cranial growth in Homo erectus: how credible are the Ngandong juveniles?

    PubMed

    Antón, S C

    1999-02-01

    Confusion exists regarding the developmental ages of numerous Asian and southeast Asian Homo erectus fossils because of Weidenreich's contention that Pithecanthropus fused its sutures prematurely relative to H. sapiens. I reevaluate the cranial developmental ages of the Ngandong "juveniles" (2, 5, 8, 9) based on a series of indicators of youth (superstructure development, suture development/fusion, and cranial thickness) and cranial contours. The Ngandong juveniles are compared with H. sapiens adults (n = 281) and subadults (n = 81) and with Ngandong and other H. erectus adults (n = 20) and subadults (n = 4). Cranial contours are assessed using bivariate plots of arc vs. chord measurements. All indicators suggest that Ngandong 5 and 9 are adults, whereas Ngandong 8 is an older juvenile or young adult and Ngandong 2 is a juvenile with a developmental age range of greater than 6 and less than 11 years. In addition, adult cranial contours and the pattern of contour development are similar between Ngandong adults and other H. erectus adults. There is nothing in the cranial contour data to suggest that Ngandong is, despite a relatively large brain, transitional in vault shape between H. erectus and H. sapiens.

  18. Neanderthal brain size at birth provides insights into the evolution of human life history

    PubMed Central

    Ponce de León, Marcia S.; Golovanova, Lubov; Doronichev, Vladimir; Romanova, Galina; Akazawa, Takeru; Kondo, Osamu; Ishida, Hajime; Zollikofer, Christoph P. E.

    2008-01-01

    From birth to adulthood, the human brain expands by a factor of 3.3, compared with 2.5 in chimpanzees [DeSilva J and Lesnik J (2006) Chimpanzee neonatal brain size: Implications for brain growth in Homo erectus. J Hum Evol 51: 207–212]. How the required extra amount of human brain growth is achieved and what its implications are for human life history and cognitive development are still a matter of debate. Likewise, because comparative fossil evidence is scarce, when and how the modern human pattern of brain growth arose during evolution is largely unknown. Virtual reconstructions of a Neanderthal neonate from Mezmaiskaya Cave (Russia) and of two Neanderthal infant skeletons from Dederiyeh Cave (Syria) now provide new comparative insights: Neanderthal brain size at birth was similar to that in recent Homo sapiens and most likely subject to similar obstetric constraints. Neanderthal brain growth rates during early infancy were higher, however. This pattern of growth resulted in larger adult brain sizes but not in earlier completion of brain growth. Because large brains growing at high rates require large, late-maturing, mothers [Leigh SR and Blomquist GE (2007) in Campbell CJ et al. Primates in perspective; pp 396–407], it is likely that Neanderthal life history was similarly slow, or even slower-paced, than in recent H. sapiens. PMID:18779579

  19. Out of Africa: modern human origins special feature: human origins: out of Africa.

    PubMed

    Tattersall, Ian

    2009-09-22

    Our species, Homo sapiens, is highly autapomorphic (uniquely derived) among hominids in the structure of its skull and postcranial skeleton. It is also sharply distinguished from other organisms by its unique symbolic mode of cognition. The fossil and archaeological records combine to show fairly clearly that our physical and cognitive attributes both first appeared in Africa, but at different times. Essentially modern bony conformation was established in that continent by the 200-150 Ka range (a dating in good agreement with dates for the origin of H. sapiens derived from modern molecular diversity). The event concerned was apparently short-term because it is essentially unanticipated in the fossil record. In contrast, the first convincing stirrings of symbolic behavior are not currently detectable until (possibly well) after 100 Ka. The radical reorganization of gene expression that underwrote the distinctive physical appearance of H. sapiens was probably also responsible for the neural substrate that permits symbolic cognition. This exaptively acquired potential lay unexploited until it was "discovered" via a cultural stimulus, plausibly the invention of language. Modern humans appear to have definitively exited Africa to populate the rest of the globe only after both their physical and cognitive peculiarities had been acquired within that continent.

  20. Late Pleistocene climate drivers of early human migration

    NASA Astrophysics Data System (ADS)

    Timmermann, Axel; Friedrich, Tobias

    2016-10-01

    On the basis of fossil and archaeological data it has been hypothesized that the exodus of Homo sapiens out of Africa and into Eurasia between ~50–120 thousand years ago occurred in several orbitally paced migration episodes. Crossing vegetated pluvial corridors from northeastern Africa into the Arabian Peninsula and the Levant and expanding further into Eurasia, Australia and the Americas, early H. sapiens experienced massive time-varying climate and sea level conditions on a variety of timescales. Hitherto it has remained difficult to quantify the effect of glacial- and millennial-scale climate variability on early human dispersal and evolution. Here we present results from a numerical human dispersal model, which is forced by spatiotemporal estimates of climate and sea level changes over the past 125 thousand years. The model simulates the overall dispersal of H. sapiens in close agreement with archaeological and fossil data and features prominent glacial migration waves across the Arabian Peninsula and the Levant region around 106–94, 89–73, 59–47 and 45–29 thousand years ago. The findings document that orbital-scale global climate swings played a key role in shaping Late Pleistocene global population distributions, whereas millennial-scale abrupt climate changes, associated with Dansgaard–Oeschger events, had a more limited regional effect.

  1. Human evolution: taxonomy and paleobiology

    PubMed Central

    WOOD, BERNARD; RICHMOND, BRIAN G.

    2000-01-01

    This review begins by setting out the context and the scope of human evolution. Several classes of evidence, morphological, molecular, and genetic, support a particularly close relationship between modern humans and the species within the genus Pan, the chimpanzee. Thus human evolution is the study of the lineage, or clade, comprising species more closely related to modern humans than to chimpanzees. Its stem species is the so-called ‘common hominin ancestor’, and its only extant member is Homo sapiens. This clade contains all the species more closely-related to modern humans than to any other living primate. Until recently, these species were all subsumed into a family, Hominidae, but this group is now more usually recognised as a tribe, the Hominini. The rest of the review sets out the formal nomenclature, history of discovery, and information about the characteristic morphology, and its behavioural implications, of the species presently included in the human clade. The taxa are considered within their assigned genera, beginning with the most primitive and finishing with Homo. Within genera, species are presented in order of geological age. The entries conclude with a list of the more important items of fossil evidence, and a summary of relevant taxonomic issues. PMID:10999270

  2. Hominid mandibular corpus shape variation and its utility for recognizing species diversity within fossil Homo

    PubMed Central

    Lague, Michael R; Collard, Nicole J; Richmond, Brian G; Wood, Bernard A

    2008-01-01

    Mandibular corpora are well represented in the hominin fossil record, yet few studies have rigorously assessed the utility of mandibular corpus morphology for species recognition, particularly with respect to the linear dimensions that are most commonly available. In this study, we explored the extent to which commonly preserved mandibular corpus morphology can be used to: (i) discriminate among extant hominid taxa and (ii) support species designations among fossil specimens assigned to the genus Homo. In the first part of the study, discriminant analysis was used to test for significant differences in mandibular corpus shape at different taxonomic levels (genus, species and subspecies) among extant hominid taxa (i.e. Homo, Pan, Gorilla, Pongo). In the second part of the study, we examined shape variation among fossil mandibles assigned to Homo(including H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster, late African H. erectus, Asian H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens). A novel randomization procedure designed for small samples (and using group ‘distinctness values’) was used to determine whether shape variation among the fossils is consistent with conventional taxonomy (or alternatively, whether a priori taxonomic groupings are completely random with respect to mandibular morphology). The randomization of ‘distinctness values’ was also used on the extant samples to assess the ability of the test to recognize known taxa. The discriminant analysis results demonstrated that, even for a relatively modest set of traditional mandibular corpus measurements, we can detect significant differences among extant hominids at the genus and species levels, and, in some cases, also at the subspecies level. Although the randomization of ‘distinctness values’ test is more conservative than discriminant analysis (based on comparisons with extant specimens), we were able to detect at least four distinct groups

  3. Choice behavior of pigeons (Columba livia), college students, and preschool children (Homo sapiens) in the Monty Hall dilemma.

    PubMed

    Mazur, James E; Kahlbaugh, Patricia E

    2012-11-01

    In the Monty Hall dilemma, an individual chooses between three options, only one of which will deliver a prize. After the initial choice, one of the nonchosen options is revealed as a losing option, and the individual can choose to stay with the original choice or switch to the other remaining option. Previous studies have found that most adults stay with their initial choice, although the chances of winning are 2/3 for switching and 1/3 for staying. Pigeons, college students, and preschool children were given many trials on this task to examine how their choices might change with experience. The college students began to switch on a majority of trials much sooner than the pigeons, contrary to the findings by Herbranson and Schroeder (2010) that pigeons perform better than people on this task. In all three groups, some individuals approximated the optimal strategy of switching on every trial, but most did not. Many of the preschoolers immediately showed a pattern of always switching or always staying and continued this pattern throughout the experiment. In a condition where the probability of winning was 90% after a switch, all college students and all but one pigeon learned to switch on nearly every trial. The results suggest that one main impediment to learning the optimal strategy in the Monty Hall task, even after repeated trials, is the difficulty in discriminating the different reinforcement probabilities for switching versus staying.

  4. A short-term longitudinal study of preschoolers' (Homo sapiens) sex segregation: the role of physical activity, sex, and time.

    PubMed

    Pellegrini, Anthony D; Long, Jeffrey D; Roseth, Cary J; Bohn, Catherine M; Van Ryzin, Mark

    2007-08-01

    The interactive influence of preschool children's level of physical activity, sex, and time on the degree of sex segregation was assessed. A sample of nursery school children was observed across much of a school year, and levels of physical activity and sex segregation were sampled during their free play periods. Following sexual selection theory, we predicted a Sex X Time X Physical Activity interaction on segregation such that high-activity girls early in the school year would interact with boys but, with time, the high-activity girls would be segregated among themselves. Boys (both high- and low-activity) should remain segregated across the year. The hypothesis was supported, and results are discussed in terms of the interactive role of biology and socialization on sex segregation. PMID:17696654

  5. How We Got Here: Evolutionary Changes in Skull Shape in Humans & Their Ancestors

    ERIC Educational Resources Information Center

    Price, Rebecca M.

    2012-01-01

    This activity uses inquiry to investigate how large changes in shape can evolve from small changes in the timing of development. Students measure skull shape in fetal, infant, juvenile, and adult chimpanzees and compare them to adult skulls of "Homo sapiens," "Homo erectus," and "Australopithecus afarensis." They conclude by re-interpreting their…

  6. The craniomandibular mechanics of being human.

    PubMed

    Wroe, Stephen; Ferrara, Toni L; McHenry, Colin R; Curnoe, Darren; Chamoli, Uphar

    2010-12-01

    Diminished bite force has been considered a defining feature of modern Homo sapiens, an interpretation inferred from the application of two-dimensional lever mechanics and the relative gracility of the human masticatory musculature and skull. This conclusion has various implications with regard to the evolution of human feeding behaviour. However, human dental anatomy suggests a capacity to withstand high loads and two-dimensional lever models greatly simplify muscle architecture, yielding less accurate results than three-dimensional modelling using multiple lines of action. Here, to our knowledge, in the most comprehensive three-dimensional finite element analysis performed to date for any taxon, we ask whether the traditional view that the bite of H. sapiens is weak and the skull too gracile to sustain high bite forces is supported. We further introduce a new method for reconstructing incomplete fossil material. Our findings show that the human masticatory apparatus is highly efficient, capable of producing a relatively powerful bite using low muscle forces. Thus, relative to other members of the superfamily Hominoidea, humans can achieve relatively high bite forces, while overall stresses are reduced. Our findings resolve apparently discordant lines of evidence, i.e. the presence of teeth well adapted to sustain high loads within a lightweight cranium and mandible.

  7. Biomechanics of the hip and birth in early Homo.

    PubMed

    Ruff, C B

    1995-12-01

    A complex of traits in the femur and pelvis of Homo erectus and early "erectus-like" specimens has been described, but never satisfactorily explained. Here the functional relationships between pelvic and femoral structure in humans are explored using both theoretical biomechanical models and empirical tests within modern samples of diverse body form (Pecos Amerindians, East Africans). Results indicate that a long femoral neck increases mediolateral bending of the femoral diaphysis and decreases gluteal abductor and hip joint reaction forces. Increasing biacetabular breadth along with femoral neck length further increases M-L bending of the femoral shaft and maintains abductor and joint reaction forces at near "normal" levels. When compared to modern humans, Homo erectus and early "erectus-like" specimens are characterized by a long femoral neck and greatly increased M-L relative to A-P bending strength of the femoral shaft, coupled with no decrease in hip joint size and a probable increase in abductor force relative to body size. All of this strongly suggests that biacetabular breadth as well as femoral neck length was relatively large in early Homo. Several features preserved in early Homo partial hip bones also indicate that the true (lower) pelvis was very M-L broad, as well as A-P narrow. This is similar to the lower pelvic shape of australopithecines and suggests that nonrotational birth, in which the newborn's head is oriented transversely through the pelvic outlet, characterized early Homo as well as Australopithecus. Because M-L breadth of the pelvis is constrained by other factors, this may have limited increases in cranial capacity within Homo until rotational birth was established during the late Middle Pleistocene. During or after the transition to rotational birth biacetabular breadth decreased, reducing the body weight moment arm about the hip and allowing femoral neck length (abductor moment arm) to also decrease, both of which reduced M-L bending of

  8. The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia

    PubMed Central

    Indriati, Etty; Swisher, Carl C.; Lepre, Christopher; Quinn, Rhonda L.; Suriyanto, Rusyad A.; Hascaryo, Agus T.; Grün, Rainer; Feibel, Craig S.; Pobiner, Briana L.; Aubert, Maxime; Lees, Wendy; Antón, Susan C.

    2011-01-01

    Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35–50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the “20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/−17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted. PMID:21738710

  9. The age of the 20 meter Solo River terrace, Java, Indonesia and the survival of Homo erectus in Asia.

    PubMed

    Indriati, Etty; Swisher, Carl C; Lepre, Christopher; Quinn, Rhonda L; Suriyanto, Rusyad A; Hascaryo, Agus T; Grün, Rainer; Feibel, Craig S; Pobiner, Briana L; Aubert, Maxime; Lees, Wendy; Antón, Susan C

    2011-01-01

    Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35-50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report (40)Ar/(39)Ar incremental heating analyses and new ESR/U-series age estimates from the "20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The (40)Ar/(39)Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/-17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and (40)Ar/(39)Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted.

  10. Homo floresiensis and the evolution of the hominin shoulder.

    PubMed

    Larson, Susan G; Jungers, William L; Morwood, Michael J; Sutikna, Thomas; Jatmiko; Saptomo, E Wahyu; Due, Rokus Awe; Djubiantono, Tony

    2007-12-01

    The holotype of Homo floresiensis, diminutive hominins with tiny brains living until 12,000 years ago on the island of Flores, is a partial skeleton (LB1) that includes a partial clavicle (LB1/5) and a nearly complete right humerus (LB1/50). Although the humerus appears fairly modern in most regards, it is remarkable in displaying only 110 degrees of humeral torsion, well below modern human average values. Assuming a modern human shoulder configuration, such a low degree of humeral torsion would result in a lateral set to the elbow. Such an elbow joint would function more nearly in a frontal than in a sagittal plane, and this is certainly not what anyone would have predicted for a tool-making Pleistocene hominin. We argue that Homo floresiensis probably did not have a modern human shoulder configuration: the clavicle was relatively short, and we suggest that the scapula was more protracted, resulting in a glenoid fossa that faced anteriorly rather than laterally. A posteriorly directed humeral head was therefore appropriate for maintaining a normally functioning elbow joint. Similar morphology in the Homo erectus Nariokotome boy (KNM-WT 15000) suggests that this shoulder configuration may represent a transitional stage in pectoral girdle evolution in the human lineage.

  11. Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa.

    PubMed

    Dirks, Paul H G M; Berger, Lee R; Roberts, Eric M; Kramers, Jan D; Hawks, John; Randolph-Quinney, Patrick S; Elliott, Marina; Musiba, Charles M; Churchill, Steven E; de Ruiter, Darryl J; Schmid, Peter; Backwell, Lucinda R; Belyanin, Georgy A; Boshoff, Pedro; Hunter, K Lindsay; Feuerriegel, Elen M; Gurtov, Alia; Harrison, James du G; Hunter, Rick; Kruger, Ashley; Morris, Hannah; Makhubela, Tebogo V; Peixotto, Becca; Tucker, Steven

    2015-01-01

    We describe the physical context of the Dinaledi Chamber within the Rising Star cave, South Africa, which contains the fossils of Homo naledi. Approximately 1550 specimens of hominin remains have been recovered from at least 15 individuals, representing a small portion of the total fossil content. Macro-vertebrate fossils are exclusively H. naledi, and occur within clay-rich sediments derived from in situ weathering, and exogenous clay and silt, which entered the chamber through fractures that prevented passage of coarser-grained material. The chamber was always in the dark zone, and not accessible to non-hominins. Bone taphonomy indicates that hominin individuals reached the chamber complete, with disarticulation occurring during/after deposition. Hominins accumulated over time as older laminated mudstone units and sediment along the cave floor were eroded. Preliminary evidence is consistent with deliberate body disposal in a single location, by a hominin species other than Homo sapiens, at an as-yet unknown date.

  12. The spread of modern humans in Europe

    PubMed Central

    Hoffecker, John F.

    2009-01-01

    The earliest credible evidence of Homo sapiens in Europe is an archaeological proxy in the form of several artifact assemblages (Bohunician) found in South-Central and possibly Eastern Europe, dating to ≤48,000 calibrated radiocarbon years before present (cal BP). They are similar to assemblages probably made by modern humans in the Levant (Emiran) at an earlier date and apparently represent a population movement into the Balkans during a warm climate interval [Greenland Interstadial 12 (GI 12)]. A second population movement may be represented by a diverse set of artifact assemblages (sometimes termed Proto-Aurignacian) found in the Balkans, parts of Southwest Europe, and probably in Eastern Europe, and dating to several brief interstadials (GI 11–GI 9) that preceded the beginning of cold Heinrich Event 4 (HE4) (≈40,000 cal BP). They are similar to contemporaneous assemblages made by modern humans in the Levant (Ahmarian). The earliest known human skeletal remains in Europe that may be unequivocally assigned to H. sapiens (Peçstera cu Oase, Romania) date to this time period (≈42,000 cal BP) but are not associated with artifacts. After the Campanian Ignimbrite volcanic eruption (40,000 cal BP) and the beginning of HE4, artifact assemblages assigned to the classic Aurignacian, an industry associated with modern human skeletal remains that seems to have developed in Europe, spread throughout the continent. PMID:19571003

  13. Out of Africa: modern human origins special feature: the spread of modern humans in Europe.

    PubMed

    Hoffecker, John F

    2009-09-22

    The earliest credible evidence of Homo sapiens in Europe is an archaeological proxy in the form of several artifact assemblages (Bohunician) found in South-Central and possibly Eastern Europe, dating to < or =48,000 calibrated radiocarbon years before present (cal BP). They are similar to assemblages probably made by modern humans in the Levant (Emiran) at an earlier date and apparently represent a population movement into the Balkans during a warm climate interval [Greenland Interstadial 12 (GI 12)]. A second population movement may be represented by a diverse set of artifact assemblages (sometimes termed Proto-Aurignacian) found in the Balkans, parts of Southwest Europe, and probably in Eastern Europe, and dating to several brief interstadials (GI 11-GI 9) that preceded the beginning of cold Heinrich Event 4 (HE4) (approximately 40,000 cal BP). They are similar to contemporaneous assemblages made by modern humans in the Levant (Ahmarian). The earliest known human skeletal remains in Europe that may be unequivocally assigned to H. sapiens (Peçstera cu Oase, Romania) date to this time period (approximately 42,000 cal BP) but are not associated with artifacts. After the Campanian Ignimbrite volcanic eruption (40,000 cal BP) and the beginning of HE4, artifact assemblages assigned to the classic Aurignacian, an industry associated with modern human skeletal remains that seems to have developed in Europe, spread throughout the continent. PMID:19571003

  14. Out of Africa: modern human origins special feature: the spread of modern humans in Europe.

    PubMed

    Hoffecker, John F

    2009-09-22

    The earliest credible evidence of Homo sapiens in Europe is an archaeological proxy in the form of several artifact assemblages (Bohunician) found in South-Central and possibly Eastern Europe, dating to < or =48,000 calibrated radiocarbon years before present (cal BP). They are similar to assemblages probably made by modern humans in the Levant (Emiran) at an earlier date and apparently represent a population movement into the Balkans during a warm climate interval [Greenland Interstadial 12 (GI 12)]. A second population movement may be represented by a diverse set of artifact assemblages (sometimes termed Proto-Aurignacian) found in the Balkans, parts of Southwest Europe, and probably in Eastern Europe, and dating to several brief interstadials (GI 11-GI 9) that preceded the beginning of cold Heinrich Event 4 (HE4) (approximately 40,000 cal BP). They are similar to contemporaneous assemblages made by modern humans in the Levant (Ahmarian). The earliest known human skeletal remains in Europe that may be unequivocally assigned to H. sapiens (Peçstera cu Oase, Romania) date to this time period (approximately 42,000 cal BP) but are not associated with artifacts. After the Campanian Ignimbrite volcanic eruption (40,000 cal BP) and the beginning of HE4, artifact assemblages assigned to the classic Aurignacian, an industry associated with modern human skeletal remains that seems to have developed in Europe, spread throughout the continent.

  15. What happened in the origin of human consciousness?

    PubMed

    Tattersall, Ian

    2004-01-01

    At some point in its evolutionary history, our species Homo sapiens ceased to be a nonlinguistic, nonsymbolic organism, living in the world as presented to it by Nature, and instead began to exist in a world that it reconstructs in its own mind. Most scientists since Darwin have been content to explain this extraordinary transformation in human consciousness by the operation of natural selection. However, the human fossil and archaeological records indicate that modern human symbolic consciousness is not the culmination of the long trend that natural selection would predict. Instead, it shows that major change in the human past has been episodic and rare and that, as far as can be determined from the archaeological record, the passage from nonsymbolic to symbolic cognition is a recent event as well as an unprecedented one. So recent, indeed, that it significantly postdates the acquisition of modern human anatomy as expressed in skeletal structure. It, thus, appears most likely that the biological (neural) capacity underwriting the radically new behavioral mode arose as an incidental exaptation in the same process that produced the new skeletal structure of Homo sapiens, but that it lay unexpressed until it was "discovered" by means of a cultural innovation, plausibly the invention of language. As in the case of the modern anatomical structure, it appears that the new capacity was initially expressed in Africa and that its various behavioral potentials were sequentially discovered in a drawn-out process that is continuing today. An "accidental" origin of the human capacity helps understand why so many human behaviors have proven self-destructive and contradictory, a feature of our species that reductionist, selection-based scenarios are hard-put to explain.

  16. Morphological and population genomic evidence that human faces have evolved to signal individual identity

    PubMed Central

    Nachman, Michael W

    2014-01-01

    Facial recognition plays a key role in human interactions, and there has been great interest in understanding the evolution of human abilities for individual recognition and tracking social relationships. Individual recognition requires sufficient cognitive abilities and phenotypic diversity within a population for discrimination to be possible. Despite the importance of facial recognition in humans, the evolution of facial identity has received little attention. Here we demonstrate that faces evolved to signal individual identity under negative frequency-dependent selection. Faces show elevated phenotypic variation and lower between-trait correlations compared to other traits. Regions surrounding face-associated SNPs show elevated diversity consistent with frequency-dependent selection. Genetic variation maintained by identity signaling tends to be shared across populations and, for some loci, predates the origin of Homo sapiens. Studies of human social evolution tend to emphasize cognitive adaptations but we show that social evolution has shaped patterns of human phenotypic and genetic diversity as well. PMID:25226282

  17. Transcatheter Aortic Valve Implantation Experience with SAPIEN 3.

    PubMed

    Ohno, Y; Tamburino, C; Barbanti, M

    2015-06-01

    Based on randomized trials with first generation devices, transcatheter aortic valve replacement (TAVI) has been included into the treatment strategy for high-risk and inoperable patients with severe aortic stenosis. Procedural complications remain a concern with TAVI, including stroke, vascular complications, paravalvular leak (PVL) and conduction disturbances. Addressing these limitations will support TAVI use in lower risk populations. This review discussed features and most recent clinical evidence of the new balloon-expandable THV (SAPIEN 3, Edwards Lifescience, Irvine, CA, USA). PMID:25900559

  18. Evolution and dispersal of the genus Homo: A landscape approach.

    PubMed

    Winder, Isabelle C; Devès, Maud H; King, Geoffrey C P; Bailey, Geoffrey N; Inglis, Robyn H; Meredith-Williams, Matthew

    2015-10-01

    The notion of the physical landscape as an arena of ecological interaction and human evolution is a powerful one, but its implementation at larger geographical and temporal scales is hampered by the challenges of reconstructing physical landscape settings in the geologically active regions where the earliest evidence is concentrated. We argue that the inherently dynamic nature of these unstable landscapes has made them important agents of biological change, creating complex topographies capable of selecting for, stimulating, obstructing or accelerating the latent and emerging properties of the human evolutionary trajectory. We use this approach, drawing on the concepts and methods of active tectonics, to develop a new perspective on the origins and dispersal of the Homo genus. We show how complex topography provides an easy evolutionary pathway to full terrestrialisation in the African context, and would have further equipped members of the genus Homo with a suite of adaptive characteristics that facilitated wide-ranging dispersal across ecological and climatic boundaries into Europe and Asia by following pathways of complex topography. We compare this hypothesis with alternative explanations for hominin dispersal, and evaluate it by mapping the distribution of topographic features at varying scales, and comparing the distribution of early Homo sites with the resulting maps and with other environmental variables. PMID:26235482

  19. Evolution and dispersal of the genus Homo: A landscape approach.

    PubMed

    Winder, Isabelle C; Devès, Maud H; King, Geoffrey C P; Bailey, Geoffrey N; Inglis, Robyn H; Meredith-Williams, Matthew

    2015-10-01

    The notion of the physical landscape as an arena of ecological interaction and human evolution is a powerful one, but its implementation at larger geographical and temporal scales is hampered by the challenges of reconstructing physical landscape settings in the geologically active regions where the earliest evidence is concentrated. We argue that the inherently dynamic nature of these unstable landscapes has made them important agents of biological change, creating complex topographies capable of selecting for, stimulating, obstructing or accelerating the latent and emerging properties of the human evolutionary trajectory. We use this approach, drawing on the concepts and methods of active tectonics, to develop a new perspective on the origins and dispersal of the Homo genus. We show how complex topography provides an easy evolutionary pathway to full terrestrialisation in the African context, and would have further equipped members of the genus Homo with a suite of adaptive characteristics that facilitated wide-ranging dispersal across ecological and climatic boundaries into Europe and Asia by following pathways of complex topography. We compare this hypothesis with alternative explanations for hominin dispersal, and evaluate it by mapping the distribution of topographic features at varying scales, and comparing the distribution of early Homo sites with the resulting maps and with other environmental variables.

  20. Geometric morphometric analysis of the crown morphology of the lower first premolar of hominins, with special attention to Pleistocene Homo.

    PubMed

    Gómez-Robles, Aida; Martinón-Torres, María; Bermúdez de Castro, José María; Prado, Leyre; Sarmiento, Susana; Arsuaga, Juan Luis

    2008-10-01

    This article is the third of a series that explores hominin dental crown morphology by means of geometric morphometrics. After the analysis of the lower second premolar and the upper first molar crown shapes, we apply the same technique to lower first premolar morphology. Our results show a clear distinction between the morphology seen in earlier hominin taxa such as Australopithecus and African early Homo, as well as Asian H. erectus, and more recent groups such as European H. heidelbergensis, H. neanderthalensis, and H. sapiens. The morphology of the earlier hominins includes an asymmetrical outline, a conspicuous talonid, and an occlusal polygon that tends to be large. The morphology of the recent hominins includes a symmetrical outline and a reduced or absent talonid. Within this later group, premolars belonging to H. heidelbergensis and H. neanderthalensis tend to possess a small and mesiolingually-displaced occlusal polygon, whereas H. sapiens specimens usually present expanded and centered occlusal polygons in an almost circular outline. The morphological differences among Paranthropus, Australopithecus, and African early Homo as studied here are small and evolutionarily less significant compared to the differences between the earlier and later homin taxa. In contrast to the lower second premolar and the upper first molar crown, the inclusion of a larger hominin sample of lower first premolars reveals a large allometric component. PMID:18639917

  1. The living fossil of human judgment.

    PubMed

    Schwarz, Michael

    2014-06-01

    Although the biases and anomalies characterizing psychometric data should serve as conclusive evidence of systematic flaws in scientific methodology, these problems are usually ignored, which reduces empirical psychology to the closed system of its error theory. However, psychometric scores are ambiguous, and response-shifts and fluctuating validities point to fundamental differences in what the measuring-apparatus questionnaire records and how the measuring-apparatus person judges. Therefore, empirical methods fail when psychology requires evidence-based knowledge about cognitive processes and phenomena. Correcting these flaws requires a reassessment of basic scientific premises and careful consideration of Homo sapiens' biosemiotic heuristics. Based on comprehensive biopsychosocial, data, the author reconstructs the evolutionary axioms of self-referenced cognitions and reveals what is usually obscured by the axioms of normal science. He substantiates the need for a paradigm shift toward basic bio-cultural principles and an evolutionary understanding of human thinking and behavior. PMID:24615167

  2. A “Copernican” Reassessment of the Human Mitochondrial DNA Tree from its Root

    PubMed Central

    Behar, Doron M.; van Oven, Mannis; Rosset, Saharon; Metspalu, Mait; Loogväli, Eva-Liis; Silva, Nuno M.; Kivisild, Toomas; Torroni, Antonio; Villems, Richard

    2012-01-01

    Mutational events along the human mtDNA phylogeny are traditionally identified relative to the revised Cambridge Reference Sequence, a contemporary European sequence published in 1981. This historical choice is a continuous source of inconsistencies, misinterpretations, and errors in medical, forensic, and population genetic studies. Here, after having refined the human mtDNA phylogeny to an unprecedented level by adding information from 8,216 modern mitogenomes, we propose switching the reference to a Reconstructed Sapiens Reference Sequence, which was identified by considering all available mitogenomes from Homo neanderthalensis. This “Copernican” reassessment of the human mtDNA tree from its deepest root should resolve previous problems and will have a substantial practical and educational influence on the scientific and public perception of human evolution by clarifying the core principles of common ancestry for extant descendants. PMID:22482806

  3. Direct evidence for human reliance on rainforest resources in late Pleistocene Sri Lanka.

    PubMed

    Roberts, Patrick; Perera, Nimal; Wedage, Oshan; Deraniyagala, Siran; Perera, Jude; Eregama, Saman; Gledhill, Andrew; Petraglia, Michael D; Lee-Thorp, Julia A

    2015-03-13

    Human occupation of tropical rainforest habitats is thought to be a mainly Holocene phenomenon. Although archaeological and paleoenvironmental data have hinted at pre-Holocene rainforest foraging, earlier human reliance on rainforest resources has not been shown directly. We applied stable carbon and oxygen isotope analysis to human and faunal tooth enamel from four late Pleistocene-to-Holocene archaeological sites in Sri Lanka. The results show that human foragers relied primarily on rainforest resources from at least ~20,000 years ago, with a distinct preference for semi-open rainforest and rain forest edges. Homo sapiens' relationship with the tropical rainforests of South Asia is therefore long-standing, a conclusion that indicates the time-depth of anthropogenic reliance and influence on these habitats.

  4. Human evolution: humanistic selection and looking to the future.

    PubMed

    Krsiak, Miloslav

    2006-10-01

    Cultural evolution has predominated over biological evolution in modern man (Homo sapiens sapiens). Cultural evolution differs from biological evolution not only by inheritance of acquired characteristics but also, as is proposed in the present essay, by another kind of selection mechanism. Whereas selection in biological evolution is executed according to a criterion of reproductive success (the natural selection), selection in cultural evolution appears to be carried out according to human and humanistic criteria (success or fitness in meeting human needs, interests and humanistic values--"humanistic selection"). Many humanistic needs or values do not seem to be prerequisite for reproductive success, yet some of them (e.g. a need for freedom) seem to be inborn. Innateness, humanistic selection (decisive at a community level) and hierarchy of some human needs, interests and values appear to give cultural evolution a generally upward trend although long periods of stagnation or even regression may occur. Modern humans appear to be still at the early stage of their cultural evolution. A further cultural evolution of man appears to be, in contrast to biological evolution, predictable (with an optimistic outlook) and testable. The problem is that the hopeful result of this test will probably be known only in the fairly remote future provided that this species will not become extinct before that. PMID:17159825

  5. Adult Neandertal clavicles from the El Sidrón site (Asturias, Spain) in the context of Homo pectoral girdle evolution.

    PubMed

    Rosas, Antonio; Rodriguez-Perez, Francisco Javier; Bastir, Markus; Estalrrich, Almudena; Huguet, Rosa; García-Tabernero, Antonio; Pastor, Juan Francisco; de la Rasilla, Marco

    2016-06-01

    We undertook a three-dimensional geometric morphometric (3DGM) analysis on 12 new Neandertal clavicle specimens from the El Sidrón site (Spain), dated to 49,000 years ago. The 3DGM methods were applied in a comparative framework in order to improve our understanding of trait polarity in features related to Homo pectoral girdle evolution, using other Neandertals, Homo sapiens, Pan, ATD6-50 (Homo antecessor), and KNM-WT 15000 (Homo ergaster/erectus) in the reference collection. Twenty-nine homologous landmarks were measured for each clavicle. Variation and morphological similarities were assessed through principal component analysis, conducted separately for the complete clavicle and the diaphysis. On average, Neandertal clavicles had significantly larger muscular entheses, double dorsal curvature, clavicle torsion, and cranial orientation of the acromial end than non-Neandertal clavicles; the El Sidrón clavicles fit this pattern. Variation within the samples was large, with extensive overlap between Homo species; only chimpanzee specimens clearly differed from the other specimens in morphometric terms. Taken together, our morphometric analyses are consistent with the following phylogenetic sequence. The primitive condition of the clavicle is manifest in the cranial orientation of both the acromial and sternal ends. The derived condition expressed in the H. sapiens + Neandertal clade is defined by caudal rotation of both the sternal and acromial ends, but with variation in the number of acromia remaining in a certain cranial orientation. Finally, the autapomorphic Neandertal condition is defined by secondarily acquired primitive cranial re-orientation of the acromial end, which varies from individual to individual. These results suggest that the pace of phylogenetic change in the pectoral girdle does not seem to follow that of other postcranial skeletal features. PMID:27260174

  6. Adult Neandertal clavicles from the El Sidrón site (Asturias, Spain) in the context of Homo pectoral girdle evolution.

    PubMed

    Rosas, Antonio; Rodriguez-Perez, Francisco Javier; Bastir, Markus; Estalrrich, Almudena; Huguet, Rosa; García-Tabernero, Antonio; Pastor, Juan Francisco; de la Rasilla, Marco

    2016-06-01

    We undertook a three-dimensional geometric morphometric (3DGM) analysis on 12 new Neandertal clavicle specimens from the El Sidrón site (Spain), dated to 49,000 years ago. The 3DGM methods were applied in a comparative framework in order to improve our understanding of trait polarity in features related to Homo pectoral girdle evolution, using other Neandertals, Homo sapiens, Pan, ATD6-50 (Homo antecessor), and KNM-WT 15000 (Homo ergaster/erectus) in the reference collection. Twenty-nine homologous landmarks were measured for each clavicle. Variation and morphological similarities were assessed through principal component analysis, conducted separately for the complete clavicle and the diaphysis. On average, Neandertal clavicles had significantly larger muscular entheses, double dorsal curvature, clavicle torsion, and cranial orientation of the acromial end than non-Neandertal clavicles; the El Sidrón clavicles fit this pattern. Variation within the samples was large, with extensive overlap between Homo species; only chimpanzee specimens clearly differed from the other specimens in morphometric terms. Taken together, our morphometric analyses are consistent with the following phylogenetic sequence. The primitive condition of the clavicle is manifest in the cranial orientation of both the acromial and sternal ends. The derived condition expressed in the H. sapiens + Neandertal clade is defined by caudal rotation of both the sternal and acromial ends, but with variation in the number of acromia remaining in a certain cranial orientation. Finally, the autapomorphic Neandertal condition is defined by secondarily acquired primitive cranial re-orientation of the acromial end, which varies from individual to individual. These results suggest that the pace of phylogenetic change in the pectoral girdle does not seem to follow that of other postcranial skeletal features.

  7. On Some Issues of Human-Animal Studies: An Introduction.

    PubMed

    Métraux, Alexandre

    2016-03-01

    Animals are "in" - since prehistoric times when humans (or their ancient ancestors) were hunting animals, and when they fabricated the Paleolithic dog as well as the Paleolithic cat. In less general terms, animals are "in" since they received names and were listed, observed, mummified, turned into totems, and, later on, dissected, tortured under laboratory conditions, trained as experimental subjects or "purified" as model organisms. And they are massively "in" again, but now from overtly legal and moral points of view, at least since the last two decades of the twentieth century. This is to say that modern members of the species Homo sapiens have always been connected to animals of the most various kinds - from the human flea (Pulex irritans) and the cat flea (Ctenocephalides felis) to marine mammals, such as dolphins and whales, from horses to parrots, from scallops to worms, and so on.

  8. Assessing the human gut microbiota in metabolic diseases.

    PubMed

    Karlsson, Fredrik; Tremaroli, Valentina; Nielsen, Jens; Bäckhed, Fredrik

    2013-10-01

    Recent findings have demonstrated that the gut microbiome complements our human genome with at least 100-fold more genes. In contrast to our Homo sapiens-derived genes, the microbiome is much more plastic, and its composition changes with age and diet, among other factors. An altered gut microbiota has been associated with several diseases, including obesity and diabetes, but the mechanisms involved remain elusive. Here we discuss factors that affect the gut microbiome, how the gut microbiome may contribute to metabolic diseases, and how to study the gut microbiome. Next-generation sequencing and development of software packages have led to the development of large-scale sequencing efforts to catalog the human microbiome. Furthermore, the use of genetically engineered gnotobiotic mouse models may increase our understanding of mechanisms by which the gut microbiome modulates host metabolism. A combination of classical microbiology, sequencing, and animal experiments may provide further insights into how the gut microbiota affect host metabolism and physiology.

  9. On Some Issues of Human-Animal Studies: An Introduction.

    PubMed

    Métraux, Alexandre

    2016-03-01

    Animals are "in" - since prehistoric times when humans (or their ancient ancestors) were hunting animals, and when they fabricated the Paleolithic dog as well as the Paleolithic cat. In less general terms, animals are "in" since they received names and were listed, observed, mummified, turned into totems, and, later on, dissected, tortured under laboratory conditions, trained as experimental subjects or "purified" as model organisms. And they are massively "in" again, but now from overtly legal and moral points of view, at least since the last two decades of the twentieth century. This is to say that modern members of the species Homo sapiens have always been connected to animals of the most various kinds - from the human flea (Pulex irritans) and the cat flea (Ctenocephalides felis) to marine mammals, such as dolphins and whales, from horses to parrots, from scallops to worms, and so on. PMID:26903370

  10. Calculation of the HOMO localization of Tetrahymena and Oxytricha telomeric quadruplex DNA.

    PubMed

    Morikawa, Masayuki; Kino, Katsuhito; Oyoshi, Takanori; Suzuki, Masayo; Kobayashi, Takanobu; Miyazawa, Hiroshi

    2015-08-15

    Several guanine-rich sequences exist in many important regions, such as telomeres, and these sequences can form quadruplex DNA structures. It was previously reported that 3'-guanines are mainly oxidized in the Tetrahymena and Oxytricha telomeric quadruplex DNA, d(TGGGGT)4, and 5'-guanines are mainly oxidized in the human telomeric quadruplex DNA, d(TAGGGT)4T. We speculated that the differences in site reactivity between d(TGGGGT)4 and d(TAGGGT)4T are induced by the localization of the HOMO. The HOMOs of the possible quadruplex structures were thus determined and the results showed that the HOMOs of d(TGGGGT)4 +3K(+) and d(TAGGGT)4T +2K(+) localized at the 5'-guanine, and that the HOMO shifted from the 5'-guanine to the 3'-guanine by the addition of a 5'-capping cation. Furthermore, we determined the influence of the cation and demonstrated that localization of the HOMO at the G-quartet plane located immediately adjacent to the cation is disfavored. The calculated HOMO localization of d(TGGGGT)4 +4K(+) and d(TAGGGT)4T +2K(+) matched the experimental results and suggest that d(TGGGGT)4 contains a 5'-capping cation in solution.

  11. A natural history of the human mind: tracing evolutionary changes in brain and cognition

    PubMed Central

    Sherwood, Chet C; Subiaul, Francys; Zawidzki, Tadeusz W

    2008-01-01

    Since the last common ancestor shared by modern humans, chimpanzees and bonobos, the lineage leading to Homo sapiens has undergone a substantial change in brain size and organization. As a result, modern humans display striking differences from the living apes in the realm of cognition and linguistic expression. In this article, we review the evolutionary changes that occurred in the descent of Homo sapiens by reconstructing the neural and cognitive traits that would have characterized the last common ancestor and comparing these with the modern human condition. The last common ancestor can be reconstructed to have had a brain of approximately 300–400 g that displayed several unique phylogenetic specializations of development, anatomical organization, and biochemical function. These neuroanatomical substrates contributed to the enhancement of behavioral flexibility and social cognition. With this evolutionary history as precursor, the modern human mind may be conceived as a mosaic of traits inherited from a common ancestry with our close relatives, along with the addition of evolutionary specializations within particular domains. These modern human-specific cognitive and linguistic adaptations appear to be correlated with enlargement of the neocortex and related structures. Accompanying this general neocortical expansion, certain higher-order unimodal and multimodal cortical areas have grown disproportionately relative to primary cortical areas. Anatomical and molecular changes have also been identified that might relate to the greater metabolic demand and enhanced synaptic plasticity of modern human brain's. Finally, the unique brain growth trajectory of modern humans has made a significant contribution to our species’ cognitive and linguistic abilities. PMID:18380864

  12. The cytotoxicity and genotoxicity of hexavalent chromium in Steller sea lion lung fibroblasts compared to human lung fibroblasts.

    PubMed

    Wise, John Pierce; Wise, Sandra S; Holmes, Amie L; LaCerte, Carolyne; Shaffiey, Fariba; Aboueissa, AbouEl-Makarim

    2010-06-01

    In this study we directly compared soluble and particulate chromate cytotoxicity and genotoxicity in human (Homo sapiens) and sea lion (Eumetopias jubatus) lung fibroblasts. Our results show that hexavalent chromium induces increased cell death and chromosome damage in both human and sea lion cells with increasing intracellular chromium ion levels. The data further indicate that both sodium chromate and lead chromate are less cytotoxic and genotoxic to sea lion cells than human cells, based on an administered dose. Differences in chromium ion uptake explained some but not all of the reduced amounts of sodium chromate-induced cell death. By contrast, uptake differences could explain the differences in sodium chromate-induced chromosome damage and particulate chromate-induced toxicity. Altogether they indicate that while hexavalent chromium induces similar toxic effects in sea lion and human cells, there are different mechanisms underlying the toxic outcomes. PMID:20211760

  13. The Cytotoxicity and Genotoxicity of Hexavalent Chromium in Steller Sea Lion Lung Fibroblasts Compared to Human Lung Fibroblasts

    PubMed Central

    Wise, John Pierce; Wise, Sandra S.; Holmes, Amie L.; LaCerte, Carolyne; Shaffiey, Fariba; Aboueissa, AbouEl-Makarim

    2010-01-01

    In this study we directly compared soluble and particulate chromate cytotoxicity and genotoxicity in human (Homo sapiens) and sea lion (Eumetopias jubatus) lung fibroblasts. Our results show that hexavalent chromium induces increased cell death and chromosome damage in both human and sea lion cells with increasing intracellular chromium ion levels. The data further indicate that both sodium chromate and lead chromate are less cytotoxic and genotoxic to sea lion cells than human cells, based on administered dose. Differences in chromium ion uptake explained some but not all of the reduced amounts of sodium chromate-induced cell death. By contrast, uptake differences could explain the differences in sodium chromate-induced chromosome damage and particulate chromate-induced toxicity. Altogether they indicate that while hexavalent chromium induces similar toxic effects in sea lion and human cells, there are different mechanisms underlying the toxic outcomes. PMID:20211760

  14. C. elegans and H. sapiens mRNAs with edited 3′ UTRs are present on polysomes

    PubMed Central

    Hundley, Heather A.; Krauchuk, Ammie A.; Bass, Brenda L.

    2008-01-01

    Adenosine deaminases that act on RNA (ADARs) are editing enzymes that convert adenosine to inosine in double-stranded RNA (dsRNA). ADARs sometimes target codons so that a single mRNA yields multiple protein isoforms. However, ADARs most often target noncoding regions of mRNAs, such as untranslated regions (UTRs). To understand the function of extensive double-stranded 3′ UTR structures, and the inosines within them, we monitored the fate of reporter and endogenous mRNAs that include structured 3′ UTRs in wild-type Caenorhabditis elegans and in strains with mutations in the ADAR genes. In general, we saw little effect of editing on stability or translatability of mRNA, although in one case an ADR-1 dependent effect was observed. Importantly, whereas previous studies indicate that inosine-containing RNAs are retained in the nucleus, we show that both C. elegans and Homo sapiens mRNAs with edited, structured 3′ UTRs are present on translating ribosomes. PMID:18719245

  15. Viral and vector zoonotic exploitation of a homo-sociome memetic complex.

    PubMed

    Rupprecht, C E; Burgess, G W

    2015-05-01

    As most newly characterized emerging infectious diseases are considered to be zoonotic, a modern pre-eminence ascribed within this classification lies clearly within the viral taxonomic realm. In particular, RNA viruses deserve special concern given their documented impact on conservation biology, veterinary medicine and public health, with an unprecedented ability to promote an evolutionary host-pathogen arms race from the ultimate infection and immunity perspective. However, besides the requisite molecular/gross anatomical and physiological bases for infectious diseases to transmit from one host to another, both viral pathogens and their reservoirs/vectors exploit a complex anthropological, cultural, historical, psychological and social suite that specifically defines the phylodynamics within Homo sapiens, unlike any other species. Some of these variables include the ecological benefits of living in groups, decisions on hunting and foraging behaviours and dietary preferences, myths and religious doctrines, health economics, travel destinations, population planning, political decisions on agricultural product bans and many others, in a homo-sociome memetic complex. Taken to an extreme, such complexities elucidate the underpinnings of explanations as to why certain viral zoonoses reside in neglected people, places and things, whereas others are chosen selectively and prioritized for active mitigation. Canine-transmitted rabies serves as one prime example of how a neglected viral zoonosis may transition to greater attention on the basis of renewed advocacy, social media, local champions and vested international community engagement. In contrast, certain bat-associated and arboviral diseases suffer from basic ignorance and perpetuated misunderstanding of fundamental reservoir and vector ecology tenets, translated into failed control policies that only exacerbate the underlying environmental conditions of concern. Beyond applied biomedical knowledge, epidemiological

  16. Viral and vector zoonotic exploitation of a homo-sociome memetic complex.

    PubMed

    Rupprecht, C E; Burgess, G W

    2015-05-01

    As most newly characterized emerging infectious diseases are considered to be zoonotic, a modern pre-eminence ascribed within this classification lies clearly within the viral taxonomic realm. In particular, RNA viruses deserve special concern given their documented impact on conservation biology, veterinary medicine and public health, with an unprecedented ability to promote an evolutionary host-pathogen arms race from the ultimate infection and immunity perspective. However, besides the requisite molecular/gross anatomical and physiological bases for infectious diseases to transmit from one host to another, both viral pathogens and their reservoirs/vectors exploit a complex anthropological, cultural, historical, psychological and social suite that specifically defines the phylodynamics within Homo sapiens, unlike any other species. Some of these variables include the ecological benefits of living in groups, decisions on hunting and foraging behaviours and dietary preferences, myths and religious doctrines, health economics, travel destinations, population planning, political decisions on agricultural product bans and many others, in a homo-sociome memetic complex. Taken to an extreme, such complexities elucidate the underpinnings of explanations as to why certain viral zoonoses reside in neglected people, places and things, whereas others are chosen selectively and prioritized for active mitigation. Canine-transmitted rabies serves as one prime example of how a neglected viral zoonosis may transition to greater attention on the basis of renewed advocacy, social media, local champions and vested international community engagement. In contrast, certain bat-associated and arboviral diseases suffer from basic ignorance and perpetuated misunderstanding of fundamental reservoir and vector ecology tenets, translated into failed control policies that only exacerbate the underlying environmental conditions of concern. Beyond applied biomedical knowledge, epidemiological

  17. Patterns of dental development in Homo, Australopithecus, Pan, and Gorilla.

    PubMed

    Smith, B H

    1994-07-01

    Smith ([1986] Nature 323:327-330) distinguished patterns of development of teeth of juvenile fossil hominids as being "more like humans" or "more like apes" based on statistical similarity to group standards. Here, this central tendency discrimination (CTD) is tested for its ability to recognize ape and human patterns of dental development in 789 subadult hominoids. Tooth development of a modern human sample (665 black southern Africans) was scored entirely by an outside investigator; pongid and fossil hominid samples (59 Pan, 50 Gorilla, and 14 fossil hominids) were scored by the author. The claim of Lampl et al. ([1993] Am. J. Phys. Anthropol. 90:113-127) that Smith's 1986 method succeeds in only 8% of human cases was not sustained. Figures for overall success of classification (87% humans, 68% apes) mask important effects of teeth sampled and age class. For humans, the power of CTD varied between 53% and 92% depending on the number and kind of teeth available--nearly that of a coin toss when data described only two nearby teeth, but quite successful with more teeth or distant teeth. For apes, only age class affected accuracy: "Infant" apes (M1 development < or = root cleft complete, unemerged) were usually classed as humans, probably because the present developmental standard for great apes is in substantial error under 3 years of age. "Juvenile" apes (M1 > or = root 1/4), however, were correctly discriminated in 87% of cases. Overall, CTD can be considered reliable (accuracy of 92% for humans and 88% for apes) when data contrast development of distant dental fields and subjects are juveniles (not infants). Restricting analysis of fossils to specimens satisfying these criteria, patterns of dental development of gracile australopithecines and Homo habilis remain classified with African apes. Those of Homo erectus and Neanderthals are classified with humans, suggesting that patterns of growth evolved substantially in the Hominidae. To standardize future research

  18. Brain size and encephalization in early to Mid-Pleistocene Homo.

    PubMed

    Rightmire, G Philip

    2004-06-01

    Important changes in the brain have occurred during the course of human evolution. Both absolute and relative size increases can be documented for species of Homo, culminating in the appearance of modern humans. One species that is particularly well-represented by fossil crania is Homo erectus. The mean capacity for 30 individuals is 973 cm(3). Within this group there is substantial variation, but brain size increases slightly in specimens from later time periods. Other Middle Pleistocene crania differ from those of Homo erectus. Characters of the facial skeleton, vault, and cranial base suggest that fossils from sites such as Arago Cave in France, the Sima de los Huesos in Spain, Bodo in Ethiopia, Broken Hill in Zambia, and perhaps Dali in China belong to the taxon Homo heidelbergensis. Ten of these mid-Quaternary hominins have brains averaging 1,206 cm(3) in volume, and many fall beyond the limits of size predicted for Homo erectus of equivalent age. When orbit height is used to construct an index of relative brain size, it is apparent that the (significant) increase in volume documented for the Middle Pleistocene individuals is not simply a consequence of larger body mass. Encephalization quotient values confirm this finding. These changes in absolute and relative brain size can be taken as further corroborative evidence for a speciation event, in which Homo erectus produced a daughter lineage. It is probable that Homo heidelbergensis originated in Africa or western Eurasia and then ranged widely across the Old World. Archaeological traces indicate that these populations differed in their technology and behavior from earlier hominins.

  19. Distinct patterns of mitochondrial genome diversity in bonobos (Pan paniscus) and humans

    PubMed Central

    2010-01-01

    Background We have analyzed the complete mitochondrial genomes of 22 Pan paniscus (bonobo, pygmy chimpanzee) individuals to assess the detailed mitochondrial DNA (mtDNA) phylogeny of this close relative of Homo sapiens. Results We identified three major clades among bonobos that separated approximately 540,000 years ago, as suggested by Bayesian analysis. Incidentally, we discovered that the current reference sequence for bonobo likely is a hybrid of the mitochondrial genomes of two distant individuals. When comparing spectra of polymorphic mtDNA sites in bonobos and humans, we observed two major differences: (i) Of all 31 bonobo mtDNA homoplasies, i.e. nucleotide changes that occurred independently on separate branches of the phylogenetic tree, 13 were not homoplasic in humans. This indicates that at least a part of the unstable sites of the mitochondrial genome is species-specific and difficult to be explained on the basis of a mutational hotspot concept. (ii) A comparison of the ratios of non-synonymous to synonymous changes (dN/dS) among polymorphic positions in bonobos and in 4902 Homo sapiens mitochondrial genomes revealed a remarkable difference in the strength of purifying selection in the mitochondrial genes of the F0F1-ATPase complex. While in bonobos this complex showed a similar low value as complexes I and IV, human haplogroups displayed 2.2 to 7.6 times increased dN/dS ratios when compared to bonobos. Conclusions Some variants of mitochondrially encoded subunits of the ATPase complex in humans very likely decrease the efficiency of energy conversion leading to production of extra heat. Thus, we hypothesize that the species-specific release of evolutionary constraints for the mitochondrial genes of the proton-translocating ATPase is a consequence of altered heat homeostasis in modern humans. PMID:20813043

  20. Origin and primary dispersal of the Mycobacterium tuberculosis Beijing genotype: Clues from human phylogeography

    PubMed Central

    Mokrousov, Igor; Ly, Ho Minh; Otten, Tatiana; Lan, Nguyen Ngoc; Vyshnevskyi, Boris; Hoffner, Sven; Narvskaya, Olga

    2005-01-01

    We suggest that the evolution of the population structure of microbial pathogens is influenced by that of modern humans. Consequently, the timing of hallmark changes in bacterial genomes within the last 100,000 yr may be attempted by comparison with relevant human migrations. Here, we used a lineage within Mycobacterium tuberculosis, a Beijing genotype, as a model and compared its phylogeography with human demography and Y chromosome-based phylogeography. We hypothesize that two key events shaped the early history of the Beijing genotype: (1) its Upper Palaeolithic origin in the Homo sapiens sapiens K-M9 cluster in Central Asia, and (2) primary Neolithic dispersal of the secondary Beijing NTF::IS6110 lineage by Proto-Sino-Tibetan farmers within east Asia (human O-M214/M122 haplogroup). The independent introductions of the Beijing strains from east Asia to northern Eurasia and South Africa were likely historically recent, whereas their differential dissemination within these areas has been influenced by demographic and climatic factors. PMID:16169923

  1. Starch Catabolism by a Prominent Human Gut Symbiont Is Directed by the Recognition of Amylose Helices

    SciTech Connect

    Koropatkin, Nicole M.; Martens, Eric C.; Gordon, Jeffrey I.; Smith, Thomas J.

    2009-01-12

    The human gut microbiota performs functions that are not encoded in our Homo sapiens genome, including the processing of otherwise undigestible dietary polysaccharides. Defining the structures of proteins involved in the import and degradation of specific glycans by saccharolytic bacteria complements genomic analysis of the nutrient-processing capabilities of gut communities. Here, we describe the atomic structure of one such protein, SusD, required for starch binding and utilization by Bacteroides thetaiotaomicron, a prominent adaptive forager of glycans in the distal human gut microbiota. The binding pocket of this unique {alpha}-helical protein contains an arc of aromatic residues that complements the natural helical structure of starch and imposes this conformation on bound maltoheptaose. Furthermore, SusD binds cyclic oligosaccharides with higher affinity than linear forms. The structures of several SusD/oligosaccharide complexes reveal an inherent ligand recognition plasticity dominated by the three-dimensional conformation of the oligosaccharides rather than specific interactions with the composite sugars.

  2. Unique Dental Morphology of Homo floresiensis and Its Evolutionary Implications

    PubMed Central

    Kaifu, Yousuke; Kono, Reiko T.; Sutikna, Thomas; Saptomo, Emanuel Wahyu; Jatmiko

    2015-01-01

    Homo floresiensis is an extinct, diminutive hominin species discovered in the Late Pleistocene deposits of Liang Bua cave, Flores, eastern Indonesia. The nature and evolutionary origins of H. floresiensis’ unique physical characters have been intensively debated. Based on extensive comparisons using linear metric analyses, crown contour analyses, and other trait-by-trait morphological comparisons, we report here that the dental remains from multiple individuals indicate that H. floresiensis had primitive canine-premolar and advanced molar morphologies, a combination of dental traits unknown in any other hominin species. The primitive aspects are comparable to H. erectus from the Early Pleistocene, whereas some of the molar morphologies are more progressive even compared to those of modern humans. This evidence contradicts the earlier claim of an entirely modern human-like dental morphology of H. floresiensis, while at the same time does not support the hypothesis that H. floresiensis originated from a much older H. habilis or Australopithecus-like small-brained hominin species currently unknown in the Asian fossil record. These results are however consistent with the alternative hypothesis that H. floresiensis derived from an earlier Asian Homo erectus population and experienced substantial body and brain size dwarfism in an isolated insular setting. The dentition of H. floresiensis is not a simple, scaled-down version of earlier hominins. PMID:26624612

  3. Unique Dental Morphology of Homo floresiensis and Its Evolutionary Implications.

    PubMed

    Kaifu, Yousuke; Kono, Reiko T; Sutikna, Thomas; Saptomo, Emanuel Wahyu; Jatmiko; Due Awe, Rokus

    2015-01-01

    Homo floresiensis is an extinct, diminutive hominin species discovered in the Late Pleistocene deposits of Liang Bua cave, Flores, eastern Indonesia. The nature and evolutionary origins of H. floresiensis' unique physical characters have been intensively debated. Based on extensive comparisons using linear metric analyses, crown contour analyses, and other trait-by-trait morphological comparisons, we report here that the dental remains from multiple individuals indicate that H. floresiensis had primitive canine-premolar and advanced molar morphologies, a combination of dental traits unknown in any other hominin species. The primitive aspects are comparable to H. erectus from the Early Pleistocene, whereas some of the molar morphologies are more progressive even compared to those of modern humans. This evidence contradicts the earlier claim of an entirely modern human-like dental morphology of H. floresiensis, while at the same time does not support the hypothesis that H. floresiensis originated from a much older H. habilis or Australopithecus-like small-brained hominin species currently unknown in the Asian fossil record. These results are however consistent with the alternative hypothesis that H. floresiensis derived from an earlier Asian Homo erectus population and experienced substantial body and brain size dwarfism in an isolated insular setting. The dentition of H. floresiensis is not a simple, scaled-down version of earlier hominins. PMID:26624612

  4. Human evolution and cognition.

    PubMed

    Tattersall, Ian

    2010-09-01

    Human beings are distinguished from all other organisms by their symbolic way of processing information about the world. This unique cognitive style is qualitatively different from all the earlier hominid cognitive styles, and is not simply an improved version of them. The hominid fossil and archaeological records show clearly that biological and technological innovations have typically been highly sporadic, and totally out of phase, since the invention of stone tools some 2.5 million years ago. They also confirm that this pattern applied in the arrival of modern cognition: the anatomically recognizable species Homo sapiens was well established long before any population of it began to show indications of behaving symbolically. This places the origin of symbolic thought in the realms of exaptation, whereby new structures come into existence before being recruited to new uses, and of emergence, whereby entire new levels of complexity are achieved through new combinations of attributes unremarkable in themselves. Both these phenomena involve entirely routine evolutionary processes; special as we human beings may consider ourselves, there was nothing special about the way we came into existence. Modern human cognition is a very recent acquisition; and its emergence ushered in an entirely new pattern of technological (and other behavioral) innovation, in which constant change results from the ceaseless exploration of the potential inherent in our new capacity.

  5. Human Dispersals Along the African Rift Valley in the Late Quaternary

    NASA Astrophysics Data System (ADS)

    Tryon, C. A.; Faith, J. T.; Peppe, D. J.

    2014-12-01

    Climate- and tectonic-driven environmental dynamics of the East African Rift System (EARS) during the Quaternary played an important role in the demographic history of early Homo sapiens, including expansions of modern humans across and out of Africa. Human forager population size, geographic range, and behaviors such as hunting strategies and residential mobility likely varied in response to changes in the local and regional environment. Throughout the Quaternary, floral and faunal change was linked at least in part to variations in moisture availability, temperature, and atmospheric CO2, which in addition to uplift and faulting, contributed to the expansion and contraction of a number of large lakes that served as biogeographic barriers to many taxa. This is particularly clear for the Lake Victoria basin, where biogeographic, geological, and paleontological evidence documents repeated expansion and contraction of the ranges of species in response to lake level and vegetation change. Across much of eastern Africa, the topography of the rift facilitated north-south dispersals, the timing of which may have depended in part on the expansion and contraction of the equatorial forest belt. Dispersal potential likely increased during the more arid periods of the late Quaternary, when the roles of lakes and forests as dispersal barriers was reduced and the extent of low net primary productivity dry grasslands increased, the latter requiring large home ranges for human foragers, conditions suitable for range expansions within H. sapiens.

  6. The Evolution of Human Longevity: Toward a Biocultural Theory.

    ERIC Educational Resources Information Center

    Mayer, Peter J.

    Homo sapiens is the only extant species for which there exists a significant post-reproductive period in the normal lifespan. Explanations for the evolution of this species-specific trait are possible through "non-deterministic" theories of aging positing "wear and tear" or the failure of nature to eliminate imperfection, or "deterministic"…

  7. Early evidence of the genus Homo in East Asia.

    PubMed

    Zhu, R X; Potts, R; Pan, Y X; Yao, H T; Lü, L Q; Zhao, X; Gao, X; Chen, L W; Gao, F; Deng, C L

    2008-12-01

    The timing and route of the earliest dispersal from Africa to Eastern Asia are contentious topics in the study of early human evolution because Asian hominin fossil sites with precise age constraints are very limited. Here we report new high-resolution magnetostratigraphic results that place stringent age controls on excavated hominin incisors and stone tools from the Yuanmou Basin, southwest China. The hominin-bearing layer resides in a reverse polarity magnetozone just above the upper boundary of the Olduvai subchron, yielding an estimated age of 1.7Ma. The finding represents the age of the earliest documented presence of Homo, with affinities to Homo erectus, in mainland East Asia. This age estimate is roughly the same as for H. erectus in island Southeast Asia and immediately prior to the oldest archaeological evidence in northeast Asia. Mammalian fauna and pollen obtained directly from the hominin site indicate that the Yuanmou hominins lived in a varied habitat of open vegetation with patches of bushland and forest on an alluvial fan close to a lake or swamp. The age and location are consistent with a rapid southern migration route of initial hominin populations into Eastern Asia. PMID:18842287

  8. Evolution of human brain functions: the functional structure of human consciousness.

    PubMed

    Cloninger, C Robert

    2009-11-01

    The functional structure of self-aware consciousness in human beings is described based on the evolution of human brain functions. Prior work on heritable temperament and character traits is extended to account for the quantum-like and holographic properties (i.e. parts elicit wholes) of self-aware consciousness. Cladistic analysis is used to identify the succession of ancestors leading to human beings. The functional capacities that emerge along this lineage of ancestors are described. The ecological context in which each cladogenesis occurred is described to illustrate the shifting balance of evolution as a complex adaptive system. Comparative neuroanatomy is reviewed to identify the brain structures and networks that emerged coincident with the emergent brain functions. Individual differences in human temperament traits were well developed in the common ancestor shared by reptiles and humans. Neocortical development in mammals proceeded in five major transitions: from early reptiles to early mammals, early primates, simians, early Homo, and modern Homo sapiens. These transitions provide the foundation for human self-awareness related to sexuality, materiality, emotionality, intellectuality, and spirituality, respectively. The functional structure of human self-aware consciousness is concerned with the regulation of five planes of being: sexuality, materiality, emotionality, intellectuality, and spirituality. Each plane elaborates neocortical functions organized around one of the five special senses. The interactions among these five planes gives rise to a 5 x 5 matrix of subplanes, which are functions that coarsely describe the focus of neocortical regulation. Each of these 25 neocortical functions regulates each of five basic motives or drives that can be measured as temperaments or basic emotions related to fear, anger, disgust, surprise, and happiness/sadness. The resulting 5 x 5 x 5 matrix of human characteristics provides a general and testable model of the

  9. Sexual dimorphism in Australopithecus afarensis was similar to that of modern humans.

    PubMed

    Reno, Philip L; Meindl, Richard S; McCollum, Melanie A; Lovejoy, C Owen

    2003-08-01

    The substantial fossil record for Australopithecus afarensis includes both an adult partial skeleton [Afar Locality (A.L.) 288-1, "Lucy"] and a large simultaneous death assemblage (A.L. 333). Here we optimize data derived from both to more accurately estimate skeletal size dimorphism. Postcranial ratios derived from A.L. 288-1 enable a significant increase in sample size compared with previous studies. Extensive simulations using modern humans, chimpanzees, and gorillas confirm that this technique is accurate and that skeletal size dimorphism in A. afarensis was most similar to that of contemporary Homo sapiens. These data eliminate some apparent discrepancies between the canine and skeletal size dimorphism in hominoids, imply that the species was not characterized by substantial sexual bimaturation, and greatly increase the probability that the reproductive strategy of A. afarensis was principally monogamy.

  10. Number of ancestral human species: a molecular perspective.

    PubMed

    Curnoe, D; Thorne, A

    2003-01-01

    Despite the remarkable developments in molecular biology over the past three decades, anthropological genetics has had only limited impact on systematics in human evolution. Genetics offers the opportunity to objectively test taxonomies based on morphology and may be used to supplement conventional approaches to hominid systematics. Our analyses, examining chromosomes and 46 estimates of genetic distance, indicate there may have been only around 4 species on the direct line to modern humans and 5 species in total. This contrasts with current taxonomies recognising up to 23 species. The genetic proximity of humans and chimpanzees has been used to suggest these species are congeneric. Our analysis of genetic distances between them is consistent with this proposal. It is time that chimpanzees, living humans and all fossil humans be classified in Homo. The creation of new genera can no longer be a solution to the complexities of fossil morphologies. Published genetic distances between common chimpanzees and bonobos, along with evidence for interbreeding, suggest they should be assigned to a single species. The short distance between humans and chimpanzees also places a strict limit on the number of possible evolutionary 'side branches' that might be recognised on the human lineage. All fossil taxa were genetically very close to each other and likely to have been below congeneric genetic distances seen for many mammals. Our estimates of genetic divergence suggest that periods of around 2 million years are required to produce sufficient genetic distance to represent speciation. Therefore, Neanderthals and so-called H. erectus were genetically so close to contemporary H. sapiens they were unlikely to have been separate species. Thus, it is likely there was only one species of human (H. sapiens) for most of the last 2 million years. We estimate the divergence time of H. sapiens from 16 genetic distances to be around 1.7 Ma which is consistent with evidence for the earliest

  11. Disproportionate Cochlear Length in Genus Homo Shows a High Phylogenetic Signal during Apes' Hearing Evolution.

    PubMed

    Braga, J; Loubes, J-M; Descouens, D; Dumoncel, J; Thackeray, J F; Kahn, J-L; de Beer, F; Riberon, A; Hoffman, K; Balaresque, P; Gilissen, E

    2015-01-01

    Changes in lifestyles and body weight affected mammal life-history evolution but little is known about how they shaped species' sensory systems. Since auditory sensitivity impacts communication tasks and environmental acoustic awareness, it may have represented a deciding factor during mammal evolution, including apes. Here, we statistically measure the influence of phylogeny and allometry on the variation of five cochlear morphological features associated with hearing capacities across 22 living and 5 fossil catarrhine species. We find high phylogenetic signals for absolute and relative cochlear length only. Comparisons between fossil cochleae and reconstructed ape ancestral morphotypes show that Australopithecus absolute and relative cochlear lengths are explicable by phylogeny and concordant with the hypothetized ((Pan,Homo),Gorilla) and (Pan,Homo) most recent common ancestors. Conversely, deviations of the Paranthropus oval window area from these most recent common ancestors are not explicable by phylogeny and body weight alone, but suggest instead rapid evolutionary changes (directional selection) of its hearing organ. Premodern (Homo erectus) and modern human cochleae set apart from living non-human catarrhines and australopiths. They show cochlear relative lengths and oval window areas larger than expected for their body mass, two features corresponding to increased low-frequency sensitivity more recent than 2 million years ago. The uniqueness of the "hypertrophied" cochlea in the genus Homo (as opposed to the australopiths) and the significantly high phylogenetic signal of this organ among apes indicate its usefulness to identify homologies and monophyletic groups in the hominid fossil record. PMID:26083484

  12. Disproportionate Cochlear Length in Genus Homo Shows a High Phylogenetic Signal during Apes’ Hearing Evolution

    PubMed Central

    Braga, J.; Loubes, J-M.; Descouens, D.; Dumoncel, J.; Thackeray, J. F.; Kahn, J-L.; de Beer, F.; Riberon, A.; Hoffman, K.; Balaresque, P.; Gilissen, E.

    2015-01-01

    Changes in lifestyles and body weight affected mammal life-history evolution but little is known about how they shaped species’ sensory systems. Since auditory sensitivity impacts communication tasks and environmental acoustic awareness, it may have represented a deciding factor during mammal evolution, including apes. Here, we statistically measure the influence of phylogeny and allometry on the variation of five cochlear morphological features associated with hearing capacities across 22 living and 5 fossil catarrhine species. We find high phylogenetic signals for absolute and relative cochlear length only. Comparisons between fossil cochleae and reconstructed ape ancestral morphotypes show that Australopithecus absolute and relative cochlear lengths are explicable by phylogeny and concordant with the hypothetized ((Pan,Homo),Gorilla) and (Pan,Homo) most recent common ancestors. Conversely, deviations of the Paranthropus oval window area from these most recent common ancestors are not explicable by phylogeny and body weight alone, but suggest instead rapid evolutionary changes (directional selection) of its hearing organ. Premodern (Homo erectus) and modern human cochleae set apart from living non-human catarrhines and australopiths. They show cochlear relative lengths and oval window areas larger than expected for their body mass, two features corresponding to increased low-frequency sensitivity more recent than 2 million years ago. The uniqueness of the “hypertrophied” cochlea in the genus Homo (as opposed to the australopiths) and the significantly high phylogenetic signal of this organ among apes indicate its usefulness to identify homologies and monophyletic groups in the hominid fossil record. PMID:26083484

  13. Disproportionate Cochlear Length in Genus Homo Shows a High Phylogenetic Signal during Apes' Hearing Evolution.

    PubMed

    Braga, J; Loubes, J-M; Descouens, D; Dumoncel, J; Thackeray, J F; Kahn, J-L; de Beer, F; Riberon, A; Hoffman, K; Balaresque, P; Gilissen, E

    2015-01-01

    Changes in lifestyles and body weight affected mammal life-history evolution but little is known about how they shaped species' sensory systems. Since auditory sensitivity impacts communication tasks and environmental acoustic awareness, it may have represented a deciding factor during mammal evolution, including apes. Here, we statistically measure the influence of phylogeny and allometry on the variation of five cochlear morphological features associated with hearing capacities across 22 living and 5 fossil catarrhine species. We find high phylogenetic signals for absolute and relative cochlear length only. Comparisons between fossil cochleae and reconstructed ape ancestral morphotypes show that Australopithecus absolute and relative cochlear lengths are explicable by phylogeny and concordant with the hypothetized ((Pan,Homo),Gorilla) and (Pan,Homo) most recent common ancestors. Conversely, deviations of the Paranthropus oval window area from these most recent common ancestors are not explicable by phylogeny and body weight alone, but suggest instead rapid evolutionary changes (directional selection) of its hearing organ. Premodern (Homo erectus) and modern human cochleae set apart from living non-human catarrhines and australopiths. They show cochlear relative lengths and oval window areas larger than expected for their body mass, two features corresponding to increased low-frequency sensitivity more recent than 2 million years ago. The uniqueness of the "hypertrophied" cochlea in the genus Homo (as opposed to the australopiths) and the significantly high phylogenetic signal of this organ among apes indicate its usefulness to identify homologies and monophyletic groups in the hominid fossil record.

  14. Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa

    PubMed Central

    Dirks, Paul HGM; Berger, Lee R; Roberts, Eric M; Kramers, Jan D; Hawks, John; Randolph-Quinney, Patrick S; Elliott, Marina; Musiba, Charles M; Churchill, Steven E; de Ruiter, Darryl J; Schmid, Peter; Backwell, Lucinda R; Belyanin, Georgy A; Boshoff, Pedro; Hunter, K Lindsay; Feuerriegel, Elen M; Gurtov, Alia; Harrison, James du G; Hunter, Rick; Kruger, Ashley; Morris, Hannah; Makhubela, Tebogo V; Peixotto, Becca; Tucker, Steven

    2015-01-01

    We describe the physical context of the Dinaledi Chamber within the Rising Star cave, South Africa, which contains the fossils of Homo naledi. Approximately 1550 specimens of hominin remains have been recovered from at least 15 individuals, representing a small portion of the total fossil content. Macro-vertebrate fossils are exclusively H. naledi, and occur within clay-rich sediments derived from in situ weathering, and exogenous clay and silt, which entered the chamber through fractures that prevented passage of coarser-grained material. The chamber was always in the dark zone, and not accessible to non-hominins. Bone taphonomy indicates that hominin individuals reached the chamber complete, with disarticulation occurring during/after deposition. Hominins accumulated over time as older laminated mudstone units and sediment along the cave floor were eroded. Preliminary evidence is consistent with deliberate body disposal in a single location, by a hominin species other than Homo sapiens, at an as-yet unknown date. DOI: http://dx.doi.org/10.7554/eLife.09561.001 PMID:26354289

  15. Genome Digging: Insight into the Mitochondrial Genome of Homo

    PubMed Central

    Ovchinnikov, Igor V.; Kholina, Olga I.

    2010-01-01

    Background A fraction of the Neanderthal mitochondrial genome sequence has a similarity with a 5,839-bp nuclear DNA sequence of mitochondrial origin (numt) on the human chromosome 1. This fact has never been interpreted. Although this phenomenon may be attributed to contamination and mosaic assembly of Neanderthal mtDNA from short sequencing reads, we explain the mysterious similarity by integration of this numt (mtAncestor-1) into the nuclear genome of the common ancestor of Neanderthals and modern humans not long before their reproductive split. Principal Findings Exploiting bioinformatics, we uncovered an additional numt (mtAncestor-2) with a high similarity to the Neanderthal mtDNA and indicated that both numts represent almost identical replicas of the mtDNA sequences ancestral to the mitochondrial genomes of Neanderthals and modern humans. In the proteins, encoded by mtDNA, the majority of amino acids distinguishing chimpanzees from humans and Neanderthals were acquired by the ancestral hominins. The overall rate of nonsynonymous evolution in Neanderthal mitochondrial protein-coding genes is not higher than in other lineages. The model incorporating the ancestral hominin mtDNA sequences estimates the average divergence age of the mtDNAs of Neanderthals and modern humans to be 450,000–485,000 years. The mtAncestor-1 and mtAncestor-2 sequences were incorporated into the nuclear genome approximately 620,000 years and 2,885,000 years ago, respectively. Conclusions This study provides the first insight into the evolution of the mitochondrial DNA in hominins ancestral to Neanderthals and humans. We hypothesize that mtAncestor-1 and mtAncestor-2 are likely to be molecular fossils of the mtDNAs of Homo heidelbergensis and a stem Homo lineage. The dN/dS dynamics suggests that the effective population size of extinct hominins was low. However, the hominin lineage ancestral to humans, Neanderthals and H. heidelbergensis, had a larger effective population size and

  16. Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo.

    PubMed

    Nishimura, Takeshi; Mori, Futoshi; Hanida, Sho; Kumahata, Kiyoshi; Ishikawa, Shigeru; Samarat, Kaouthar; Miyabe-Nishiwaki, Takako; Hayashi, Misato; Tomonaga, Masaki; Suzuki, Juri; Matsuzawa, Tetsuro; Matsuzawa, Teruo

    2016-03-01

    We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD) with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved "Out of Africa" to explore the more severe climates of

  17. Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo

    PubMed Central

    Nishimura, Takeshi; Mori, Futoshi; Hanida, Sho; Kumahata, Kiyoshi; Ishikawa, Shigeru; Samarat, Kaouthar; Miyabe-Nishiwaki, Takako; Hayashi, Misato; Tomonaga, Masaki; Suzuki, Juri; Matsuzawa, Tetsuro; Matsuzawa, Teruo

    2016-01-01

    We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD) with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved “Out of Africa” to explore the more severe climates of

  18. Impaired Air Conditioning within the Nasal Cavity in Flat-Faced Homo.

    PubMed

    Nishimura, Takeshi; Mori, Futoshi; Hanida, Sho; Kumahata, Kiyoshi; Ishikawa, Shigeru; Samarat, Kaouthar; Miyabe-Nishiwaki, Takako; Hayashi, Misato; Tomonaga, Masaki; Suzuki, Juri; Matsuzawa, Tetsuro; Matsuzawa, Teruo

    2016-03-01

    We are flat-faced hominins with an external nose that protrudes from the face. This feature was derived in the genus Homo, along with facial flattening and reorientation to form a high nasal cavity. The nasal passage conditions the inhaled air in terms of temperature and humidity to match the conditions required in the lung, and its anatomical variation is believed to be evolutionarily sensitive to the ambient atmospheric conditions of a given habitat. In this study, we used computational fluid dynamics (CFD) with three-dimensional topology models of the nasal passage under the same simulation conditions, to investigate air-conditioning performance in humans, chimpanzees, and macaques. The CFD simulation showed a horizontal straight flow of inhaled air in chimpanzees and macaques, contrasting with the upward and curved flow in humans. The inhaled air is conditioned poorly in humans compared with nonhuman primates. Virtual modifications to the human external nose topology, in which the nasal vestibule and valve are modified to resemble those of chimpanzees, change the airflow to be horizontal, but have little influence on the air-conditioning performance in humans. These findings suggest that morphological variation of the nasal passage topology was only weakly sensitive to the ambient atmosphere conditions; rather, the high nasal cavity in humans was formed simply by evolutionary facial reorganization in the divergence of Homo from the other hominin lineages, impairing the air-conditioning performance. Even though the inhaled air is not adjusted well within the nasal cavity in humans, it can be fully conditioned subsequently in the pharyngeal cavity, which is lengthened in the flat-faced Homo. Thus, the air-conditioning faculty in the nasal passages was probably impaired in early Homo members, although they have survived successfully under the fluctuating climate of the Plio-Pleistocene, and then they moved "Out of Africa" to explore the more severe climates of

  19. Patterns of differences in brain morphology in humans as compared to extant apes

    PubMed Central

    Aldridge, Kristina

    2010-01-01

    Although human evolution is characterized by a vast increase in brain size, it is not clear whether or not certain regions of the brain are enlarged disproportionately in humans, or how this enlargement relates to differences in overall neural morphology. The aim of this study is to determine whether or not there are specific suites of features that distinguish the morphology of the human brain from that of apes. The study sample consists of whole brain, in vivo magnetic resonance images (MRIs) of anatomically modern humans (Homo sapiens sapiens) and five ape species (gibbons, orangutans, gorillas, chimpanzees, bonobos). Twenty-nine 3D landmarks, including surface and internal features of the brain were located on 3D MRI reconstructions of each individual using MEASURE software. Landmark coordinate data were scaled for differences in size and analyzed using Euclidean Distance Matrix Analysis (EDMA) to statistically compare the brains of each non-human ape species to the human sample. Results of analyses show both a pattern of brain morphology that is consistently different between all apes and humans, as well as patterns that differ among species. Further, both the consistent and species-specific patterns include cortical and subcortical features. The pattern that remains consistent across species indicates a morphological reorganization of 1) relationships between cortical and subcortical frontal structures, 2) expansion of the temporal lobe and location of the amygdala, and 3) expansion of the anterior parietal region. Additionally, results demonstrate that, although there is a pattern of morphology that uniquely defines the human brain, there are also patterns that uniquely differentiate human morphology from the morphology of each non-human ape species, indicating that reorganization of neural morphology occurred at the evolutionary divergence of each of these groups. PMID:21056456

  20. Body size and its consequences: allometry and the lower limb length of Liang Bua 1 (Homo floresiensis).

    PubMed

    Holliday, Trenton W; Franciscus, Robert G

    2009-09-01

    Bivariate femoral length allometry in recent humans, Pan, and Gorilla is investigated with special reference to the diminutive Liang Bua (LB) 1 specimen (the holotype of Homo floresiensis) and six early Pleistocene femora referred to the genus Homo. Relative to predicted body mass, Pan and Gorilla femora show strong negative length allometry while recent human femora evince isometry to positive allometry, depending on sample composition and line-fitting technique employed. The allometric trajectories of Pan and Homo show convergence near the small body size range of LB 1, such that LB 1 manifests a low percentage deviation (d(yx) of Smith [1980]) from the Pan allometric trajectory and falls well within the 95% confidence limits around the Pan individuals (but also outside the 95% confidence limits for recent Homo). In contrast, the six early Pleistocene Homo femora, belonging to larger individuals, show much greater d(yx) values from both Pan and Gorilla and fall well above the 95% confidence limits for these taxa. All but one of these Pleistocene Homo specimens falls within the 95% confidence limits of the recent human sample. Similar results are obtained when femoral length is regressed on femoral head diameter in unlogged bivariate space. Regardless of the ultimate taxonomic status of LB 1, these findings are consistent with a prediction made by us (Franciscus and Holliday, 1992) that hominins in the small body size range of A.L. 288-1 ("Lucy"), including members of the genus Homo, will tend to possess short, ape-like lower limbs as a function of body size scaling.

  1. In silico modification of Zn2+ binding group of suberoylanilide hydroxamic acid (SAHA) by organoselenium compounds as Homo sapiens class II HDAC inhibitor of cervical cancer

    NASA Astrophysics Data System (ADS)

    Sumo Friend Tambunan, Usman; Bakri, Ridla; Aditya Parikesit, Arli; Ariyani, Titin; Dyah Puspitasari, Ratih; Kerami, Djati

    2016-02-01

    Cervical cancer is the most common cancer in women, and ranks seventh of all cancers worldwide, with 529000 cases in 2008 and more than 85% cases occur in developing countries. One way to treat this cancer is through the inhibition of HDAC enzymes which play a strategic role in the regulation of gene expression. Suberoyl Anilide Hydroxamic Acid (SAHA) or Vorinostat is a drug which commercially available to treat the cancer, but still has some side effects. This research present in silico SAHA modification in Zinc Binding Group (ZBG) by organoselenium compound to get ligands which less side effect. From molecular docking simulation, and interaction analysis, there are five best ligands, namely CC27, HA27, HB28, IB25, and KA7. These five ligands have better binding affinity than the standards, and also have interaction with Zn2+ cofactor of inhibited HDAC enzymes. This research is expected to produce more potent HDAC inhibitor as novel drug for cervical cancer treatment.

  2. The evolutionary history of the hominin hand since the last common ancestor of Pan and Homo.

    PubMed

    Tocheri, Matthew W; Orr, Caley M; Jacofsky, Marc C; Marzke, Mary W

    2008-04-01

    Molecular evidence indicates that the last common ancestor of the genus Pan and the hominin clade existed between 8 and 4 million years ago (Ma). The current fossil record indicates the Pan-Homo last common ancestor existed at least 5 Ma and most likely between 6 and 7 Ma. Together, the molecular and fossil evidence has important consequences for interpreting the evolutionary history of the hand within the tribe Hominini (hominins). Firstly, parsimony supports the hypothesis that the hand of the last common ancestor most likely resembled that of an extant great ape overall (Pan, Gorilla, and Pongo), and that of an African ape in particular. Second, it provides a context for interpreting the derived changes to the hand that have evolved in various hominins. For example, the Australopithecus afarensis hand is likely derived in comparison with that of the Pan-Homo last common ancestor in having shorter fingers relative to thumb length and more proximo-distally oriented joints between its capitate, second metacarpal, and trapezium. This evidence suggests that these derived features evolved prior to the intensification of stone tool-related hominin behaviors beginning around 2.5 Ma. However, a majority of primitive features most likely present in the Pan-Homo last common ancestor are retained in the hands of Australopithecus, Paranthropus/early Homo, and Homo floresiensis. This evidence suggests that further derived changes to the hands of other hominins such as modern humans and Neandertals did not evolve until after 2.5 Ma and possibly even later than 1.5 Ma, which is currently the earliest evidence of Acheulian technology. The derived hands of modern humans and Neandertals may indicate a morphological commitment to tool-related manipulative behaviors beyond that observed in other hominins, including those (e.g. H. floresiensis) which may be descended from earlier tool-making species. PMID:18380869

  3. Protein Analysis of Sapienic Acid-Treated Porphyromonas gingivalis Suggests Differential Regulation of Multiple Metabolic Pathways

    PubMed Central

    Dawson, Deborah V.; Blanchette, Derek R.; Drake, David R.; Wertz, Philip W.; Brogden, Kim A.

    2015-01-01

    ABSTRACT Lipids endogenous to skin and mucosal surfaces exhibit potent antimicrobial activity against Porphyromonas gingivalis, an important colonizer of the oral cavity implicated in periodontitis. Our previous work demonstrated the antimicrobial activity of the fatty acid sapienic acid (C16:1Δ6) against P. gingivalis and found that sapienic acid treatment alters both protein and lipid composition from those in controls. In this study, we further examined whole-cell protein differences between sapienic acid-treated bacteria and untreated controls, and we utilized open-source functional association and annotation programs to explore potential mechanisms for the antimicrobial activity of sapienic acid. Our analyses indicated that sapienic acid treatment induces a unique stress response in P. gingivalis resulting in differential expression of proteins involved in a variety of metabolic pathways. This network of differentially regulated proteins was enriched in protein-protein interactions (P = 2.98 × 10−8), including six KEGG pathways (P value ranges, 2.30 × 10−5 to 0.05) and four Gene Ontology (GO) molecular functions (P value ranges, 0.02 to 0.04), with multiple suggestive enriched relationships in KEGG pathways and GO molecular functions. Upregulated metabolic pathways suggest increases in energy production, lipid metabolism, iron acquisition and processing, and respiration. Combined with a suggested preferential metabolism of serine, which is necessary for fatty acid biosynthesis, these data support our previous findings that the site of sapienic acid antimicrobial activity is likely at the bacterial membrane. IMPORTANCE P. gingivalis is an important opportunistic pathogen implicated in periodontitis. Affecting nearly 50% of the population, periodontitis is treatable, but the resulting damage is irreversible and eventually progresses to tooth loss. There is a great need for natural products that can be used to treat and/or prevent the overgrowth of

  4. "H. Sapiens" as Ecologically Special: What Does Language Contribute?

    ERIC Educational Resources Information Center

    Ross, Don

    2007-01-01

    This paper inquires into the extent to which humans are specially constituted relative to other animals by their language. First a principled concept of evolutionary specialness is operationalized. Then it is agreed that humans satisfy the criteria for this sort of specialness in consequence of the kind of cultural evolution in which they have…

  5. Shared Pattern of Endocranial Shape Asymmetries among Great Apes, Anatomically Modern Humans, and Fossil Hominins

    PubMed Central

    Balzeau, Antoine; Gilissen, Emmanuel; Grimaud-Hervé, Dominique

    2012-01-01

    Anatomical asymmetries of the human brain are a topic of major interest because of their link with handedness and cognitive functions. Their emergence and occurrence have been extensively explored in human fossil records to document the evolution of brain capacities and behaviour. We quantified for the first time antero-posterior endocranial shape asymmetries in large samples of great apes, modern humans and fossil hominins through analysis of “virtual” 3D models of skull and endocranial cavity and we statistically test for departures from symmetry. Once based on continuous variables, we show that the analysis of these brain asymmetries gives original results that build upon previous analysis based on discrete traits. In particular, it emerges that the degree of petalial asymmetries differs between great apes and hominins without modification of their pattern. We indeed demonstrate the presence of shape asymmetries in great apes, with a pattern similar to modern humans but with a lower variation and a lower degree of fluctuating asymmetry. More importantly, variations in the position of the frontal and occipital poles on the right and left hemispheres would be expected to show some degree of antisymmetry when population distribution is considered, but the observed pattern of variation among the samples is related to fluctuating asymmetry for most of the components of the petalias. Moreover, the presence of a common pattern of significant directional asymmetry for two components of the petalias in hominids implicates that the observed traits were probably inherited from the last common ancestor of extant African great apes and Homo sapiens. These results also have important implications for the possible relationships between endocranial shape asymmetries and functional capacities in hominins. It emphasizes the uncoupling between lateralized activities, some of them well probably distinctive to Homo, and large-scale cerebral lateralization itself, which is not

  6. The Stem Species of Our Species: A Place for the Archaic Human Cranium from Ceprano, Italy

    PubMed Central

    Mounier, Aurélien; Condemi, Silvana; Manzi, Giorgio

    2011-01-01

    One of the present challenges in the study of human evolution is to recognize the hominin taxon that was ancestral to Homo sapiens. Some researchers regard H. heidelbergensis as the stem species involved in the evolutionary divergence leading to the emergence of H. sapiens in Africa, and to the evolution of the Neandertals in Europe. Nevertheless, the diagnosis and hypodigm of H. heidelbergensis still remain to be clarified. Here we evaluate the morphology of the incomplete cranium (calvarium) known as Ceprano whose age has been recently revised to the mid of the Middle Pleistocene, so as to test whether this specimen may be included in H. heidelbergensis. The analyses were performed according to a phenetic routine including geometric morphometrics and the evaluation of diagnostic discrete traits. The results strongly support the uniqueness of H. heidelbergensis on a wide geographical horizon, including both Eurasia and Africa. In this framework, the Ceprano calvarium – with its peculiar combination of archaic and derived traits – may represent, better than other penecontemporaneous specimens, an appropriate ancestral stock of this species, preceding the appearance of regional autapomorphic features. PMID:21533096

  7. New magnetostratigraphic dates of Lantian Homo erectus

    NASA Astrophysics Data System (ADS)

    Zhisheng, An; Kun, Ho Chuan

    1989-09-01

    Skeletal remains of Homo erectus found in Pleistocene loess at two sites near Lantian in central China are of greatly different geologic age. The cranium found in the fossil-bearing strata at Gongwangling is about 1.15 myr old whereas the remains found at the Chenjiawo locality in middle Pleistocene loess are about 0.65 myr old. The dating is based on new paleomagnetic polarity determinations and on the lithostratigraphic position of the fossils in the loess-paleosol sequence. Our results confirm that both localities are older than the first occupation of Zhoukoudian. New dates, palaeoenvironmental settings, and morphological features of the hominids from Lantian localities have significant bearing on the understanding of adaptive radiations of the middle and late hominids in Asia.

  8. Body proportions of Australopithecus afarensis and A. africanus and the origin of the genus Homo.

    PubMed

    McHenry, H M; Berger, L R

    1998-07-01

    New discoveries of A. africanus fossils from Member 4 Sterkfontein reveal a body form quite unlike earlier Australopithecus species. The new adult material consists of over 48 fore- and hindlimb specimens and includes an associated partial skeleton, Stw 431. The forelimbs and relatively large: the average size of their joints corresponds to a modern human with body mass of 53 kg. The hindlimbs are much smaller with an average size matching a modern human of only 33 kg. Analyses of the Stw 431 partial skeleton confirm these results. In contrast, A. afarensis and anamensis more closely approximate a human pattern of forelimb joint size. This is an unanticipated complication in our understanding of early human evolution. In general, craniodental morphology tracks time in species of Australopithecus: A. anamensis (3.5-4.1 Ma) is the the most primitive with a strongly sloping symphysis, large canine roots, etc., A. afarensis (3.0-3.6 Ma) is less primitive, and A. africanus (2.6-3.0 Ma) shares many derived characteristics with early Homo (e.g., expanded brain, reduced canine, bicuspid lower third premolar, reduced prognathism, greater flexion of the cranial base, deeper TMJ). the new postcranial material, however, reveals an apparently primitive morphology of relatively large forelimb and small hindlimb joints resembling more the pongid than the human pattern. More pongid-like proportions are also present in the two known associated partial skeletons of H. habilis (OH 62 KNM-ER 3735). This may imply either (1) that A. africanus and H. habilis evolved craniodental characters in parallel with the lineage leading to later Homo, or (2) that fore- to hindlimb proportions of A. afarensis (and perhaps A. anamensis) evolved independent of the lineage leading to Homo and does not imply a close phylogenetic link with Homo. Both of these explanations or any other phylogeny imply homoplasy.

  9. Human occupation of the Arabian Empty Quarter during MIS 5: evidence from Mundafan Al-Buhayrah, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Groucutt, Huw S.; White, Tom S.; Clark-Balzan, Laine; Parton, Ash; Crassard, Rémy; Shipton, Ceri; Jennings, Richard P.; Parker, Adrian G.; Breeze, Paul S.; Scerri, Eleanor M. L.; Alsharekh, Abdullah; Petraglia, Michael D.

    2015-07-01

    The Empty Quarter (or Rub' al Khali) of the Arabian Peninsula is the largest continuous sandy desert in the world. It has been known for several decades that Late Pleistocene and Holocene deposits, representing phases of wetter climate, are preserved there. These sequences have yielded palaeontological evidence in the form of a variety of vertebrate and invertebrate fossils and have been dated using various radiometric techniques. However, evidence for human presence during these wetter phases has until now been ephemeral. Here, we report on the first stratified and dated archaeology from the Empty Quarter, recovered from the site of Mundafan Al-Buhayrah (MDF-61). Human occupation at the site, represented by stone tools, has been dated to the later part of Marine Isotope Stage (MIS) 5 using multiple luminescence dating techniques (multigrain and single grain OSL, TT-OSL). The sequence consists primarily of lacustrine and palustrine sediments, from which evidence for changing local environmental conditions has been obtained through analysis of fossil assemblages (phytoliths and non-marine molluscs and ostracods). The discovery of securely-dated archaeological material at ∼100 to 80 ka in the Empty Quarter has important implications for hypotheses concerning the timing and routes of dispersal of Homo sapiens out of Africa, which have been much debated. Consequently, the data presented here fill a crucial gap in palaeoenvironmental and archaeological understanding of the southern Arabian interior. Fossils of H. sapiens in the Levant, also dated to MIS 5, together with Middle Palaeolithic archaeological sites in Arabia and India are thought to represent the earliest dispersal of our species out of Africa. We suggest that the widespread occurrence of similar lithic technologies across southern Asia, coupled with a growing body of evidence for environmental amelioration across the Saharo-Arabian belt, indicates that occupation of the Levant by H. sapiens during MIS 5

  10. The Hominin Sites and Paleolakes Drilling Project: inferring the environmental context of human evolution from eastern African rift lake deposits

    NASA Astrophysics Data System (ADS)

    Cohen, A.; Campisano, C.; Arrowsmith, R.; Asrat, A.; Behrensmeyer, A. K.; Deino, A.; Feibel, C.; Hill, A.; Johnson, R.; Kingston, J.; Lamb, H.; Lowenstein, T.; Noren, A.; Olago, D.; Owen, R. B.; Potts, R.; Reed, K.; Renaut, R.; Schäbitz, F.; Tiercelin, J.-J.; Trauth, M. H.; Wynn, J.; Ivory, S.; Brady, K.; O'Grady, R.; Rodysill, J.; Githiri, J.; Russell, J.; Foerster, V.; Dommain, R.; Rucina, S.; Deocampo, D.; Russell, J.; Billingsley, A.; Beck, C.; Dorenbeck, G.; Dullo, L.; Feary, D.; Garello, D.; Gromig, R.; Johnson, T.; Junginger, A.; Karanja, M.; Kimburi, E.; Mbuthia, A.; McCartney, T.; McNulty, E.; Muiruri, V.; Nambiro, E.; Negash, E. W.; Njagi, D.; Wilson, J. N.; Rabideaux, N.; Raub, T.; Sier, M. J.; Smith, P.; Urban, J.; Warren, M.; Yadeta, M.; Yost, C.; Zinaye, B.

    2016-02-01

    The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.

  11. A modern human pattern of dental development in Lower Pleistocene hominids from Atapuerca-TD6 (Spain)

    PubMed Central

    Bermúdez de Castro, J. M.; Rosas, A.; Carbonell, E.; Nicolás, M. E.; Rodríguez, J.; Arsuaga, J. L.

    1999-01-01

    The study of life history evolution in hominids is crucial for the discernment of when and why humans have acquired our unique maturational pattern. Because the development of dentition is critically integrated into the life cycle in mammals, the determination of the time and pattern of dental development represents an appropriate method to infer changes in life history variables that occurred during hominid evolution. Here we present evidence derived from Lower Pleistocene human fossil remains recovered from the TD6 level (Aurora stratum) of the Gran Dolina site in the Sierra de Atapuerca, northern Spain. These hominids present a pattern of development similar to that of Homo sapiens, although some aspects (e.g., delayed M3 calcification) are not as derived as that of European populations and people of European origin. This evidence, taken together with the present knowledge of cranial capacity of these and other late Early Pleistocene hominids, supports the view that as early as 0.8 Ma at least one Homo species shared with modern humans a prolonged pattern of maturation. PMID:10097189

  12. A modern human pattern of dental development in lower pleistocene hominids from Atapuerca-TD6 (Spain).

    PubMed

    Bermúdez de Castro, J M; Rosas, A; Carbonell, E; Nicolás, M E; Rodríguez, J; Arsuaga, J L

    1999-03-30

    The study of life history evolution in hominids is crucial for the discernment of when and why humans have acquired our unique maturational pattern. Because the development of dentition is critically integrated into the life cycle in mammals, the determination of the time and pattern of dental development represents an appropriate method to infer changes in life history variables that occurred during hominid evolution. Here we present evidence derived from Lower Pleistocene human fossil remains recovered from the TD6 level (Aurora stratum) of the Gran Dolina site in the Sierra de Atapuerca, northern Spain. These hominids present a pattern of development similar to that of Homo sapiens, although some aspects (e.g., delayed M3 calcification) are not as derived as that of European populations and people of European origin. This evidence, taken together with the present knowledge of cranial capacity of these and other late Early Pleistocene hominids, supports the view that as early as 0.8 Ma at least one Homo species shared with modern humans a prolonged pattern of maturation.

  13. A neonatal perspective on Homo erectus brain growth.

    PubMed

    Cofran, Zachary; DeSilva, Jeremy M

    2015-04-01

    The Mojokerto calvaria has been central to assessment of brain growth in Homo erectus, but different analytical approaches and uncertainty in the specimen's age at death have hindered consensus on the nature of H. erectus brain growth. We simulate average annual rates (AR) of absolute endocranial volume (ECV) growth and proportional size change (PSC) in H. erectus, utilizing estimates of H. erectus neonatal ECV and a range of ages for Mojokerto. These values are compared with resampled ARs and PSCs from ontogenetic series of humans, chimpanzees, and gorillas from birth to six years. Results are consistent with other studies of ECV growth in extant taxa. There is extensive overlap in PSC between all living species through the first postnatal year, with continued but lesser overlap between humans and chimpanzees to age six. Human ARs are elevated above those of apes, although there is modest overlap up to 0.50 years. Ape ARs overlap throughout the sequence, with gorillas slightly elevated over chimpanzees up to 0.50 years. Simulated H. erectus PSCs can be found in all living species by 0.50 years, and the median falls below the human and chimpanzee ranges after 2.5 years. H. erectus ARs are elevated above those of all extant taxa prior to 0.50 years, and after two years they fall out of the human range but are still above ape ranges. A review of evidence for the age at death of Mojokerto supports an estimate of around one year, indicating absolute brain growth rates in the lower half of the human range. These results point to secondary altriciality in H. erectus, implying that key human adaptations for increasing the energy budget of females may have been established by at least 1 Ma. PMID:25771994

  14. Molecular genetic determinants of human brain size.

    PubMed

    Tang, Bor Luen

    2006-07-01

    Cognitive skills such as tool use, syntactical languages, and self-awareness differentiate humans from other primates. The underlying basis for this cognitive difference has been widely associated with a high encephalization quotient and an anatomically distinct, exceptionally large cerebral cortex. Investigations on congenital microcephaly had revealed several genes that affect mammalian brain size when mutated. At least four of these, microcephalin (MCPH1), abnormal spindle-like microcephaly-associated (ASPM), cyclin-dependent kinase 5 regulatory associated protein 2 (CDK5RAP2), and centromere-associated protein J (CENPJ) are known to have undergone significant positive selection in the great apes and human lineages during primate evolution. MCPH1 and ASPM both have very young single nucleotide polymorphism haplotypes associated with modern humans, and these genes are presumably still evolving in Homo sapiens. Microcephalin has a role in DNA damage response and regulation of cell cycle checkpoints. The other known microcephaly-associated genes encode microtubule-associated centrosomal proteins that might regulate neural progenitor cell division and cell number. Recent reports have also unveiled a previously unknown function of ephrins and Eph in the regulation of neural progenitor cell death with a consequential effect on brain size. Understanding the mechanism for developmental control of brain organogenesis by these genes, and others such as FOXP2, shall provide fresh perspectives on the evolution of human intelligence. PMID:16716254

  15. Molecular genetic determinants of human brain size.

    PubMed

    Tang, Bor Luen

    2006-07-01

    Cognitive skills such as tool use, syntactical languages, and self-awareness differentiate humans from other primates. The underlying basis for this cognitive difference has been widely associated with a high encephalization quotient and an anatomically distinct, exceptionally large cerebral cortex. Investigations on congenital microcephaly had revealed several genes that affect mammalian brain size when mutated. At least four of these, microcephalin (MCPH1), abnormal spindle-like microcephaly-associated (ASPM), cyclin-dependent kinase 5 regulatory associated protein 2 (CDK5RAP2), and centromere-associated protein J (CENPJ) are known to have undergone significant positive selection in the great apes and human lineages during primate evolution. MCPH1 and ASPM both have very young single nucleotide polymorphism haplotypes associated with modern humans, and these genes are presumably still evolving in Homo sapiens. Microcephalin has a role in DNA damage response and regulation of cell cycle checkpoints. The other known microcephaly-associated genes encode microtubule-associated centrosomal proteins that might regulate neural progenitor cell division and cell number. Recent reports have also unveiled a previously unknown function of ephrins and Eph in the regulation of neural progenitor cell death with a consequential effect on brain size. Understanding the mechanism for developmental control of brain organogenesis by these genes, and others such as FOXP2, shall provide fresh perspectives on the evolution of human intelligence.

  16. SAPIENS: Spreading Activation Processor for Information Encoded in Network Structures. Technical Report No. 296.

    ERIC Educational Resources Information Center

    Ortony, Andrew; Radin, Dean I.

    The product of researchers' efforts to develop a computer processor which distinguishes between relevant and irrelevant information in the database, Spreading Activation Processor for Information Encoded in Network Structures (SAPIENS) exhibits (1) context sensitivity, (2) efficiency, (3) decreasing activation over time, (4) summation of…

  17. Archaic and modern human distal humeral morphology.

    PubMed

    Yokley, Todd R; Churchill, Steven E

    2006-12-01

    The morphology of the proximal ulna has been shown to effectively differentiate archaic or premodern humans (such as Homo heidelbergensis and H. neanderthalensis) from modern humans (H. sapiens). Accordingly, the morphology of adjacent, articulating elements should be able to distinguish these two broad groups as well. Here we test the taxonomic utility of another portion of the elbow, the distal humerus, as a discriminator of archaic and modern humans. Principal components analysis was employed on a suite of log-raw and log-shape distal humeral measures to examine differences between Neandertal and modern human distal humeri. In addition, the morphological affinities of Broken Hill (Kabwe) E.898, an archaic human distal humeral fragment from the middle Pleistocene of Zambia, and five Pliocene and early Pleistocene australopith humeri were assessed. The morphometric analyses effectively differentiated the Neandertals from the other groups, while the Broken Hill humerus appears morphologically similar to modern human distal humeri. Thus, an archaic/modern human dichotomy-as previously reported for proximal ulnar morphology-is not supported with respect to distal humeral morphology. Relative to australopiths and modern humans, Neandertal humeri are characterized by large olecranon fossae and small distodorsal medial and lateral pillars. The seeming disparity in morphological affinities of proximal ulnae (in which all archaic human groups appear distinct from modern humans) and distal humeri (in which Neandertals appear distinct from modern humans, but other archaic humans do not) is probably indicative of a highly variable, possibly transitional population of which our knowledge is hampered by sample-size limitations imposed by the scarcity of middle-to-late Pleistocene premodern human fossils outside of Europe.

  18. The mitochondrial Italian Human Proteome Project initiative (mt-HPP).

    PubMed

    Urbani, Andrea; De Canio, Michele; Palmieri, Ferdinando; Sechi, Salvatore; Bini, Luca; Castagnola, Massimo; Fasano, Mauro; Modesti, Alessandra; Roncada, Paola; Timperio, Anna Maria; Bonizzi, Luigi; Brunori, Maurizio; Cutruzzolà, Francesca; De Pinto, Vito; Di Ilio, Carmine; Federici, Giorgio; Folli, Franco; Foti, Salvatore; Gelfi, Cecilia; Lauro, Davide; Lucacchini, Antonio; Magni, Fulvio; Messana, Irene; Pandolfi, Pier Paolo; Papa, Sergio; Pucci, Piero; Sacchetta, Paolo

    2013-08-01

    Mitochondria carry maternally inherited genetic material, called the mitochondrial genome (mtDNA), which can be defined as the 25th human chromosome. The chromosome-centric Human Proteome Project (c-HPP) has initially focused its activities addressing the characterization and quantification of the nuclear encoded proteins. Following the last International HUPO Congress in Boston (September 2012) it was clear that however small the mitochondrial chromosome is, it plays an important role in many biological and physiopathological functions. Mutations in the mtDNA have been shown to be associated with dozens of unexplained disorders and the information contained in the mtDNA should be of major relevance to the understanding of many human diseases. Within this paper we describe the Italian initiative of the Human Proteome Project dedicated to mitochondria as part of both programs: chromosome-centric (c-HPP) and Biology/Disease (B/D-HPP). The mt-HPP has finally shifted the attention of the HUPO community outside the nuclear chromosomes with the general purpose to highlight the mitochondrial processes influencing the human health. Following this vision and considering the large interest and evidence collected on the non-Mendelian heredity of Homo sapiens associated with mt-chromosome and with the microbial commensal ecosystem constituting our organism we may speculate that this program will represent an initial step toward other HPP initiatives focusing on human phenotypic heredity.

  19. From Darwinian to technological evolution: forgetting the human lottery.

    PubMed

    Tintino, Giorgio

    2014-01-01

    The GRIN technologies (-geno, -robo, -info, -nano) promise to change the inner constitution of human body and its own existence. This transformation involves the structure of our lives and represent a brave new world that we have to explore and to manage. In this sense, the traditional tools of humanism seems very inadequate to think the biotech century and there is a strong demand of a new thought for the evolution and the concrete history of life. The posthuman philosophy tries to take this new path of human existence in all of its novelty since GRIN technologies seem to promise new and unexpected paths of evolution to living beings and, above all, man. For this, the post-human thought, as we see, is a new anthropological overview on the concrete evolution of human being, an overview that involves an epistemological revolution of the categories that humanism uses to conceptualize the journey that divides the Homo sapiens from the man. But, is this right? PMID:25684379

  20. Taphonomy of the Tianyuandong human skeleton and faunal remains.

    PubMed

    Fernández-Jalvo, Yolanda; Andrews, Peter; Tong, HaoWen

    2015-06-01

    Tianyuan Cave is an Upper Palaeolithic site, 6 km from the core area of the Zhoukoudian Site Complex. Tianyuandong (or Tianyuan Cave) yielded one ancient (though not the earliest) fossil skeleton of Homo sapiens in China (42-39 ka cal BP). Together with the human skeleton, abundant animal remains were found, but no stone tools were recovered. The animal fossil remains are extremely fragmentary, in contrast to human skeletal elements that are, for the most part, complete. We undertook a taphonomic study to investigate the circumstances of preservation of the human skeleton in Tianyuan Cave, and in course of this we considered four hypotheses: funerary ritual, cannibalism, carnivore activity or natural death. Taphonomic results characterize the role of human action in the site and how these agents acted in the past. Because of disturbance of the human skeleton during its initial excavation, it is not known if it was in a grave cut or if there was any funerary ritual. No evidence was found for cannibalism or carnivore activity in relation to the human skeleton, suggesting natural death as the most reasonable possibility. PMID:25929706

  1. Taphonomy of the Tianyuandong human skeleton and faunal remains.

    PubMed

    Fernández-Jalvo, Yolanda; Andrews, Peter; Tong, HaoWen

    2015-06-01

    Tianyuan Cave is an Upper Palaeolithic site, 6 km from the core area of the Zhoukoudian Site Complex. Tianyuandong (or Tianyuan Cave) yielded one ancient (though not the earliest) fossil skeleton of Homo sapiens in China (42-39 ka cal BP). Together with the human skeleton, abundant animal remains were found, but no stone tools were recovered. The animal fossil remains are extremely fragmentary, in contrast to human skeletal elements that are, for the most part, complete. We undertook a taphonomic study to investigate the circumstances of preservation of the human skeleton in Tianyuan Cave, and in course of this we considered four hypotheses: funerary ritual, cannibalism, carnivore activity or natural death. Taphonomic results characterize the role of human action in the site and how these agents acted in the past. Because of disturbance of the human skeleton during its initial excavation, it is not known if it was in a grave cut or if there was any funerary ritual. No evidence was found for cannibalism or carnivore activity in relation to the human skeleton, suggesting natural death as the most reasonable possibility.

  2. From Darwinian to technological evolution: forgetting the human lottery.

    PubMed

    Tintino, Giorgio

    2014-01-01

    The GRIN technologies (-geno, -robo, -info, -nano) promise to change the inner constitution of human body and its own existence. This transformation involves the structure of our lives and represent a brave new world that we have to explore and to manage. In this sense, the traditional tools of humanism seems very inadequate to think the biotech century and there is a strong demand of a new thought for the evolution and the concrete history of life. The posthuman philosophy tries to take this new path of human existence in all of its novelty since GRIN technologies seem to promise new and unexpected paths of evolution to living beings and, above all, man. For this, the post-human thought, as we see, is a new anthropological overview on the concrete evolution of human being, an overview that involves an epistemological revolution of the categories that humanism uses to conceptualize the journey that divides the Homo sapiens from the man. But, is this right?

  3. Fitness cost of LINE-1 (L1) activity in humans

    PubMed Central

    Boissinot, Stephane; Davis, Jerel; Entezam, Ali; Petrov, Dimitri; Furano, Anthony V.

    2006-01-01

    The self-replicating LINE-1 (L1) retrotransposon family is the dominant retrotransposon family in mammals and has generated 30–40% of their genomes. Active L1 families are present in modern mammals but the important question of whether these currently active families affect the genetic fitness of their hosts has not been addressed. This issue is of particular relevance to humans as Homo sapiens contains the active L1 Ta1 subfamily of the human specific Ta (L1Pa1) L1 family. Although DNA insertions generated by the Ta1 subfamily can cause genetic defects in current humans, these are relatively rare, and it is not known whether Ta1-generated inserts or any other property of Ta1 elements have been sufficiently deleterious to reduce the fitness of humans. Here we show that full-length (FL) Ta1 elements, but not the truncated Ta1 elements or SINE (Alu) insertions generated by Ta1 activity, were subject to negative selection. Thus, one or more properties unique to FL L1 elements constitute a genetic burden for modern humans. We also found that the FL Ta1 elements became more deleterious as the expansion of Ta1 has proceeded. Because this expansion is ongoing, the Ta1 subfamily almost certainly continues to decrease the fitness of modern humans. PMID:16766655

  4. Molar crown inner structural organization in Javanese Homo erectus.

    PubMed

    Zanolli, Clément

    2015-01-01

    This contribution investigates the inner organizational pattern (tooth tissue proportions and enamel-dentine junction morphology) of seven Homo erectus permanent molar crowns from the late Lower-early Middle Pleistocene Kabuh Formation of the Sangiran Dome (Central Java, Indonesia). The previous study of their external characteristics confirmed the degree of time-related structural reduction occurred in Javanese H. erectus, and also revealed a combination of nonmetric features which are rare in the Lower and early Middle Pleistocene dental record, but more frequently found in recent humans. In accordance with their outer occlusal morphology, the specimens exhibit a set of derived internal features, such as thick to hyperthick enamel, an incomplete expression of the crest patterns at the enamel-dentine junction (EDJ) level, a sharp EDJ topography. As a whole, these features differ from those expressed in some penecontemporaneous specimens/samples representing African H. erectus/ergaster and H. heidelbergensis, as well as in Neanderthals, but occur in recent human populations. Further research in virtual dental paleoanthropology to be developed at macroregional scale would clarify the polarity and intensity of the intermittent exchanges between continental and insular Southeast Asia around the Lower to Middle Pleistocene boundary, as well as should shed light on the still poorly understood longitudinal evolutionary dynamics across continental Asia. PMID:25209431

  5. The evolution of early Homo: a reply to Scott.

    PubMed

    Van Arsdale, A P; Wolpoff, M H

    2014-03-01

    Scott presents a welcome reply to our article, "A single lineage in early Pleistocene Homo" (Van Arsdale and Wolpoff ). However, Scott's reply mischaracterizes and fails to directly address the hypothesis of a single lineage that we test. Additionally, the approach taken by Scott fails to replicate the methods used in our analysis. As Scott himself suggests, our null hypothesis of a single evolving lineage in early Homo remains without refutation. Although many evolutionary scenarios might explain the complex pattern of variation present in the early Homo fossil record, the most parsimonious remains that of a single lineage displaying evolutionary change over time. PMID:24372272

  6. PELDOR in rotationally symmetric homo-oligomers

    NASA Astrophysics Data System (ADS)

    Giannoulis, Angeliki; Ward, Richard; Branigan, Emma; Naismith, James H.; Bode, Bela E.

    2013-10-01

    Nanometre distance measurements by pulsed electron-electron double resonance (PELDOR) spectroscopy have become an increasingly important tool in structural biology. The theoretical underpinning of the experiment is well defined for systems containing two nitroxide spin-labels (spin pairs); however, recently experiments have been reported on homo-oligomeric membrane proteins consisting of up to eight spin-labelled monomers. We have explored the theory behind these systems by examining model systems based on multiple spins arranged in rotationally symmetric polygons. The results demonstrate that with a rising number of spins within the test molecule, increasingly strong distortions appear in distance distributions obtained from an analysis based on the simple spin pair approach. These distortions are significant over a range of system sizes and remain so even when random errors are introduced into the symmetry of the model. We present an alternative approach to the extraction of distances on such systems based on a minimisation that properly treats multi-spin correlations. We demonstrate the utility of this approach on a spin-labelled mutant of the heptameric Mechanosensitive Channel of Small Conductance of E. coli.

  7. Heterochronic processes in human evolution: an ontogenetic analysis of the hominid pelvis.

    PubMed

    Berge, C

    1998-04-01

    Changes in pelvic shape in human ontogeny and hominid phylogeny suggest that the heterochronic processes involved differ greatly from the neotenic process traditionally described in the evolution of the skull. The morphology of 150 juvenile and adult pelves of African apes, 60 juvenile and adult pelves of modern humans, two adult pelves and a juvenile hip bone of australopithecines (Sts 14, AL 288, MLD 7) was studied. Multivariate results, ontogenetic allometries, and growth curves confirm that the pelvic growth pattern in humans differs markedly from those of the African apes. The results permit the following conclusions. First, the appearance of a new feature (acetabulo-cristal buttress and cristal tubercle) at the time of human birth allows the addition of traits, such as the attainment of a proportionally narrower pelvis, with more sagittally positioned iliac blades. Pelvic proportions and orientation change progressively in early childhood as bipedalism is practiced. Other changes in pelvic proportions occur later with the adolescent growth spurt. Second, comparison of juvenile and adult australopithecines to modern humans indicates that 1) some pelvic traits of adult Australopithecus resemble those of neonate Homo; 2) the pelvic growth of Australopithecus was probably closer to that of apes, than to that of humans; and 3) prolonged growth in length of hindlimb and pelvis after sexual maturity seems to be a unique feature of Homo. The position of the acetabulo-cristal buttress and of the cristal tubercle on the ilium are similar in adult Australopithecus and neonate Homo suggesting that this feature may have been displaced later during hominid evolution. Progressive displacement of the acetabulo-cristal buttress on the ilium occurs both during hominid evolution (from Australopithecus to Homo sapiens) and human growth (from neonate to adult). This suggests peramorphic evolution of the pelvic morphology of hominids combining three processes of recapitulation

  8. Heterochronic processes in human evolution: an ontogenetic analysis of the hominid pelvis.

    PubMed

    Berge, C

    1998-04-01

    Changes in pelvic shape in human ontogeny and hominid phylogeny suggest that the heterochronic processes involved differ greatly from the neotenic process traditionally described in the evolution of the skull. The morphology of 150 juvenile and adult pelves of African apes, 60 juvenile and adult pelves of modern humans, two adult pelves and a juvenile hip bone of australopithecines (Sts 14, AL 288, MLD 7) was studied. Multivariate results, ontogenetic allometries, and growth curves confirm that the pelvic growth pattern in humans differs markedly from those of the African apes. The results permit the following conclusions. First, the appearance of a new feature (acetabulo-cristal buttress and cristal tubercle) at the time of human birth allows the addition of traits, such as the attainment of a proportionally narrower pelvis, with more sagittally positioned iliac blades. Pelvic proportions and orientation change progressively in early childhood as bipedalism is practiced. Other changes in pelvic proportions occur later with the adolescent growth spurt. Second, comparison of juvenile and adult australopithecines to modern humans indicates that 1) some pelvic traits of adult Australopithecus resemble those of neonate Homo; 2) the pelvic growth of Australopithecus was probably closer to that of apes, than to that of humans; and 3) prolonged growth in length of hindlimb and pelvis after sexual maturity seems to be a unique feature of Homo. The position of the acetabulo-cristal buttress and of the cristal tubercle on the ilium are similar in adult Australopithecus and neonate Homo suggesting that this feature may have been displaced later during hominid evolution. Progressive displacement of the acetabulo-cristal buttress on the ilium occurs both during hominid evolution (from Australopithecus to Homo sapiens) and human growth (from neonate to adult). This suggests peramorphic evolution of the pelvic morphology of hominids combining three processes of recapitulation

  9. The Homo habitat niche: using the avian fossil record to depict ecological characteristics of Palaeolithic Eurasian hominins

    NASA Astrophysics Data System (ADS)

    Finlayson, Clive; Carrión, José; Brown, Kimberly; Finlayson, Geraldine; Sánchez-Marco, Antonio; Fa, Darren; Rodríguez-Vidal, Joaquín; Fernández, Santiago; Fierro, Elena; Bernal-Gómez, Marco; Giles-Pacheco, Francisco

    2011-06-01

    Although hardly applied to human palaeoecology, bird fossils offer a unique opportunity for quantitative studies of the hominin habitat. Here we reconstruct the Homo habitat niche across a large area of the Palaearctic, based on a database of avian fauna for Pleistocene sites. Our results reveal a striking association between Homo and habitat mosaics. A mix of open savannah-type woodland, wetlands and rocky habitats emerges as the predominant combination occupied by Homo across a wide geographical area, from the earliest populations of the Lower Palaeolithic to the latest hunter-gatherer communities of the Upper Palaeolithic. This observation is in keeping with the view that such landscapes have had long standing selective value for hominins.

  10. An earlier origin for stone tool making: implications for cognitive evolution and the transition to Homo.

    PubMed

    Lewis, Jason E; Harmand, Sonia

    2016-07-01

    The discovery of the earliest known stone tools at Lomekwi 3 (LOM3) from West Turkana, Kenya, dated to 3.3 Ma, raises new questions about the mode and tempo of key adaptations in the hominin lineage. The LOM3 tools date to before the earliest known fossils attributed to Homo at 2.8 Ma. They were made and deposited in a more C3 environment than were the earliest Oldowan tools at 2.6 Ma. Their discovery leads to renewed investigation on the timing of the emergence of human-like manipulative capabilities in early hominins and implications for reconstructing cognition. The LOM3 artefacts form part of an emerging paradigm shift in palaeoanthropology, in which: tool-use and tool-making behaviours are not limited to the genus Homo; cranial, post-cranial and behavioural diversity in early Homo is much wider than previously thought; and these evolutionary changes may not have been direct adaptations to living in savannah grassland environments.This article is part of the themed issue 'Major transitions in human evolution'. PMID:27298464

  11. Descriptions of the lower limb skeleton of Homo floresiensis.

    PubMed

    Jungers, W L; Larson, S G; Harcourt-Smith, W; Morwood, M J; Sutikna, T; Due Awe, Rokhus; Djubiantono, T

    2009-11-01

    Bones of the lower extremity have been recovered for up to nine different individuals of Homo floresiensis - LB1, LB4, LB6, LB8, LB9, LB10, LB11, LB13, and LB14. LB1 is represented by a bony pelvis (damaged but now repaired), femora, tibiae, fibulae, patellae, and numerous foot bones. LB4/2 is an immature right tibia lacking epiphyses. LB6 includes a fragmentary metatarsal and two pedal phalanges. LB8 is a nearly complete right tibia (shorter than that of LB1). LB9 is a fragment of a hominin femoral diaphysis. LB10 is a proximal hallucal phalanx. LB11 includes pelvic fragments and a fragmentary metatarsal. LB13 is a patellar fragment, and LB14 is a fragment of an acetabulum. All skeletal remains recovered from Liang Bua were extremely fragile, and some were badly damaged when they were removed temporarily from Jakarta. At present, virtually all fossil materials have been returned, stabilized, and hardened. These skeletal remains are described and illustrated photographically. The lower limb skeleton exhibits a uniquely mosaic pattern, with many primitive-like morphologies; we have been unable to find this combination of ancient and derived (more human-like) features in either healthy or pathological modern humans, regardless of body size. Bilateral asymmetries are slight in the postcranium, and muscle markings are clearly delineated on all bones. The long bones are robust, and the thickness of their cortices is well within the ranges seen in healthy modern humans. LB1 is most probably a female based on the shape of her greater sciatic notch, and the marked degree of lateral iliac flaring recalls that seen in australopithecines such as "Lucy" (AL 288-1). The metatarsus has a human-like robusticity formula, but the proximal pedal phalanges are relatively long and robust (and slightly curved). The hallux is fully adducted, but we suspect that a medial longitudinal arch was absent. PMID:19062072

  12. Descriptions of the lower limb skeleton of Homo floresiensis.

    PubMed

    Jungers, W L; Larson, S G; Harcourt-Smith, W; Morwood, M J; Sutikna, T; Due Awe, Rokhus; Djubiantono, T

    2009-11-01

    Bones of the lower extremity have been recovered for up to nine different individuals of Homo floresiensis - LB1, LB4, LB6, LB8, LB9, LB10, LB11, LB13, and LB14. LB1 is represented by a bony pelvis (damaged but now repaired), femora, tibiae, fibulae, patellae, and numerous foot bones. LB4/2 is an immature right tibia lacking epiphyses. LB6 includes a fragmentary metatarsal and two pedal phalanges. LB8 is a nearly complete right tibia (shorter than that of LB1). LB9 is a fragment of a hominin femoral diaphysis. LB10 is a proximal hallucal phalanx. LB11 includes pelvic fragments and a fragmentary metatarsal. LB13 is a patellar fragment, and LB14 is a fragment of an acetabulum. All skeletal remains recovered from Liang Bua were extremely fragile, and some were badly damaged when they were removed temporarily from Jakarta. At present, virtually all fossil materials have been returned, stabilized, and hardened. These skeletal remains are described and illustrated photographically. The lower limb skeleton exhibits a uniquely mosaic pattern, with many primitive-like morphologies; we have been unable to find this combination of ancient and derived (more human-like) features in either healthy or pathological modern humans, regardless of body size. Bilateral asymmetries are slight in the postcranium, and muscle markings are clearly delineated on all bones. The long bones are robust, and the thickness of their cortices is well within the ranges seen in healthy modern humans. LB1 is most probably a female based on the shape of her greater sciatic notch, and the marked degree of lateral iliac flaring recalls that seen in australopithecines such as "Lucy" (AL 288-1). The metatarsus has a human-like robusticity formula, but the proximal pedal phalanges are relatively long and robust (and slightly curved). The hallux is fully adducted, but we suspect that a medial longitudinal arch was absent.

  13. OrthoDisease: a database of human disease orthologs.

    PubMed

    O'Brien, Kevin P; Westerlund, Isabelle; Sonnhammer, Erik L L

    2004-08-01

    One of the greatest promises of genome sequencing projects is to further the understanding of human diseases and to develop new therapies. Model organism genomes have been sequenced in parallel to human genomes to provide effective tools for the investigation of human gene function. Many of their genes share a common ancestry and function with human genes, and this is particularly true for orthologous genes. Here we present OrthoDisease, a comprehensive database of model organism genes that are orthologous to human disease genes. OrthoDisease was constructed by applying the Inparanoid ortholog detection algorithm to disease genes derived from the Online Mendelian Inheritance in Man database (OMIM). Pairwise whole genome/proteome comparisons between Homo sapiens and six other organisms were performed to identify ortholog clusters. OMIM numbers were extracted from the OMIM Morbid Map and were converted to gene sequences using the Locuslink mim2loc and loc2acc tables. These were mapped to Inparanoid ortholog clusters using Blast. The number of ortholog clusters in OrthoDisease with each respective species is currently: M. musculus, 1,354; D. melanogaster, 724; C. elegans, 533; A. thaliana, 398; S. cerevisiae, 290; and E. coli, 153. The database is accessible online at http://orthodisease.cgb.ki.se, and can be searched with disease or protein names. The web interface presents all ortholog clusters that include a selected disease gene. A capability to download the entire dataset is also provided.

  14. Middle Pleistocene lower back and pelvis from an aged human individual from the Sima de los Huesos site, Spain

    PubMed Central

    Bonmatí, Alejandro; Gómez-Olivencia, Asier; Arsuaga, Juan-Luis; Carretero, José Miguel; Gracia, Ana; Martínez, Ignacio; Lorenzo, Carlos; Bérmudez de Castro, José María; Carbonell, Eudald

    2010-01-01

    We report a nearly complete lumbar spine from the Middle Pleistocene site of the Sima de los Huesos (SH) that is assigned to the previously published SH male Pelvis 1 [Arsuaga JL, et al. (1999). Nature 399: 255–258]. The “SH Pelvis 1 individual” is a unique nearly complete lumbo-pelvic complex from the human Middle Pleistocene fossil record, and offers a rare glimpse into the anatomy and past lifeways of Homo heidelbergensis. A revised reconstruction of Pelvis 1, together with the current fossil evidence, confirms our previous hypothesis that the morphology of this pelvis represents the primitive pattern within the genus Homo. Here we argue that this primitive pattern is also characterized by sexual dimorphism in the pelvic canal shape, implying complicated deliveries. In addition, this individual shows signs of lumbar kyphotic deformity, spondylolisthesis, and Baastrup disease. This suite of lesions would have postural consequences and was most likely painful. As a result, the individual’s daily physical activities would have been restricted to some extent. Reexamination of the age-at-death agrees with this individual being over 45 y old, relying on the modern human pattern of changes of the articular surfaces of the os coxae. The presence of degenerative pathological lesions and the advanced age-at-death of this individual make it the most ancient postcranial evidence of an aged individual in the human fossil record. Additional nonpathological SH lumbo-pelvic remains are consistent with previous hypotheses, suggesting a less-pronounced sagittal spinal curvature in Neandertals compared with Homo sapiens. PMID:20937858

  15. The integration hypothesis of human language evolution and the nature of contemporary languages

    PubMed Central

    Miyagawa, Shigeru; Ojima, Shiro; Berwick, Robert C.; Okanoya, Kazuo

    2014-01-01

    How human language arose is a mystery in the evolution of Homo sapiens. Miyagawa et al. (2013) put forward a proposal, which we will call the Integration Hypothesis of human language evolution, that holds that human language is composed of two components, E for expressive, and L for lexical. Each component has an antecedent in nature: E as found, for example, in birdsong, and L in, for example, the alarm calls of monkeys. E and L integrated uniquely in humans to give rise to language. A challenge to the Integration Hypothesis is that while these non-human systems are finite-state in nature, human language is known to require characterization by a non-finite state grammar. Our claim is that E and L, taken separately, are in fact finite-state; when a grammatical process crosses the boundary between E and L, it gives rise to the non-finite state character of human language. We provide empirical evidence for the Integration Hypothesis by showing that certain processes found in contemporary languages that have been characterized as non-finite state in nature can in fact be shown to be finite-state. We also speculate on how human language actually arose in evolution through the lens of the Integration Hypothesis. PMID:24936195

  16. The integration hypothesis of human language evolution and the nature of contemporary languages.

    PubMed

    Miyagawa, Shigeru; Ojima, Shiro; Berwick, Robert C; Okanoya, Kazuo

    2014-01-01

    How human language arose is a mystery in the evolution of Homo sapiens. Miyagawa et al. (2013) put forward a proposal, which we will call the Integration Hypothesis of human language evolution, that holds that human language is composed of two components, E for expressive, and L for lexical. Each component has an antecedent in nature: E as found, for example, in birdsong, and L in, for example, the alarm calls of monkeys. E and L integrated uniquely in humans to give rise to language. A challenge to the Integration Hypothesis is that while these non-human systems are finite-state in nature, human language is known to require characterization by a non-finite state grammar. Our claim is that E and L, taken separately, are in fact finite-state; when a grammatical process crosses the boundary between E and L, it gives rise to the non-finite state character of human language. We provide empirical evidence for the Integration Hypothesis by showing that certain processes found in contemporary languages that have been characterized as non-finite state in nature can in fact be shown to be finite-state. We also speculate on how human language actually arose in evolution through the lens of the Integration Hypothesis.

  17. Characterizing the Evolutionary Path(s) to Early Homo

    PubMed Central

    Schroeder, Lauren; Roseman, Charles C.; Cheverud, James M.; Ackermann, Rebecca R.

    2014-01-01

    Numerous studies suggest that the transition from Australopithecus to Homo was characterized by evolutionary innovation, resulting in the emergence and coexistence of a diversity of forms. However, the evolutionary processes necessary to drive such a transition have not been examined. Here, we apply statistical tests developed from quantitative evolutionary theory to assess whether morphological differences among late australopith and early Homo species in Africa have been shaped by natural selection. Where selection is demonstrated, we identify aspects of morphology that were most likely under selective pressure, and determine the nature (type, rate) of that selection. Results demonstrate that selection must be invoked to explain an Au. africanus—Au. sediba—Homo transition, while transitions from late australopiths to various early Homo species that exclude Au. sediba can be achieved through drift alone. Rate tests indicate that selection is largely directional, acting to rapidly differentiate these taxa. Reconstructions of patterns of directional selection needed to drive the Au. africanus—Au. sediba—Homo transition suggest that selection would have affected all regions of the skull. These results may indicate that an evolutionary path to Homo without Au. sediba is the simpler path and/or provide evidence that this pathway involved more reliance on cultural adaptations to cope with environmental change. PMID:25470780

  18. Bailout perventricular pulmonary valve implantation following failed percutaneous attempt using the Edwards Sapien transcatheter heart valve.

    PubMed

    Cubeddu, Roberto J; Hijazi, Ziyad M

    2011-02-01

    Percutaneous pulmonary valve implantation has emerged as an attractive and less invasive alternative to open-heart surgery. Nevertheless, major technical challenges and procedural complications may still occur. We report a 44-year-old woman with severe dextroscoliosis, and history of Tetralogy of Fallot repair, who underwent an attempt at percutaneous implantation of a 23-mm Edwards SAPIEN transcatheter heart valve (THV) for recurrent stenosis of the right ventricle to pulmonary artery conduit. The procedure was complicated by valve migration into the right ventricle requiring emergent surgical removal using inflow-occlusion technique to avoid cardiopulmonary bypass. A hybrid off-pump perventricular approach was then used in the operating room to successfully implant a 26-mm Edwards Sapien THV under fluoroscopic guidance. © 2010 Wiley-Liss, Inc. PMID:20518008

  19. RNA editing differently affects protein-coding genes in D. melanogaster and H. sapiens

    PubMed Central

    Grassi, Luigi; Leoni, Guido; Tramontano, Anna

    2015-01-01

    When an RNA editing event occurs within a coding sequence it can lead to a different encoded amino acid. The biological significance of these events remains an open question: they can modulate protein functionality, increase the complexity of transcriptomes or arise from a loose specificity of the involved enzymes. We analysed the editing events in coding regions that produce or not a change in the encoded amino acid (nonsynonymous and synonymous events, respectively) in D. melanogaster and in H. sapiens and compared them with the appropriate random models. Interestingly, our results show that the phenomenon has rather different characteristics in the two organisms. For example, we confirm the observation that editing events occur more frequently in non-coding than in coding regions, and report that this effect is much more evident in H. sapiens. Additionally, in this latter organism, editing events tend to affect less conserved residues. The less frequently occurring editing events in Drosophila tend to avoid drastic amino acid changes. Interestingly, we find that, in Drosophila, changes from less frequently used codons to more frequently used ones are favoured, while this is not the case in H. sapiens. PMID:26169954

  20. RNA editing differently affects protein-coding genes in D. melanogaster and H. sapiens.

    PubMed

    Grassi, Luigi; Leoni, Guido; Tramontano, Anna

    2015-01-01

    When an RNA editing event occurs within a coding sequence it can lead to a different encoded amino acid. The biological significance of these events remains an open question: they can modulate protein functionality, increase the complexity of transcriptomes or arise from a loose specificity of the involved enzymes. We analysed the editing events in coding regions that produce or not a change in the encoded amino acid (nonsynonymous and synonymous events, respectively) in D. melanogaster and in H. sapiens and compared them with the appropriate random models. Interestingly, our results show that the phenomenon has rather different characteristics in the two organisms. For example, we confirm the observation that editing events occur more frequently in non-coding than in coding regions, and report that this effect is much more evident in H. sapiens. Additionally, in this latter organism, editing events tend to affect less conserved residues. The less frequently occurring editing events in Drosophila tend to avoid drastic amino acid changes. Interestingly, we find that, in Drosophila, changes from less frequently used codons to more frequently used ones are favoured, while this is not the case in H. sapiens.

  1. The posterior border of the sphenoid greater wing and its phylogenetic usefulness in human evolution.

    PubMed

    Braga, J; Crubézy, E; Elyaqtine, M

    1998-12-01

    The elucidation of patterns of cranial skeletal maturation and growth in fossil hominids is possible not only through dental studies but also by mapping different aspects of ossification in both extant African apes and humans. However, knowledge of normal skeletal development in large samples of extant great apes is flimsy. To remedy this situation, this paper offers an extensive survey and thorough discussion of the ossification of the posterior border of the sphenoid greater wing. Indeed, this area provides much information about basicranial skeletal maturation. We investigate three variants: the absence of the foramen spinosum and the position of both the foramen spinosum and the foramen ovale in relation to the sphenosquamosal suture. Providing original data about humans and 1,425 extant great ape skulls and using a sample of 64 fossil hominids, this study aimed to test whether different ossification patterns occurred during the course of human evolution. The incidence of three derived morphologies located on the posterior border of the sphenoid greater wing increases during human evolution at different geological periods. The evolutionary polarity of these three derived morphologies is assessed by outgroup comparison and ontogenetic methods. During human evolution, there is a clear trend for the foramen spinosum to be present and wholly located on the posterior area of the sphenoid greater wing. Moreover, in all the great ape species and in Australopithecus afarensis, the sphenosquamosal suture may split the foramen ovale. Inversely, the foramen ovale always lies wholly within the sphenoid greater wing in Australopithecus africanus, robust australopithecines, early Homo, H. erectus (and/or H. ergaster), and Homo sapiens. From ontogenetic studies in humans, we conclude that, during human evolution, the ossification of the posterior area of the sphenoid greater wing progressively surrounded the middle meningeal artery (passing through the foramen spinosum) and

  2. Human cloning and embryo research: the 2003 John J. Conley Lecture on medical ethics.

    PubMed

    George, Robert P

    2004-01-01

    The author, a member of the U.S. President's Council on Bioethics, discusses ethical issues raised by human cloning, whether for purposes of bringing babies to birth or for research purposes. He first argues that every cloned human embryo is a new, distinct, and enduring organism, belonging to the species Homo sapiens, and directing its own development toward maturity. He then distinguishes between two types of capacities belonging to individual organisms belonging to this species, an immediately exerciseable capacity and a basic natural capacity that develops over time. He argues that it is the second type of capacity that is the ground for full moral respect, and that this capacity (and its concomitant degree of respect) belongs to cloned human embryos no less than to adult human beings. He then considers and rejects counter-arguments to his position, including the suggestion that the capacity of embryos is equivalent to the capacity of somatic cells, that full human rights are afforded only to human organisms with functioning brains, that the possibility of twinning diminishes the moral status of embryos, that the fact that people do not typically mourn the loss of early embryos implies that they have a diminished moral status, that the fact that early spontaneous abortions occur frequently diminishes the moral status of embryos, and that his arguments depend upon a concept of ensoulment. He concludes that if the moral status of cloned human embryos is equivalent to that of adults, then public policy should be based upon this assumption.

  3. Beringia and the global dispersal of modern humans.

    PubMed

    Hoffecker, John F; Elias, Scott A; O'Rourke, Dennis H; Scott, G Richard; Bigelow, Nancy H

    2016-01-01

    Until recently, the settlement of the Americas seemed largely divorced from the out-of-Africa dispersal of anatomically modern humans, which began at least 50,000 years ago. Native Americans were thought to represent a small subset of the Eurasian population that migrated to the Western Hemisphere less than 15,000 years ago. Archeological discoveries since 2000 reveal, however, that Homo sapiens occupied the high-latitude region between Northeast Asia and northwest North America (that is, Beringia) before 30,000 years ago and the Last Glacial Maximum (LGM). The settlement of Beringia now appears to have been part of modern human dispersal in northern Eurasia. A 2007 model, the Beringian Standstill Hypothesis, which is based on analysis of mitochondrial DNA (mtDNA) in living people, derives Native Americans from a population that occupied Beringia during the LGM. The model suggests a parallel between ancestral Native Americans and modern human populations that retreated to refugia in other parts of the world during the arid LGM. It is supported by evidence of comparatively mild climates and rich biota in south-central Beringia at this time (30,000-15,000 years ago). These and other developments suggest that the settlement of the Americas may be integrated with the global dispersal of modern humans. PMID:27061035

  4. Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany

    PubMed Central

    Wagner, Günther A.; Krbetschek, Matthias; Degering, Detlev; Bahain, Jean-Jacques; Shao, Qingfeng; Falguères, Christophe; Voinchet, Pierre; Dolo, Jean-Michel; Garcia, Tristan; Rightmire, G. Philip

    2010-01-01

    The Mauer mandible, holotype of Homo heidelbergensis, was found in 1907 in fluvial sands deposited by the Neckar River 10 km southeast of Heidelberg, Germany. The fossil is an important key to understanding early human occupation of Europe north of the Alps. Given the associated mammal fauna and the geological context, the find layer has been placed in the early Middle Pleistocene, but confirmatory chronometric evidence has hitherto been missing. Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 ± 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa. We address the paleoanthropological significance of the Mauer jaw in light of this dating evidence. PMID:21041630

  5. Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany.

    PubMed

    Wagner, Günther A; Krbetschek, Matthias; Degering, Detlev; Bahain, Jean-Jacques; Shao, Qingfeng; Falguères, Christophe; Voinchet, Pierre; Dolo, Jean-Michel; Garcia, Tristan; Rightmire, G Philip

    2010-11-16

    The Mauer mandible, holotype of Homo heidelbergensis, was found in 1907 in fluvial sands deposited by the Neckar River 10 km southeast of Heidelberg, Germany. The fossil is an important key to understanding early human occupation of Europe north of the Alps. Given the associated mammal fauna and the geological context, the find layer has been placed in the early Middle Pleistocene, but confirmatory chronometric evidence has hitherto been missing. Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 ± 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa. We address the paleoanthropological significance of the Mauer jaw in light of this dating evidence.

  6. Are human embryos Kantian persons?: Kantian considerations in favor of embryonic stem cell research.

    PubMed

    Manninen, Bertha Alvarez

    2008-01-01

    One argument used by detractors of human embryonic stem cell research (hESCR) invokes Kant's formula of humanity, which proscribes treating persons solely as a means to an end, rather than as ends in themselves. According to Fuat S. Oduncu, for example, adhering to this imperative entails that human embryos should not be disaggregated to obtain pluripotent stem cells for hESCR. Given that human embryos are Kantian persons from the time of their conception, killing them to obtain their cells for research fails to treat them as ends in themselves. This argument assumes two points that are rather contentious given a Kantian framework. First, the argument assumes that when Kant maintains that humanity must be treated as an end in itself, he means to argue that all members of the species Homo sapiens must be treated as ends in themselves; that is, that Kant regards personhood as co-extensive with belonging to the species Homo sapiens. Second, the argument assumes that the event of conception is causally responsible for the genesis of a Kantian person and that, therefore, an embryo is a Kantian person from the time of its conception. In this paper, I will present challenges against these two assumptions by engaging in an exegetical study of some of Kant's works. First, I will illustrate that Kant did not use the term "humanity" to denote a biological species, but rather the capacity to set ends according to reason. Second, I will illustrate that it is difficult given a Kantian framework to denote conception (indeed any biological event) as causally responsible for the creation of a person. Kant ascribed to a dualistic view of human agency, and personhood, according to him, was derived from the supersensible capacity for reason. To argue that a Kantian person is generated due to the event of conception ignores Kant's insistence in various aspects of his work that it is not possible to understand the generation of a person qua a physical operation. Finally, I will end the

  7. Are human embryos Kantian persons?: Kantian considerations in favor of embryonic stem cell research

    PubMed Central

    Manninen, Bertha Alvarez

    2008-01-01

    One argument used by detractors of human embryonic stem cell research (hESCR) invokes Kant's formula of humanity, which proscribes treating persons solely as a means to an end, rather than as ends in themselves. According to Fuat S. Oduncu, for example, adhering to this imperative entails that human embryos should not be disaggregated to obtain pluripotent stem cells for hESCR. Given that human embryos are Kantian persons from the time of their conception, killing them to obtain their cells for research fails to treat them as ends in themselves. This argument assumes two points that are rather contentious given a Kantian framework. First, the argument assumes that when Kant maintains that humanity must be treated as an end in itself, he means to argue that all members of the species Homo sapiens must be treated as ends in themselves; that is, that Kant regards personhood as co-extensive with belonging to the species Homo sapiens. Second, the argument assumes that the event of conception is causally responsible for the genesis of a Kantian person and that, therefore, an embryo is a Kantian person from the time of its conception. In this paper, I will present challenges against these two assumptions by engaging in an exegetical study of some of Kant's works. First, I will illustrate that Kant did not use the term "humanity" to denote a biological species, but rather the capacity to set ends according to reason. Second, I will illustrate that it is difficult given a Kantian framework to denote conception (indeed any biological event) as causally responsible for the creation of a person. Kant ascribed to a dualistic view of human agency, and personhood, according to him, was derived from the supersensible capacity for reason. To argue that a Kantian person is generated due to the event of conception ignores Kant's insistence in various aspects of his work that it is not possible to understand the generation of a person qua a physical operation. Finally, I will end the

  8. Fossil skulls reveal that blood flow rate to the brain increased faster than brain volume during human evolution

    NASA Astrophysics Data System (ADS)

    Seymour, Roger S.; Bosiocic, Vanya; Snelling, Edward P.

    2016-08-01

    The evolution of human cognition has been inferred from anthropological discoveries and estimates of brain size from fossil skulls. A more direct measure of cognition would be cerebral metabolic rate, which is proportional to cerebral blood flow rate (perfusion). The hominin cerebrum is supplied almost exclusively by the internal carotid arteries. The sizes of the foramina that transmitted these vessels in life can be measured in hominin fossil skulls and used to calculate cerebral perfusion rate. Perfusion in 11 species of hominin ancestors, from Australopithecus to archaic Homo sapiens, increases disproportionately when scaled against brain volume (the allometric exponent is 1.41). The high exponent indicates an increase in the metabolic intensity of cerebral tissue in later Homo species, rather than remaining constant (1.0) as expected by a linear increase in neuron number, or decreasing according to Kleiber's Law (0.75). During 3 Myr of hominin evolution, cerebral tissue perfusion increased 1.7-fold, which, when multiplied by a 3.5-fold increase in brain size, indicates a 6.0-fold increase in total cerebral blood flow rate. This is probably associated with increased interneuron connectivity, synaptic activity and cognitive function, which all ultimately depend on cerebral metabolic rate.

  9. Ontogenetic study of allometric variation in Homo and Pan mandibles.

    PubMed

    Singh, Nandini

    2014-02-01

    Investigating ontogenetic variation and allometry in the mandible can provide valuable insight and aid in addressing questions related to the ontogeny of the skull. Here, patterns of ontogenetic shape change and allometric trajectories were examined in the mandible of 187 sub-adult and adult humans, bonobos, and chimpanzees. Procrustes-based geometric morphometrics was employed to quantify and analyze mandibular form. Thirty three-dimensional landmarks were used to capture the overall morphology of the mandible, and the landmarks were analyzed as a whole and subdivided into separate anterior and posterior units. Principal component analyses in Procrustes shape-space and form-space, and multivariate regressions were used to examine patterns of ontogenetic and allometric shape change. Results suggest that humans are distinct from Pan both in their mandibular morphology, particularly in the anterior-alveolar region, and direction of allometric trajectory. Chimpanzees and bonobos have parallel ontogenetic trajectories, but also show differences in mandibular shape. Species-specific features and adult mandibular shape are established before or by the eruption of the deciduous dentition. This suggests that developmental processes prior to deciduous teeth eruption have a stronger effect establishing taxa-specific phenotypes than later postnatal effects. This additionally implies that divergent trajectories between Pan and Homo do not contribute much to the adult mandibular shape after deciduous teeth eruption. Separate analyses of the anterior-alveolar region and ascending ramus show that these regions are semi-independent in their developmental pattern of shape change and allometry. This implies that allometric variation and ontogenetic shape change in the hominoid mandible is decoupled.

  10. Short faces, big tongues: developmental origin of the human chin.

    PubMed

    Coquerelle, Michael; Prados-Frutos, Juan Carlos; Rojo, Rosa; Mitteroecker, Philipp; Bastir, Markus

    2013-01-01

    During the course of human evolution, the retraction of the face underneath the braincase, and closer to the cervical column, has reduced the horizontal dimension of the vocal tract. By contrast, the relative size of the tongue has not been reduced, implying a rearrangement of the space at the back of the vocal tract to allow breathing and swallowing. This may have left a morphological signature such as a chin (mental prominence) that can potentially be interpreted in Homo. Long considered an autopomorphic trait of Homo sapiens, various extinct hominins show different forms of mental prominence. These features may be the evolutionary by-product of equivalent developmental constraints correlated with an enlarged tongue. In order to investigate developmental mechanisms related to this hypothesis, we compare modern 34 human infants against 8 chimpanzee fetuses, whom development of the mandibular symphysis passes through similar stages. The study sets out to test that the shared ontogenetic shape changes of the symphysis observed in both species are driven by the same factor--space restriction at the back of the vocal tract and the associated arrangement of the tongue and hyoid bone. We apply geometric morphometric methods to extensive three-dimensional anatomical landmarks and semilandmarks configuration, capturing the geometry of the cervico-craniofacial complex including the hyoid bone, tongue muscle and the mandible. We demonstrate that in both species, the forward displacement of the mental region derives from the arrangement of the tongue and hyoid bone, in order to cope with the relative horizontal narrowing of the oral cavity. Because humans and chimpanzees share this pattern of developmental integration, the different forms of mental prominence seen in some extinct hominids likely originate from equivalent ontogenetic constraints. Variations in this process could account for similar morphologies.

  11. Short faces, big tongues: developmental origin of the human chin.

    PubMed

    Coquerelle, Michael; Prados-Frutos, Juan Carlos; Rojo, Rosa; Mitteroecker, Philipp; Bastir, Markus

    2013-01-01

    During the course of human evolution, the retraction of the face underneath the braincase, and closer to the cervical column, has reduced the horizontal dimension of the vocal tract. By contrast, the relative size of the tongue has not been reduced, implying a rearrangement of the space at the back of the vocal tract to allow breathing and swallowing. This may have left a morphological signature such as a chin (mental prominence) that can potentially be interpreted in Homo. Long considered an autopomorphic trait of Homo sapiens, various extinct hominins show different forms of mental prominence. These features may be the evolutionary by-product of equivalent developmental constraints correlated with an enlarged tongue. In order to investigate developmental mechanisms related to this hypothesis, we compare modern 34 human infants against 8 chimpanzee fetuses, whom development of the mandibular symphysis passes through similar stages. The study sets out to test that the shared ontogenetic shape changes of the symphysis observed in both species are driven by the same factor--space restriction at the back of the vocal tract and the associated arrangement of the tongue and hyoid bone. We apply geometric morphometric methods to extensive three-dimensional anatomical landmarks and semilandmarks configuration, capturing the geometry of the cervico-craniofacial complex including the hyoid bone, tongue muscle and the mandible. We demonstrate that in both species, the forward displacement of the mental region derives from the arrangement of the tongue and hyoid bone, in order to cope with the relative horizontal narrowing of the oral cavity. Because humans and chimpanzees share this pattern of developmental integration, the different forms of mental prominence seen in some extinct hominids likely originate from equivalent ontogenetic constraints. Variations in this process could account for similar morphologies. PMID:24260566

  12. Dual-laser homo-FRET on the cell surface.

    PubMed

    Bene, László; Ungvári, Tamás; Fedor, Roland; Nagy, István; Damjanovich, László

    2015-05-01

    Inhomogeneous broadening and red-edge effects have been detected on a highly mobile system of fluorescently conjugated mAbs targeted to cell surface receptors. By exploiting site-selective spectroscopy and the characteristic loss of homo-FRET on increasing excitation and decreasing emission wavelengths, contributions of physical rotation and homo-FRET to the depolarization of fluorescence anisotropy have been separated. Absolute homo-FRET efficiency has been determined by ratioing two anisotropies: a homo-FRET-sensitive one, which is excited at the absorption main band and detected at the long wavelength region of emission, and a homo-FRET-insensitive one, which is excited at the long wavelength region of absorption and detected at the short wavelength region of emission. Because the anisotropies are simultaneously detected in a unified detection scheme of a dual T-format arrangement, the method is applicable for the real-time tracking of dynamical changes of physical rotations and proximities. The utility of the method is demonstrated in the context of the MHCII molecule and the heavy and light chains of the MHCI molecule, a system of three receptors with well-characterized close mutual proximities. Although the method is presented for a flow cytometer, it can also be realized in a fluorescence microscope capable for dual-laser excitation and dual-anisotropy detection.

  13. Gas-phase Dissociation of homo-DNA Oligonucleotides

    NASA Astrophysics Data System (ADS)

    Stucki, Silvan R.; Désiron, Camille; Nyakas, Adrien; Marti, Simon; Leumann, Christian J.; Schürch, Stefan

    2013-12-01

    Synthetic modified oligonucleotides are of interest for diagnostic and therapeutic applications, as their biological stability, pairing selectivity, and binding strength can be considerably increased by the incorporation of unnatural structural elements. Homo-DNA is an oligonucleotide homologue based on dideoxy-hexopyranosyl sugar moieties, which follows the Watson-Crick A-T and G-C base pairing system, but does not hybridize with complementary natural DNA and RNA. Homo-DNA has found application as a bioorthogonal element in templated chemistry applications. The gas-phase dissociation of homo-DNA has been investigated by ESI-MS/MS and MALDI-MS/MS, and mechanistic aspects of its gas-phase dissociation are discussed. Experiments revealed a charge state dependent preference for the loss of nucleobases, which are released either as neutrals or as anions. In contrast to DNA, nucleobase loss from homo-DNA was found to be decoupled from backbone cleavage, thus resulting in stable products. This renders an additional stage of ion activation necessary in order to generate sequence-defining fragment ions. Upon MS3 of the primary base-loss ion, homo-DNA was found to exhibit unspecific backbone dissociation resulting in a balanced distribution of all fragment ion series.

  14. A Critical Evaluation of the Down Syndrome Diagnosis for LB1, Type Specimen of Homo floresiensis

    PubMed Central

    Baab, Karen L.; Brown, Peter; Falk, Dean; Richtsmeier, Joan T.; Hildebolt, Charles F.; Smith, Kirk; Jungers, William

    2016-01-01

    The Liang Bua hominins from Flores, Indonesia, have been the subject of intense scrutiny and debate since their initial description and classification in 2004. These remains have been assigned to a new species, Homo floresiensis, with the partial skeleton LB1 as the type specimen. The Liang Bua hominins are notable for their short stature, small endocranial volume, and many features that appear phylogenetically primitive relative to modern humans, despite their late Pleistocene age. Recently, some workers suggested that the remains represent members of a small-bodied island population of modern Austro-Melanesian humans, with LB1 exhibiting clinical signs of Down syndrome. Many classic Down syndrome signs are soft tissue features that could not be assessed in skeletal remains. Moreover, a definitive diagnosis of Down syndrome can only be made by genetic analysis as the phenotypes associated with Down syndrome are variable. Most features that contribute to the Down syndrome phenotype are not restricted to Down syndrome but are seen in other chromosomal disorders and in the general population. Nevertheless, we re-evaluated the presence of those phenotypic features used to support this classification by comparing LB1 to samples of modern humans diagnosed with Down syndrome and euploid modern humans using comparative morphometric analyses. We present new data regarding neurocranial, brain, and symphyseal shape in Down syndrome, additional estimates of stature for LB1, and analyses of inter- and intralimb proportions. The presence of cranial sinuses is addressed using CT images of LB1. We found minimal congruence between the LB1 phenotype and clinical descriptions of Down syndrome. We present important differences between the phenotypes of LB1 and individuals with Down syndrome, and quantitative data that characterize LB1 as an outlier compared with Down syndrome and non-Down syndrome groups. Homo floresiensis remains a phenotypically unique, valid species with its roots

  15. A Critical Evaluation of the Down Syndrome Diagnosis for LB1, Type Specimen of Homo floresiensis.

    PubMed

    Baab, Karen L; Brown, Peter; Falk, Dean; Richtsmeier, Joan T; Hildebolt, Charles F; Smith, Kirk; Jungers, William

    2016-01-01

    The Liang Bua hominins from Flores, Indonesia, have been the subject of intense scrutiny and debate since their initial description and classification in 2004. These remains have been assigned to a new species, Homo floresiensis, with the partial skeleton LB1 as the type specimen. The Liang Bua hominins are notable for their short stature, small endocranial volume, and many features that appear phylogenetically primitive relative to modern humans, despite their late Pleistocene age. Recently, some workers suggested that the remains represent members of a small-bodied island population of modern Austro-Melanesian humans, with LB1 exhibiting clinical signs of Down syndrome. Many classic Down syndrome signs are soft tissue features that could not be assessed in skeletal remains. Moreover, a definitive diagnosis of Down syndrome can only be made by genetic analysis as the phenotypes associated with Down syndrome are variable. Most features that contribute to the Down syndrome phenotype are not restricted to Down syndrome but are seen in other chromosomal disorders and in the general population. Nevertheless, we re-evaluated the presence of those phenotypic features used to support this classification by comparing LB1 to samples of modern humans diagnosed with Down syndrome and euploid modern humans using comparative morphometric analyses. We present new data regarding neurocranial, brain, and symphyseal shape in Down syndrome, additional estimates of stature for LB1, and analyses of inter- and intralimb proportions. The presence of cranial sinuses is addressed using CT images of LB1. We found minimal congruence between the LB1 phenotype and clinical descriptions of Down syndrome. We present important differences between the phenotypes of LB1 and individuals with Down syndrome, and quantitative data that characterize LB1 as an outlier compared with Down syndrome and non-Down syndrome groups. Homo floresiensis remains a phenotypically unique, valid species with its roots

  16. Evolutionary reversals of limb proportions in early hominids? Evidence from KNM-ER 3735 (Homo habilis).

    PubMed

    Haeusler, Martin; McHenry, Henry M

    2007-10-01

    Upper-to-lower limb proportions of Homo habilis are often said to be more ape-like than those of its reputed ancestor, Australopithecus afarensis. Such proportions would either imply multiple evolutionary reversals or parallel development of a relatively short upper limb in A. afarensis and later Homo. However, assessments of limb proportions are complicated by the fragmentary nature of the two known H. habilis skeletons, OH 62 and KNM-ER 3735. Initially, KNM-ER 3735 was compared to A.L. 288-1 (A. afarensis) using a single modern human and chimpanzee as reference. Here, based on a larger comparative sample, we find that the relative size of the distal humerus, radial head, and shaft of both KNM-ER 3735 and A.L. 288-1 lie within the range of variation of modern humans, whereas their sacra are small as is the case for all early hominids. In addition, their manual phalanges are similar in having a gracile base but robust midshaft. Contrary to earlier studies, the fossils are not differentiable from each other statistically with respect to all features listed above. On the other hand, they differ in robusticity of the scapular spine and relative length of the radial neck. An exact randomization test suggests only a very low probability of finding a similar degree of difference within a single species of extant hominoids. In contrast to the consensus view, we conclude that A.L. 288-1 had a short, human-like forearm, whereas KNM-ER 3735 possessed a distinctly longer forearm and more powerful shoulder girdle. This interpretation fits with earlier conclusions that suggested human-like humerofemoral proportions but chimpanzee-like brachial proportions for Homo habilis. Thus, the scenario of a unidirectional, progressive change in limb proportions within the hominid lineage is not supported by our work.

  17. A Critical Evaluation of the Down Syndrome Diagnosis for LB1, Type Specimen of Homo floresiensis.

    PubMed

    Baab, Karen L; Brown, Peter; Falk, Dean; Richtsmeier, Joan T; Hildebolt, Charles F; Smith, Kirk; Jungers, William

    2016-01-01

    The Liang Bua hominins from Flores, Indonesia, have been the subject of intense scrutiny and debate since their initial description and classification in 2004. These remains have been assigned to a new species, Homo floresiensis, with the partial skeleton LB1 as the type specimen. The Liang Bua hominins are notable for their short stature, small endocranial volume, and many features that appear phylogenetically primitive relative to modern humans, despite their late Pleistocene age. Recently, some workers suggested that the remains represent members of a small-bodied island population of modern Austro-Melanesian humans, with LB1 exhibiting clinical signs of Down syndrome. Many classic Down syndrome signs are soft tissue features that could not be assessed in skeletal remains. Moreover, a definitive diagnosis of Down syndrome can only be made by genetic analysis as the phenotypes associated with Down syndrome are variable. Most features that contribute to the Down syndrome phenotype are not restricted to Down syndrome but are seen in other chromosomal disorders and in the general population. Nevertheless, we re-evaluated the presence of those phenotypic features used to support this classification by comparing LB1 to samples of modern humans diagnosed with Down syndrome and euploid modern humans using comparative morphometric analyses. We present new data regarding neurocranial, brain, and symphyseal shape in Down syndrome, additional estimates of stature for LB1, and analyses of inter- and intralimb proportions. The presence of cranial sinuses is addressed using CT images of LB1. We found minimal congruence between the LB1 phenotype and clinical descriptions of Down syndrome. We present important differences between the phenotypes of LB1 and individuals with Down syndrome, and quantitative data that characterize LB1 as an outlier compared with Down syndrome and non-Down syndrome groups. Homo floresiensis remains a phenotypically unique, valid species with its roots

  18. Yawn contagion in humans and bonobos: emotional affinity matters more than species.

    PubMed

    Palagi, Elisabetta; Norscia, Ivan; Demuru, Elisa

    2014-01-01

    In humans and apes, yawn contagion echoes emotional contagion, the basal layer of empathy. Hence, yawn contagion is a unique tool to compare empathy across species. If humans are the most empathic animal species, they should show the highest empathic response also at the level of emotional contagion. We gathered data on yawn contagion in humans (Homo sapiens) and bonobos (Pan paniscus) by applying the same observational paradigm and identical operational definitions. We selected a naturalistic approach because experimental management practices can produce different psychological and behavioural biases in the two species, and differential attention to artificial stimuli. Within species, yawn contagion was highest between strongly bonded subjects. Between species, sensitivity to others' yawns was higher in humans than in bonobos when involving kin and friends but was similar when considering weakly-bonded subjects. Thus, emotional contagion is not always highest in humans. The cognitive components concur in empowering emotional affinity between individuals. Yet, when they are not in play, humans climb down from the empathic podium to return to the "understory", which our species shares with apes. PMID:25165630

  19. The human semicircular canals orientation is more similar to the bonobos than to the chimpanzees.

    PubMed

    El Khoury, Marwan; Braga, José; Dumoncel, Jean; Nancy, Javotte; Esclassan, Remi; Vaysse, Frederic

    2014-01-01

    For some traits, the human genome is more closely related to either the bonobo or the chimpanzee genome than they are to each other. Therefore, it becomes crucial to understand whether and how morphostructural differences between humans, chimpanzees and bonobos reflect the well known phylogeny. Here we comparatively investigated intra and extra labyrinthine semicircular canals orientation using 260 computed tomography scans of extant humans (Homo sapiens), bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). Humans and bonobos proved more similarities between themselves than with chimpanzees. This finding did not fit with the well established chimpanzee - bonobo monophyly. One hypothesis was convergent evolution in which bonobos and humans produce independently similar phenotypes possibly in response to similar selective pressures that may be associated with postural adaptations. Another possibility was convergence following a "random walk" (Brownian motion) evolutionary model. A more parsimonious explanation was that the bonobo-human labyrinthine shared morphology more closely retained the ancestral condition with chimpanzees being subsequently derived. Finally, these results might be a consequence of genetic diversity and incomplete lineage sorting. The remarkable symmetry of the Semicircular Canals was the second major finding of this article with possible applications in taphonomy. It has the potential to investigate altered fossils, inferring the probability of post-mortem deformation which can lead to difficulties in understanding taxonomic variation, phylogenetic relationships, and functional morphology.

  20. The Human Semicircular Canals Orientation Is More Similar to the Bonobos than to the Chimpanzees

    PubMed Central

    El Khoury, Marwan; Braga, José; Dumoncel, Jean; Nancy, Javotte; Esclassan, Remi; Vaysse, Frederic

    2014-01-01

    For some traits, the human genome is more closely related to either the bonobo or the chimpanzee genome than they are to each other. Therefore, it becomes crucial to understand whether and how morphostructural differences between humans, chimpanzees and bonobos reflect the well known phylogeny. Here we comparatively investigated intra and extra labyrinthine semicircular canals orientation using 260 computed tomography scans of extant humans (Homo sapiens), bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). Humans and bonobos proved more similarities between themselves than with chimpanzees. This finding did not fit with the well established chimpanzee – bonobo monophyly. One hypothesis was convergent evolution in which bonobos and humans produce independently similar phenotypes possibly in response to similar selective pressures that may be associated with postural adaptations. Another possibility was convergence following a “random walk” (Brownian motion) evolutionary model. A more parsimonious explanation was that the bonobo-human labyrinthine shared morphology more closely retained the ancestral condition with chimpanzees being subsequently derived. Finally, these results might be a consequence of genetic diversity and incomplete lineage sorting. The remarkable symmetry of the Semicircular Canals was the second major finding of this article with possible applications in taphonomy. It has the potential to investigate altered fossils, inferring the probability of post-mortem deformation which can lead to difficulties in understanding taxonomic variation, phylogenetic relationships, and functional morphology. PMID:24710502

  1. Language and life history: a new perspective on the development and evolution of human language.

    PubMed

    Locke, John L; Bogin, Barry

    2006-06-01

    It has long been claimed that Homo sapiens is the only species that has language, but only recently has it been recognized that humans also have an unusual pattern of growth and development. Social mammals have two stages of pre-adult development: infancy and juvenility. Humans have two additional prolonged and pronounced life history stages: childhood, an interval of four years extending between infancy and the juvenile period that follows, and adolescence, a stage of about eight years that stretches from juvenility to adulthood. We begin by reviewing the primary biological and linguistic changes occurring in each of the four pre-adult ontogenetic stages in human life history. Then we attempt to trace the evolution of childhood and juvenility in our hominin ancestors. We propose that several different forms of selection applied in infancy and childhood; and that, in adolescence, elaborated vocal behaviors played a role in courtship and intrasexual competition, enhancing fitness and ultimately integrating performative and pragmatic skills with linguistic knowledge in a broad faculty of language. A theoretical consequence of our proposal is that fossil evidence of the uniquely human stages may be used, with other findings, to date the emergence of language. If important aspects of language cannot appear until sexual maturity, as we propose, then a second consequence is that the development of language requires the whole of modern human ontogeny. Our life history model thus offers new ways of investigating, and thinking about, the evolution, development, and ultimately the nature of human language.

  2. Yawn contagion in humans and bonobos: emotional affinity matters more than species

    PubMed Central

    Norscia, Ivan; Demuru, Elisa

    2014-01-01

    In humans and apes, yawn contagion echoes emotional contagion, the basal layer of empathy. Hence, yawn contagion is a unique tool to compare empathy across species. If humans are the most empathic animal species, they should show the highest empathic response also at the level of emotional contagion. We gathered data on yawn contagion in humans (Homo sapiens) and bonobos (Pan paniscus) by applying the same observational paradigm and identical operational definitions. We selected a naturalistic approach because experimental management practices can produce different psychological and behavioural biases in the two species, and differential attention to artificial stimuli. Within species, yawn contagion was highest between strongly bonded subjects. Between species, sensitivity to others’ yawns was higher in humans than in bonobos when involving kin and friends but was similar when considering weakly-bonded subjects. Thus, emotional contagion is not always highest in humans. The cognitive components concur in empowering emotional affinity between individuals. Yet, when they are not in play, humans climb down from the empathic podium to return to the “understory”, which our species shares with apes. PMID:25165630

  3. Histological definition of the vomeronasal organ in humans and chimpanzees, with a comparison to other primates.

    PubMed

    Smith, Timothy D; Bhatnagar, Kunwar P; Shimp, Kristin L; Kinzinger, Jonathan H; Bonar, Christopher J; Burrows, Annie M; Mooney, Mark P; Siegel, Michael I

    2002-06-01

    The vomeronasal organ (VNO) is a chemosensory structure that has morphological indications of functionality in strepsirhine and New World primates examined to date. In these species, it is thought to mediate certain socio-sexual behaviors. The functionality and even existence of the VNO in Old World primates has been debated. Most modern texts state that the VNO is absent in Old World monkeys, apes, and humans. A recent study on the VNO in the chimpanzee (Smith et al., 2001b) challenged this notion, demonstrating the need for further comparative studies of primates. In particular, there is a need to establish how the human/chimpanzee VNO differs from that of other primates and even nonhomologous mucosal ducts. Histochemical and microscopic morphological characteristics of the VNO and nasopalatine duct (NPD) were examined in 51 peri- and postnatal primates, including humans, chimpanzees, five species of New World monkeys, and seven strepsirhine species. The nasal septum was removed from each primate and histologically processed for coronal sectioning. Selected anteroposterior intervals of the VNO were variously stained with alcian blue (AB)-periodic acid-Schiff (PAS), PAS only, Gomori trichrome, or hematoxylin-eosin procedures. All strepsirhine species had well developed VNOs, with a prominent neuroepithelium and vomeronasal cartilages that nearly surrounded the VNO. New World monkeys had variable amounts of neuroepithelia, whereas Pan troglodytes and Homo sapiens had no recognizable neuroepithelium or vomeronasal nerves (VNNs). Certain unidentified cell types of the human/chimpanzee VNO require further examination (immunohistochemical and electron microscopic). The VNOs of P. troglodytes, H. sapiens, and New World monkeys exhibited different histochemistry of mucins compared to strepsirhine species. The nasopalatine region showed great variation among species. It is a blind-ended pit in P. troglodytes, a glandular recess in H. sapiens, a mucous-producing duct in

  4. L'os temporal du Petit-Puymoyen

    NASA Astrophysics Data System (ADS)

    Elyaqtine, Mustapha

    1997-12-01

    The temporal bone discovered by Bœuf within the fauna from the Petit-Puymoyen site is studied. It is attributed to an individual whose age is estimated at 2/4 years and that possesses a mastoid fissure. This characteristic, constant in Homo sapiens neanderthalensis and absent in Homo sapiens sapiens, allows to conclude that it is more likely that this individual be allocated to the Neanderthal lineage rather than to the anatomically modern human one.

  5. [Scientific ethics and the use of human material or data].

    PubMed

    Valenzuela, Carlos Y

    2012-03-01

    A scientific article censured by superposing obstacles to its reading remembers the censure of Galileo made by the Inquisition. The censure followed the failure to obtain the informed consent (IC) to disclose results of old samples. At present, the use of collected data or samples for a new research needs a new IC, in most ethical protocols. The Helsinki Code allows the research ethics committees the authorization for the use of that information. This norm is founded rather in commercial, legal or protective arguments than in ethical bases. This article criticizes this norm from the Scientific Ethics viewpoint because: i) the ownership of the genome and environment that originate a person is not of such person but of the human society and Homo sapiens species, ii) a person is not the unique owner of that information; laboratories, institutions, health services and research teams add constituents to it, iii) several violations to this norm occurring in medical, labor, legal and social practice show it as biased against science, iv) if this stored information and its use are beneficial for humankind (its proper owner) it is ethically obligatory to use it. It is proposed to create an anonymous World Bank for Human Information with open access and universal transparency. This universal collection of data handled under universal accepted ethical norms should prevent exclusive private use of public information, non-publication of negative results, illicit and unethical use of human data.

  6. A single lineage in early Pleistocene Homo: size variation continuity in early Pleistocene Homo crania from East Africa and Georgia.

    PubMed

    Van Arsdale, Adam P; Wolpoff, Milford H

    2013-03-01

    The relationship between Homo habilis and early African Homo erectus has been contentious because H. habilis was hypothesized to be an evolutionary stage between Australopithecus and H. erectus, more than a half-century ago. Recent work re-dating key African early Homo localities and the discovery of new fossils in East Africa and Georgia provide the opportunity for a productive re-evaluation of this topic. Here, we test the hypothesis that the cranial sample from East Africa and Georgia represents a single evolutionary lineage of Homo spanning the approximately 1.9-1.5 Mya time period, consisting of specimens attributed to H. habilis and H. erectus. To address issues of small sample sizes in each time period, and uneven representation of cranial data, we developed a novel nonparametric randomization technique based on the variance in an index of pairwise difference from a broad set of fossil comparisons. We fail to reject the hypothesis of a single lineage this period by identifying a strong, time-dependent pattern of variation throughout the sequence. These results suggest the need for a reappraisal of fossil evidence from other regions within this time period and highlight the critical nature of the Plio-Pleistocene boundary for understanding the early evolution of the genus Homo.

  7. A single lineage in early Pleistocene Homo: size variation continuity in early Pleistocene Homo crania from East Africa and Georgia.

    PubMed

    Van Arsdale, Adam P; Wolpoff, Milford H

    2013-03-01

    The relationship between Homo habilis and early African Homo erectus has been contentious because H. habilis was hypothesized to be an evolutionary stage between Australopithecus and H. erectus, more than a half-century ago. Recent work re-dating key African early Homo localities and the discovery of new fossils in East Africa and Georgia provide the opportunity for a productive re-evaluation of this topic. Here, we test the hypothesis that the cranial sample from East Africa and Georgia represents a single evolutionary lineage of Homo spanning the approximately 1.9-1.5 Mya time period, consisting of specimens attributed to H. habilis and H. erectus. To address issues of small sample sizes in each time period, and uneven representation of cranial data, we developed a novel nonparametric randomization technique based on the variance in an index of pairwise difference from a broad set of fossil comparisons. We fail to reject the hypothesis of a single lineage this period by identifying a strong, time-dependent pattern of variation throughout the sequence. These results suggest the need for a reappraisal of fossil evidence from other regions within this time period and highlight the critical nature of the Plio-Pleistocene boundary for understanding the early evolution of the genus Homo. PMID:23461332

  8. [Evolution of human brain and intelligence].

    PubMed

    Lakatos, László; Janka, Zoltán

    2008-07-30

    The biological evolution, including human evolution is mainly driven by environmental changes. Accidental genetic modifications and their innovative results make the successful adaptation possible. As we know the human evolution started 7-8 million years ago in the African savannah, where upright position and bipedalism were significantly advantageous. The main drive of improving manual actions and tool making could be to obtain more food. Our ancestor got more meat due to more successful hunting, resulting in more caloric intake, more protein and essential fatty acid in the meal. The nervous system uses disproportionally high level of energy, so better quality of food was a basic condition for the evolution of huge human brain. The size of human brain was tripled during 3.5 million years, it increased from the average of 450 cm3 of Australopithecinae to the average of 1350 cm3 of Homo sapiens. A genetic change in the system controlling gene expression could happen about 200 000 years ago, which influenced the development of nervous system, the sensorimotor function and learning ability for motor processes. The appearance and stabilisation of FOXP2 gene structure as feature of modern man coincided with the first presence and quick spread of Homo sapiens on the whole Earth. This genetic modification made opportunity for human language, as the basis of abrupt evolution of human intelligence. The brain region being responsible for human language is the left planum temporale, which is much larger in left hemisphere. This shows the most typical human brain asymmetry. In this case the anatomical asymmetry means a clearly defined functional asymmetry as well, where the brain hemispheres act differently. The preference in using hands, the lateralised using of tools resulted in the brain asymmetry, which is the precondition of human language and intelligence. However, it cannot be held anymore, that only humans make tools, because our closest relatives, the chimpanzees are

  9. Design of intelligent nucleobases and DNA HOMO mapping.

    PubMed

    Saito, Isao

    2002-01-01

    We have designed a new nucleobase, benzodeazaadenine (BDA) that has a stronger charge transport ability than guanine and is not destroyed during charge transport process. By incorporating this new nucleobase into DNA, we demonstrated a protocol for real DNA nano-wire that is far superior to natural DNA. We also demonstrated that the selectivity for the interaction of Mn(II) ion with guanine N7 in G runs is a HOMO-controlled process, and as a consequence, the selectivity for G-metal ion interactions obtained by 15N-NMR studies would directly reflect the HOMO distribution of G-containing sequences in B-DNA.

  10. [Human nutrition in the context of evolutionary medicine].

    PubMed

    Ströhle, Alexander; Wolters, Maike; Hahn, Andreas

    2009-01-01

    Evolutionary medicine has gained increasing attention in recent years by implying that a food selection similar to that of the Paleolithic may prevent diseases. This article is an attempt to characterize the food selection during hominid evolution based on current paleontologic research. Hominid evolution can be divided into multiple phases; and the nutrition ecology of the plio-pleistocene hominids can be tentatively characterized. According to new results of isotope analysis, the Australopithecines did ingest small amounts of animal food already 4.5-2.5 million years ago, while consuming a mainly plant based abrasive diet, which was similar to that of recent chimpanzees. Compared to the Australopithecines, the first representatives of Homo such as H. erectus and H. habilis (2.5-1.5 million years before today) were likely to consume a diet providing more energy and nutrients, which might also have been related to the more gracile dentition. Like H. sapiens the members of this species also consumed an omnivore diet. Assumptions about the nutrition ecology of the archaic and the modern H. sapiens are often concluded by analogies based on the living of historic and recent foragers (hunter-gatherers). As the few detailed ethnographic data show, the diet composition of the individual hunter-gatherer groups varied considerably and ranged from a nearly pure animal-based diet to a diet dominated by plants. All in all the eating behaviour of prehistoric humans was, like that of their pleistocene ancestors, very flexible. Except for focussing on an energy and nutrient-rich diet there was neither specialization in certain foods, nor a typical plant-animal ratio nor a defined macronutrient distribution. Correspondingly, it is impossible to justify details given by representatives of evolutionary medicine on "the Paleolithic diet" empirically. PMID:19412746

  11. [Human nutrition in the context of evolutionary medicine].

    PubMed

    Ströhle, Alexander; Wolters, Maike; Hahn, Andreas

    2009-01-01

    Evolutionary medicine has gained increasing attention in recent years by implying that a food selection similar to that of the Paleolithic may prevent diseases. This article is an attempt to characterize the food selection during hominid evolution based on current paleontologic research. Hominid evolution can be divided into multiple phases; and the nutrition ecology of the plio-pleistocene hominids can be tentatively characterized. According to new results of isotope analysis, the Australopithecines did ingest small amounts of animal food already 4.5-2.5 million years ago, while consuming a mainly plant based abrasive diet, which was similar to that of recent chimpanzees. Compared to the Australopithecines, the first representatives of Homo such as H. erectus and H. habilis (2.5-1.5 million years before today) were likely to consume a diet providing more energy and nutrients, which might also have been related to the more gracile dentition. Like H. sapiens the members of this species also consumed an omnivore diet. Assumptions about the nutrition ecology of the archaic and the modern H. sapiens are often concluded by analogies based on the living of historic and recent foragers (hunter-gatherers). As the few detailed ethnographic data show, the diet composition of the individual hunter-gatherer groups varied considerably and ranged from a nearly pure animal-based diet to a diet dominated by plants. All in all the eating behaviour of prehistoric humans was, like that of their pleistocene ancestors, very flexible. Except for focussing on an energy and nutrient-rich diet there was neither specialization in certain foods, nor a typical plant-animal ratio nor a defined macronutrient distribution. Correspondingly, it is impossible to justify details given by representatives of evolutionary medicine on "the Paleolithic diet" empirically.

  12. Functional epialleles at an endogenous human centromere.

    PubMed

    Maloney, Kristin A; Sullivan, Lori L; Matheny, Justyne E; Strome, Erin D; Merrett, Stephanie L; Ferris, Alyssa; Sullivan, Beth A

    2012-08-21

    Human centromeres are defined by megabases of homogenous alpha-satellite DNA arrays that are packaged into specialized chromatin marked by the centromeric histone variant, centromeric protein A (CENP-A). Although most human chromosomes have a single higher-order repeat (HOR) array of alpha satellites, several chromosomes have more than one HOR array. Homo sapiens chromosome 17 (HSA17) has two juxtaposed HOR arrays, D17Z1 and D17Z1-B. Only D17Z1 has been linked to CENP-A chromatin assembly. Here, we use human artificial chromosome assembly assays to show that both D17Z1 and D17Z1-B can support de novo centromere assembly independently. We extend these in vitro studies and demonstrate, using immunostaining and chromatin analyses, that in human cells the centromere can be assembled at D17Z1 or D17Z1-B. Intriguingly, some humans are functional heterozygotes, meaning that CENP-A is located at a different HOR array on the two HSA17 homologs. The site of CENP-A assembly on HSA17 is stable and is transmitted through meiosis, as evidenced by inheritance of CENP-A location through multigenerational families. Differences in histone modifications are not linked clearly with active and inactive D17Z1 and D17Z1-B arrays; however, we detect a correlation between the presence of variant repeat units of D17Z1 and CENP-A assembly at the opposite array, D17Z1-B. Our studies reveal the presence of centromeric epialleles on an endogenous human chromosome and suggest genomic complexities underlying the mechanisms that determine centromere identity in humans.

  13. Upper Pleistocene Human Dispersals out of Africa: A Review of the Current State of the Debate

    PubMed Central

    Beyin, Amanuel

    2011-01-01

    Although there is a general consensus on African origin of early modern humans, there is disagreement about how and when they dispersed to Eurasia. This paper reviews genetic and Middle Stone Age/Middle Paleolithic archaeological literature from northeast Africa, Arabia, and the Levant to assess the timing and geographic backgrounds of Upper Pleistocene human colonization of Eurasia. At the center of the discussion lies the question of whether eastern Africa alone was the source of Upper Pleistocene human dispersals into Eurasia or were there other loci of human expansions outside of Africa? The reviewed literature hints at two modes of early modern human colonization of Eurasia in the Upper Pleistocene: (i) from multiple Homo sapiens source populations that had entered Arabia, South Asia, and the Levant prior to and soon after the onset of the Last Interglacial (MIS-5), (ii) from a rapid dispersal out of East Africa via the Southern Route (across the Red Sea basin), dating to ~74–60 kya. PMID:21716744

  14. New ages for human occupation and climatic change at Lake Mungo, Australia

    NASA Astrophysics Data System (ADS)

    Bowler, James M.; Johnston, Harvey; Olley, Jon M.; Prescott, John R.; Roberts, Richard G.; Shawcross, Wilfred; Spooner, Nigel A.

    2003-02-01

    Australia's oldest human remains, found at Lake Mungo, include the world's oldest ritual ochre burial (Mungo III) and the first recorded cremation (Mungo I). Until now, the importance of these finds has been constrained by limited chronologies and palaeoenvironmental information. Mungo III, the source of the world's oldest human mitochondrial DNA, has been variously estimated at 30 thousand years (kyr) old, 42-45kyr old and 62 +/- 6kyr old, while radiocarbon estimates placed the Mungo I cremation near 20-26kyr ago. Here we report a new series of 25 optical ages showing that both burials occurred at 40 +/- 2kyr ago and that humans were present at Lake Mungo by 50-46kyr ago, synchronously with, or soon after, initial occupation of northern and western Australia. Stratigraphic evidence indicates fluctuations between lake-full and drier conditions from 50 to 40kyr ago, simultaneously with increased dust deposition, human arrival and continent-wide extinction of the megafauna. This was followed by sustained aridity between 40 and 30kyr ago. This new chronology corrects previous estimates for human burials at this important site and provides a new picture of Homo sapiens adapting to deteriorating climate in the world's driest inhabited continent.

  15. Comparison of SAPIEN 3 and SAPIEN XT transcatheter heart valve stent-frame expansion: evaluation using multi-slice computed tomography

    PubMed Central

    Kazuno, Yoshio; Maeno, Yoshio; Kawamori, Hiroyuki; Takahashi, Nobuyuki; Abramowitz, Yigal; Babak, Hariri; Kashif, Mohammad; Chakravarty, Tarun; Nakamura, Mamoo; Cheng, Wen; Friedman, John; Berman, Daniel; Makkar, Raj R.; Jilaihawi, Hasan

    2016-01-01

    Aims Stent-frame morphology of the newer-generation, balloon-expandable transcatheter heart valve (THV), the SAPIEN 3 (S3), after transcatheter aortic valve implantation (TAVI) is unknown. We evaluated the THV stent-frame morphology post TAVI of the S3 using multi-slice computed tomography (MSCT) compared with the prior-generation THV, SAPIEN XT (S-XT). Methods and results A total of 94 consecutive participants of RESOLVE registry (NCT02318342) had MSCT after balloon-expandable TAVI (S3 = 39 and S-XT = 55). The morphology of the THV stent-frame was evaluated for expansion area and eccentricity at the THV-inflow, native annulus, mid-THV and THV-outflow levels. Mean %-expansion area for the S3 and the S-XT was 100.9 ± 5.7 and 96.1 ± 5.5%, respectively (P < 0.001). In the S3 group, the THV-inflow level had the largest value of %-expansion area, which decreased from THV-inflow to mid-THV level (105.2 ± 6.4 to 96.5 ± 5.9%, P < 0.001). However, in the S-XT group, %-expansion area increased from THV-inflow level to mid-THV level (93.2 ± 6.2 to 95.1 ± 6.1%, P = 0.0058). On nominal delivery balloon volume, the S3 in 88.5% of cases had overexpansion at the THV-inflow level. The observed degree of THV oversizing of the S3 was significantly lower than the S-XT (6.3 ± 8.6 vs. 11.8 ± 8.5%, P = 0.0027). Nonetheless, the incidence of post-procedural paravalvular aortic regurgitation (PVR) ≥ mild following the S3 TAVI was also significantly lower than the S-XT TAVI (17.9 vs. 43.6%, P = 0.014). Conclusion The newer-generation, balloon-expandable device, the S3, has a flared inflow morphology, whereas the prior-generation device, the S-XT, has relatively constrained inflow morphology post TAVI. This may contribute to a lesser degree of PVR with the S3. PMID:27002141

  16. Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo.

    PubMed

    Roach, Neil T; Venkadesan, Madhusudhan; Rainbow, Michael J; Lieberman, Daniel E

    2013-06-27

    Some primates, including chimpanzees, throw objects occasionally, but only humans regularly throw projectiles with high speed and accuracy. Darwin noted that the unique throwing abilities of humans, which were made possible when bipedalism emancipated the arms, enabled foragers to hunt effectively using projectiles. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence of when, how and why hominins evolved the ability to generate high-speed throws. Here we use experimental studies of humans throwing projectiles to show that our throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately 2 million years ago in the species Homo erectus. Taking into consideration archaeological evidence suggesting that hunting activity intensified around this time, we conclude that selection for throwing as a means to hunt probably had an important role in the evolution of the genus Homo. PMID:23803849

  17. Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo.

    PubMed

    Roach, Neil T; Venkadesan, Madhusudhan; Rainbow, Michael J; Lieberman, Daniel E

    2013-06-27

    Some primates, including chimpanzees, throw objects occasionally, but only humans regularly throw projectiles with high speed and accuracy. Darwin noted that the unique throwing abilities of humans, which were made possible when bipedalism emancipated the arms, enabled foragers to hunt effectively using projectiles. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence of when, how and why hominins evolved the ability to generate high-speed throws. Here we use experimental studies of humans throwing projectiles to show that our throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately 2 million years ago in the species Homo erectus. Taking into consideration archaeological evidence suggesting that hunting activity intensified around this time, we conclude that selection for throwing as a means to hunt probably had an important role in the evolution of the genus Homo.

  18. Cytotoxicity and Genotoxicity of Hexavalent Chromium in Human and North Atlantic Right Whale (Eubalaena glacialis) Lung Cells

    PubMed Central

    Chen, Tânia Li; Wise, Sandra S.; Holmes, Amie; Shaffiey, Fariba; Wise, John Pierce; Thompson, W. Douglas; Kraus, Scott; Wise, John Pierce

    2009-01-01

    Humans and cetaceans are exposed to a wide range of contaminants. In this study, we compared the cytotoxic and genotoxic effects of a metal pollutant, hexavalent chromium [Cr(VI)], which has been shown to cause damage in lung cells from both humans and North Atlantic right whales. Our results show that Cr induces increased cell death and chromosome damage in lung cells from both species with increasing intracellular Cr ion levels. Soluble Cr(VI) induced less of a cytotoxic and genotoxic effect on administered dose in right whale (Eubalaena glacialis) cells than in human (Homo sapiens) cells. Whereas, particulate Cr(VI) induced a similar cytotoxic effect but less of a genotoxic effect based on administered dose in right whale cells than in human cells. Differences in chromium ion uptake explained some but not all of the soluble chromate-induced cell death and chromosome damage. Uptake differences of lead ions could explain the differences in particulate chromate-induced toxicity. The data show that both forms of Cr(VI) are less genotoxic to right whale than human lung cells, and that soluble Cr(VI) induces a similar cytotoxic effect in both right whale and human cells, while particulate Cr(VI) is more cytotoxic to right whale lung cells. PMID:19632355

  19. Human phylogeography and diversity

    PubMed Central

    Harcourt, Alexander H.

    2016-01-01

    Homo sapiens phylogeography begins with the species’ origin nearly 200 kya in Africa. First signs of the species outside Africa (in Arabia) are from 125 kya. Earliest dates elsewhere are now 100 kya in China, 45 kya in Australia and southern Europe (maybe even 60 kya in Australia), 32 kya in northeast Siberia, and maybe 20 kya in the Americas. Humans reached arctic regions and oceanic islands last—arctic North America about 5 kya, mid- and eastern Pacific islands about 2–1 kya, and New Zealand about 700 y ago. Initial routes along coasts seem the most likely given abundant and easily harvested shellfish there as indicated by huge ancient oyster shell middens on all continents. Nevertheless, the effect of geographic barriers—mountains and oceans—is clear. The phylogeographic pattern of diasporas from several single origins—northeast Africa to Eurasia, southeast Eurasia to Australia, and northeast Siberia to the Americas—allows the equivalent of a repeat experiment on the relation between geography and phylogenetic and cultural diversity. On all continents, cultural diversity is high in productive low latitudes, presumably because such regions can support populations of sustainable size in a small area, therefore allowing a high density of cultures. Of course, other factors operate. South America has an unusually low density of cultures in its tropical latitudes. A likely factor is the phylogeographic movement of peoples from the Old World bringing novel and hence, lethal diseases to the New World, a foretaste, perhaps, of present day global transport of tropical diseases. PMID:27432967

  20. Human phylogeography and diversity.

    PubMed

    Harcourt, Alexander H

    2016-07-19

    Homo sapiens phylogeography begins with the species' origin nearly 200 kya in Africa. First signs of the species outside Africa (in Arabia) are from 125 kya. Earliest dates elsewhere are now 100 kya in China, 45 kya in Australia and southern Europe (maybe even 60 kya in Australia), 32 kya in northeast Siberia, and maybe 20 kya in the Americas. Humans reached arctic regions and oceanic islands last-arctic North America about 5 kya, mid- and eastern Pacific islands about 2-1 kya, and New Zealand about 700 y ago. Initial routes along coasts seem the most likely given abundant and easily harvested shellfish there as indicated by huge ancient oyster shell middens on all continents. Nevertheless, the effect of geographic barriers-mountains and oceans-is clear. The phylogeographic pattern of diasporas from several single origins-northeast Africa to Eurasia, southeast Eurasia to Australia, and northeast Siberia to the Americas-allows the equivalent of a repeat experiment on the relation between geography and phylogenetic and cultural diversity. On all continents, cultural diversity is high in productive low latitudes, presumably because such regions can support populations of sustainable size in a small area, therefore allowing a high density of cultures. Of course, other factors operate. South America has an unusually low density of cultures in its tropical latitudes. A likely factor is the phylogeographic movement of peoples from the Old World bringing novel and hence, lethal diseases to the New World, a foretaste, perhaps, of present day global transport of tropical diseases. PMID:27432967

  1. [Beyond eugenics: posthumanism as Homo patiens denials].

    PubMed

    Ballesteros Llompart, Jesús

    2012-01-01

    Throughout history there have been attempts to overcome human limitations by means of technique. The novelty of the 20th century has been to try to extirpate all the faults, the suffering, the disease, and even the death. This power has been attributed successively to machines (the futurism), to the genetic information (the eugenism) and to the electronic information (the posthumanism). In all cases, it's unknown the distinction between inevitable faults, ontological deficiencies, as the reality of death, and avoidable ones, sociological deficiencies, as the deaths due to circumstances as lack of drinkable water, of medicaments, wars or any other type of violence. The due way of confronting the human faults is to try to eradicate their avoidable causes and at the same time to understand the sense of those that cannot be avoided, as occasion of the self-overcoming and the opening to the Transcendence.

  2. [Beyond eugenics: posthumanism as Homo patiens denials].

    PubMed

    Ballesteros Llompart, Jesús

    2012-01-01

    Throughout history there have been attempts to overcome human limitations by means of technique. The novelty of the 20th century has been to try to extirpate all the faults, the suffering, the disease, and even the death. This power has been attributed successively to machines (the futurism), to the genetic information (the eugenism) and to the electronic information (the posthumanism). In all cases, it's unknown the distinction between inevitable faults, ontological deficiencies, as the reality of death, and avoidable ones, sociological deficiencies, as the deaths due to circumstances as lack of drinkable water, of medicaments, wars or any other type of violence. The due way of confronting the human faults is to try to eradicate their avoidable causes and at the same time to understand the sense of those that cannot be avoided, as occasion of the self-overcoming and the opening to the Transcendence. PMID:22548654

  3. Human longevity at the cost of reproductive success.

    PubMed

    Westendorp, R G; Kirkwood, T B

    The disposable soma theory on the evolution of ageing states that longevity requires investments in somatic maintenance that reduce the resources available for reproduction. Experiments in Drosophila melanogaster indicate that trade-offs of this kind exist in non-human species. We have determined the interrelationship between longevity and reproductive success in Homo sapiens using a historical data set from the British aristocracy. The number of progeny was small when women died at an early age, increased with the age of death, reaching a plateau through the sixth, seventh and eighth decades of life, but decreased again in women who died at an age of 80 years or over. Age at first childbirth was lowest in women who died early and highest for women who died at the oldest ages. When account was taken only of women who had reached menopause, who were aged 60 years and over, female longevity was negatively correlated with number of progeny and positively correlated with age at first childbirth. The findings show that human life histories involve a trade-off between longevity and reproduction.

  4. The gourmet ape: evolution and human food preferences.

    PubMed

    Krebs, John R

    2009-09-01

    This review explores the relation between evolution, ecology, and culture in determining human food preferences. The basic physiology and morphology of Homo sapiens sets boundaries to our eating habits, but within these boundaries human food preferences are remarkably varied, both within and between populations. This does not mean that variation is entirely cultural or learned, because genes and culture may coevolve to determine variation in dietary habits. This coevolution has been well elucidated in some cases, such as lactose tolerance (lactase persistence) in adults, but is less well understood in others, such as in favism in the Mediterranean and other regions. Genetic variation in bitter taste sensitivity has been well documented, and it affects food preferences (eg, avoidance of cruciferous vegetables). The selective advantage of this variation is not clear. In African populations, there is an association between insensitivity to bitter taste and the prevalence of malaria, which suggests that insensitivity may have been selected for in regions in which eating bitter plants would confer some protection against malaria. Another, more general, hypothesis is that variation in bitter taste sensitivity has coevolved with the use of spices in cooking, which, in turn, is thought to be a cultural tradition that reduces the dangers of microbial contamination of food. Our evolutionary heritage of food preferences and eating habits leaves us mismatched with the food environments we have created, which leads to problems such as obesity and type 2 diabetes.

  5. Visuospatial integration and human evolution: the fossil evidence.

    PubMed

    Bruner, Emiliano; Lozano, Marina; Lorenzo, Carlos

    2016-06-20

    Visuospatial integration concerns the ability to coordinate the inner and outer environments, namely the central nervous system and the outer spatial elements, through the interface of the body. This integration is essential for every basic human activity, from locomotion and grasping to speech or tooling. Visuospatial integration is even more fundamental when dealing with theories on extended mind, embodiment, and material engagement. According to the hypotheses on extended cognition, the nervous system, the body and the external objects work as a single integrated unit, and what we call "mind" is the process resulting from such interaction. Because of the relevance of culture and material culture in humans, important changes in such processes were probably crucial for the evolution of Homo sapiens. Much information in this sense can be supplied by considering issues in neuroarchaeology and cognitive sciences. Nonetheless, fossils and their anatomy can also provide evidence according to changes involving physical and body aspects. In this article, we review three sources of morphological information concerning visuospatial management and fossils: evolutionary neuroanatomy, manipulative behaviors, and hand evolution.

  6. Systems vaccinology: probing humanity's diverse immune systems with vaccines.

    PubMed

    Pulendran, Bali

    2014-08-26

    Homo sapiens are genetically diverse, but dramatic demographic and socioeconomic changes during the past century have created further diversification with respect to age, nutritional status, and the incidence of associated chronic inflammatory disorders and chronic infections. These shifting demographics pose new challenges for vaccination, as emerging evidence suggests that age, the metabolic state, and chronic infections can exert major influences on the immune system. Thus, a key public health challenge is learning how to reprogram suboptimal immune systems to induce effective vaccine immunity. Recent advances have applied systems biological analysis to define molecular signatures induced early after vaccination that correlate with and predict the later adaptive immune responses in humans. Such "systems vaccinology" approaches offer an integrated picture of the molecular networks driving vaccine immunity, and are beginning to yield novel insights about the immune system. Here we discuss the promise of systems vaccinology in probing humanity's diverse immune systems, and in delineating the impact of genes, the environment, and the microbiome on protective immunity induced by vaccination. Such insights will be critical in reengineering suboptimal immune systems in immunocompromised populations. PMID:25136102

  7. Visuospatial integration and human evolution: the fossil evidence.

    PubMed

    Bruner, Emiliano; Lozano, Marina; Lorenzo, Carlos

    2016-06-20

    Visuospatial integration concerns the ability to coordinate the inner and outer environments, namely the central nervous system and the outer spatial elements, through the interface of the body. This integration is essential for every basic human activity, from locomotion and grasping to speech or tooling. Visuospatial integration is even more fundamental when dealing with theories on extended mind, embodiment, and material engagement. According to the hypotheses on extended cognition, the nervous system, the body and the external objects work as a single integrated unit, and what we call "mind" is the process resulting from such interaction. Because of the relevance of culture and material culture in humans, important changes in such processes were probably crucial for the evolution of Homo sapiens. Much information in this sense can be supplied by considering issues in neuroarchaeology and cognitive sciences. Nonetheless, fossils and their anatomy can also provide evidence according to changes involving physical and body aspects. In this article, we review three sources of morphological information concerning visuospatial management and fossils: evolutionary neuroanatomy, manipulative behaviors, and hand evolution. PMID:26829574

  8. Dating the Homo erectus bearing travertine from Kocabaş (Denizli, Turkey) at at least 1.1 Ma

    NASA Astrophysics Data System (ADS)

    Lebatard, Anne-Elisabeth; Alçiçek, M. Cihat; Rochette, Pierre; Khatib, Samir; Vialet, Amélie; Boulbes, Nicolas; Bourlès, Didier L.; Demory, François; Guipert, Gaspard; Mayda, Serdar; Titov, Vadim V.; Vidal, Laurence; de Lumley, Henry

    2014-03-01

    Since its discovery within a travertine quarry, the fragmentary cranium of the only known Turkish Homo erectus, the Kocabaş hominid, has led to conflicting biochronological estimations. First estimated to be ˜500 ka old, the partial skull presents a combination of archaic and evolved features that puts it as an intermediate specimen between the Dmanisi fossils (Homo georgicus) and the Chinese Zhoukoudian skulls (Homo erectus) respectively dated to 1.8 to ˜0.8 Ma. Here we present a multidisciplinary study combining sedimentological, paleontological and paleoanthropological observations together with cosmogenic nuclide concentration and paleomagnetic measurements to provide an absolute chronological framework for the Upper fossiliferous Travertine unit where the Kocabaş hominid and fauna were discovered. The 26Al/10Be burial ages determined on pebbles from conglomeratic levels framing the Upper fossiliferous Travertine unit, which exhibits an inverse polarity, constrains its deposition to before the Cobb Mountain sub-chron, that is between 1.22 and ˜1.5 Ma. The alternative match of the normal polarity recorded above the travertine with the Jaramillo subchron (lower limit 1.07 Ma) may also be marginally compatible with cosmogenic nuclides interpretation, thus the proposed minimum age of 1.1 Ma for the end of massive travertine deposition. The actual age of the fossils is likely to be in the 1.1-1.3 Ma range. This absolute date is in close agreement with the paleoanthropological conclusions based on morphometric comparisons implying that Kocabaş hominid belongs to the Homo erectus s.l. group that includes Chinese and African fossils, and is different from Middle and Upper Pleistocene specimens. Furthermore, this date is confirmed by the large mammal assemblage, typical of the late Villafranchian. Because it attests to the antiquity of human occupation of the Anatolian Peninsula and one of the waves of settlements out of Africa, this work challenges the current

  9. The origin and dispersion of human parasitic diseases in the old world (Africa, Europe and Madagascar).

    PubMed

    Nozais, Jean-Pierre

    2003-01-01

    The ancestors of present-day man (Homo sapiens sapiens) appeared in East Africa some three and a half million years ago (Australopithecs), and then migrated to Europe, Asia, and later to the Americas, thus beginning the differentiation process. The passage from nomadic to sedentary life took place in the Middle East in around 8000 BC. Wars, spontaneous migrations and forced migrations (slave trade) led to enormous mixtures of populations in Europe and Africa and favoured the spread of numerous parasitic diseases with specific strains according to geographic area. The three human plasmodia (Plasmodium falciparum, P. vivax, and P. malariae) were imported from Africa into the Mediterranean region with the first human migrations, but it was the Neolithic revolution (sedentarisation, irrigation, population increase) which brought about actual foci for malaria. The reservoir for Leishmania infantum and L. donovani--the dog--has been domesticated for thousands of years. Wild rodents as reservoirs of L. major have also long been in contact with man and probably were imported from tropical Africa across the Sahara. L. tropica, by contrast, followed the migrations of man, its only reservoir. L. infantum and L. donovani spread with man and his dogs from West Africa. Likewise, for thousands of years, the dog has played an important role in the spread and the endemic character of hydatidosis through sheep (in Europe and North Africa) and dromadary (in the Sahara and North Africa). Schistosoma haematobium and S. mansoni have existed since prehistoric times in populations living in or passing through the Sahara. These populations then transported them to countries of Northern Africa where the specific, intermediary hosts were already present. Madagascar was inhabited by populations of Indonesian origin who imported lymphatic filariosis across the Indian Ocean (possibly of African origin since the Indonesian sailors had spent time on the African coast before reaching Madagascar

  10. Computational discovery of Epstein-Barr virus targeted human genes and signalling pathways

    PubMed Central

    Mei, Suyu; Zhang, Kun

    2016-01-01

    Epstein-Barr virus (EBV) plays important roles in the origin and the progression of human carcinomas, e.g. diffuse large B cell tumors, T cell lymphomas, etc. Discovering EBV targeted human genes and signaling pathways is vital to understand EBV tumorigenesis. In this study we propose a noise-tolerant homolog knowledge transfer method to reconstruct functional protein-protein interactions (PPI) networks between Epstein-Barr virus and Homo sapiens. The training set is augmented via homolog instances and the homolog noise is counteracted by support vector machine (SVM). Additionally we propose two methods to define subcellular co-localization (i.e. stringent and relaxed), based on which to further derive physical PPI networks. Computational results show that the proposed method achieves sound performance of cross validation and independent test. In the space of 648,672 EBV-human protein pairs, we obtain 51,485 functional interactions (7.94%), 869 stringent physical PPIs and 46,050 relaxed physical PPIs. Fifty-eight evidences are found from the latest database and recent literature to validate the model. This study reveals that Epstein-Barr virus interferes with normal human cell life, such as cholesterol homeostasis, blood coagulation, EGFR binding, p53 binding, Notch signaling, Hedgehog signaling, etc. The proteome-wide predictions are provided in the supplementary file for further biomedical research. PMID:27470517

  11. ProNormz--an integrated approach for human proteins and protein kinases normalization.

    PubMed

    Subramani, Suresh; Raja, Kalpana; Natarajan, Jeyakumar

    2014-02-01

    The task of recognizing and normalizing protein name mentions in biomedical literature is a challenging task and important for text mining applications such as protein-protein interactions, pathway reconstruction and many more. In this paper, we present ProNormz, an integrated approach for human proteins (HPs) tagging and normalization. In Homo sapiens, a greater number of biological processes are regulated by a large human gene family called protein kinases by post translational phosphorylation. Recognition and normalization of human protein kinases (HPKs) is considered to be important for the extraction of the underlying information on its regulatory mechanism from biomedical literature. ProNormz distinguishes HPKs from other HPs besides tagging and normalization. To our knowledge, ProNormz is the first normalization system available to distinguish HPKs from other HPs in addition to gene normalization task. ProNormz incorporates a specialized synonyms dictionary for human proteins and protein kinases, a set of 15 string matching rules and a disambiguation module to achieve the normalization. Experimental results on benchmark BioCreative II training and test datasets show that our integrated approach achieve a fairly good performance and outperforms more sophisticated semantic similarity and disambiguation systems presented in BioCreative II GN task. As a freely available web tool, ProNormz is useful to developers as extensible gene normalization implementation, to researchers as a standard for comparing their innovative techniques, and to biologists for normalization and categorization of HPs and HPKs mentions in biomedical literature. URL: http://www.biominingbu.org/pronormz.

  12. Computational discovery of Epstein-Barr virus targeted human genes and signalling pathways.

    PubMed

    Mei, Suyu; Zhang, Kun

    2016-01-01

    Epstein-Barr virus (EBV) plays important roles in the origin and the progression of human carcinomas, e.g. diffuse large B cell tumors, T cell lymphomas, etc. Discovering EBV targeted human genes and signaling pathways is vital to understand EBV tumorigenesis. In this study we propose a noise-tolerant homolog knowledge transfer method to reconstruct functional protein-protein interactions (PPI) networks between Epstein-Barr virus and Homo sapiens. The training set is augmented via homolog instances and the homolog noise is counteracted by support vector machine (SVM). Additionally we propose two methods to define subcellular co-localization (i.e. stringent and relaxed), based on which to further derive physical PPI networks. Computational results show that the proposed method achieves sound performance of cross validation and independent test. In the space of 648,672 EBV-human protein pairs, we obtain 51,485 functional interactions (7.94%), 869 stringent physical PPIs and 46,050 relaxed physical PPIs. Fifty-eight evidences are found from the latest database and recent literature to validate the model. This study reveals that Epstein-Barr virus interferes with normal human cell life, such as cholesterol homeostasis, blood coagulation, EGFR binding, p53 binding, Notch signaling, Hedgehog signaling, etc. The proteome-wide predictions are provided in the supplementary file for further biomedical research. PMID:27470517

  13. In vitro susceptibility of T lymphocytes from chimpanzees (Pan troglodytes) to human herpesvirus 6 (HHV-6): a potential animal model to study the interaction between HHV-6 and human immunodeficiency virus type 1 in vivo.

    PubMed Central

    Lusso, P; Markham, P D; DeRocco, S E; Gallo, R C

    1990-01-01

    The in vitro susceptibility of several nonhuman primate species to human herpesvirus 6 (HHV-6) was investigated. Only peripheral blood mononuclear cells from chimpanzees (Pan troglodytes) were found permissive to productive infection by HHV-6, indicating that the host range of HHV-6, albeit limited, may not be restricted to Homo sapiens. However, natural HHV-6 infection in chimpanzees, as well as in the other species tested, could not be documented by serological analysis. As previously observed with human cells, HHV-6 infection of chimpanzee peripheral blood mononuclear cells was highly cytopathic and the infected cells exhibited phenotypic features of activated T lymphocytes. Although in humans the majority of HHV-6-infected lymphocytes displayed the CD4 antigen, in chimpanzees a mixed CD4+ and CD8+ phenotype was observed. HHV-6 was also shown to productively coinfect individual chimpanzee T cells with human immunodeficiency virus type 1, resulting in an accelerated induction of cytopathicity. In light of these findings, we propose the utilization of chimpanzees as a potential animal model system to investigate the in vivo interaction between HHV-6 and human immunodeficiency virus type 1 and its relevance to the development of acquired immune deficiency syndrome. Images PMID:2159541

  14. The Dawn of Human Matrilineal Diversity

    PubMed Central

    Behar, Doron M.; Villems, Richard; Soodyall, Himla; Blue-Smith, Jason; Pereira, Luisa; Metspalu, Ene; Scozzari, Rosaria; Makkan, Heeran; Tzur, Shay; Comas, David; Bertranpetit, Jaume; Quintana-Murci, Lluis; Tyler-Smith, Chris; Wells, R. Spencer; Rosset, Saharon

    2008-01-01

    The quest to explain demographic history during the early part of human evolution has been limited because of the scarce paleoanthropological record from the Middle Stone Age. To shed light on the structure of the mitochondrial DNA (mtDNA) phylogeny at the dawn of Homo sapiens, we constructed a matrilineal tree composed of 624 complete mtDNA genomes from sub-Saharan Hg L lineages. We paid particular attention to the Khoi and San (Khoisan) people of South Africa because they are considered to be a unique relic of hunter-gatherer lifestyle and to carry paternal and maternal lineages belonging to the deepest clades known among modern humans. Both the tree phylogeny and coalescence calculations suggest that Khoisan matrilineal ancestry diverged from the rest of the human mtDNA pool 90,000–150,000 years before present (ybp) and that at least five additional, currently extant maternal lineages existed during this period in parallel. Furthermore, we estimate that a minimum of 40 other evolutionarily successful lineages flourished in sub-Saharan Africa during the period of modern human dispersal out of Africa approximately 60,000–70,000 ybp. Only much later, at the beginning of the Late Stone Age, about 40,000 ybp, did introgression of additional lineages occur into the Khoisan mtDNA pool. This process was further accelerated during the recent Bantu expansions. Our results suggest that the early settlement of humans in Africa was already matrilineally structured and involved small, separately evolving isolated populations. PMID:18439549

  15. From monkey-like action recognition to human language: an evolutionary framework for neurolinguistics.

    PubMed

    Arbib, Michael A

    2005-04-01

    The article analyzes the neural and functional grounding of language skills as well as their emergence in hominid evolution, hypothesizing stages leading from abilities known to exist in monkeys and apes and presumed to exist in our hominid ancestors right through to modern spoken and signed languages. The starting point is the observation that both premotor area F5 in monkeys and Broca's area in humans contain a "mirror system" active for both execution and observation of manual actions, and that F5 and Broca's area are homologous brain regions. This grounded the mirror system hypothesis of Rizzolatti and Arbib (1998) which offers the mirror system for grasping as a key neural "missing link" between the abilities of our nonhuman ancestors of 20 million years ago and modern human language, with manual gestures rather than a system for vocal communication providing the initial seed for this evolutionary process. The present article, however, goes "beyond the mirror" to offer hypotheses on evolutionary changes within and outside the mirror systems which may have occurred to equip Homo sapiens with a language-ready brain. Crucial to the early stages of this progression is the mirror system for grasping and its extension to permit imitation. Imitation is seen as evolving via a so-called simple system such as that found in chimpanzees (which allows imitation of complex "object-oriented" sequences but only as the result of extensive practice) to a so-called complex system found in humans (which allows rapid imitation even of complex sequences, under appropriate conditions) which supports pantomime. This is hypothesized to have provided the substrate for the development of protosign, a combinatorially open repertoire of manual gestures, which then provides the scaffolding for the emergence of protospeech (which thus owes little to nonhuman vocalizations), with protosign and protospeech then developing in an expanding spiral. It is argued that these stages involve

  16. From monkey-like action recognition to human language: an evolutionary framework for neurolinguistics.

    PubMed

    Arbib, Michael A

    2005-04-01

    The article analyzes the neural and functional grounding of language skills as well as their emergence in hominid evolution, hypothesizing stages leading from abilities known to exist in monkeys and apes and presumed to exist in our hominid ancestors right through to modern spoken and signed languages. The starting point is the observation that both premotor area F5 in monkeys and Broca's area in humans contain a "mirror system" active for both execution and observation of manual actions, and that F5 and Broca's area are homologous brain regions. This grounded the mirror system hypothesis of Rizzolatti and Arbib (1998) which offers the mirror system for grasping as a key neural "missing link" between the abilities of our nonhuman ancestors of 20 million years ago and modern human language, with manual gestures rather than a system for vocal communication providing the initial seed for this evolutionary process. The present article, however, goes "beyond the mirror" to offer hypotheses on evolutionary changes within and outside the mirror systems which may have occurred to equip Homo sapiens with a language-ready brain. Crucial to the early stages of this progression is the mirror system for grasping and its extension to permit imitation. Imitation is seen as evolving via a so-called simple system such as that found in chimpanzees (which allows imitation of complex "object-oriented" sequences but only as the result of extensive practice) to a so-called complex system found in humans (which allows rapid imitation even of complex sequences, under appropriate conditions) which supports pantomime. This is hypothesized to have provided the substrate for the development of protosign, a combinatorially open repertoire of manual gestures, which then provides the scaffolding for the emergence of protospeech (which thus owes little to nonhuman vocalizations), with protosign and protospeech then developing in an expanding spiral. It is argued that these stages involve

  17. Cranial vault thickness in primates: Homo erectus does not have uniquely thick vault bones.

    PubMed

    Copes, Lynn E; Kimbel, William H

    2016-01-01

    Extremely thick cranial vaults have been noted as a diagnostic characteristic of Homo erectus since the first fossil of the species was identified, but relatively little work has been done on elucidating its etiology or variation across fossils, living humans, or extant non-human primates. Cranial vault thickness (CVT) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown. We obtained measurements of cranial vault thickness in fossil hominins from the literature and supplemented those data with additional measurements taken on African fossil specimens. Total CVT and the thickness of the cortical and diploë layers individually were compared to measures of CVT in extant species measured from more than 500 CT scans of human and non-human primates. Frontal and parietal CVT in fossil primates was compared to a regression of CVT on cranial capacity calculated for extant species. Even after controlling for cranial capacity, African and Asian H. erectus do not have uniquely high frontal or parietal thickness residuals, either among hominins or extant primates. Extant primates with residual CVT thickness similar to or exceeding H. erectus (depending on the sex and bone analyzed) include Nycticebus coucang, Perodicticus potto, Alouatta caraya, Lophocebus albigena, Galago alleni, Mandrillus sphinx, and Propithecus diadema. However, the especially thick vaults of extant non-human primates that overlap with H. erectus values are composed primarily of cortical bone, while H. erectus and other hominins have diploë-dominated vault bones. Thus, the combination of thick vaults comprised of a thickened diploë layer may be a reliable autapomorphy for members of the genus Homo. PMID:26767964

  18. Cranial vault thickness in primates: Homo erectus does not have uniquely thick vault bones.

    PubMed

    Copes, Lynn E; Kimbel, William H

    2016-01-01

    Extremely thick cranial vaults have been noted as a diagnostic characteristic of Homo erectus since the first fossil of the species was identified, but relatively little work has been done on elucidating its etiology or variation across fossils, living humans, or extant non-human primates. Cranial vault thickness (CVT) is not a monolithic trait, and the responsiveness of its layers to environmental stimuli is unknown. We obtained measurements of cranial vault thickness in fossil hominins from the literature and supplemented those data with additional measurements taken on African fossil specimens. Total CVT and the thickness of the cortical and diploë layers individually were compared to measures of CVT in extant species measured from more than 500 CT scans of human and non-human primates. Frontal and parietal CVT in fossil primates was compared to a regression of CVT on cranial capacity calculated for extant species. Even after controlling for cranial capacity, African and Asian H. erectus do not have uniquely high frontal or parietal thickness residuals, either among hominins or extant primates. Extant primates with residual CVT thickness similar to or exceeding H. erectus (depending on the sex and bone analyzed) include Nycticebus coucang, Perodicticus potto, Alouatta caraya, Lophocebus albigena, Galago alleni, Mandrillus sphinx, and Propithecus diadema. However, the especially thick vaults of extant non-human primates that overlap with H. erectus values are composed primarily of cortical bone, while H. erectus and other hominins have diploë-dominated vault bones. Thus, the combination of thick vaults comprised of a thickened diploë layer may be a reliable autapomorphy for members of the genus Homo.

  19. Human Development, Human Evolution.

    ERIC Educational Resources Information Center

    Smillie, David

    One of the truly remarkable events in human evolution is the unprecedented increase in the size of the brain of "Homo" over a brief span of 2 million years. It would appear that some significant selective pressure or opportunity presented itself to this branch of the hominid line and caused a rapid increase in the brain, introducing a wholly new…

  20. Early human use of marine resources and pigment in South Africa during the Middle Pleistocene.

    PubMed

    Marean, Curtis W; Bar-Matthews, Miryam; Bernatchez, Jocelyn; Fisher, Erich; Goldberg, Paul; Herries, Andy I R; Jacobs, Zenobia; Jerardino, Antonieta; Karkanas, Panagiotis; Minichillo, Tom; Nilssen, Peter J; Thompson, Erin; Watts, Ian; Williams, Hope M

    2007-10-18

    Genetic and anatomical evidence suggests that Homo sapiens arose in Africa between 200 and 100 thousand years (kyr) ago, and recent evidence indicates symbolic behaviour may have appeared approximately 135-75 kyr ago. From 195-130 kyr ago, the world was in a fluctuating but predominantly glacial stage (marine isotope stage MIS6); much of Africa was cooler and drier, and dated archaeological sites are rare. Here we show that by approximately 164 kyr ago (+/-12 kyr) at Pinnacle Point (on the south coast of South Africa) humans expanded their diet to include marine resources, perhaps as a response to these harsh environmental conditions. The earliest previous evidence for human use of marine resources and coastal habitats was dated to approximately 125 kyr ago. Coincident with this diet and habitat expansion is an early use and modification of pigment, probably for symbolic behaviour, as well as the production of bladelet stone tool technology, previously dated to post-70 kyr ago. Shellfish may have been crucial to the survival of these early humans as they expanded their home ranges to include coastlines and followed the shifting position of the coast when sea level fluctuated over the length of MIS6. PMID:17943129

  1. No Distinction of Orthology/Paralogy between Human and Chimpanzee Rh Blood Group Genes

    PubMed Central

    Kitano, Takashi; Kim, Choong-Gon; Blancher, Antoine; Saitou, Naruya

    2016-01-01

    On human (Homo sapiens) chromosome 1, there is a tandem duplication encompassing Rh blood group genes (Hosa_RHD and Hosa_RHCE). This duplication occurred in the common ancestor of humans, chimpanzees (Pan troglodytes), and gorillas, after splitting from their common ancestor with orangutans. Although several studies have been conducted on ape Rh blood group genes, the clear genome structures of the gene clusters remain unknown. Here, we determined the genome structure of the gene cluster of chimpanzee Rh genes by sequencing five BAC (Bacterial Artificial Chromosome) clones derived from chimpanzees. We characterized three complete loci (Patr_RHα, Patr_RHβ, and Patr_RHγ). In the Patr_RHβ locus, a short version of the gene, which lacked the middle part containing exons 4–8, was observed. The Patr_RHα and Patr_RHβ genes were located on the locations corresponding to Hosa_RHD and Hosa_RHCE, respectively, and Patr_RHγ was in the immediate vicinity of Patr_RHβ. Sequence comparisons revealed high sequence similarity between Patr_RHβ and Hosa_RHCE, while the chimpanzee Rh gene closest to Hosa_RHD was not Patr_RHα but rather Patr_RHγ. The results suggest that rearrangements and gene conversions frequently occurred between these genes and that the classic orthology/paralogy dichotomy no longer holds between human and chimpanzee Rh blood group genes. PMID:26872772

  2. Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions

    PubMed Central

    Boivin, Nicole L.; Zeder, Melinda A.; Fuller, Dorian Q.; Crowther, Alison; Larson, Greger; Erlandson, Jon M.; Denham, Tim; Petraglia, Michael D.

    2016-01-01

    The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens. A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity—the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences. PMID:27274046

  3. Femoral morphology and femoropelvic musculoskeletal anatomy of humans and great apes: a comparative virtopsy study.

    PubMed

    Morimoto, Naoki; Ponce de León, Marcia S; Nishimura, Takeshi; Zollikofer, Christoph P E

    2011-09-01

    The proximal femoral morphology of fossil hominins is routinely interpreted in terms of muscular topography and associated locomotor modes. However, the detailed correspondence between hard and soft tissue structures in the proximal femoral region of extant great apes is relatively unknown, because dissection protocols typically do not comprise in-depth osteological descriptions. Here, we use computed tomography and virtopsy (virtual dissection) for non-invasive examination of the femoropelvic musculoskeletal anatomy in Pan troglodytes, P. paniscus, Gorilla gorilla, Pongo pygmaeus, and Homo sapiens. Specifically, we analyze the topographic relationship between muscle attachment sites and surface structures of the proximal femoral shaft such as the lateral spiral pilaster. Our results show that the origin of the vastus lateralis muscle is anterior to the insertion of gluteus maximus in all examined great ape specimens and humans. In gorillas and orangutans, the insertion of gluteus maximus is on the inferior (anterolateral) side of the lateral spiral pilaster. In chimpanzees, however, the maximus insertion is on its superior (posteromedial) side, similar to the situation in modern humans. These findings support the hypothesis that chimpanzees and humans exhibit a shared-derived musculoskeletal topography of the proximal femoral region, irrespective of their different locomotor modes, whereas gorillas and orangutans represent the primitive condition. Caution is thus warranted when inferring locomotor behavior from the surface topography of the proximal femur of fossil hominins, as the morphology of this region may contain a strong phyletic signal that tends to blur locomotor adaptation.

  4. Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions.

    PubMed

    Boivin, Nicole L; Zeder, Melinda A; Fuller, Dorian Q; Crowther, Alison; Larson, Greger; Erlandson, Jon M; Denham, Tim; Petraglia, Michael D

    2016-06-01

    The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity-the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences. PMID:27274046

  5. Ecological consequences of human niche construction: Examining long-term anthropogenic shaping of global species distributions.

    PubMed

    Boivin, Nicole L; Zeder, Melinda A; Fuller, Dorian Q; Crowther, Alison; Larson, Greger; Erlandson, Jon M; Denham, Tim; Petraglia, Michael D

    2016-06-01

    The exhibition of increasingly intensive and complex niche construction behaviors through time is a key feature of human evolution, culminating in the advanced capacity for ecosystem engineering exhibited by Homo sapiens A crucial outcome of such behaviors has been the dramatic reshaping of the global biosphere, a transformation whose early origins are increasingly apparent from cumulative archaeological and paleoecological datasets. Such data suggest that, by the Late Pleistocene, humans had begun to engage in activities that have led to alterations in the distributions of a vast array of species across most, if not all, taxonomic groups. Changes to biodiversity have included extinctions, extirpations, and shifts in species composition, diversity, and community structure. We outline key examples of these changes, highlighting findings from the study of new datasets, like ancient DNA (aDNA), stable isotopes, and microfossils, as well as the application of new statistical and computational methods to datasets that have accumulated significantly in recent decades. We focus on four major phases that witnessed broad anthropogenic alterations to biodiversity-the Late Pleistocene global human expansion, the Neolithic spread of agriculture, the era of island colonization, and the emergence of early urbanized societies and commercial networks. Archaeological evidence documents millennia of anthropogenic transformations that have created novel ecosystems around the world. This record has implications for ecological and evolutionary research, conservation strategies, and the maintenance of ecosystem services, pointing to a significant need for broader cross-disciplinary engagement between archaeology and the biological and environmental sciences.

  6. Pathogen prevalence predicts human cross-cultural variability in individualism/collectivism.

    PubMed

    Fincher, Corey L; Thornhill, Randy; Murray, Damian R; Schaller, Mark

    2008-06-01

    Pathogenic diseases impose selection pressures on the social behaviour of host populations. In humans (Homo sapiens), many psychological phenomena appear to serve an antipathogen defence function. One broad implication is the existence of cross-cultural differences in human cognition and behaviour contingent upon the relative presence of pathogens in the local ecology. We focus specifically on one fundamental cultural variable: differences in individualistic versus collectivist values. We suggest that specific behavioural manifestations of collectivism (e.g. ethnocentrism, conformity) can inhibit the transmission of pathogens; and so we hypothesize that collectivism (compared with individualism) will more often characterize cultures in regions that have historically had higher prevalence of pathogens. Drawing on epidemiological data and the findings of worldwide cross-national surveys of individualism/collectivism, our results support this hypothesis: the regional prevalence of pathogens has a strong positive correlation with cultural indicators of collectivism and a strong negative correlation with individualism. The correlations remain significant even when controlling for potential confounding variables. These results help to explain the origin of a paradigmatic cross-cultural difference, and reveal previously undocumented consequences of pathogenic diseases on the variable nature of human societies.

  7. Pathogen prevalence predicts human cross-cultural variability in individualism/collectivism

    PubMed Central

    Fincher, Corey L; Thornhill, Randy; Murray, Damian R; Schaller, Mark

    2008-01-01

    Pathogenic diseases impose selection pressures on the social behaviour of host populations. In humans (Homo sapiens), many psychological phenomena appear to serve an antipathogen defence function. One broad implication is the existence of cross-cultural differences in human cognition and behaviour contingent upon the relative presence of pathogens in the local ecology. We focus specifically on one fundamental cultural variable: differences in individualistic versus collectivist values. We suggest that specific behavioural manifestations of collectivism (e.g. ethnocentrism, conformity) can inhibit the transmission of pathogens; and so we hypothesize that collectivism (compared with individualism) will more often characterize cultures in regions that have historically had higher prevalence of pathogens. Drawing on epidemiological data and the findings of worldwide cross-national surveys of individualism/collectivism, our results support this hypothesis: the regional prevalence of pathogens has a strong positive correlation with cultural indicators of collectivism and a strong negative correlation with individualism. The correlations remain significant even when controlling for potential confounding variables. These results help to explain the origin of a paradigmatic cross-cultural difference, and reveal previously undocumented consequences of pathogenic diseases on the variable nature of human societies. PMID:18302996

  8. NMR structural inference of symmetric homo-oligomers.

    PubMed

    Chandola, Himanshu; Yan, Anthony K; Potluri, Shobha; Donald, Bruce R; Bailey-Kellogg, Chris

    2011-12-01

    Symmetric homo-oligomers represent a majority of proteins, and determining their structures helps elucidate important biological processes, including ion transport, signal transduction, and transcriptional regulation. In order to account for the noise and sparsity in the distance restraints used in Nuclear Magnetic Resonance (NMR) structure determination of cyclic (C(n)) symmetric homo-oligomers, and the resulting uncertainty in the determined structures, we develop a Bayesian structural inference approach. In contrast to traditional NMR structure determination methods, which identify a small set of low-energy conformations, the inferential approach characterizes the entire posterior distribution of conformations. Unfortunately, traditional stochastic techniques for inference may under-sample the rugged landscape of the posterior, missing important contributions from high-quality individual conformations and not accounting for the possible aggregate effects on inferred quantities from numerous unsampled conformations. However, by exploiting the geometry of symmetric homo-oligomers, we develop an algorithm that provides provable guarantees for the posterior distribution and the inferred mean atomic coordinates. Using experimental restraints for three proteins, we demonstrate that our approach is able to objectively characterize the structural diversity supported by the data. By simulating spurious and missing restraints, we further demonstrate that our approach is robust, degrading smoothly with noise and sparsity. PMID:21718128

  9. Cranial size variation and lineage diversity in early Pleistocene Homo.

    PubMed

    Scott, Jeremiah E

    2014-03-01

    A recent article in this journal concluded that a sample of early Pleistocene hominin crania assigned to genus Homo exhibits a pattern of size variation that is time dependent, with specimens from different time periods being more different from each other, on average, than are specimens from the same time period. The authors of this study argued that such a pattern is not consistent with the presence of multiple lineages within the sample, but rather supports the hypothesis that the fossils represent an anagenetically evolving lineage (i.e., an evolutionary species). However, the multiple-lineage models considered in that study do not reflect the multiple-species alternatives that have been proposed for early Pleistocene Homo. Using simulated data sets, I show that fossil assemblages that contain multiple lineages can exhibit the time-dependent pattern of variation specified for the single-lineage model under certain conditions, particularly when temporal overlap among fossil specimens attributed to the lineages is limited. These results do not reject the single-lineage hypothesis, but they do indicate that rejection of multiple lineages in the early Pleistocene Homo fossil record is premature, and that other sources of variation, such as differences in cranial shape, should be considered. PMID:24588348

  10. Reidentification of Ebola Virus E718 and ME as Ebola Virus/H.sapiens-tc/COD/1976/Yambuku-Ecran

    PubMed Central

    Lofts, Loreen L.; Kugelman, Jeffrey R.; Smither, Sophie J.; Lever, Mark S.; van der Groen, Guido; Johnson, Karl M.; Radoshitzky, Sheli R.; Bavari, Sina; Jahrling, Peter B.; Towner, Jonathan S.; Nichol, Stuart T.; Palacios, Gustavo

    2014-01-01

    Ebola virus (EBOV) was discovered in 1976 around Yambuku, Zaire. A lack of nomenclature standards resulted in a variety of designations for each isolate, leading to confusion in the literature and databases. We sequenced the genome of isolate E718/ME/Ecran and unified the various designations under Ebola virus/H.sapiens-tc/COD/1976/Yambuku-Ecran. PMID:25414499

  11. The Brazilian megamastofauna of the Pleistocene/Holocene transition and its relationship with the early human settlement of the continent

    NASA Astrophysics Data System (ADS)

    Hubbe, Alex; Hubbe, Mark; Neves, Walter A.

    2013-03-01

    One of the most intriguing questions regarding the Brazilian Late Quaternary extinct megafauna and Homo sapiens is to what extent they coexisted and how humans could have contributed to the former's extinction. The aim of this article is to review the chronological and archaeological evidences of their coexistence in Brazil and to evaluate the degree of direct interaction between them. Critical assessment of the Brazilian megafauna chronological data shows that several of the late Pleistoscene/early Holocene dates available so far cannot be considered reliable, but the few that do suggest that at least two species (Catonyx cuvieri, ground sloth; Smilodon populator, saber-toothed cat) survived until the beginning of the Holocene in Southeast Brazil. Archaeological data indicates that the first human groups arrived in Brazil and were inhabiting this region during the last millennia of the Pleistocene and, consequently, they coexisted with the extinct fauna in some parts of Brazil for at least one thousand years. There is no robust evidence favoring any kind of direct interaction between humans and megafauna prior to their extinction. To date, it is not possible to properly judge the indirect influence of humans (landscape transformation, introduction of predators, among others) in this extinction event. Intense and to some extent unique climate changes between the Last Glacial Maximum and the Holocene favors the interpretation that they had a major contribution to the megafauna extinction, although the scarcity of data impedes the proper testing of this hypothesis.

  12. Comparative cytotoxicity and genotoxicity of particulate and soluble hexavalent chromium in human and sperm whale (Physeter macrocephalus) skin cells.

    PubMed

    Li Chen, Tânia; LaCerte, Carolyne; Wise, Sandra S; Holmes, Amie; Martino, Julieta; Wise, John Pierce; Thompson, W Douglas; Wise, John Pierce

    2012-01-01

    Chromium (Cr) is a global marine pollutant, present in marine mammal tissues. Hexavalent chromium [Cr(VI)] is a known human carcinogen. In this study, we compare the cytotoxic and clastogenic effects of Cr(VI) in human (Homo sapiens) and sperm whale (Physeter macrocephalus) skin fibroblasts. Our data show that increasing concentrations of both particulate and soluble Cr(VI) induce increasing amounts of cytotoxicity and clastogenicity in human and sperm whale skin cells. Furthermore, the data show that sperm whale cells are resistant to these effects exhibiting less cytotoxicity and genotoxicity than the human cells. Differences in Cr uptake accounted for some but not all of the differences in particulate and soluble Cr(VI) genotoxicity, although it did explain the differences in particulate Cr(VI) cytotoxicity. Altogether, the data indicate that Cr(VI) is a genotoxic threat to whales, but also suggest that whales have evolved cellular mechanisms to protect them against the genotoxicity of environmental agents such as Cr(VI).

  13. Comparative Cytotoxicity and Genotoxicity of Particulate and Soluble Hexavalent Chromium in Human and Sperm Whale (Physeter macrocephalus) Skin Cells

    PubMed Central

    Li Chen, Tânia; LaCerte, Carolyne; Wise, Sandra S.; Holmes, Amie; Martino, Julieta; Wise, John Pierce; Thompson, W. Douglas; Wise, John Pierce

    2014-01-01

    Chromium (Cr) is a global marine pollutant, present in marine mammal tissues. Hexavalent chromium [Cr(VI)] is a known human carcinogen. In this study we compare the cytotoxic and clastogenic effects of Cr(VI) in human (Homo sapiens) and sperm whale (Physeter macrocephalus) skin fibroblasts. Our data show that increasing concentrations of both particulate and soluble Cr(VI) induce increasing amounts of cytotoxicity and clastogenicity in human and sperm whale skin cells. Furthermore, the data show that sperm whale cells are resistant to these effects exhibiting less cytotoxicity and genotoxicity than the human cells. Differences in Cr uptake accounted for some but not all of the differences in particulate and soluble Cr(VI) genotoxicity, although it did explain the differences in particulate Cr(VI) cytotoxicity. Altogether the data indicate that Cr(VI) is a genotoxic threat to whales, but also suggest that whales have evolved cellular mechanisms to protect them against the genotoxicity of environmental agents such as Cr(VI). PMID:21466859

  14. Searching for signatures of cold adaptations in modern and archaic humans: hints from the brown adipose tissue genes.

    PubMed

    Sazzini, M; Schiavo, G; De Fanti, S; Martelli, P L; Casadio, R; Luiselli, D

    2014-09-01

    Adaptation to low temperatures has been reasonably developed in the human species during the colonization of the Eurasian landmass subsequent to Out of Africa migrations of anatomically modern humans. In addition to morphological and cultural changes, also metabolic ones are supposed to have favored human isolation from cold and body heat production and this can be hypothesized also for most Neandertal and at least for some Denisovan populations, which lived in geographical areas that strongly experienced the last glacial period. Modulation of non-shivering thermogenesis, for which adipocytes belonging to the brown adipose tissue are the most specialized cells, might have driven these metabolic adaptations. To perform an exploratory analysis aimed at looking into this hypothesis, variation at 28 genes involved in such functional pathway was investigated in modern populations from different climate zones, as well as in Neandertal and Denisovan genomes. Patterns of variation at the LEPR gene, strongly related to increased heat dissipation by mitochondria, appeared to have been shaped by positive selection in modern East Asians, but not in Europeans. Moreover, a single potentially cold-adapted LEPR allele, different from the supposed adaptive one identified in Homo sapiens, was found also in Neandertal and Denisovan genomes. These findings suggest that independent mechanisms for cold adaptations might have been developed in different non-African human groups, as well as that the evolution of possible enhanced thermal efficiency in Neandertals and in some Denisovan populations has plausibly entailed significant changes also in other functional pathways than in the examined one.

  15. Searching for signatures of cold adaptations in modern and archaic humans: hints from the brown adipose tissue genes

    PubMed Central

    Sazzini, M; Schiavo, G; De Fanti, S; Martelli, P L; Casadio, R; Luiselli, D

    2014-01-01

    Adaptation to low temperatures has been reasonably developed in the human species during the colonization of the Eurasian landmass subsequent to Out of Africa migrations of anatomically modern humans. In addition to morphological and cultural changes, also metabolic ones are supposed to have favored human isolation from cold and body heat production and this can be hypothesized also for most Neandertal and at least for some Denisovan populations, which lived in geographical areas that strongly experienced the last glacial period. Modulation of non-shivering thermogenesis, for which adipocytes belonging to the brown adipose tissue are the most specialized cells, might have driven these metabolic adaptations. To perform an exploratory analysis aimed at looking into this hypothesis, variation at 28 genes involved in such functional pathway was investigated in modern populations from different climate zones, as well as in Neandertal and Denisovan genomes. Patterns of variation at the LEPR gene, strongly related to increased heat dissipation by mitochondria, appeared to have been shaped by positive selection in modern East Asians, but not in Europeans. Moreover, a single potentially cold-adapted LEPR allele, different from the supposed adaptive one identified in Homo sapiens, was found also in Neandertal and Denisovan genomes. These findings suggest that independent mechanisms for cold adaptations might have been developed in different non-African human groups, as well as that the evolution of possible enhanced thermal efficiency in Neandertals and in some Denisovan populations has plausibly entailed significant changes also in other functional pathways than in the examined one. PMID:24667833

  16. Who Was Helping? The Scope for Female Cooperative Breeding in Early Homo

    PubMed Central

    Bell, Adrian Viliami; Hinde, Katie; Newson, Lesley

    2013-01-01

    Derived aspects of our human life history, such as short interbirth intervals and altricial newborns, have been attributed to male provisioning of nutrient-rich meat within monogamous relationships. However, many primatologists and anthropologists have questioned the relative importance of pair-bonding and biparental care, pointing to evidence that cooperative breeding better characterizes human reproductive and child-care relationships. We present a mathematical model with empirically-informed parameter ranges showing that natural selection favors cooperation among mothers over a wide range of conditions. In contrast, our analysis provides a far more narrow range of support for selection favoring male coalition-based monogamy over more promiscuous independent males, suggesting that provisioning within monogamous relationships may fall short of explaining the evolution of Homo life history. Rather, broader cooperative networks within and between the sexes provide the primary basis for our unique life history. PMID:24367605

  17. ESR dating of tooth enamel from yunxian homo erectus site, China

    NASA Astrophysics Data System (ADS)

    Chen, Tie-Mei; Yang, Quan; Hu, Yan-Qiu; Bao, Wen-Bo; Li, Tian-Yuan

    Two almost complete fossil hominid crania (EV9001 and EV9002) were found in 1989 and 1990 in Middle Pleistocene terrace deposit of Han River, Yunxian county, Hubei province, China. They are classified as Homo erectus. Nine fossil animal teeth stratigraphically associated with the skulls were selected for electron spin resonance (ESR) dating. The simple exponential function was used for determination of the accumulated dose De and its appropriateness was discussed on the base of the experimental study. The closed system assumption was checked and the early uranium uptake model was applied to age determination. A mean age value was yielded to be 581±93 ka. It deviates from the palaeomagnetic dating result of 830-870 ka. Micro-regional complete saturation of ESR signal in enamel of very high U-content may account for the underestimation of ESR ages. Nevertheless both ESR and palaeomagnetic dating results place Yunxian crania in between the Homo erectus of Lantian and Zhoukoudian, which means that Yunxian crania constitute an important link in the human evolutionary lineage of China.

  18. Evolutionary Aspects of Human Exercise – Born to Run Purposefully

    PubMed Central

    Mattson, Mark P.

    2012-01-01

    This article is intended to raise awareness of the adaptive value of endurance exercise (particularly running) in the evolutionary history of humans, and the implications of the genetic disposition to exercise for the aging populations of modern technology-driven societies. The genome of Homo sapiens has evolved to support the svelte phenotype of an endurance runner, setting him/her apart from all other primates. The cellular and molecular mechanisms underlying the competitive advantages conferred by exercise capacity in youth can also provide a survival benefit beyond the reproductive period. These mechanisms include up-regulation of genes encoding proteins involved in protecting cells against oxidative stress, disposing of damaged proteins and organelles, and enhancing bioenergetics. Particularly fascinating are the signaling mechanisms by which endurance running changes the structure and functional capabilities of the brain and, conversely, the mechanisms by which the brain integrates metabolic, cardiovascular and behavioral responses to exercise. As an emerging example, I highlight the roles of brain-derived neurotrophic factor (BDNF) as a mediator of the effects of exercise on the brain, and BDNF s critical role in regulating metabolic and cardiovascular responses to endurance running. A better understanding of such healthspan-extending actions of endurance exercise may lead to new approaches for improving quality of life as we advance in the coming decades and centuries. PMID:22394472

  19. Dynamic control of strand excision during human DNA mismatch repair.

    PubMed

    Jeon, Yongmoon; Kim, Daehyung; Martín-López, Juana V; Lee, Ryanggeun; Oh, Jungsic; Hanne, Jeungphill; Fishel, Richard; Lee, Jong-Bong

    2016-03-22

    Mismatch repair (MMR) is activated by evolutionarily conserved MutS homologs (MSH) and MutL homologs (MLH/PMS). MSH recognizes mismatched nucleotides and form extremely stable sliding clamps that may be bound by MLH/PMS to ultimately authorize strand-specific excision starting at a distant 3'- or 5'-DNA scission. The mechanical processes associated with a complete MMR reaction remain enigmatic. The purified human (Homo sapien or Hs) 5'-MMR excision reaction requires the HsMSH2-HsMSH6 heterodimer, the 5' → 3' exonuclease HsEXOI, and the single-stranded binding heterotrimer HsRPA. The HsMLH1-HsPMS2 heterodimer substantially influences 5'-MMR excision in cell extracts but is not required in the purified system. Using real-time single-molecule imaging, we show that HsRPA or Escherichia coli EcSSB restricts HsEXOI excision activity on nicked or gapped DNA. HsMSH2-HsMSH6 activates HsEXOI by overcoming HsRPA/EcSSB inhibition and exploits multiple dynamic sliding clamps to increase tract length. Conversely, HsMLH1-HsPMS2 regulates tract length by controlling the number of excision complexes, providing a link to 5' MMR.

  20. Clavicle length, throwing performance and the reconstruction of the Homo erectus shoulder.

    PubMed

    Roach, Neil T; Richmond, Brian G

    2015-03-01

    Powerful, accurate throwing may have been an important mode of early hunting and defense. Previous work has shown that throwing performance is functionally linked to several anatomical shifts in the upper body that occurred during human evolution. The final shift to occur is the inferior reorientation of the shoulder. Fossil scapulae show the earliest evidence of a more inferior glenoid in Homo erectus. However, where the scapula rests on the thorax is uncertain. The relative length of the clavicle, the only skeletal attachment of the scapula to the torso, is quite variable. Depending on which fossils or skeletal measures are used to reconstruct the H. erectus shoulder, either a novel, anteriorly facing shoulder configuration or a modern human-like lateral orientation is possible. These competing hypotheses have led to very different conclusions regarding the throwing ability and hunting behavior of early Homo. Here, we evaluate competing models of H. erectus shoulder morphology and examine how these models relate to throwing performance. To address these questions, we collected skeletal measures from fossil and extant taxa, as well as anthropometric (N = 36) and kinematic (N = 27) data from Daasanach throwers from northwestern Kenya. Our data show that all H. erectus fossil clavicles fall within the normal range of modern human variation. We find that a commonly used metric for normalizing clavicle length, the claviculohumeral ratio, poorly predicts shoulder position on the torso. Furthermore, no significant relationship between clavicle length and any measure of throwing performance was found. These data support reconstructing the H. erectus shoulder as modern human-like, with a laterally facing glenoid, and suggest that the capacity for high speed throwing dates back nearly two million years. PMID:25439706

  1. Continuity or discontinuity in the European Early Pleistocene human settlement: the Atapuerca evidence

    NASA Astrophysics Data System (ADS)

    Bermúdez de Castro, José María; Martinón-Torres, María; Blasco, Ruth; Rosell, Jordi; Carbonell, Eudald

    2013-09-01

    The nature, timing, pattern, favourable circumstances and impediments of the human occupation of the European continent during the Early Pleistocene are hot topics in Quaternary studies. In particular, the problem of the (dis) continuity of the settlement of Europe in this period is an important matter of discussion, which has been approached in the last decade from different points of view. The Gran Dolina (TD) and Sima del Elefante (TE) cave sites in the Sierra de Atapuerca, (Spain) include large and quasi-continuous stratigraphic sequences that stretch back from at least 1.2 million years ago (Ma) to the Matuyama/Brunhes boundary. The archaeological and paleontological record from these sites can help to test different hypotheses about the character of the human settlement in this region and period. Furthermore, the TD6 level has yielded a large collection of human fossil remains attributed to Homo antecessor. According to different geochronological methods, as well as to paleomagnetic and biostratigraphical analyses, these hominins belong to an age range of 0.96-0.80 Ma. Unfortunately, the finding in 2007 of some human fossil remains in the TE9 level, dated to about 1.22 Ma, was not enough to conclude whether H. antecessor had deep roots in the European Early Pleistocene. A set of derived features of H. antecessor shared with both the Neanderthal lineage and modern humans suggests that this species is related, and not far, from the most recent common ancestor (MRCA) of Homo neanderthalensis and Homo sapiens. If we assume that there was a lineal biological relationship between the TE9 and TD6 hominins, we should reconsider many of the conclusions achieved in previous paleontological and genetic studies. In addition, we would be obliged to build a highly complicated paleogeographical scenario for the origin of the MRCA. Although continuity in the settlement of Europe during the entire late Early Pleistocene is not discarded (e.g. in refuge areas), it seems that

  2. Mojokerto revisited: evidence for an intermediate pattern of brain growth in Homo erectus.

    PubMed

    O'Connell, Caitlin A; DeSilva, Jeremy M

    2013-08-01

    Brain development in Homo erectus is a subject of great interest, and the infant calvaria from Mojokerto, Indonesia, has featured prominently in these debates. Some researchers have suggested that the pattern of brain development in H. erectus resembled that of non-human apes, while others argue for a more human-like growth pattern. In this study, we retested hypotheses regarding brain ontogeny in H. erectus using new methods (resampling), and data from additional H. erectus crania. Our results reveal that humans achieve 62% (±10%) and chimpanzees 80% (±9%) of their adult endocranial volume by 0.5-1.5 years of age. Using brain mass data, humans achieve on average 65% and chimpanzees 81% of adult size by 0.5-1.5 years. When compared with adult H. erectus crania (n = 9) from Indonesian sites greater than 1.2 million years old, Mojokerto had reached ∼70% of its adult cranial capacity. Mojokerto thus falls almost directly between the average growth in humans and chimpanzees, and well within the range of both. We therefore suggest that brain development in H. erectus cannot be dichotomized as either ape-like or human-like; it was H. erectus-like. These data indicate that H. erectus may have had a unique developmental pattern that should be considered as an important step along the continuum of brain ontogeny between apes and humans. PMID:23815827

  3. On human self-domestication, psychiatry, and eugenics.

    PubMed

    Brüne, Martin

    2007-10-05

    The hypothesis that anatomically modern homo sapiens could have undergone changes akin to those observed in domesticated animals has been contemplated in the biological sciences for at least 150 years. The idea had already plagued philosophers such as Rousseau, who considered the civilization of man as going against human nature, and eventually "sparked over" to the medical sciences in the late 19th and early 20th century. At that time, human "self-domestication" appealed to psychiatry, because it served as a causal explanation for the alleged degeneration of the "erbgut" (genetic material) of entire populations and the presumed increase of mental disorders. Consequently, Social Darwinists emphasised preventing procreation by people of "lower genetic value" and positively selecting favourable traits in others. Both tendencies culminated in euthanasia and breeding programs ("Lebensborn") during the Nazi regime in Germany. Whether or not domestication actually plays a role in some anatomical changes since the late Pleistocene period is, from a biological standpoint, contentious, and the currently resurrected debate depends, in part, on the definitional criteria applied. However, the example of human self-domestication may illustrate that scientific ideas, especially when dealing with human biology, are prone to misuse, particularly if "is" is confused with "ought", i.e., if moral principles are deduced from biological facts. Although such naturalistic fallacies appear to be banned, modern genetics may, at least in theory, pose similar ethical problems to medicine, including psychiatry. In times during which studies into the genetics of psychiatric disorders are scientifically more valued than studies into environmental causation of disorders (which is currently the case), the prospects of genetic therapy may be tempting to alter the human genome in patients, probably at costs that no-one can foresee. In the case of "self-domestication", it is proposed that human

  4. On human self-domestication, psychiatry, and eugenics

    PubMed Central

    Brüne, Martin

    2007-01-01

    The hypothesis that anatomically modern homo sapiens could have undergone changes akin to those observed in domesticated animals has been contemplated in the biological sciences for at least 150 years. The idea had already plagued philosophers such as Rousseau, who considered the civilisation of man as going against human nature, and eventually "sparked over" to the medical sciences in the late 19th and early 20th century. At that time, human "self-domestication" appealed to psychiatry, because it served as a causal explanation for the alleged degeneration of the "erbgut" (genetic material) of entire populations and the presumed increase of mental disorders. Consequently, Social Darwinists emphasised preventing procreation by people of "lower genetic value" and positively selecting favourable traits in others. Both tendencies culminated in euthanasia and breeding programs ("Lebensborn") during the Nazi regime in Germany. Whether or not domestication actually plays a role in some anatomical changes since the late Pleistocene period is, from a biological standpoint, contentious, and the currently resurrected debate depends, in part, on the definitional criteria applied. However, the example of human self-domestication may illustrate that scientific ideas, especially when dealing with human biology, are prone to misuse, particularly if "is" is confused with "ought", i.e., if moral principles are deduced from biological facts. Although such naturalistic fallacies appear to be banned, modern genetics may, at least in theory, pose similar ethical problems to medicine, including psychiatry. In times during which studies into the genetics of psychiatric disorders are scientifically more valued than studies into environmental causation of disorders (which is currently the case), the prospects of genetic therapy may be tempting to alter the human genome in patients, probably at costs that no-one can foresee. In the case of "self-domestication", it is proposed that human

  5. Entamoeba lysyl-tRNA Synthetase Contains a Cytokine-Like Domain with Chemokine Activity towards Human Endothelial Cells

    PubMed Central

    Han, Jung Min; Kim, Sunghoon; Celada, Antonio; Ribas de Pouplana, Lluís

    2011-01-01

    Immunological pressure encountered by protozoan parasites drives the selection of strategies to modulate or avoid the immune responses of their hosts. Here we show that the parasite Entamoeba histolytica has evolved a chemokine that mimics the sequence, structure, and function of the human cytokine HsEMAPII (Homo sapiens endothelial monocyte activating polypeptide II). This Entamoeba EMAPII-like polypeptide (EELP) is translated as a domain attached to two different aminoacyl-tRNA synthetases (aaRS) that are overexpressed when parasites are exposed to inflammatory signals. EELP is dispensable for the tRNA aminoacylation activity of the enzymes that harbor it, and it is cleaved from them by Entamoeba proteases to generate a standalone cytokine. Isolated EELP acts as a chemoattractant for human cells, but its cell specificity is different from that of HsEMAPII. We show that cell specificity differences between HsEMAPII and EELP can be swapped by site directed mutagenesis of only two residues in the cytokines' signal sequence. Thus, Entamoeba has evolved a functional mimic of an aaRS-associated human cytokine with modified cell specificity. PMID:22140588

  6. The EuroPhysiome, STEP and a roadmap for the virtual physiological human.

    PubMed

    Fenner, J W; Brook, B; Clapworthy, G; Coveney, P V; Feipel, V; Gregersen, H; Hose, D R; Kohl, P; Lawford, P; McCormack, K M; Pinney, D; Thomas, S R; Van Sint Jan, S; Waters, S; Viceconti, M

    2008-09-13

    Biomedical science and its allied disciplines are entering a new era in which computational methods and technologies are poised to play a prevalent role in supporting collaborative investigation of the human body. Within Europe, this has its focus in the virtual physiological human (VPH), which is an evolving entity that has emerged from the EuroPhysiome initiative and the strategy for the EuroPhysiome (STEP) consortium. The VPH is intended to be a solution to common infrastructure needs for physiome projects across the globe, providing a unifying architecture that facilitates integration and prediction, ultimately creating a framework capable of describing Homo sapiens in silico. The routine reliance of the biomedical industry, biomedical research and clinical practice on information technology (IT) highlights the importance of a tailor-made and robust IT infrastructure, but numerous challenges need to be addressed if the VPH is to become a mature technological reality. Appropriate investment will reap considerable rewards, since it is anticipated that the VPH will influence all sectors of society, with implications predominantly for improved healthcare, improved competitiveness in industry and greater understanding of (patho)physiological processes. This paper considers issues pertinent to the development of the VPH, highlighted by the work of the STEP consortium. PMID:18559316

  7. The evolution of the human pelvis: changing adaptations to bipedalism, obstetrics and thermoregulation.

    PubMed

    Gruss, Laura Tobias; Schmitt, Daniel

    2015-03-01

    The fossil record of the human pelvis reveals the selective priorities acting on hominin anatomy at different points in our evolutionary history, during which mechanical requirements for locomotion, childbirth and thermoregulation often conflicted. In our earliest upright ancestors, fundamental alterations of the pelvis compared with non-human primates facilitated bipedal walking. Further changes early in hominin evolution produced a platypelloid birth canal in a pelvis that was wide overall, with flaring ilia. This pelvic form was maintained over 3-4 Myr with only moderate changes in response to greater habitat diversity, changes in locomotor behaviour and increases in brain size. It was not until Homo sapiens evolved in Africa and the Middle East 200 000 years ago that the narrow anatomically modern pelvis with a more circular birth canal emerged. This major change appears to reflect selective pressures for further increases in neonatal brain size and for a narrow body shape associated with heat dissipation in warm environments. The advent of the modern birth canal, the shape and alignment of which require fetal rotation during birth, allowed the earliest members of our species to deal obstetrically with increases in encephalization while maintaining a narrow body to meet thermoregulatory demands and enhance locomotor performance.

  8. Unnatural amino acids increase activity and specificity of synthetic substrates for human and malarial cathepsin C.

    Pu