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Sample records for earliest modern human

  1. The earliest modern humans outside Africa.

    PubMed

    Hershkovitz, Israel; Weber, Gerhard W; Quam, Rolf; Duval, Mathieu; Grün, Rainer; Kinsley, Leslie; Ayalon, Avner; Bar-Matthews, Miryam; Valladas, Helene; Mercier, Norbert; Arsuaga, Juan Luis; Martinón-Torres, María; Bermúdez de Castro, José María; Fornai, Cinzia; Martín-Francés, Laura; Sarig, Rachel; May, Hila; Krenn, Viktoria A; Slon, Viviane; Rodríguez, Laura; García, Rebeca; Lorenzo, Carlos; Carretero, Jose Miguel; Frumkin, Amos; Shahack-Gross, Ruth; Bar-Yosef Mayer, Daniella E; Cui, Yaming; Wu, Xinzhi; Peled, Natan; Groman-Yaroslavski, Iris; Weissbrod, Lior; Yeshurun, Reuven; Tsatskin, Alexander; Zaidner, Yossi; Weinstein-Evron, Mina

    2018-01-26

    To date, the earliest modern human fossils found outside of Africa are dated to around 90,000 to 120,000 years ago at the Levantine sites of Skhul and Qafzeh. A maxilla and associated dentition recently discovered at Misliya Cave, Israel, was dated to 177,000 to 194,000 years ago, suggesting that members of the Homo sapiens clade left Africa earlier than previously thought. This finding changes our view on modern human dispersal and is consistent with recent genetic studies, which have posited the possibility of an earlier dispersal of Homo sapiens around 220,000 years ago. The Misliya maxilla is associated with full-fledged Levallois technology in the Levant, suggesting that the emergence of this technology is linked to the appearance of Homo sapiens in the region, as has been documented in Africa. Copyright © 2018, The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  2. 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.

  3. Earliest evidence of modern human life history in North African early Homo sapiens.

    PubMed

    Smith, Tanya M; Tafforeau, Paul; Reid, Donald J; Grün, Rainer; Eggins, Stephen; Boutakiout, Mohamed; Hublin, Jean-Jacques

    2007-04-10

    Recent developmental studies demonstrate that early fossil hominins possessed shorter growth periods than living humans, implying disparate life histories. Analyses of incremental features in teeth provide an accurate means of assessing the age at death of developing dentitions, facilitating direct comparisons with fossil and modern humans. It is currently unknown when and where the prolonged modern human developmental condition originated. Here, an application of x-ray synchrotron microtomography reveals that an early Homo sapiens juvenile from Morocco dated at 160,000 years before present displays an equivalent degree of tooth development to modern European children at the same age. Crown formation times in the juvenile's macrodont dentition are higher than modern human mean values, whereas root development is accelerated relative to modern humans but is less than living apes and some fossil hominins. The juvenile from Jebel Irhoud is currently the oldest-known member of Homo with a developmental pattern (degree of eruption, developmental stage, and crown formation time) that is more similar to modern H. sapiens than to earlier members of Homo. This study also underscores the continuing importance of North Africa for understanding the origins of human anatomical and behavioral modernity. Corresponding biological and cultural changes may have appeared relatively late in the course of human evolution.

  4. Onwards and upwards in the Caucasus - A multidisciplinary approach to understanding the lifeways of the earliest modern humans in Armenia

    NASA Astrophysics Data System (ADS)

    Kandel, Andrew; Gasparyan, Boris; Bruch, Angela; Deckers, Katleen; Nahapetyan, Samvel; Weissbrod, Lior

    2013-04-01

    The Armenian Highlands have functioned as a gateway with regards to the peopling of the Southern Caucasus. Most importantly, changes in climate have long controlled access to this remote and often inhospitable mountainous region. Here we present the results of the multidisciplinary study of Aghitu-3 Cave which brings together researchers from the fields of archaeology, geology and geomorphology, zooarchaeology, paleobotany and paleoclimate. By integrating these areas of study, we have reconstructed the lifeways of the earliest behaviorally (and presumably anatomically) modern humans who settled Southern Armenia about 35,000 (cal BP) years ago and placed this occupational sequence within a framework of environmental change. These first Upper Paleolithic inhabitants of Armenia made temporary use of this basalt cave located along the Vorotan River corridor at an altitude of 1601 m during seasonal forays into the highlands. The infrequent use of this site as a hunting camp comes to an end at about 31,000 cal BP. The next package of sediment shows little evidence of human occupation, although fauna seem to flourish during the time between 31-29,000 cal BP. Following this phase of depopulation, the intensity of occupation increases substantially after 29,000 cal BP. Human presence is amply documented in the numerous stone artifacts, faunal remains and fireplaces that cover the site. These changes in population movement are echoed in the sequence of sediments preserved in the cave and can be correlated with the fluctuating climatic conditions associated with the late Pleistocene.

  5. New immature hominin fossil from European Lower Pleistocene shows the earliest evidence of a modern human dental development pattern

    PubMed Central

    Bermúdez de Castro, José María; Martinón-Torres, María; Prado, Leyre; Gómez-Robles, Aida; Rosell, Jordi; López-Polín, Lucía; Arsuaga, Juan Luís; Carbonell, Eudald

    2010-01-01

    Here we present data concerning the pattern of dental development derived from the microcomputed tomography (microCT) study of a recently discovered immature hominin mandible with a mixed dentition recovered from the TD6 level of the Gran Dolina Lower Pleistocene cave site in Sierra de Atapuerca, northern Spain. These data confirm our previous results that nearly 1 million years ago at least one European hominin species had a fully modern pattern of dental development with a clear slowdown in the development of the molar field regarding the anterior dental field. Furthermore, using available information about enamel formation times and root extension rates in chimpanzees, early hominins, and modern humans, we have estimated that the formation time of the upper and lower first molars of individual 5 (H5) from TD6, which had just erupted at the time of the death of this individual, ranges between 5.3 and 6.6 y. Therefore, the eruption time of the first permanent molars (M1) in the TD6 hominins was within the range of variation of modern human populations. Because the time of M1 eruption in primates is a robust marker of life history, we suggest, as a working hypothesis, that these hominins had a prolonged childhood in the range of the variation of modern humans. If this hypothesis is true, it implies that the appearance in Homo of this important developmental biological feature and an associated increase in brain size preceded the development of the neocortical areas leading to the cognitive capabilities that are thought to be exclusive to Homo sapiens. PMID:20547843

  6. Earliest land plants created modern levels of atmospheric oxygen.

    PubMed

    Lenton, Timothy M; Dahl, Tais W; Daines, Stuart J; Mills, Benjamin J W; Ozaki, Kazumi; Saltzman, Matthew R; Porada, Philipp

    2016-08-30

    The progressive oxygenation of the Earth's atmosphere was pivotal to the evolution of life, but the puzzle of when and how atmospheric oxygen (O2) first approached modern levels (∼21%) remains unresolved. Redox proxy data indicate the deep oceans were oxygenated during 435-392 Ma, and the appearance of fossil charcoal indicates O2 >15-17% by 420-400 Ma. However, existing models have failed to predict oxygenation at this time. Here we show that the earliest plants, which colonized the land surface from ∼470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial-the net long-term source of O2 We use a trait-based ecophysiological model to predict that cryptogamic vegetation cover could have achieved ∼30% of today's global terrestrial net primary productivity by ∼445 Ma. Data from modern bryophytes suggests this plentiful early plant material had a much higher molar C:P ratio (∼2,000) than marine biomass (∼100), such that a given weathering flux of phosphorus could support more organic carbon burial. Furthermore, recent experiments suggest that early plants selectively increased the flux of phosphorus (relative to alkalinity) weathered from rocks. Combining these effects in a model of long-term biogeochemical cycling, we reproduce a sustained +2‰ increase in the carbonate carbon isotope (δ(13)C) record by ∼445 Ma, and predict a corresponding rise in O2 to present levels by 420-400 Ma, consistent with geochemical data. This oxygen rise represents a permanent shift in regulatory regime to one where fire-mediated negative feedbacks stabilize high O2 levels.

  7. Earliest land plants created modern levels of atmospheric oxygen

    PubMed Central

    Lenton, Timothy M.; Dahl, Tais W.; Daines, Stuart J.; Mills, Benjamin J. W.; Ozaki, Kazumi; Saltzman, Matthew R.; Porada, Philipp

    2016-01-01

    The progressive oxygenation of the Earth’s atmosphere was pivotal to the evolution of life, but the puzzle of when and how atmospheric oxygen (O2) first approached modern levels (∼21%) remains unresolved. Redox proxy data indicate the deep oceans were oxygenated during 435–392 Ma, and the appearance of fossil charcoal indicates O2 >15–17% by 420–400 Ma. However, existing models have failed to predict oxygenation at this time. Here we show that the earliest plants, which colonized the land surface from ∼470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial—the net long-term source of O2. We use a trait-based ecophysiological model to predict that cryptogamic vegetation cover could have achieved ∼30% of today’s global terrestrial net primary productivity by ∼445 Ma. Data from modern bryophytes suggests this plentiful early plant material had a much higher molar C:P ratio (∼2,000) than marine biomass (∼100), such that a given weathering flux of phosphorus could support more organic carbon burial. Furthermore, recent experiments suggest that early plants selectively increased the flux of phosphorus (relative to alkalinity) weathered from rocks. Combining these effects in a model of long-term biogeochemical cycling, we reproduce a sustained +2‰ increase in the carbonate carbon isotope (δ13C) record by ∼445 Ma, and predict a corresponding rise in O2 to present levels by 420–400 Ma, consistent with geochemical data. This oxygen rise represents a permanent shift in regulatory regime to one where fire-mediated negative feedbacks stabilize high O2 levels. PMID:27528678

  8. Earliest land plants created modern levels of atmospheric oxygen

    NASA Astrophysics Data System (ADS)

    Lenton, Timothy M.; Dahl, Tais W.; Daines, Stuart J.; Mills, Benjamin J. W.; Ozaki, Kazumi; Saltzman, Matthew R.; Porada, Philipp

    2016-08-01

    The progressive oxygenation of the Earth’s atmosphere was pivotal to the evolution of life, but the puzzle of when and how atmospheric oxygen (O2) first approached modern levels (˜21%) remains unresolved. Redox proxy data indicate the deep oceans were oxygenated during 435-392 Ma, and the appearance of fossil charcoal indicates O2 >15-17% by 420-400 Ma. However, existing models have failed to predict oxygenation at this time. Here we show that the earliest plants, which colonized the land surface from ˜470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial—the net long-term source of O2. We use a trait-based ecophysiological model to predict that cryptogamic vegetation cover could have achieved ˜30% of today’s global terrestrial net primary productivity by ˜445 Ma. Data from modern bryophytes suggests this plentiful early plant material had a much higher molar C:P ratio (˜2,000) than marine biomass (˜100), such that a given weathering flux of phosphorus could support more organic carbon burial. Furthermore, recent experiments suggest that early plants selectively increased the flux of phosphorus (relative to alkalinity) weathered from rocks. Combining these effects in a model of long-term biogeochemical cycling, we reproduce a sustained +2‰ increase in the carbonate carbon isotope (δ13C) record by ˜445 Ma, and predict a corresponding rise in O2 to present levels by 420-400 Ma, consistent with geochemical data. This oxygen rise represents a permanent shift in regulatory regime to one where fire-mediated negative feedbacks stabilize high O2 levels.

  9. Diet and the evolution of the earliest human ancestors

    PubMed Central

    Teaford, Mark F.; Ungar, Peter S.

    2000-01-01

    Over the past decade, discussions of the evolution of the earliest human ancestors have focused on the locomotion of the australopithecines. Recent discoveries in a broad range of disciplines have raised important questions about the influence of ecological factors in early human evolution. Here we trace the cranial and dental traits of the early australopithecines through time, to show that between 4.4 million and 2.3 million years ago, the dietary capabilities of the earliest hominids changed dramatically, leaving them well suited for life in a variety of habitats and able to cope with significant changes in resource availability associated with long-term and short-term climatic fluctuations. PMID:11095758

  10. The earliest modern mongoose (Carnivora, Herpestidae) from Africa (late Miocene of Chad)

    NASA Astrophysics Data System (ADS)

    Peigné, Stéphane; Bonis, Louis; Likius, Andossa; Mackaye, Hassane Taïsso; Vignaud, Patrick; Brunet, Michel

    2005-06-01

    We report on the earliest modern mongooses of Africa, from the late Miocene (ca. 7 Ma) of the hominid locality TM 266, Toros-Menalla, Chad. The material is based on fragmentary dentitions of three individuals. The main diagnostic feature of the Chadian species is the great development of the shear in the carnassials, which distinguishes the Chadian specimens from all extant herpestids except Herpestes and Galerella. In comparison with most extinct and extant Herpestes, the species from Toros-Menalla differs by a markedly smaller size and, depending on the species, relatively more elongated carnassials, more transversely elongated M1 and more reduced p4. On the basis of a great morphological similarity and the absence of significant differences, we assign our material to Galerella sanguinea; the Chadian finding therefore represents the earliest appearance of an extant species of Herpestidae. This record ties the first appearance of the genus to a minimum age of ca. 7 Ma, which is consistent with the estimated divergence date of 11.4 Ma known from the literature for the species of Galerella.

  11. The earliest modern mongoose (Carnivora, Herpestidae) from Africa (late Miocene of Chad).

    PubMed

    Peigné, Stéphane; de Bonis, Louis; Likius, Andossa; Mackaye, Hassane Taïsso; Vignaud, Patrick; Brunet, Michel

    2005-06-01

    We report on the earliest modern mongooses of Africa, from the late Miocene (ca. 7 Ma) of the hominid locality TM 266, Toros-Menalla, Chad. The material is based on fragmentary dentitions of three individuals. The main diagnostic feature of the Chadian species is the great development of the shear in the carnassials, which distinguishes the Chadian specimens from all extant herpestids except Herpestes and Galerella. In comparison with most extinct and extant Herpestes, the species from Toros-Menalla differs by a markedly smaller size and, depending on the species, relatively more elongated carnassials, more transversely elongated M1 and more reduced p4. On the basis of a great morphological similarity and the absence of significant differences, we assign our material to Galerella sanguinea; the Chadian finding therefore represents the earliest appearance of an extant species of Herpestidae. This record ties the first appearance of the genus to a minimum age of ca. 7 Ma, which is consistent with the estimated divergence date of 11.4 Ma known from the literature for the species of Galerella.

  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. Earliest Directly-Dated Human Skull-Cups

    PubMed Central

    Bello, Silvia M.; Parfitt, Simon A.; Stringer, Chris B.

    2011-01-01

    Background The use of human braincases as drinking cups and containers has extensive historic and ethnographic documentation, but archaeological examples are extremely rare. In the Upper Palaeolithic of western Europe, cut-marked and broken human bones are widespread in the Magdalenian (∼15 to 12,000 years BP) and skull-cup preparation is an element of this tradition. Principal Findings Here we describe the post-mortem processing of human heads at the Upper Palaeolithic site of Gough's Cave (Somerset, England) and identify a range of modifications associated with the production of skull-cups. New analyses of human remains from Gough's Cave demonstrate the skilled post-mortem manipulation of human bodies. Results of the research suggest the processing of cadavers for the consumption of body tissues (bone marrow), accompanied by meticulous shaping of cranial vaults. The distribution of cut-marks and percussion features indicates that the skulls were scrupulously 'cleaned' of any soft tissues, and subsequently modified by controlled removal of the facial region and breakage of the cranial base along a sub-horizontal plane. The vaults were also ‘retouched’, possibly to make the broken edges more regular. This manipulation suggests the shaping of skulls to produce skull-cups. Conclusions Three skull-cups have been identified amongst the human bones from Gough's Cave. New ultrafiltered radiocarbon determinations provide direct dates of about 14,700 cal BP, making these the oldest directly dated skull-cups and the only examples known from the British Isles. PMID:21359211

  14. European early modern humans and the fate of the Neandertals

    PubMed Central

    Trinkaus, Erik

    2007-01-01

    A consideration of the morphological aspects of the earliest modern humans in Europe (more than ≈33,000 B.P.) and the subsequent Gravettian human remains indicates that they possess an anatomical pattern congruent with the autapomorphic (derived) morphology of the earliest (Middle Paleolithic) African modern humans. However, they exhibit a variable suite of features that are either distinctive Neandertal traits and/or plesiomorphic (ancestral) aspects that had been lost among the African Middle Paleolithic modern humans. These features include aspects of neurocranial shape, basicranial external morphology, mandibular ramal and symphyseal form, dental morphology and size, and anteroposterior dental proportions, as well as aspects of the clavicles, scapulae, metacarpals, and appendicular proportions. The ubiquitous and variable presence of these morphological features in the European earlier modern human samples can only be parsimoniously explained as a product of modest levels of assimilation of Neandertals into early modern human populations as the latter dispersed across Europe. This interpretation is in agreement with current analyses of recent and past human molecular data. PMID:17452632

  15. Single amino acid radiocarbon dating of Upper Paleolithic modern humans.

    PubMed

    Marom, Anat; McCullagh, James S O; Higham, Thomas F G; Sinitsyn, Andrey A; Hedges, Robert E M

    2012-05-01

    Archaeological bones are usually dated by radiocarbon measurement of extracted collagen. However, low collagen content, contamination from the burial environment, or museum conservation work, such as addition of glues, preservatives, and fumigants to "protect" archaeological materials, have previously led to inaccurate dates. These inaccuracies in turn frustrate the development of archaeological chronologies and, in the Paleolithic, blur the dating of such key events as the dispersal of anatomically modern humans. Here we describe a method to date hydroxyproline found in collagen (~10% of collagen carbon) as a bone-specific biomarker that removes impurities, thereby improving dating accuracy and confidence. This method is applied to two important sites in Russia and allows us to report the earliest direct ages for the presence of anatomically modern humans on the Russian Plain. These dates contribute considerably to our understanding of the emergence of the Mid-Upper Paleolithic and the complex suite of burial behaviors that begin to appear during this period.

  16. A Fish Assemblage from the Middle Eocene from Libya (Dur At-Talah) and the Earliest Record of Modern African Fish Genera

    PubMed Central

    Otero, Olga; Pinton, Aurélie; Cappetta, Henri; Adnet, Sylvain; Valentin, Xavier; Salem, Mustapha; Jaeger, Jean-Jacques

    2015-01-01

    In the early nineteen sixties, Arambourg and Magnier found some freshwater fish (i.e., Polypterus sp., Siluriformes indet. and Lates sp.) mixed with marine members in an Eocene vertebrate assemblage at Gebel Coquin, in the southern Libyan Desert. This locality, aged ca 37–39Ma and now known under the name of Dur At-Talah, has been recently excavated. A new fish assemblage, mostly composed of teeth, was collected by the Mission Paléontologique Franco-Libyenne. In this paper, we describe freshwater fish members including a dipnoan (Protopterus sp.), and several actinopterygians: bichir (Polypterus sp.), aba fish (Gymnarchus sp.), several catfishes (Chrysichthys sp. and a mochokid indet.), several characiforms (including the tiger fish Hydrocynus sp., and one or two alestin-like fish), and perciforms (including the snake-head fish Parachanna sp. and at least one cichlid). Together with the fossiliferous outcrops at Birket Qarun in Egypt, the Libyan site at Dur At-Talah reduces a 10-Ma chronological gap in the fossil record of African freshwater fish. Their fish assemblages overlap in their composition and thus constitute a rather homogenous, original and significant amount of new elements regarding the Paleogene African ichthyofauna. This supports the establishment of the modern African freshwater fish fauna during this time period because these sites mostly contain the earliest members known in modern genera. PMID:26674637

  17. A Fish Assemblage from the Middle Eocene from Libya (Dur At-Talah) and the Earliest Record of Modern African Fish Genera.

    PubMed

    Otero, Olga; Pinton, Aurélie; Cappetta, Henri; Adnet, Sylvain; Valentin, Xavier; Salem, Mustapha; Jaeger, Jean-Jacques

    2015-01-01

    In the early nineteen sixties, Arambourg and Magnier found some freshwater fish (i.e., Polypterus sp., Siluriformes indet. and Lates sp.) mixed with marine members in an Eocene vertebrate assemblage at Gebel Coquin, in the southern Libyan Desert. This locality, aged ca 37-39Ma and now known under the name of Dur At-Talah, has been recently excavated. A new fish assemblage, mostly composed of teeth, was collected by the Mission Paléontologique Franco-Libyenne. In this paper, we describe freshwater fish members including a dipnoan (Protopterus sp.), and several actinopterygians: bichir (Polypterus sp.), aba fish (Gymnarchus sp.), several catfishes (Chrysichthys sp. and a mochokid indet.), several characiforms (including the tiger fish Hydrocynus sp., and one or two alestin-like fish), and perciforms (including the snake-head fish Parachanna sp. and at least one cichlid). Together with the fossiliferous outcrops at Birket Qarun in Egypt, the Libyan site at Dur At-Talah reduces a 10-Ma chronological gap in the fossil record of African freshwater fish. Their fish assemblages overlap in their composition and thus constitute a rather homogenous, original and significant amount of new elements regarding the Paleogene African ichthyofauna. This supports the establishment of the modern African freshwater fish fauna during this time period because these sites mostly contain the earliest members known in modern genera.

  18. On the Emergence of Modern Humans

    ERIC Educational Resources Information Center

    Amati, Daniele; Shallice, Tim

    2007-01-01

    The emergence of modern humans with their extraordinary cognitive capacities is ascribed to a novel type of cognitive computational process (sustained non-routine multi-level operations) required for abstract projectuality, held to be the common denominator of the cognitive capacities specific to modern humans. A brain operation (latching) that…

  19. The modern human colonization of western Eurasia: when and where?

    NASA Astrophysics Data System (ADS)

    Hublin, Jean-Jacques

    2015-06-01

    Dating the timing of the replacement of local Neandertal populations by modern humans in western Eurasia at the dawn of the Upper Palaeolithic remains challenging due to the scarcity of the palaeontological evidence and to the complexity of the archaeological record. Furthermore, key specimens have been discovered in the course of excavations that unfortunately did not meet today's archaeological standards. The importance of site-formation processes in the considered time period makes it sometimes difficult to precisely assign fragmentary remains a posteriori to distinct techno-complexes. The improvements in dating methods have however allowed for the clarification of many chronological issues in the past decade. Archaeological and palaeontological evidence strongly suggest that the initial modern colonization of eastern Europe and central Asia should be related to the spread of techno-complexes assigned to the Initial Upper Palaeolithic. This first expansion may have started as early as 48 ka cal BP. The earliest phases of the Aurignacian complex (Protoaurignacian and Early Aurignacian) seem to represent another modern wave of migrations, starting in the Levant area. The expansion of this techno-complex throughout Europe completed the modern colonization of the continent. The interpretation of a third group of industries referred to as "transitional assemblages" in western and central Europe is much debated. At least in part, these assemblages might have been produced by Neandertal groups that may have survived until c. 41 ka cal BP, according to the directly dated Neandertal specimens of Saint-Césaire (France) and Spy (Belgium).

  20. 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

  1. The First Modern Human Dispersals across Africa

    PubMed Central

    Rito, Teresa; Richards, Martin B.; Fernandes, Verónica; Alshamali, Farida; Cerny, Viktor

    2013-01-01

    The emergence of more refined chronologies for climate change and archaeology in prehistoric Africa, and for the evolution of human mitochondrial DNA (mtDNA), now make it feasible to test more sophisticated models of early modern human dispersals suggested by mtDNA distributions. Here we have generated 42 novel whole-mtDNA genomes belonging to haplogroup L0, the most divergent clade in the maternal line of descent, and analysed them alongside the growing database of African lineages belonging to L0’s sister clade, L1’6. We propose that the last common ancestor of modern human mtDNAs (carried by “mitochondrial Eve”) possibly arose in central Africa ~180 ka, at a time of low population size. By ~130 ka two distinct groups of anatomically modern humans co-existed in Africa: broadly, the ancestors of many modern-day Khoe and San populations in the south and a second central/eastern African group that includes the ancestors of most extant worldwide populations. Early modern human dispersals correlate with climate changes, particularly the tropical African “megadroughts” of MIS 5 (marine isotope stage 5, 135–75 ka) which paradoxically may have facilitated expansions in central and eastern Africa, ultimately triggering the dispersal out of Africa of people carrying haplogroup L3 ~60 ka. Two south to east migrations are discernible within haplogroup LO. One, between 120 and 75 ka, represents the first unambiguous long-range modern human dispersal detected by mtDNA and might have allowed the dispersal of several markers of modernity. A second one, within the last 20 ka signalled by L0d, may have been responsible for the spread of southern click-consonant languages to eastern Africa, contrary to the view that these eastern examples constitute relicts of an ancient, much wider distribution. PMID:24236171

  2. Single amino acid radiocarbon dating of Upper Paleolithic modern humans

    PubMed Central

    Marom, Anat; McCullagh, James S. O.; Higham, Thomas F. G.; Sinitsyn, Andrey A.; Hedges, Robert E. M.

    2012-01-01

    Archaeological bones are usually dated by radiocarbon measurement of extracted collagen. However, low collagen content, contamination from the burial environment, or museum conservation work, such as addition of glues, preservatives, and fumigants to “protect” archaeological materials, have previously led to inaccurate dates. These inaccuracies in turn frustrate the development of archaeological chronologies and, in the Paleolithic, blur the dating of such key events as the dispersal of anatomically modern humans. Here we describe a method to date hydroxyproline found in collagen (∼10% of collagen carbon) as a bone-specific biomarker that removes impurities, thereby improving dating accuracy and confidence. This method is applied to two important sites in Russia and allows us to report the earliest direct ages for the presence of anatomically modern humans on the Russian Plain. These dates contribute considerably to our understanding of the emergence of the Mid-Upper Paleolithic and the complex suite of burial behaviors that begin to appear during this period. PMID:22517758

  3. Dating of Modern Human Evolution

    NASA Astrophysics Data System (ADS)

    Grun, R.

    Dating studies on palaoeanthropological sites is usually carried out on material associ- ated with the human remains, such as the sediment, charcoal or other fauna rather than the human specimen itself. The reason lies in the fact that most dating techniques are destructive and because the hominid remains are too rare to be sacrificed for dating. This indirect dating approach is in many cases not satisfactory, because: (i) the human remains are often buried into the sediments and the association with other materials is uncertain (e.g. Skhul, Qafzeh, etc.); (ii) faunal remains or minerals from the sediment are re-worked from older deposits (see e.g. present discussion of the age of the Homo erectus remains in Indonesia; (iii) the hominid fossils were discovered at a time when no careful excavations were carried out and it is impossible to correlate the specimen with other datable material (which applies tonearly 90% of all palaeoanthropological specimens). For example, the hominid burial site of Qafzeh in Israel has been dated by several independent dating laboratories with a multitude of methods. However, the data are still not accepted by some because the dating has not been carried out on the hominid specimen. Until recently, hominid fossils could only be dated by radiocarbon. This method reaches back to about 40,000 years. As a consequence, all the older fossils could not be analysed and many important questions in our understanding of human evolution could not be addressed. Human remains are scarce and extremely valuable, therefore any sort of destruction has to be kept to an absolute minimum. This is of particular importance in Australia where any human fossils are sacred. Thus, for the analysis of hominid material it was necessary to develop a more or less non-destructive techniques. This has been ac- complished in recent years by the application of ESR dating of tooth enamel and a combination of gamma spectrometric and TIMS U-series dating of bones. The exam

  4. New evidence on the earliest human presence at high northern latitudes in northeast Asia.

    PubMed

    Zhu, R X; Potts, R; Xie, F; Hoffman, K A; Deng, C L; Shi, C D; Pan, Y X; Wang, H Q; Shi, R P; Wang, Y C; Shi, G H; Wu, N Q

    2004-09-30

    The timing of early human dispersal to Asia is a central issue in the study of human evolution. Excavations in predominantly lacustrine sediments at Majuangou, Nihewan basin, north China, uncovered four layers of indisputable hominin stone tools. Here we report magnetostratigraphic results that constrain the age of the four artefact layers to an interval of nearly 340,000 yr between the Olduvai subchron and the Cobb Mountain event. The lowest layer, about 1.66 million years old (Myr), provides the oldest record of stone-tool processing of animal tissues in east Asia. The highest layer, at about 1.32 Myr, correlates with the stone tool layer at Xiaochangliang, previously considered the oldest archaeological site in this region. The findings at Majuangou indicate that the oldest known human presence in northeast Asia at 40 degrees N is only slightly younger than that in western Asia. This result implies that a long yet rapid migration from Africa, possibly initiated during a phase of warm climate, enabled early human populations to inhabit northern latitudes of east Asia over a prolonged period.

  5. Volcanic ash layers illuminate the resilience of Neanderthals and early modern humans to natural hazards.

    PubMed

    Lowe, John; Barton, Nick; Blockley, Simon; Ramsey, Christopher Bronk; Cullen, Victoria L; Davies, William; Gamble, Clive; Grant, Katharine; Hardiman, Mark; Housley, Rupert; Lane, Christine S; Lee, Sharen; Lewis, Mark; MacLeod, Alison; Menzies, Martin; Müller, Wolfgang; Pollard, Mark; Price, Catherine; Roberts, Andrew P; Rohling, Eelco J; Satow, Chris; Smith, Victoria C; Stringer, Chris B; Tomlinson, Emma L; White, Dustin; Albert, Paul; Arienzo, Ilenia; Barker, Graeme; Boric, Dusan; Carandente, Antonio; Civetta, Lucia; Ferrier, Catherine; Guadelli, Jean-Luc; Karkanas, Panagiotis; Koumouzelis, Margarita; Müller, Ulrich C; Orsi, Giovanni; Pross, Jörg; Rosi, Mauro; Shalamanov-Korobar, Ljiljiana; Sirakov, Nikolay; Tzedakis, Polychronis C

    2012-08-21

    Marked changes in human dispersal and development during the Middle to Upper Paleolithic transition have been attributed to massive volcanic eruption and/or severe climatic deterioration. We test this concept using records of volcanic ash layers of the Campanian Ignimbrite eruption dated to ca. 40,000 y ago (40 ka B.P.). The distribution of the Campanian Ignimbrite has been enhanced by the discovery of cryptotephra deposits (volcanic ash layers that are not visible to the naked eye) in archaeological cave sequences. They enable us to synchronize archaeological and paleoclimatic records through the period of transition from Neanderthal to the earliest anatomically modern human populations in Europe. Our results confirm that the combined effects of a major volcanic eruption and severe climatic cooling failed to have lasting impacts on Neanderthals or early modern humans in Europe. We infer that modern humans proved a greater competitive threat to indigenous populations than natural disasters.

  6. Volcanic ash layers illuminate the resilience of Neanderthals and early modern humans to natural hazards

    PubMed Central

    Lowe, John; Barton, Nick; Blockley, Simon; Ramsey, Christopher Bronk; Cullen, Victoria L.; Davies, William; Gamble, Clive; Grant, Katharine; Hardiman, Mark; Housley, Rupert; Lane, Christine S.; Lee, Sharen; Lewis, Mark; MacLeod, Alison; Menzies, Martin; Müller, Wolfgang; Pollard, Mark; Price, Catherine; Roberts, Andrew P.; Rohling, Eelco J.; Satow, Chris; Smith, Victoria C.; Stringer, Chris B.; Tomlinson, Emma L.; White, Dustin; Albert, Paul; Arienzo, Ilenia; Barker, Graeme; Borić, Dušan; Carandente, Antonio; Civetta, Lucia; Ferrier, Catherine; Guadelli, Jean-Luc; Karkanas, Panagiotis; Koumouzelis, Margarita; Müller, Ulrich C.; Orsi, Giovanni; Pross, Jörg; Rosi, Mauro; Shalamanov-Korobar, Ljiljiana; Sirakov, Nikolay; Tzedakis, Polychronis C.

    2012-01-01

    Marked changes in human dispersal and development during the Middle to Upper Paleolithic transition have been attributed to massive volcanic eruption and/or severe climatic deterioration. We test this concept using records of volcanic ash layers of the Campanian Ignimbrite eruption dated to ca. 40,000 y ago (40 ka B.P.). The distribution of the Campanian Ignimbrite has been enhanced by the discovery of cryptotephra deposits (volcanic ash layers that are not visible to the naked eye) in archaeological cave sequences. They enable us to synchronize archaeological and paleoclimatic records through the period of transition from Neanderthal to the earliest anatomically modern human populations in Europe. Our results confirm that the combined effects of a major volcanic eruption and severe climatic cooling failed to have lasting impacts on Neanderthals or early modern humans in Europe. We infer that modern humans proved a greater competitive threat to indigenous populations than natural disasters. PMID:22826222

  7. Earliest humans in Europe: The age of TD6 Gran Dolina, Atapuerca, Spain

    USGS Publications Warehouse

    Falgueres, Christophe; Bahain, J.-J.; Yokoyama, Y.; Arsuaga, J.L.; Bermudez de Castro, Jose Maria; Carbonell, E.; Bischoff, J.L.; Dolo, J.-M.

    1999-01-01

    Hominid remains found in 1994 from the stratified Gran Dolina karst-filling at the Atapuerca site in NE Spain were dated to somewhat greater than 780 ka based on palaeomagnetic measurements, making these the oldest known hominids in Europe (sensu stricto). We report new ESR and U-series results on teeth from four levels of the Gran Dolina deposit which confirm the palaeomagnetic evidence, and indicate that TD6 (from which the human remains have been recovered) dates to the end of the Early Pleistocene. The results for the other levels are consistent with estimates based mainly on microfaunal evidence, and suggest that TD8, TD10 and TD11 date to the Middle Pleistocene. (C) 1999 Academic Press.

  8. Modern Agriculture in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Lanegran, David A.

    2000-01-01

    Discusses the four sections of the Advanced Placement (AP) human geography course focusing on agriculture: (1) development and diffusion of agriculture; (2) major agricultural production regions; (3) rural land use and change; and (4) impacts of modern agricultural change. Includes references and a resource list. (CMK)

  9. The evolution of modern human brain shape.

    PubMed

    Neubauer, Simon; Hublin, Jean-Jacques; Gunz, Philipp

    2018-01-01

    Modern humans have large and globular brains that distinguish them from their extinct Homo relatives. The characteristic globularity develops during a prenatal and early postnatal period of rapid brain growth critical for neural wiring and cognitive development. However, it remains unknown when and how brain globularity evolved and how it relates to evolutionary brain size increase. On the basis of computed tomographic scans and geometric morphometric analyses, we analyzed endocranial casts of Homo sapiens fossils ( N = 20) from different time periods. Our data show that, 300,000 years ago, brain size in early H. sapiens already fell within the range of present-day humans. Brain shape, however, evolved gradually within the H. sapiens lineage, reaching present-day human variation between about 100,000 and 35,000 years ago. This process started only after other key features of craniofacial morphology appeared modern and paralleled the emergence of behavioral modernity as seen from the archeological record. Our findings are consistent with important genetic changes affecting early brain development within the H. sapiens lineage since the origin of the species and before the transition to the Later Stone Age and the Upper Paleolithic that mark full behavioral modernity.

  10. The evolution of modern human brain shape

    PubMed Central

    Neubauer, Simon; Hublin, Jean-Jacques; Gunz, Philipp

    2018-01-01

    Modern humans have large and globular brains that distinguish them from their extinct Homo relatives. The characteristic globularity develops during a prenatal and early postnatal period of rapid brain growth critical for neural wiring and cognitive development. However, it remains unknown when and how brain globularity evolved and how it relates to evolutionary brain size increase. On the basis of computed tomographic scans and geometric morphometric analyses, we analyzed endocranial casts of Homo sapiens fossils (N = 20) from different time periods. Our data show that, 300,000 years ago, brain size in early H. sapiens already fell within the range of present-day humans. Brain shape, however, evolved gradually within the H. sapiens lineage, reaching present-day human variation between about 100,000 and 35,000 years ago. This process started only after other key features of craniofacial morphology appeared modern and paralleled the emergence of behavioral modernity as seen from the archeological record. Our findings are consistent with important genetic changes affecting early brain development within the H. sapiens lineage since the origin of the species and before the transition to the Later Stone Age and the Upper Paleolithic that mark full behavioral modernity. PMID:29376123

  11. Earliest effects of sudden occlusions on pressure profiles in selected locations of the human systemic arterial system

    NASA Astrophysics Data System (ADS)

    Majka, Marcin; Gadda, Giacomo; Taibi, Angelo; Gałązka, Mirosław; Zieliński, Piotr

    2017-03-01

    We have developed a numerical simulation method for predicting the time dependence (wave form) of pressure at any location in the systemic arterial system in humans. The method uses the matlab-Simulink environment. The input data include explicitly the geometry of the arterial tree, treated up to an arbitrary bifurcation level, and the elastic properties of arteries as well as rheological parameters of blood. Thus, the impact of anatomic details of an individual subject can be studied. The method is applied here to reveal the earliest stages of mechanical reaction of the pressure profiles to sudden local blockages (thromboses or embolisms) of selected arteries. The results obtained with a purely passive model provide reference data indispensable for studies of longer-term effects due to neural and humoral mechanisms. The reliability of the results has been checked by comparison of two available sets of anatomic, elastic, and rheological data involving (i) 55 and (ii) 138 arterial segments. The remaining arteries have been replaced with the appropriate resistive elements. Both models are efficient in predicting an overall shift of pressure, whereas the accuracy of the 55-segment model in reproducing the detailed wave forms and stabilization times turns out dependent on the location of the blockage and the observation point.

  12. Facial ontogeny in Neanderthals and modern humans

    PubMed Central

    Bastir, Markus; O'Higgins, Paul; Rosas, Antonio

    2007-01-01

    One hundred and fifty years after the discovery of Neanderthals, it is held that this morphologically and genetically distinct human species does not differ from modern Homo sapiens in its craniofacial ontogenetic trajectory after the early post-natal period. This is striking given the evident morphological differences between these species, since it implies that all of the major differences are established by the early post-natal period and carried into adulthood through identical trajectories, despite the extent to which mechanical and spatial factors are thought to influence craniofacial ontogeny. Here, we present statistical and morphological analyses demonstrating that the spatio-temporal processes responsible for craniofacial ontogenetic transformations differ. The findings emphasize that pre-natal as well as post-natal ontogeny are both important in establishing the cranial morphological differences between adult Neanderthals and modern humans. PMID:17311777

  13. Continuity of Microblade Technology in the Indian Subcontinent Since 45 ka: Implications for the Dispersal of Modern Humans

    PubMed Central

    Mishra, Sheila; Chauhan, Naveen; Singhvi, Ashok K.

    2013-01-01

    We extend the continuity of microblade technology in the Indian Subcontinent to 45 ka, on the basis of optical dating of microblade assemblages from the site of Mehtakheri, (22° 13' 44″ N Lat 76° 01' 36″ E Long) in Madhya Pradesh, India. Microblade technology in the Indian Subcontinent is continuously present from its first appearance until the Iron Age (~3 ka), making its association with modern humans undisputed. It has been suggested that microblade technology in the Indian Subcontinent was developed locally by modern humans after 35 ka. The dates reported here from Mehtakheri show this inference to be untenable and suggest alternatively that this technology arrived in the Indian Subcontinent with the earliest modern humans. It also shows that modern humans in Indian Subcontinent and SE Asia were associated with differing technologies and this calls into question the “southern dispersal” route of modern humans from Africa through India to SE Asia and then to Australia. We suggest that modern humans dispersed from Africa in two stages coinciding with the warmer interglacial conditions of MIS 5 and MIS 3. Competitive interactions between African modern humans and Indian archaics who shared an adaptation to tropical environments differed from that between modern humans and archaics like Neanderthals and Denisovans, who were adapted to temperate environments. Thus, while modern humans expanded into temperate regions during warmer climates, their expansion into tropical regions, like the Indian Subcontinent, in competition with similarly adapted populations, occurred during arid climates. Thus modern humans probably entered the Indian Subcontinent during the arid climate of MIS 4 coinciding with their disappearance from the Middle East and Northern Africa. The out of phase expansion of modern humans into tropical versus temperate regions has been one of the factors affecting the dispersal of modern humans from Africa during the period 200–40 ka. PMID

  14. The revolution that wasn't: a new interpretation of the origin of modern human behavior.

    PubMed

    Mcbrearty, S; Brooks, A S

    2000-11-01

    Proponents of the model known as the "human revolution" claim that modern human behaviors arose suddenly, and nearly simultaneously, throughout the Old World ca. 40-50 ka. This fundamental behavioral shift is purported to signal a cognitive advance, a possible reorganization of the brain, and the origin of language. Because the earliest modern human fossils, Homo sapiens sensu stricto, are found in Africa and the adjacent region of the Levant at >100 ka, the "human revolution" model creates a time lag between the appearance of anatomical modernity and perceived behavioral modernity, and creates the impression that the earliest modern Africans were behaviorally primitive. This view of events stems from a profound Eurocentric bias and a failure to appreciate the depth and breadth of the African archaeological record. In fact, many of the components of the "human revolution" claimed to appear at 40-50 ka are found in the African Middle Stone Age tens of thousands of years earlier. These features include blade and microlithic technology, bone tools, increased geographic range, specialized hunting, the use of aquatic resources, long distance trade, systematic processing and use of pigment, and art and decoration. These items do not occur suddenly together as predicted by the "human revolution" model, but at sites that are widely separated in space and time. This suggests a gradual assembling of the package of modern human behaviors in Africa, and its later export to other regions of the Old World. The African Middle and early Late Pleistocene hominid fossil record is fairly continuous and in it can be recognized a number of probably distinct species that provide plausible ancestors for H. sapiens. The appearance of Middle Stone Age technology and the first signs of modern behavior coincide with the appearance of fossils that have been attributed to H. helmei, suggesting the behavior of H. helmei is distinct from that of earlier hominid species and quite similar to that

  15. Human performance in the modern cockpit

    NASA Technical Reports Server (NTRS)

    Dismukes, R. K.; Cohen, M. M.

    1992-01-01

    This panel was organized by the Aerospace Human Factors Committee to illustrate behavioral research on the perceptual, cognitive, and group processes that determine crew effectiveness in modern cockpits. Crew reactions to the introduction of highly automated systems in the cockpit will be reported on. Automation can improve operational capabilities and efficiency and can reduce some types of human error, but may also introduce entirely new opportunities for error. The problem solving and decision making strategies used by crews led by captains with various personality profiles will be discussed. Also presented will be computational approaches to modeling the cognitive demands of cockpit operations and the cognitive capabilities and limitations of crew members. Factors contributing to aircrew deviations from standard operating procedures and misuse of checklist, often leading to violations, incidents, or accidents will be examined. The mechanisms of visual perception pilots use in aircraft control and the implications of these mechanisms for effective design of visual displays will be discussed.

  16. Genetic evidence and the modern human origins debate.

    PubMed

    Relethford, J H

    2008-06-01

    A continued debate in anthropology concerns the evolutionary origin of 'anatomically modern humans' (Homo sapiens sapiens). Different models have been proposed to examine the related questions of (1) where and when anatomically modern humans first appeared and (2) the genetic and evolutionary relationship between modern humans and earlier human populations. Genetic data have been increasingly used to address these questions. Genetic data on living human populations have been used to reconstruct the evolutionary history of the human species by considering how global patterns of human variation could be produced given different evolutionary scenarios. Of particular interest are gene trees that reconstruct the time and place of the most recent common ancestor of humanity for a given haplotype and the analysis of regional differences in genetic diversity. Ancient DNA has also allowed a direct assessment of genetic variation in European Neandertals. Together with the fossil record, genetic data provide insight into the origin of modern humans. The evidence points to an African origin of modern humans dating back to 200,000 years followed by later expansions of moderns out of Africa across the Old World. What is less clear is what happened when these early modern humans met preexisting 'archaic human' populations outside of Africa. At present, it is difficult to distinguish between a model of total genetic replacement and a model that includes some degree of genetic mixture.

  17. Earliest human occupations at Dmanisi (Georgian Caucasus) dated to 1.85–1.78 Ma

    PubMed Central

    Ferring, Reid; Oms, Oriol; Agustí, Jordi; Berna, Francesco; Nioradze, Medea; Shelia, Teona; Tappen, Martha; Vekua, Abesalom; Zhvania, David; Lordkipanidze, David

    2011-01-01

    The early Pleistocene colonization of temperate Eurasia by Homo erectus was not only a significant biogeographic event but also a major evolutionary threshold. Dmanisi's rich collection of hominin fossils, revealing a population that was small-brained with both primitive and derived skeletal traits, has been dated to the earliest Upper Matuyama chron (ca. 1.77 Ma). Here we present archaeological and geologic evidence that push back Dmanisi's first occupations to shortly after 1.85 Ma and document repeated use of the site over the last half of the Olduvai subchron, 1.85–1.78 Ma. These discoveries show that the southern Caucasus was occupied repeatedly before Dmanisi's hominin fossil assemblage accumulated, strengthening the probability that this was part of a core area for the colonization of Eurasia. The secure age for Dmanisi's first occupations reveals that Eurasia was probably occupied before Homo erectus appears in the East African fossil record. PMID:21646521

  18. The earliest known reptile

    NASA Astrophysics Data System (ADS)

    Smithson, T. R.

    1989-12-01

    AMNIOTES (reptiles, birds and mammals) are distinguished from non-amniote tetrapods (amphibians) by the presence of complex embryonic membranes. One of these, the amnion, gives its name to the group. Very few skeletal characters distinguish amniotes from amphibians1, making it difficult to recognize early amniotes in the fossil record. The earliest amniote fossil identified so far is Hylonomus from the Westphalian (Upper Carboniferous) of Joggins, Nova Scotia2,3, (~300 Myr). I report here the discovery of a much earlier amniote skeleton from the Brigantian (Lower Carboniferous) of Scotland (~338 Myr) 4, which thus represents the earliest occurrence of amniotes in the fossil record. The specimen was collected from the East Kirkton Limestone, near Bathgate, West Lothian4-8, and is part of a unique terrestrial fauna that includes eurypterids, myriapods, scorpions and the earliest-known harvestman spider7,9, together with the earliest known temno-spondyls, a group that may include the ancestors of all living amphibians10. It will make an important contribution to our knowledge of early amniote morphology and the interrelationships of tetrapods.

  19. Early Pleistocene third metacarpal from Kenya and the evolution of modern human-like hand morphology

    PubMed Central

    Ward, Carol V.; Tocheri, Matthew W.; Plavcan, J. Michael; Brown, Francis H.; Manthi, Fredrick Kyalo

    2014-01-01

    Despite discoveries of relatively complete hands from two early hominin species (Ardipithecus ramidus and Australopithecus sediba) and partial hands from another (Australopithecus afarensis), fundamental questions remain about the evolution of human-like hand anatomy and function. These questions are driven by the paucity of hand fossils in the hominin fossil record between 800,000 and 1.8 My old, a time interval well documented for the emergence and subsequent proliferation of Acheulian technology (shaped bifacial stone tools). Modern and Middle to Late Pleistocene humans share a suite of derived features in the thumb, wrist, and radial carpometacarpal joints that is noticeably absent in early hominins. Here we show that one of the most distinctive features of this suite in the Middle Pleistocene to recent human hand, the third metacarpal styloid process, was present ∼1.42 Mya in an East African hominin from Kaitio, West Turkana, Kenya. This fossil thus provides the earliest unambiguous evidence for the evolution of a key shared derived characteristic of modern human and Neandertal hand morphology and suggests that the distinctive complex of radial carpometacarpal joint features in the human hand arose early in the evolution of the genus Homo and probably in Homo erectus sensu lato. PMID:24344276

  20. The Amazing Labyrinth: An Ancient-Modern Humanities Unit

    ERIC Educational Resources Information Center

    Ladensack, Carl

    1973-01-01

    The image of the labyrinth from mythology can find modern day parallelisms in architecture, art, music, and literature--all of which contributes to a humanities unit combining the old with the new. (MM)

  1. The Divergence of Neandertal and Modern Human Y Chromosomes.

    PubMed

    Mendez, Fernando L; Poznik, G David; Castellano, Sergi; Bustamante, Carlos D

    2016-04-07

    Sequencing the genomes of extinct hominids has reshaped our understanding of modern human origins. Here, we analyze ∼120 kb of exome-captured Y-chromosome DNA from a Neandertal individual from El Sidrón, Spain. We investigate its divergence from orthologous chimpanzee and modern human sequences and find strong support for a model that places the Neandertal lineage as an outgroup to modern human Y chromosomes-including A00, the highly divergent basal haplogroup. We estimate that the time to the most recent common ancestor (TMRCA) of Neandertal and modern human Y chromosomes is ∼588 thousand years ago (kya) (95% confidence interval [CI]: 447-806 kya). This is ∼2.1 (95% CI: 1.7-2.9) times longer than the TMRCA of A00 and other extant modern human Y-chromosome lineages. This estimate suggests that the Y-chromosome divergence mirrors the population divergence of Neandertals and modern human ancestors, and it refutes alternative scenarios of a relatively recent or super-archaic origin of Neandertal Y chromosomes. The fact that the Neandertal Y we describe has never been observed in modern humans suggests that the lineage is most likely extinct. We identify protein-coding differences between Neandertal and modern human Y chromosomes, including potentially damaging changes to PCDH11Y, TMSB4Y, USP9Y, and KDM5D. Three of these changes are missense mutations in genes that produce male-specific minor histocompatibility (H-Y) antigens. Antigens derived from KDM5D, for example, are thought to elicit a maternal immune response during gestation. It is possible that incompatibilities at one or more of these genes played a role in the reproductive isolation of the two groups. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. The Divergence of Neandertal and Modern Human Y Chromosomes

    PubMed Central

    Mendez, Fernando L.; Poznik, G. David; Castellano, Sergi; Bustamante, Carlos D.

    2016-01-01

    Sequencing the genomes of extinct hominids has reshaped our understanding of modern human origins. Here, we analyze ∼120 kb of exome-captured Y-chromosome DNA from a Neandertal individual from El Sidrón, Spain. We investigate its divergence from orthologous chimpanzee and modern human sequences and find strong support for a model that places the Neandertal lineage as an outgroup to modern human Y chromosomes—including A00, the highly divergent basal haplogroup. We estimate that the time to the most recent common ancestor (TMRCA) of Neandertal and modern human Y chromosomes is ∼588 thousand years ago (kya) (95% confidence interval [CI]: 447–806 kya). This is ∼2.1 (95% CI: 1.7–2.9) times longer than the TMRCA of A00 and other extant modern human Y-chromosome lineages. This estimate suggests that the Y-chromosome divergence mirrors the population divergence of Neandertals and modern human ancestors, and it refutes alternative scenarios of a relatively recent or super-archaic origin of Neandertal Y chromosomes. The fact that the Neandertal Y we describe has never been observed in modern humans suggests that the lineage is most likely extinct. We identify protein-coding differences between Neandertal and modern human Y chromosomes, including potentially damaging changes to PCDH11Y, TMSB4Y, USP9Y, and KDM5D. Three of these changes are missense mutations in genes that produce male-specific minor histocompatibility (H-Y) antigens. Antigens derived from KDM5D, for example, are thought to elicit a maternal immune response during gestation. It is possible that incompatibilities at one or more of these genes played a role in the reproductive isolation of the two groups. PMID:27058445

  3. Late Pleistocene human skeleton and mtDNA link Paleoamericans and modern Native Americans.

    PubMed

    Chatters, James C; Kennett, Douglas J; Asmerom, Yemane; Kemp, Brian M; Polyak, Victor; Blank, Alberto Nava; Beddows, Patricia A; Reinhardt, Eduard; Arroyo-Cabrales, Joaquin; Bolnick, Deborah A; Malhi, Ripan S; Culleton, Brendan J; Erreguerena, Pilar Luna; Rissolo, Dominique; Morell-Hart, Shanti; Stafford, Thomas W

    2014-05-16

    Because of differences in craniofacial morphology and dentition between the earliest American skeletons and modern Native Americans, separate origins have been postulated for them, despite genetic evidence to the contrary. We describe a near-complete human skeleton with an intact cranium and preserved DNA found with extinct fauna in a submerged cave on Mexico's Yucatan Peninsula. This skeleton dates to between 13,000 and 12,000 calendar years ago and has Paleoamerican craniofacial characteristics and a Beringian-derived mitochondrial DNA (mtDNA) haplogroup (D1). Thus, the differences between Paleoamericans and Native Americans probably resulted from in situ evolution rather than separate ancestry. Copyright © 2014, American Association for the Advancement of Science.

  4. Appendicular robusticity and the paleobiology of modern human emergence.

    PubMed

    Trinkaus, E

    1997-11-25

    The emergence of modern humans in the Late Pleistocene, whatever its phylogenetic history, was characterized by a series of behaviorally important shifts reflected in aspects of human hard tissue biology and the archeological record. To elucidate these shifts further, diaphyseal cross-sectional morphology was analyzed by using cross-sectional areas and second moments of area of the mid-distal humerus and midshaft femur. The humeral diaphysis indicates a gradual reduction in habitual load levels from Eurasian late archaic, to Early Upper Paleolithic early modern, to Middle Upper Paleolithic early modern hominids, with the Levantine Middle Paleolithic early modern humans being a gracile anomalous outlier. The femoral diaphysis, once variation in ecogeographically patterned body proportions is taken into account, indicates no changes across the pre-30,000 years B.P. samples in habitual locomotor load levels, followed by a modest decrease through the Middle Upper Paleolithic.

  5. Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada.

    PubMed

    Bourgeon, Lauriane; Burke, Ariane; Higham, Thomas

    2017-01-01

    The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present), i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP). In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the "Beringian standstill hypothesis", which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period.

  6. Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada

    PubMed Central

    Bourgeon, Lauriane; Burke, Ariane; Higham, Thomas

    2017-01-01

    The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present), i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP). In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the “Beringian standstill hypothesis”, which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period. PMID:28060931

  7. Investigating the nature and timing of the earliest human occupation of North America using a novel integration of biogeochemistry and sediment micromorphology

    NASA Astrophysics Data System (ADS)

    Shillito, Lisa-Marie; Jenkins, Dennis; Blong, John; Stafford, Thomas; Bull, Ian

    2017-04-01

    Coprolites contain a suite of biomolecules and microfossils, making them incredibly useful palaeoenvironmental and palaeodietary archives. The short-term nature of their production within the human body offers a very high temporal resolution, contrasting with traditional dietary proxies in archaeology such as skeletal C/N isotopes, which give an average lifetime signal. Some of the earliest evidence of human occupation in North America is a coprolite from Paisley Caves (Oregon, USA) which contained ancient human DNA in a matrix dated between 14,170 to 14,340 cal BP. However, there have been debates over the stratigraphic integrity and preservation of the aDNA. This debate is difficult to resolve as there is currently little understanding of the nature of biomolecule taphonomy and movement within the cave environment. Before broader questions of palaeodiet and resource use of these early settlers can be investigated, the identification of coprolite proxies as human or otherwise must be confirmed, and their stratigraphic integrity assessed. This research aims to address these issues by using a novel integration of biogeochemistry and sediment microstratigraphy to investigate the survival and taphonomy of different biomolecules within the cave environment and to understand how these early settlers interacted with their seasonal environment.

  8. 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

  9. 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.

  10. An early modern human presence in Sumatra 73,000-63,000 years ago.

    PubMed

    Westaway, K E; Louys, J; Awe, R Due; Morwood, M J; Price, G J; Zhao, J-X; Aubert, M; Joannes-Boyau, R; Smith, T M; Skinner, M M; Compton, T; Bailey, R M; van den Bergh, G D; de Vos, J; Pike, A W G; Stringer, C; Saptomo, E W; Rizal, Y; Zaim, J; Santoso, W D; Trihascaryo, A; Kinsley, L; Sulistyanto, B

    2017-08-17

    Genetic evidence for anatomically modern humans (AMH) out of Africa before 75 thousand years ago (ka) and in island southeast Asia (ISEA) before 60 ka (93-61 ka) predates accepted archaeological records of occupation in the region. Claims that AMH arrived in ISEA before 60 ka (ref. 4) have been supported only by equivocal or non-skeletal evidence. AMH evidence from this period is rare and lacks robust chronologies owing to a lack of direct dating applications, poor preservation and/or excavation strategies and questionable taxonomic identifications. Lida Ajer is a Sumatran Pleistocene cave with a rich rainforest fauna associated with fossil human teeth. The importance of the site is unclear owing to unsupported taxonomic identification of these fossils and uncertainties regarding the age of the deposit, therefore it is rarely considered in models of human dispersal. Here we reinvestigate Lida Ajer to identify the teeth confidently and establish a robust chronology using an integrated dating approach. Using enamel-dentine junction morphology, enamel thickness and comparative morphology, we show that the teeth are unequivocally AMH. Luminescence and uranium-series techniques applied to bone-bearing sediments and speleothems, and coupled uranium-series and electron spin resonance dating of mammalian teeth, place modern humans in Sumatra between 73 and 63 ka. This age is consistent with biostratigraphic estimations, palaeoclimate and sea-level reconstructions, and genetic evidence for a pre-60 ka arrival of AMH into ISEA. Lida Ajer represents, to our knowledge, the earliest evidence of rainforest occupation by AMH, and underscores the importance of reassessing the timing and environmental context of the dispersal of modern humans out of Africa.

  11. An early modern human presence in Sumatra 73,000-63,000 years ago

    NASA Astrophysics Data System (ADS)

    Westaway, K. E.; Louys, J.; Awe, R. Due; Morwood, M. J.; Price, G. J.; Zhao, J.-X.; Aubert, M.; Joannes-Boyau, R.; Smith, T. M.; Skinner, M. M.; Compton, T.; Bailey, R. M.; van den Bergh, G. D.; de Vos, J.; Pike, A. W. G.; Stringer, C.; Saptomo, E. W.; Rizal, Y.; Zaim, J.; Santoso, W. D.; Trihascaryo, A.; Kinsley, L.; Sulistyanto, B.

    2017-08-01

    Genetic evidence for anatomically modern humans (AMH) out of Africa before 75 thousand years ago (ka) and in island southeast Asia (ISEA) before 60 ka (93-61 ka) predates accepted archaeological records of occupation in the region. Claims that AMH arrived in ISEA before 60 ka (ref. 4) have been supported only by equivocal or non-skeletal evidence. AMH evidence from this period is rare and lacks robust chronologies owing to a lack of direct dating applications, poor preservation and/or excavation strategies and questionable taxonomic identifications. Lida Ajer is a Sumatran Pleistocene cave with a rich rainforest fauna associated with fossil human teeth. The importance of the site is unclear owing to unsupported taxonomic identification of these fossils and uncertainties regarding the age of the deposit, therefore it is rarely considered in models of human dispersal. Here we reinvestigate Lida Ajer to identify the teeth confidently and establish a robust chronology using an integrated dating approach. Using enamel-dentine junction morphology, enamel thickness and comparative morphology, we show that the teeth are unequivocally AMH. Luminescence and uranium-series techniques applied to bone-bearing sediments and speleothems, and coupled uranium-series and electron spin resonance dating of mammalian teeth, place modern humans in Sumatra between 73 and 63 ka. This age is consistent with biostratigraphic estimations, palaeoclimate and sea-level reconstructions, and genetic evidence for a pre-60 ka arrival of AMH into ISEA. Lida Ajer represents, to our knowledge, the earliest evidence of rainforest occupation by AMH, and underscores the importance of reassessing the timing and environmental context of the dispersal of modern humans out of Africa.

  12. The earliest well-dated archeological site in the hyper-arid Tarim Basin and its implications for prehistoric human migration and climatic change

    NASA Astrophysics Data System (ADS)

    Han, WenXia; Yu, LuPeng; Lai, ZhongPing; Madsen, David; Yang, Shengli

    2014-07-01

    The routes and timing of human occupation of the Tibetan Plateau (TP) are crucial for understanding the evolution of Tibetan populations and associated paleoclimatic conditions. Many archeological sites have been found in/around the Tarim Basin, on the northern margin of the Tibetan Plateau. Unfortunately, most of these sites are surface sites and cannot be directly dated. Their ages can only be estimated based on imprecise artifact comparisons. We recently found and dated an archeological site on a terrace along the Keriya River. Our ages indicate that the site was occupied at ~ 7.0-7.6 ka, making it the earliest well-dated archeological site yet identified in the Tarim Basin. This suggests that early human foragers migrated into this region prior to ~ 7.0-7.6 ka during the early to mid-Holocene climatic optimum, which may have provided the impetus for populating the region. We hypothesize that the Keriya River, together with the other rivers originating from the TP, may have served as access routes onto the TP for early human foragers. These rivers may also have served as stepping stones for migration further west into the now hyper-arid regions of the Tarim Basin, leading ultimately to the development of the Silk Road.

  13. The Date of Interbreeding between Neandertals and Modern Humans

    PubMed Central

    Sankararaman, Sriram; Patterson, Nick; Li, Heng; Pääbo, Svante; Reich, David

    2012-01-01

    Comparisons of DNA sequences between Neandertals and present-day humans have shown that Neandertals share more genetic variants with non-Africans than with Africans. This could be due to interbreeding between Neandertals and modern humans when the two groups met subsequent to the emergence of modern humans outside Africa. However, it could also be due to population structure that antedates the origin of Neandertal ancestors in Africa. We measure the extent of linkage disequilibrium (LD) in the genomes of present-day Europeans and find that the last gene flow from Neandertals (or their relatives) into Europeans likely occurred 37,000–86,000 years before the present (BP), and most likely 47,000–65,000 years ago. This supports the recent interbreeding hypothesis and suggests that interbreeding may have occurred when modern humans carrying Upper Paleolithic technologies encountered Neandertals as they expanded out of Africa. PMID:23055938

  14. Human factors in modern traffic systems.

    PubMed

    Noy, Y I

    1997-10-01

    Traffic systems are undergoing enormous change with the advent of Intelligent Transport Systems (ITS). Although productivity and quality of mobility are emerging interests, safety remains the predominant preoccupation of ITS human factors. It should be evident that while intelligent technologies may have the potential to improve traffic safety, they also have the potential to adversely affect it. Ultimately, the effect on safety depends on the specific technologies that are invoked and the manner in which they are incorporated within the vehicle as well as within the larger road transportation system. Current automotive developments can be characterized as technology-centred solutions rather than user-centred solutions. Greater effort must be directed at understanding and accommodating the human element in the road transportation system in order that future transportation objectives can be achieved. There is a need to expand the scope of traditional human factors to include macro-level effects as well as to place greater emphasis on understanding human interactions with other elements of the system. There is also increasing recognition of the urgent need for systematic procedures and criteria for testing the safety of ITS prior to large-scale market penetration.

  15. Ancient gene flow from early modern humans into Eastern Neanderthals

    PubMed Central

    Kuhlwilm, Martin; Gronau, Ilan; Hubisz, Melissa J.; de Filippo, Cesare; Prado-Martinez, Javier; Kircher, Martin; Fu, Qiaomei; Burbano, Hernán A.; Lalueza-Fox, Carles; de la Rasilla, Marco; Rosas, Antonio; Rudan, Pavao; Brajkovic, Dejana; Kucan, Željko; Gušic, Ivan; Marques-Bonet, Tomas; Andrés, Aida M.; Viola, Bence; Pääbo, Svante; Meyer, Matthias; Siepel, Adam; Castellano, Sergi

    2016-01-01

    It has been shown that Neanderthals contributed genetically to modern humans outside Africa 47,000–65,000 years ago. Here, we analyze the genomes of a Neanderthal and a Denisovan from the Altai Mountains in Siberia together with the sequences of chromosome 21 of two Neanderthals from Spain and Croatia. We find that a population that diverged early from other modern humans in Africa contributed genetically to the ancestors of Neanderthals from the Altai Mountains roughly 100,000 years ago. By contrast, we do not detect such a genetic contribution in the Denisovan or the two European Neanderthals. We conclude that in addition to later interbreeding events, the ancestors of Neanderthals from the Altai Mountains and of modern humans met and interbred, possibly in the Near East, many thousands of years earlier than previously reported. PMID:26886800

  16. Morphological Integration of the Modern Human Mandible during Ontogeny

    PubMed Central

    Polanski, Joshua M.

    2011-01-01

    Craniofacial integration is prevalent in anatomical modernity research. Little investigation has been done on mandibular integration. Integration patterns were quantified in a longitudinal modern human sample of mandibles. This integration pattern is one of modularization between the alveolar and muscle attachment regions, but with age-specific differences. The ascending ramus and nonalveolar portions of the corpus remain integrated throughout ontogeny. The alveolar region is dynamic, becoming modularized according to the needs of the mandible at a particular developmental stage. Early in ontogeny, this modularity reflects the need for space for the developing dentition; later, modularity is more reflective of mastication. The overall pattern of modern human mandibular integration follows the integration pattern seen in other mammals, including chimpanzees. Given the differences in craniofacial integration patterns between humans and chimpanzees, but the similarities in mandibular integration, it is likely that the mandible has played the more passive role in hominin skull evolution. PMID:21716741

  17. Ancient gene flow from early modern humans into Eastern Neanderthals.

    PubMed

    Kuhlwilm, Martin; Gronau, Ilan; Hubisz, Melissa J; de Filippo, Cesare; Prado-Martinez, Javier; Kircher, Martin; Fu, Qiaomei; Burbano, Hernán A; Lalueza-Fox, Carles; de la Rasilla, Marco; Rosas, Antonio; Rudan, Pavao; Brajkovic, Dejana; Kucan, Željko; Gušic, Ivan; Marques-Bonet, Tomas; Andrés, Aida M; Viola, Bence; Pääbo, Svante; Meyer, Matthias; Siepel, Adam; Castellano, Sergi

    2016-02-25

    It has been shown that Neanderthals contributed genetically to modern humans outside Africa 47,000-65,000 years ago. Here we analyse the genomes of a Neanderthal and a Denisovan from the Altai Mountains in Siberia together with the sequences of chromosome 21 of two Neanderthals from Spain and Croatia. We find that a population that diverged early from other modern humans in Africa contributed genetically to the ancestors of Neanderthals from the Altai Mountains roughly 100,000 years ago. By contrast, we do not detect such a genetic contribution in the Denisovan or the two European Neanderthals. We conclude that in addition to later interbreeding events, the ancestors of Neanderthals from the Altai Mountains and early modern humans met and interbred, possibly in the Near East, many thousands of years earlier than previously thought.

  18. From Neandertals to modern humans: New data on the Uluzzian.

    PubMed

    Villa, Paola; Pollarolo, Luca; Conforti, Jacopo; Marra, Fabrizio; Biagioni, Cristian; Degano, Ilaria; Lucejko, Jeannette J; Tozzi, Carlo; Pennacchioni, Massimo; Zanchetta, Giovanni; Nicosia, Cristiano; Martini, Marco; Sibilia, Emanuela; Panzeri, Laura

    2018-01-01

    Having thrived in Eurasia for 350,000 years Neandertals disappeared from the record around 40,000-37,000 years ago, after modern humans entered Europe. It was a complex process of population interactions that included cultural exchanges and admixture between Neandertals and dispersing groups of modern humans. In Europe Neandertals are always associated with the Mousterian while the Aurignacian is associated with modern humans only. The onset of the Aurignacian is preceded by "transitional" industries which show some similarities with the Mousterian but also contain modern tool forms. Information on these industries is often incomplete or disputed and this is true of the Uluzzian. We present the results of taphonomic, typological and technological analyses of two Uluzzian sites, Grotta La Fabbrica (Tuscany) and the newly discovered site of Colle Rotondo (Latium). Comparisons with Castelcivita and Grotta del Cavallo show that the Uluzzian is a coherent cultural unit lasting about five millennia, replaced by the Protoaurignacian before the eruption of the Campanian Ignimbrite. The lack of skeletal remains at our two sites and the controversy surrounding the stratigraphic position of modern human teeth at Cavallo makes it difficult to reach agreement about authorship of the Uluzzian, for which alternative hypotheses have been proposed. Pending the discovery of DNA or further human remains, these hypotheses can only be evaluated by archaeological arguments, i.e. evidence of continuities and discontinuities between the Uluzzian and the preceding and succeeding culture units in Italy. However, in the context of "transitional" industries with disputed dates for the arrival of modern humans in Europe, and considering the case of the Châtelperronian, an Upper Paleolithic industry made by Neandertals, typo-technology used as an indicator of hominin authorship has limited predictive value. We corroborate previous suggestions that the Middle-to-Upper Paleolithic transition

  19. From Neandertals to modern humans: New data on the Uluzzian

    PubMed Central

    Pollarolo, Luca; Conforti, Jacopo; Marra, Fabrizio; Biagioni, Cristian; Degano, Ilaria; Lucejko, Jeannette J.; Tozzi, Carlo; Pennacchioni, Massimo; Zanchetta, Giovanni; Nicosia, Cristiano; Martini, Marco; Sibilia, Emanuela; Panzeri, Laura

    2018-01-01

    Having thrived in Eurasia for 350,000 years Neandertals disappeared from the record around 40,000–37,000 years ago, after modern humans entered Europe. It was a complex process of population interactions that included cultural exchanges and admixture between Neandertals and dispersing groups of modern humans. In Europe Neandertals are always associated with the Mousterian while the Aurignacian is associated with modern humans only. The onset of the Aurignacian is preceded by “transitional” industries which show some similarities with the Mousterian but also contain modern tool forms. Information on these industries is often incomplete or disputed and this is true of the Uluzzian. We present the results of taphonomic, typological and technological analyses of two Uluzzian sites, Grotta La Fabbrica (Tuscany) and the newly discovered site of Colle Rotondo (Latium). Comparisons with Castelcivita and Grotta del Cavallo show that the Uluzzian is a coherent cultural unit lasting about five millennia, replaced by the Protoaurignacian before the eruption of the Campanian Ignimbrite. The lack of skeletal remains at our two sites and the controversy surrounding the stratigraphic position of modern human teeth at Cavallo makes it difficult to reach agreement about authorship of the Uluzzian, for which alternative hypotheses have been proposed. Pending the discovery of DNA or further human remains, these hypotheses can only be evaluated by archaeological arguments, i.e. evidence of continuities and discontinuities between the Uluzzian and the preceding and succeeding culture units in Italy. However, in the context of “transitional” industries with disputed dates for the arrival of modern humans in Europe, and considering the case of the Châtelperronian, an Upper Paleolithic industry made by Neandertals, typo-technology used as an indicator of hominin authorship has limited predictive value. We corroborate previous suggestions that the Middle-to-Upper Paleolithic

  20. A Reassessment of Bergmann's Rule in Modern Humans

    PubMed Central

    Foster, Frederick; Collard, Mark

    2013-01-01

    It is widely accepted that modern humans conform to Bergmann's rule, which holds that body size in endothermic species will increase as temperature decreases. However, there are reasons to question the reliability of the findings on which this consensus is based. One of these is that the main studies that have reported that modern humans conform to Bergmann's rule have employed samples that contain a disproportionately large number of warm-climate and northern hemisphere groups. With this in mind, we used latitudinally-stratified and hemisphere-specific samples to re-assess the relationship between modern human body size and temperature. We found that when groups from north and south of the equator were analyzed together, Bergmann's rule was supported. However, when groups were separated by hemisphere, Bergmann's rule was only supported in the northern hemisphere. In the course of exploring these results further, we found that the difference between our northern and southern hemisphere subsamples is due to the limited latitudinal and temperature range in the latter subsample. Thus, our study suggests that modern humans do conform to Bergmann's rule but only when there are major differences in latitude and temperature among groups. Specifically, groups must span more than 50 degrees of latitude and/or more than 30°C for it to hold. This finding has important implications for work on regional variation in human body size and its relationship to temperature. PMID:24015229

  1. On the origin of modern humans: Asian perspectives.

    PubMed

    Bae, Christopher J; Douka, Katerina; Petraglia, Michael D

    2017-12-08

    The traditional "out of Africa" model, which posits a dispersal of modern Homo sapiens across Eurasia as a single wave at ~60,000 years ago and the subsequent replacement of all indigenous populations, is in need of revision. Recent discoveries from archaeology, hominin paleontology, geochronology, genetics, and paleoenvironmental studies have contributed to a better understanding of the Late Pleistocene record in Asia. Important findings highlighted here include growing evidence for multiple dispersals predating 60,000 years ago in regions such as southern and eastern Asia. Modern humans moving into Asia met Neandertals, Denisovans, mid-Pleistocene Homo , and possibly H. floresiensis , with some degree of interbreeding occurring. These early human dispersals, which left at least some genetic traces in modern populations, indicate that later replacements were not wholesale. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  2. Insights into Modern Human Prehistory Using Ancient Genomes.

    PubMed

    Yang, Melinda A; Fu, Qiaomei

    2018-03-01

    The genetic relationship of past modern humans to today's populations and each other was largely unknown until recently, when advances in ancient DNA sequencing allowed for unprecedented analysis of the genomes of these early people. These ancient genomes reveal new insights into human prehistory not always observed studying present-day populations, including greater details on the genetic diversity, population structure, and gene flow that characterized past human populations, particularly in early Eurasia, as well as increased insight on the relationship between archaic and modern humans. Here, we review genetic studies on ∼45000- to 7500-year-old individuals associated with mainly preagricultural cultures found in Eurasia, the Americas, and Africa. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The genome of a Mongolian individual reveals the genetic imprints of Mongolians on modern human populations.

    PubMed

    Bai, Haihua; Guo, Xiaosen; Zhang, Dong; Narisu, Narisu; Bu, Junjie; Jirimutu, Jirimutu; Liang, Fan; Zhao, Xiang; Xing, Yanping; Wang, Dingzhu; Li, Tongda; Zhang, Yanru; Guan, Baozhu; Yang, Xukui; Yang, Zili; Shuangshan, Shuangshan; Su, Zhe; Wu, Huiguang; Li, Wenjing; Chen, Ming; Zhu, Shilin; Bayinnamula, Bayinnamula; Chang, Yuqi; Gao, Ying; Lan, Tianming; Suyalatu, Suyalatu; Huang, Hui; Su, Yan; Chen, Yujie; Li, Wenqi; Yang, Xu; Feng, Qiang; Wang, Jian; Yang, Huanming; Wang, Jun; Wu, Qizhu; Yin, Ye; Zhou, Huanmin

    2014-11-05

    Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]-1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  4. The Genome of a Mongolian Individual Reveals the Genetic Imprints of Mongolians on Modern Human Populations

    PubMed Central

    Wu, Qizhu; Yin, Ye; Zhou, Huanmin

    2014-01-01

    Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]–1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians. PMID:25377941

  5. The shaping of modern human immune systems by multiregional admixture with archaic humans.

    PubMed

    Abi-Rached, Laurent; Jobin, Matthew J; Kulkarni, Subhash; McWhinnie, Alasdair; Dalva, Klara; Gragert, Loren; Babrzadeh, Farbod; Gharizadeh, Baback; Luo, Ma; Plummer, Francis A; Kimani, Joshua; Carrington, Mary; Middleton, Derek; Rajalingam, Raja; Beksac, Meral; Marsh, Steven G E; Maiers, Martin; Guethlein, Lisbeth A; Tavoularis, Sofia; Little, Ann-Margaret; Green, Richard E; Norman, Paul J; Parham, Peter

    2011-10-07

    Whole genome comparisons identified introgression from archaic to modern humans. Our analysis of highly polymorphic human leukocyte antigen (HLA) class I, vital immune system components subject to strong balancing selection, shows how modern humans acquired the HLA-B*73 allele in west Asia through admixture with archaic humans called Denisovans, a likely sister group to the Neandertals. Virtual genotyping of Denisovan and Neandertal genomes identified archaic HLA haplotypes carrying functionally distinctive alleles that have introgressed into modern Eurasian and Oceanian populations. These alleles, of which several encode unique or strong ligands for natural killer cell receptors, now represent more than half the HLA alleles of modern Eurasians and also appear to have been later introduced into Africans. Thus, adaptive introgression of archaic alleles has significantly shaped modern human immune systems.

  6. Neandertal versus Modern Human Dietary Responses to Climatic Fluctuations

    PubMed Central

    El Zaatari, Sireen; Grine, Frederick E.; Ungar, Peter S.; Hublin, Jean-Jacques

    2016-01-01

    The Neandertal lineage developed successfully throughout western Eurasia and effectively survived the harsh and severely changing environments of the alternating glacial/interglacial cycles from the middle of the Pleistocene until Marine Isotope Stage 3. Yet, towards the end of this stage, at the time of deteriorating climatic conditions that eventually led to the Last Glacial Maximum, and soon after modern humans entered western Eurasia, the Neandertals disappeared. Western Eurasia was by then exclusively occupied by modern humans. We use occlusal molar microwear texture analysis to examine aspects of diet in western Eurasian Paleolithic hominins in relation to fluctuations in food supplies that resulted from the oscillating climatic conditions of the Pleistocene. There is demonstrable evidence for differences in behavior that distinguish Upper Paleolithic humans from members of the Neandertal lineage. Specifically, whereas the Neandertals altered their diets in response to changing paleoecological conditions, the diets of Upper Paleolithic humans seem to have been less affected by slight changes in vegetation/climatic conditions but were linked to changes in their technological complexes. The results of this study also indicate differences in resource exploitation strategies between these two hominin groups. We argue that these differences in subsistence strategies, if they had already been established at the time of the first contact between these two hominin taxa, may have given modern humans an advantage over the Neandertals, and may have contributed to the persistence of our species despite habitat-related changes in food availabilities associated with climate fluctuations. PMID:27119336

  7. Neandertal versus Modern Human Dietary Responses to Climatic Fluctuations.

    PubMed

    El Zaatari, Sireen; Grine, Frederick E; Ungar, Peter S; Hublin, Jean-Jacques

    2016-01-01

    The Neandertal lineage developed successfully throughout western Eurasia and effectively survived the harsh and severely changing environments of the alternating glacial/interglacial cycles from the middle of the Pleistocene until Marine Isotope Stage 3. Yet, towards the end of this stage, at the time of deteriorating climatic conditions that eventually led to the Last Glacial Maximum, and soon after modern humans entered western Eurasia, the Neandertals disappeared. Western Eurasia was by then exclusively occupied by modern humans. We use occlusal molar microwear texture analysis to examine aspects of diet in western Eurasian Paleolithic hominins in relation to fluctuations in food supplies that resulted from the oscillating climatic conditions of the Pleistocene. There is demonstrable evidence for differences in behavior that distinguish Upper Paleolithic humans from members of the Neandertal lineage. Specifically, whereas the Neandertals altered their diets in response to changing paleoecological conditions, the diets of Upper Paleolithic humans seem to have been less affected by slight changes in vegetation/climatic conditions but were linked to changes in their technological complexes. The results of this study also indicate differences in resource exploitation strategies between these two hominin groups. We argue that these differences in subsistence strategies, if they had already been established at the time of the first contact between these two hominin taxa, may have given modern humans an advantage over the Neandertals, and may have contributed to the persistence of our species despite habitat-related changes in food availabilities associated with climate fluctuations.

  8. The Shaping of Modern Human Immune Systems by Multiregional Admixture with Archaic Humans

    PubMed Central

    Abi-Rached, Laurent; Jobin, Matthew J; Kulkarni, Subhash; McWhinnie, Alasdair; Dalva, Klara; Gragert, Loren; Babrzadeh, Farbod; Gharizadeh, Baback; Luo, Ma; Plummer, Francis A; Kimani, Joshua; Carrington, Mary; Middleton, Derek; Rajalingam, Raja; Beksac, Meral; Marsh, Steven GE; Maiers, Martin; Guethlein, Lisbeth A; Tavoularis, Sofia; Little, Ann-Margaret; Green, Richard E; Norman, Paul J; Parham, Peter

    2013-01-01

    Whole genome comparisons identified introgression from archaic to modern humans. Our analysis of highly polymorphic HLA class I, vital immune system components subject to strong balancing selection, shows how modern humans acquired the HLA-B*73 allele in west Asia through admixture with archaic humans called Denisovans, a likely sister group to the Neandertals. Virtual genotyping of Denisovan and Neandertal genomes identified archaic HLA haplotypes carrying functionally distinctive alleles that have introgressed into modern Eurasian and Oceanian populations. These alleles, of which several encode unique or strong ligands for natural killer cell receptors, now represent more than half the HLA alleles of modern Eurasians and also appear to have been later introduced into Africans. Thus, adaptive introgression of archaic alleles has significantly shaped modern human immune systems. PMID:21868630

  9. Early modern human lithic technology from Jerimalai, East Timor.

    PubMed

    Marwick, Ben; Clarkson, Chris; O'Connor, Sue; Collins, Sophie

    2016-12-01

    Jerimalai is a rock shelter in East Timor with cultural remains dated to 42,000 years ago, making it one of the oldest known sites of modern human activity in island Southeast Asia. It has special global significance for its record of early pelagic fishing and ancient shell fish hooks. It is also of regional significance for its early occupation and comparatively large assemblage of Pleistocene stone artefacts. Three major findings arise from our study of the stone artefacts. First, there is little change in lithic technology over the 42,000 year sequence, with the most noticeable change being the addition of new artefact types and raw materials in the mid-Holocene. Second, the assemblage is dominated by small chert cores and implements rather than pebble tools and choppers, a pattern we argue pattern, we argue, that is common in island SE Asian sites as opposed to mainland SE Asian sites. Third, the Jerimalai assemblage bears a striking resemblance to the assemblage from Liang Bua, argued by the Liang Bua excavation team to be associated with Homo floresiensis. We argue that the near proximity of these two islands along the Indonesian island chain (c.100 km apart), the long antiquity of modern human occupation in the region (as documented at Jerimalai), and the strong resemblance of distinctive flake stone technologies seen at both sites, raises the intriguing possibility that both the Liang Bua and Jerimalai assemblages were created by modern humans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Technological complexity and the global dispersal of modern humans.

    PubMed

    Hoffecker, John F; Hoffecker, Ian T

    2017-11-01

    Anatomically modern humans (Homo sapiens) dispersed out of Africa roughly 120,000 years ago and again after 75,000 years ago. The early dispersal was geographically restricted to the Arabian Peninsula, Levant, and possibly parts of southern Asia. The later dispersal was ultimately global in scope, including areas not previously occupied by Homo. One explanation for the contrast between the two out-of-Africa dispersals is that the modern humans who expanded into Eurasia 120,000 years ago lacked the functionally and structurally complex technology of recent hunter-gatherers. This technology, which includes, for example, mechanical projectiles, snares and traps, and sewn clothing, provides not only expanded dietary breadth and increased rates of foraging efficiency and success in places where plant and animal productivity is low, but protection from cold weather in places where winter temperatures are low. The absence of complex technology before 75,000 years ago also may explain why modern humans in the Levant did not develop sedentary settlements and agriculture 120,000 years ago (i.e., during the Last Interglacial). © 2017 Wiley Periodicals, Inc.

  11. Ancient, Renaissance, and Modern: The Human in the Humanities.

    ERIC Educational Resources Information Center

    Kallendorf, Craig

    1987-01-01

    Highlights major points concerning the scope and purpose of the humanities from five educational treatises from the Italian Renaissance. Compares them with Allan Bloom's and E. D. Hirsch, Jr.'s, ideas and revisionist approaches to literature studies. Concludes that the right and left perceive the humanities as a means to political power. (DMM)

  12. 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. Copyright © 2012 Elsevier GmbH. All rights reserved.

  13. Human Factors Engineering Aspects of Modifications in Control Room Modernization

    SciTech Connect

    Hugo, Jacques; Clefton, Gordon; Joe, Jeffrey

    This report describes the basic aspects of control room modernization projects in the U.S. nuclear industry and the need for supplementary guidance on the integration of human factors considerations into the licensing and regulatory aspects of digital upgrades. The report pays specific attention to the integration of principles described in NUREG-0711 (Human Factors Engineering Program Review Model) and how supplementary guidance can help to raise general awareness in the industry regarding the complexities of control room modernization projects created by many interdependent regulations, standards and guidelines. The report also describes how human factors engineering principles and methods provided by variousmore » resources and international standards can help in navigating through the process of licensing digital upgrades. In particular, the integration of human factors engineering guidance and requirements into the process of licensing digital upgrades can help reduce uncertainty related to development of technical bases for digital upgrades that will avoid the introduction of new failure modes.« less

  14. Malocclusion in Early Anatomically Modern Human: A Reflection on the Etiology of Modern Dental Misalignment

    PubMed Central

    Sarig, Rachel; Slon, Viviane; Abbas, Janan; May, Hila; Shpack, Nir; Vardimon, Alexander Dan; Hershkovitz, Israel

    2013-01-01

    Malocclusions are common in modern populations. Yet, as the study of occlusion requires an almost intact dentition in both the maxilla and mandible, searching for the ultimate cause of malocclusion is a challenge: relatively little ancient material is available for research on occlusal states. The Qafzeh 9 skull is unique, as its preserved dentition allowed us to investigate the presence and manifestations of malocclusion. The aim of this study was thus to examine the occlusal condition in the Qafzeh 9 specimen in light of modern knowledge regarding the etiology of malocclusion. We revealed a pathologic occlusion in the Qafzeh 9 skull that probably originated in the early developmental stage of the dentition, and was aggravated by forces applied by mastication. When arch continuity is interrupted due to misalignment of teeth as in this case, force transmission is not equal on both sides, causing intra-arch outcomes such as mesialization of the teeth, midline deviation, rotations and the aggravation of crowding. All are evident in the Qafzeh 9 skull: the midline deviates to the left; the incisors rotate mesio-buccally; the left segment is constricted; the left first molar is buccally positioned and the left premolars palatally tilted. The inter-arch evaluation revealed anterior cross bite with functional shift that might affect force transmission and bite force. In conclusion, the findings of the current study suggest that malocclusion of developmental origin was already present in early anatomically modern humans (AMH) (the present case being the oldest known case, dated to ca. 100,000 years); that there is no basis to the notion that early AMH had a better adjustment between teeth and jaw size; and that jaw-teeth size discrepancy could be found in prehistoric populations and is not a recent phenomenon. PMID:24278319

  15. African and Asian perspectives on the origins of modern humans.

    PubMed

    Clark, J D

    1992-08-29

    The ways in which the cultural evidence - in its chronological context - can be used to imply behavioural patterning and to identify possible causes of change are discussed. Improved reliability in dating methods, suites of dates from different regional localities, and new, firmly dated fossil hominids from crucial regions such as northeast Africa, the Levant, India and China, are essential for clarification of the origin and spread of the modern genepool. Hominid ancestry in Africa is reviewed, as well as the claims for an independent origin in Asia. The cultural differences and changes within Africa, West and South Asia and the Far East in the later Middle and early Upper Pleistocene are examined and compared, and some behavioural implications are suggested, taking account of the evolutionary frameworks suggested by the 'multiregional evolution' and 'Noah's Ark' hypotheses of human evolution. A possible explanation is proposed for the cultural differences between Africa, West Asia and India on the one hand, and southeast Asia and the Far East on the other. The apparent hiatus between the appearance of the first anatomically modern humans, ca. 100 ka ago, and the appearance of the Upper Palaeolithic and other contemporaneous technological and behavioural changes around 40 ka ago, is discussed. It is suggested that the anatomical changes occurred first, and that neurological changes permitted the development of fully syntactic language some 50 ka later. The intellectual and behavioural revolution, best demonstrated by the 'Upper Palaeolithic' of Eurasia, seems to have been dependent on this linguistic development - within the modern genepool - and triggered the rapid migration of human populations throughout the Old World.

  16. Impact of human aging and modern lifestyle on gut microbiota.

    PubMed

    Valle Gottlieb, Maria Gabriela; Closs, Vera Elizabeth; Junges, Vilma Maria; Schwanke, Carla Helena Augustin

    2018-06-13

    Human evolution and lifestyle changes caused by the agricultural and industrial revolutions have led to great advances in medicine and increased life expectancy, whilst also profoundly altering the ecological relationships and disease patterns of populations. Studies involving populations that still enjoy a rural way of life and with traits similar to the Paleolithic period reveal them to present a more robust, resistant and diverse gut microbiota, in comparison to highly industrialized civilizations. The human diet has expanded and broadened to include the consumption of high-calorie foods, particularly from animal sources such as game meat and eggs. For some time, authors have been alert to the fact that a modern lifestyle leads to reduced intake of beneficial bacteria, suggesting that nonpathogenic bacteria are being eradicated. Furthermore, therapeutic procedures, including the use of probiotics and prebiotics, have been proposed to lead to recovery of this microbiota, which is altered due to both the ageing process and lifestyle related aspects. Accordingly, this article aims to review the impact of human aging and modern lifestyle on gut microbiota, within an evolutionary, ecological, epidemiological and therapeutic context.

  17. The earliest settlers' antiquity and evolutionary history of Indian populations: evidence from M2 mtDNA lineage

    PubMed Central

    2008-01-01

    Background The "out of Africa" model postulating single "southern route" dispersal posits arrival of "Anatomically Modern Human" to Indian subcontinent around 66–70 thousand years before present (kyBP). However the contributions and legacy of these earliest settlers in contemporary Indian populations, owing to the complex past population dynamics and later migrations has been an issue of controversy. The high frequency of mitochondrial lineage "M2" consistent with its greater age and distribution suggests that it may represent the phylogenetic signature of earliest settlers. Accordingly, we attempted to re-evaluate the impact and contribution of earliest settlers in shaping the genetic diversity and structure of contemporary Indian populations; using our newly sequenced 72 and 4 published complete mitochondrial genomes of this lineage. Results The M2 lineage, harbouring two deep rooting subclades M2a and M2b encompasses approximately one tenth of the mtDNA pool of studied tribes. The phylogeographic spread and diversity indices of M2 and its subclades among the tribes of different geographic regions and linguistic phyla were investigated in detail. Further the reconstructed demographic history of M2 lineage as a surrogate of earliest settlers' component revealed that the demographic events with pronounced regional variations had played pivotal role in shaping the complex net of populations phylogenetic relationship in Indian subcontinent. Conclusion Our results suggest that tribes of southern and eastern region along with Dravidian and Austro-Asiatic speakers of central India are the modern representatives of earliest settlers of subcontinent. The Last Glacial Maximum aridity and post LGM population growth mechanised some sort of homogeneity and redistribution of earliest settlers' component in India. The demic diffusion of agriculture and associated technologies around 3 kyBP, which might have marginalized hunter-gatherer, is coincidental with the decline of

  18. Three-dimensional Procrustes analysis of modern human craniofacial form.

    PubMed

    Badawi-Fayad, Jackie; Cabanis, Emmanuel-Alain

    2007-03-01

    The objective of this study was to analyze modern human craniofacial form using 3D Procrustes superimposition in order to establish a reference model and validate it on computed tomography (CT). The sample consists of 136 specimens from five modern human regional groups. Thirty-three craniofacial landmark coordinates have been recorded using a Microscribe and calculated on CT scans for five crania from the sample. Procrustes superimposition has been performed to calculate the mean shape, and a discriminant analysis has also been carried out to estimate the variability of shape. The results show that the repeatability of measurements made on CT and on Microscribe is excellent (R = 0.99). There is no major distinctiveness in the craniofacial shape; however, discriminant function 1 separates out the European crania from the others, especially African and American. It includes the width and the length of the face, the flatness of the upper face, the prognathism of the maxilla, as well as the length and the inclination of the palate. The width of the maxilla and the palate do not show a great variability. This may be the common invariant feature responsible for the alignment of the teeth in all specimens. It may correspond to functional patterns related to masticatory constraints manifested by the important interproximal and occlusal dental wear in all specimens. This study confirms the high accuracy of measurements made on CT scan and the importance of geometric morphometrics, which provides an accurate characterization of the overall craniofacial shape and its variation within the entire population.

  19. Learning about human population history from ancient and modern genomes.

    PubMed

    Stoneking, Mark; Krause, Johannes

    2011-08-18

    Genome-wide data, both from SNP arrays and from complete genome sequencing, are becoming increasingly abundant and are now even available from extinct hominins. These data are providing new insights into population history; in particular, when combined with model-based analytical approaches, genome-wide data allow direct testing of hypotheses about population history. For example, genome-wide data from both contemporary populations and extinct hominins strongly support a single dispersal of modern humans from Africa, followed by two archaic admixture events: one with Neanderthals somewhere outside Africa and a second with Denisovans that (so far) has only been detected in New Guinea. These new developments promise to reveal new stories about human population history, without having to resort to storytelling.

  20. Ontogeny of modern human longitudinal body and transverse shoulder proportions.

    PubMed

    Frelat, Mélanie A; Coquerelle, Michael; Trinkaus, Erik

    2017-03-01

    Whereas variation of modern human adult body size and shape has been widely studied in the context of ecogeographical clines, little is known about the differential growth patterns of transverse and longitudinal dimensions among human populations. Our study explored the ontogenetic variation of those body proportions in modern humans. We compared results from four different approaches to study cross-sectional skeletal samples of Africans (n = 43), Amerindians (n = 69) and Europeans (n = 40) from 0 to 14 years of age. Clavicle, humerus, and femur intermetaphyseal lengths, and femoral distal metaphyseal breadth, were measured. Average ontogenetic trajectories were computed in order to compare the growth patterns of the three groups. Our findings demonstrated that the three geographical groups shared similar absolute and relative patterns of change with age for the four dimensions considered. Although interpopulation differences existed in transverse to longitudinal as well as in interlimb proportions, those differences did not seem to remain constant throughout ontogeny, similar to what has been shown for intralimb proportions. Growth rates of transverse shoulder proportions differed between populations from different regions after 10 years, whereas those for longitudinal proportions were very similar. The ontogeny of transverse shoulder proportions is more complex than what is observed for bi-iliac breadth, suggesting that transverse shoulder to limb proportions are not solely influenced by ecogeographical conditions. Our analysis demonstrates that methodologies that incorporate critical dimensions of body form could shed new light on human adaptation in both paleontological and neontological contexts. © 2016 Wiley Periodicals, Inc.

  1. Transmission between Archaic and Modern Human Ancestors during the Evolution of the Oncogenic Human Papillomavirus 16.

    PubMed

    Pimenoff, Ville N; de Oliveira, Cristina Mendes; Bravo, Ignacio G

    2017-01-01

    Every human suffers through life a number of papillomaviruses (PVs) infections, most of them asymptomatic. A notable exception are persistent infections by Human papillomavirus 16 (HPV16), the most oncogenic infectious agent for humans and responsible for most infection-driven anogenital cancers. Oncogenic potential is not homogeneous among HPV16 lineages, and genetic variation within HPV16 exhibits some geographic structure. However, an in-depth analysis of the HPV16 evolutionary history was still wanting. We have analyzed extant HPV16 diversity and compared the evolutionary and phylogeographical patterns of humans and of HPV16. We show that codivergence with modern humans explains at most 30% of the present viral geographical distribution. The most explanatory scenario suggests that ancestral HPV16 already infected ancestral human populations and that viral lineages co-diverged with the hosts in parallel with the split between archaic Neanderthal-Denisovans and ancestral modern human populations, generating the ancestral HPV16A and HPV16BCD viral lineages, respectively. We propose that after out-of-Africa migration of modern human ancestors, sexual transmission between human populations introduced HPV16A into modern human ancestor populations. We hypothesize that differential coevolution of HPV16 lineages with different but closely related ancestral human populations and subsequent host-switch events in parallel with introgression of archaic alleles into the genomes of modern human ancestors may be largely responsible for the present-day differential prevalence and association with cancers for HPV16 variants. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  2. Adaptations to local environments in modern human populations.

    PubMed

    Jeong, Choongwon; Di Rienzo, Anna

    2014-12-01

    After leaving sub-Saharan Africa around 50000-100000 years ago, anatomically modern humans have quickly occupied extremely diverse environments. Human populations were exposed to further environmental changes resulting from cultural innovations, such as the spread of farming, which gave rise to new selective pressures related to pathogen exposures and dietary shifts. In addition to changing the frequency of individual adaptive alleles, natural selection may also shape the overall genetic architecture of adaptive traits. Here, we review recent advances in understanding the genetic architecture of adaptive human phenotypes based on insights from the studies of lactase persistence, skin pigmentation and high-altitude adaptation. These adaptations evolved in parallel in multiple human populations, providing a chance to investigate independent realizations of the evolutionary process. We suggest that the outcome of adaptive evolution is often highly variable even under similar selective pressures. Finally, we highlight a growing need for detecting adaptations that did not follow the classical sweep model and for incorporating new sources of genetic evidence such as information from ancient DNA. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Chew Bahir, southern Ethiopia: an archive of environmental history during the evolution and dispersal of anatomically modern humans

    NASA Astrophysics Data System (ADS)

    Schaebitz, F.; Asrat, A.; Lamb, H. F.; Trauth, M. H.; Junginger, A.; Foerster, V. E.; Guenter, C.; Viehberg, F. A.; Just, J.; Roberts, H. M.; Chapot, M. S.; Leng, M. J.; Dean, J.; Cohen, A. S.

    2016-12-01

    Chew Bahir is a tectonic basin in the southern Ethiopian Rift, close to the Lower Omo valley, site of earliest known fossil of anatomically modern humans. It was drilled in Nov-Dec 2014 as part of the Hominin Sites and Paleolakes Drilling Project (HSPDP) and the Collaborative Research Center (CRC806) "Our Way to Europe". Two overlapping cores of mostly clayey silts, reaching a composite depths of 280m, were collected and may cover the last 500,000 years, thus providing a potential record of environmental history during the evolution and spread of anatomically modern humans. Here we present the lithology and stratigraphy of the composite core as well as results of high resolution MSCL and XRF scanning data. Initial sedimentological and geochemical results show that the Chew Bahir deposits are a sensitive record of changes in moisture, sediment influx, provenance, transport and diagenetic processes, evident from mineralogy, elemental concentration and physical properties. The potassium record is highly sensitive to changes in moisture balance (Foerster et al. 2015). XRF and XRD data suggest that the process linking climate with potassium concentrations is the diagenetic illitization of smectites during dry episodes with high alkalinity and salinity in the closed-basin lake. The core records will allow tests of the various hypotheses about the influence of environmental change on the evolution and dispersal of anatomically modern humans. Foerster, V., Vogelsang, R., Junginger, A., Asrat, A., Lamb, H.F., Schaebitz, F., Trauth, M.H. (2015): Environmental Change and Human Occupation of Southern Ethiopia and Northern Kenya during the last 20,000 years. Quaternary Science Reviews, 129: 333-340. doi:10.1016/j.quascirev.2015.10.026.

  4. Synchrotron Study of Strontium in Modern and Ancient Human Bones

    NASA Astrophysics Data System (ADS)

    Pingitore, N. E.; Cruz-Jimenez, G.

    2001-05-01

    Archaeologists use the strontium in human bone to reconstruct diet and migration in ancient populations. Because mammals discriminate against strontium relative to calcium, carnivores show lower bone Sr/Ca ratios than herbivores. Thus, in a single population, bone Sr/Ca ratios can discriminate a meat-rich from a vegetarian diet. Also, the ratio of 87-Sr to 86-Sr in soils varies with the underlying geology; incorporated into the food chain, this local signature becomes embedded in our bones. The Sr isotopic ratio in the bones of individuals or populations which migrate to a different geologic terrane will gradually change as bone remodels. In contrast, the isotopic ratio of tooth enamel is fixed at an early age and is not altered later in life. Addition of Sr to bone during post-mortem residence in moist soil or sediment compromises application of the Sr/Ca or Sr-isotope techniques. If this post-mortem Sr resides in a different atomic environment than the Sr deposited in vivo, x-ray absorption spectroscopy could allow us to distinguish pristine from contaminated, and thus unreliable, samples. Initial examination of a suite of modern and ancient human and animal bones by extended x-ray absorption fine structure (EXAFS) showed no obvious differences between the fresh and buried materials. We note, with obvious concern, that the actual location of Sr in modern bone is controversial: there is evidence both that Sr substitutes for Ca and that Sr is sorbed on the surfaces of bone crystallites. Additional material is being studied.

  5. Morphology and function of Neandertal and modern human ear ossicles

    PubMed Central

    David, Romain; Gunz, Philipp; Schmidt, Tobias; Spoor, Fred; Hublin, Jean-Jacques

    2016-01-01

    The diminutive middle ear ossicles (malleus, incus, stapes) housed in the tympanic cavity of the temporal bone play an important role in audition. The few known ossicles of Neandertals are distinctly different from those of anatomically modern humans (AMHs), despite the close relationship between both human species. Although not mutually exclusive, these differences may affect hearing capacity or could reflect covariation with the surrounding temporal bone. Until now, detailed comparisons were hampered by the small sample of Neandertal ossicles and the unavailability of methods combining analyses of ossicles with surrounding structures. Here, we present an analysis of the largest sample of Neandertal ossicles to date, including many previously unknown specimens, covering a wide geographic and temporal range. Microcomputed tomography scans and 3D geometric morphometrics were used to quantify shape and functional properties of the ossicles and the tympanic cavity and make comparisons with recent and extinct AMHs as well as African apes. We find striking morphological differences between ossicles of AMHs and Neandertals. Ossicles of both Neandertals and AMHs appear derived compared with the inferred ancestral morphology, albeit in different ways. Brain size increase evolved separately in AMHs and Neandertals, leading to differences in the tympanic cavity and, consequently, the shape and spatial configuration of the ossicles. Despite these different evolutionary trajectories, functional properties of the middle ear of AMHs and Neandertals are largely similar. The relevance of these functionally equivalent solutions is likely to conserve a similar auditory sensitivity level inherited from their last common ancestor. PMID:27671643

  6. Ichnotaxonomy of the Laetoli trackways: The earliest hominin footprints

    NASA Astrophysics Data System (ADS)

    Meldrum, D. J.; Lockley, Martin G.; Lucas, Spencer G.; Musiba, Charles

    2011-04-01

    At 3.6 Ma, the Laetoli Pliocene hominin trackways are the earliest direct evidence of hominin bipedalism. Three decades since their discovery, not only is the question of their attribution still discussed, but marked differences in interpretation concerning the footprints' qualitative features and the inferred nature of the early hominin foot morphology remain. Here, we establish a novel ichnotaxon, Praehominipes laetoliensis, for these tracks and clarify the distinctions of these footprints from those of later hominins, especially modern humans. We also contrast hominin, human, and ape footprints to establish morphological features of these footprints correlated with a midtarsal break versus a stiff longitudinal arch. Original photos, including stereo photographs, and casts of footprints from the 1978 Laetoli excavation, confirm midtarsal flexibility, and repeatedly indicate an associated midfoot pressure ridge. In contrast, the modern human footprint reflects the derived arched-foot architecture, combined with a stiff-legged striding gait. Fossilized footprints of unshod modern human pedestrians in Hawaii and Nicaragua unambiguously illustrate these contrasts. Some points of comparisons with ape footprints are complicated by a variable hallucal position and the distinct manner of ape facultative bipedalism. In contrast to the comparatively rigid platform of the modern human foot, midtarsal flexibility is present in the chimpanzee foot. In ape locomotion, flexion at the transverse tarsal joint, referred to as the "midtarsal break," uncouples the respective functions of the prehensile forefoot and the propulsive hindfoot during grasp-climbing. At some point after the transition to habitual bipedalism, these grasp-climb adaptations, presumed to be present in the last common ancestor of apes and humans, were initially compromised by the loss of divergence of the hallux. An analogous trajectory is evident along an array of increasingly terrestrial extant ape species

  7. Early modern human diversity suggests subdivided population structure and a complex out-of-Africa scenario

    PubMed Central

    Gunz, Philipp; Bookstein, Fred L.; Mitteroecker, Philipp; Stadlmayr, Andrea; Seidler, Horst; Weber, Gerhard W.

    2009-01-01

    The interpretation of genetic evidence regarding modern human origins depends, among other things, on assessments of the structure and the variation of ancient populations. Because we lack genetic data from the time when the first anatomically modern humans appeared, between 200,000 and 60,000 years ago, instead we exploit the phenotype of neurocranial geometry to compare the variation in early modern human fossils with that in other groups of fossil Homo and recent modern humans. Variation is assessed as the mean-squared Procrustes distance from the group average shape in a representation based on several hundred neurocranial landmarks and semilandmarks. We find that the early modern group has more shape variation than any other group in our sample, which covers 1.8 million years, and that they are morphologically similar to recent modern humans of diverse geographically dispersed populations but not to archaic groups. Of the currently competing models of modern human origins, some are inconsistent with these findings. Rather than a single out-of-Africa dispersal scenario, we suggest that early modern humans were already divided into different populations in Pleistocene Africa, after which there followed a complex migration pattern. Our conclusions bear implications for the inference of ancient human demography from genetic models and emphasize the importance of focusing research on those early modern humans, in particular, in Africa. PMID:19307568

  8. Human fertility, molecular genetics, and natural selection in modern societies.

    PubMed

    Tropf, Felix C; Stulp, Gert; Barban, Nicola; Visscher, Peter M; Yang, Jian; Snieder, Harold; Mills, Melinda C

    2015-01-01

    Research on genetic influences on human fertility outcomes such as number of children ever born (NEB) or the age at first childbirth (AFB) has been solely based on twin and family-designs that suffer from problematic assumptions and practical limitations. The current study exploits recent advances in the field of molecular genetics by applying the genomic-relationship-matrix based restricted maximum likelihood (GREML) methods to quantify for the first time the extent to which common genetic variants influence the NEB and the AFB of women. Using data from the UK and the Netherlands (N = 6,758), results show significant additive genetic effects on both traits explaining 10% (SE = 5) of the variance in the NEB and 15% (SE = 4) in the AFB. We further find a significant negative genetic correlation between AFB and NEB in the pooled sample of -0.62 (SE = 0.27, p-value = 0.02). This finding implies that individuals with genetic predispositions for an earlier AFB had a reproductive advantage and that natural selection operated not only in historical, but also in contemporary populations. The observed postponement in the AFB across the past century in Europe contrasts with these findings, suggesting an evolutionary override by environmental effects and underscoring that evolutionary predictions in modern human societies are not straight forward. It emphasizes the necessity for an integrative research design from the fields of genetics and social sciences in order to understand and predict fertility outcomes. Finally, our results suggest that we may be able to find genetic variants associated with human fertility when conducting GWAS-meta analyses with sufficient sample size.

  9. Interactions of neanderthals and modern humans: what can be inferred from mitochondrial DNA?

    PubMed

    Cyran, Krzysztof A; Kimmel, Marek

    2005-07-01

    This paper reviews the state-of-the-art knowledge concerning the relationship between Neanderthals and Upper Paleolithic modern humans. The branching-process method is applied to infer the upper limit of hypothetical Neanderthal admixture, consistent with the evidence based on mitochon- drial DNA sequences of contemporary modern humans, as well as Neanderthal and early modern European H. sapiens fossils. As a result, a maximum value of 15% admixture is obtained. This estimate is discussed in the context of its consequences for the two competing theories of modern human origin.

  10. Understanding the emergence of modern humans and the disappearance of Neanderthals: Insights from Kaldar Cave (Khorramabad Valley, Western Iran).

    PubMed

    Bazgir, Behrouz; Ollé, Andreu; Tumung, Laxmi; Becerra-Valdivia, Lorena; Douka, Katerina; Higham, Thomas; van der Made, Jan; Picin, Andrea; Saladié, Palmira; López-García, Juan Manuel; Blain, Hugues-Alexandre; Allué, Ethel; Fernández-García, Mónica; Rey-Rodríguez, Iván; Arceredillo, Diego; Bahrololoumi, Faranak; Azimi, Moloudsadat; Otte, Marcel; Carbonell, Eudald

    2017-03-02

    Kaldar Cave is a key archaeological site that provides evidence of the Middle to Upper Palaeolithic transition in Iran. Excavations at the site in 2014-2015 led to the discovery of cultural remains generally associated with anatomically modern humans (AMHs) and evidence of a probable Neanderthal-made industry in the basal layers. Attempts have been made to establish a chronology for the site. These include four thermoluminescence (TL) dates for Layer 4, ranging from 23,100 ± 3300 to 29,400 ± 2300 BP, and three AMS radiocarbon dates from charcoal samples belonging to the lower part of the same layer, yielding ages of 38,650-36,750 cal BP, 44,200-42,350 cal BP, and 54,400-46,050 cal BP (all at the 95.4% confidence level). Kaldar Cave is the first well-stratified Late Palaeolithic locality to be excavated in the Zagros which is one of the earliest sites with cultural materials attributed to early AMHs in western Asia. It also offers an opportunity to study the technological differences between the Mousterian and the first Upper Palaeolithic lithic technologies as well as the human behaviour in the region. In this study, we present a detailed description of the newly excavated stratigraphy, quantified results from the lithic assemblages, preliminary faunal remains analyses, geochronologic data, taphonomic aspects, and an interpretation of the regional paleoenvironment.

  11. The Economic Importance of Human Capital in Modernization.

    ERIC Educational Resources Information Center

    Schultz, Theodore W.

    1993-01-01

    Human capital invests in new forms of physical capital, hence, human capital is key to economic progress. Lists eight attributes of human capital; for example, human capital cannot be separated from person who has it, and human capital is not visible. Human capital is necessary component when attempting to improve a person's income and welfare in…

  12. The derived FOXP2 variant of modern humans was shared with Neandertals.

    PubMed

    Krause, Johannes; Lalueza-Fox, Carles; Orlando, Ludovic; Enard, Wolfgang; Green, Richard E; Burbano, Hernán A; Hublin, Jean-Jacques; Hänni, Catherine; Fortea, Javier; de la Rasilla, Marco; Bertranpetit, Jaume; Rosas, Antonio; Pääbo, Svante

    2007-11-06

    Although many animals communicate vocally, no extant creature rivals modern humans in language ability. Therefore, knowing when and under what evolutionary pressures our capacity for language evolved is of great interest. Here, we find that our closest extinct relatives, the Neandertals, share with modern humans two evolutionary changes in FOXP2, a gene that has been implicated in the development of speech and language. We furthermore find that in Neandertals, these changes lie on the common modern human haplotype, which previously was shown to have been subject to a selective sweep. These results suggest that these genetic changes and the selective sweep predate the common ancestor (which existed about 300,000-400,000 years ago) of modern human and Neandertal populations. This is in contrast to more recent age estimates of the selective sweep based on extant human diversity data. Thus, these results illustrate the usefulness of retrieving direct genetic information from ancient remains for understanding recent human evolution.

  13. Levantine cranium from Manot Cave (Israel) foreshadows the first European modern humans.

    PubMed

    Hershkovitz, Israel; Marder, Ofer; Ayalon, Avner; Bar-Matthews, Miryam; Yasur, Gal; Boaretto, Elisabetta; Caracuta, Valentina; Alex, Bridget; Frumkin, Amos; Goder-Goldberger, Mae; Gunz, Philipp; Holloway, Ralph L; Latimer, Bruce; Lavi, Ron; Matthews, Alan; Slon, Viviane; Mayer, Daniella Bar-Yosef; Berna, Francesco; Bar-Oz, Guy; Yeshurun, Reuven; May, Hila; Hans, Mark G; Weber, Gerhard W; Barzilai, Omry

    2015-04-09

    A key event in human evolution is the expansion of modern humans of African origin across Eurasia between 60 and 40 thousand years (kyr) before present (bp), replacing all other forms of hominins. Owing to the scarcity of human fossils from this period, these ancestors of all present-day non-African modern populations remain largely enigmatic. Here we describe a partial calvaria, recently discovered at Manot Cave (Western Galilee, Israel) and dated to 54.7 ± 5.5 kyr bp (arithmetic mean ± 2 standard deviations) by uranium-thorium dating, that sheds light on this crucial event. The overall shape and discrete morphological features of the Manot 1 calvaria demonstrate that this partial skull is unequivocally modern. It is similar in shape to recent African skulls as well as to European skulls from the Upper Palaeolithic period, but different from most other early anatomically modern humans in the Levant. This suggests that the Manot people could be closely related to the first modern humans who later successfully colonized Europe. Thus, the anatomical features used to support the 'assimilation model' in Europe might not have been inherited from European Neanderthals, but rather from earlier Levantine populations. Moreover, at present, Manot 1 is the only modern human specimen to provide evidence that during the Middle to Upper Palaeolithic interface, both modern humans and Neanderthals contemporaneously inhabited the southern Levant, close in time to the likely interbreeding event with Neanderthals.

  14. Early Modern Humans and Morphological Variation in Southeast Asia: Fossil Evidence from Tam Pa Ling, Laos

    PubMed Central

    Demeter, Fabrice; Shackelford, Laura; Westaway, Kira; Duringer, Philippe; Bacon, Anne-Marie; Ponche, Jean-Luc; Wu, Xiujie; Sayavongkhamdy, Thongsa; Zhao, Jian-Xin; Barnes, Lani; Boyon, Marc; Sichanthongtip, Phonephanh; Sénégas, Frank; Karpoff, Anne-Marie; Patole-Edoumba, Elise; Coppens, Yves; Braga, José

    2015-01-01

    Little is known about the timing of modern human emergence and occupation in Eastern Eurasia. However a rapid migration out of Africa into Southeast Asia by at least 60 ka is supported by archaeological, paleogenetic and paleoanthropological data. Recent discoveries in Laos, a modern human cranium (TPL1) from Tam Pa Ling‘s cave, provided the first evidence for the presence of early modern humans in mainland Southeast Asia by 63-46 ka. In the current study, a complete human mandible representing a second individual, TPL 2, is described using discrete traits and geometric morphometrics with an emphasis on determining its population affinity. The TPL2 mandible has a chin and other discrete traits consistent with early modern humans, but it retains a robust lateral corpus and internal corporal morphology typical of archaic humans across the Old World. The mosaic morphology of TPL2 and the fully modern human morphology of TPL1 suggest that a large range of morphological variation was present in early modern human populations residing in the eastern Eurasia by MIS 3. PMID:25849125

  15. The Humanities Approach to the Modern Secondary School Curriculum.

    ERIC Educational Resources Information Center

    Miller, Bernard S.

    The humanities curriculum described in this book is designed as a multidisciplinary, integrated approach to learning. Chapter 1 discusses a definition of the humanities; the segmented curriculum; student expectations; teacher training and the importance of the faculty; the humanities and the sciences; organizing a humanities program; advantages of…

  16. Early Human Migrations (ca. 13,000 Years Ago) or Postcontact Europeans for the Earliest Spread of Mycobacterium leprae and Mycobacterium lepromatosis to the Americas

    PubMed Central

    2017-01-01

    For over a century, it has been widely accepted that leprosy did not exist in the Americas before the arrival of Europeans. This proposition was based on a combination of historical, paleopathological, and representational studies. Further support came from molecular studies in 2005 and 2009 that four Mycobacterium leprae single-nucleotide polymorphisms (SNPs) and then 16 SNP subtypes correlated with general geographic regions, suggesting the M. leprae subtypes in the Americas were consistent with European strains. Shortly thereafter, a number of studies proposed that leprosy first came to the Americas with human migrations around 12,000 or 13,000 years ago. These studies are based primarily on subsequent molecular data, especially the discovery of a new leprosy species Mycobacterium lepromatosis and its close association with diffuse lepromatous leprosy, a severe, aggressive form of lepromatous leprosy, which is most common in Mexico and the Caribbean Islands. A review of these and subsequent molecular data finds no evidence for either leprosy species in the Americas before the arrival of Europeans, and strains of both species of leprosy found in eastern Mexico, Caribbean Islands, and Brazil came from Europe while strains found in western Mexico are consistent with their arrival via direct voyages from the Philippines. PMID:29250112

  17. Early Human Migrations (ca. 13,000 Years Ago) or Postcontact Europeans for the Earliest Spread of Mycobacterium leprae and Mycobacterium lepromatosis to the Americas.

    PubMed

    Mark, Samuel

    2017-01-01

    For over a century, it has been widely accepted that leprosy did not exist in the Americas before the arrival of Europeans. This proposition was based on a combination of historical, paleopathological, and representational studies. Further support came from molecular studies in 2005 and 2009 that four Mycobacterium leprae single-nucleotide polymorphisms (SNPs) and then 16 SNP subtypes correlated with general geographic regions, suggesting the M. leprae subtypes in the Americas were consistent with European strains. Shortly thereafter, a number of studies proposed that leprosy first came to the Americas with human migrations around 12,000 or 13,000 years ago. These studies are based primarily on subsequent molecular data, especially the discovery of a new leprosy species Mycobacterium lepromatosis and its close association with diffuse lepromatous leprosy, a severe, aggressive form of lepromatous leprosy, which is most common in Mexico and the Caribbean Islands. A review of these and subsequent molecular data finds no evidence for either leprosy species in the Americas before the arrival of Europeans, and strains of both species of leprosy found in eastern Mexico, Caribbean Islands, and Brazil came from Europe while strains found in western Mexico are consistent with their arrival via direct voyages from the Philippines.

  18. Unconstrained cranial evolution in Neandertals and modern humans compared to common chimpanzees

    PubMed Central

    Weaver, Timothy D.; Stringer, Chris B.

    2015-01-01

    A variety of lines of evidence support the idea that neutral evolutionary processes (genetic drift, mutation) have been important in generating cranial differences between Neandertals and modern humans. But how do Neandertals and modern humans compare with other species? And how do these comparisons illuminate the evolutionary processes underlying cranial diversification? To address these questions, we used 27 standard cranial measurements collected on 2524 recent modern humans, 20 Neandertals and 237 common chimpanzees to estimate split times between Neandertals and modern humans, and between Pan troglodytes verus and two other subspecies of common chimpanzee. Consistent with a neutral divergence, the Neandertal versus modern human split-time estimates based on cranial measurements are similar to those based on DNA sequences. By contrast, the common chimpanzee cranial estimates are much lower than DNA-sequence estimates. Apparently, cranial evolution has been unconstrained in Neandertals and modern humans compared with common chimpanzees. Based on these and additional analyses, it appears that cranial differentiation in common chimpanzees has been restricted by stabilizing natural selection. Alternatively, this restriction could be due to genetic and/or developmental constraints on the amount of within-group variance (relative to effective population size) available for genetic drift to act on. PMID:26468243

  19. [Mitochondrial DNA polymorphisms shared between modern humans and neanderthals: adaptive convergence or evidence for interspecific hybridization?].

    PubMed

    Maliarchuk, B A

    2013-09-01

    An analysis of the variability of the nucleotide sequences in the mitochondrial genome of modern humans, neanderthals, Denisovans, and other primates has shown that there are shared polymorphisms at positions 2758 and 7146 between modern Homo sapiens (in phylogenetic cluster L2'3'4'5'6) and Homo neanderthalensis (in the group of European neanderthals younger than 48000 years). It is suggested that the convergence may be due to adaptive changes in the mitochondrial genomes of modern humans and neanderthals or interspecific hybridization associated with mtDNA recombination.

  20. The early Upper Paleolithic human skeleton from the Abrigo do Lagar Velho (Portugal) and modern human emergence in Iberia

    PubMed Central

    Duarte, Cidália; Maurício, João; Pettitt, Paul B.; Souto, Pedro; Trinkaus, Erik; van der Plicht, Hans; Zilhão, João

    1999-01-01

    The discovery of an early Upper Paleolithic human burial at the Abrigo do Lagar Velho, Portugal, has provided evidence of early modern humans from southern Iberia. The remains, the largely complete skeleton of a ≈4-year-old child buried with pierced shell and red ochre, is dated to ca. 24,500 years B.P. The cranium, mandible, dentition, and postcrania present a mosaic of European early modern human and Neandertal features. The temporal bone has an intermediate-sized juxtamastoid eminence. The mandibular mentum osseum and the dental size and proportions, supported by mandibular ramal features, radial tuberosity orientation, and diaphyseal curvature, as well as the pubic proportions align the skeleton with early modern humans. Body proportions, reflected in femorotibial lengths and diaphyseal robusticity plus tibial condylar displacement, as well as mandibular symphyseal retreat and thoracohumeral muscle insertions, align the skeleton with the Neandertals. This morphological mosaic indicates admixture between regional Neandertals and early modern humans dispersing into southern Iberia. It establishes the complexities of the Late Pleistocene emergence of modern humans and refutes strict replacement models of modern human origins. PMID:10377462

  1. A HUMAN FACTORS ENGINEERING PROCESS TO SUPPORT HUMAN-SYSTEM INTERFACE DESIGN IN CONTROL ROOM MODERNIZATION

    SciTech Connect

    Kovesdi, C.; Joe, J.; Boring, R.

    The primary objective of the United States (U.S.) Department of Energy (DOE) Light Water Reactor Sustainability (LWRS) program is to sustain operation of the existing commercial nuclear power plants (NPPs) through a multi-pathway approach in conducting research and development (R&D). The Advanced Instrumentation, Information, and Control (II&C) System Technologies pathway conducts targeted R&D to address aging and reliability concerns with legacy instrumentation and control (I&C) and other information systems in existing U.S. NPPs. Control room modernization is an important part following this pathway, and human factors experts at Idaho National Laboratory (INL) have been involved in conducting R&D to supportmore » migration of new digital main control room (MCR) technologies from legacy analog and legacy digital I&C. This paper describes a human factors engineering (HFE) process that supports human-system interface (HSI) design in MCR modernization activities, particularly with migration of old digital to new digital I&C. The process described in this work is an expansion from the LWRS Report INL/EXT-16-38576, and is a requirements-driven approach that aligns with NUREG-0711 requirements. The work described builds upon the existing literature by adding more detail around key tasks and decisions to make when transitioning from HSI Design into Verification and Validation (V&V). The overall objective of this process is to inform HSI design and elicit specific, measurable, and achievable human factors criteria for new digital technologies. Upon following this process, utilities should have greater confidence with transitioning from HSI design into V&V.« less

  2. The earliest ion channels in protocellular membranes

    NASA Astrophysics Data System (ADS)

    Mijajlovic, Milan; Pohorille, Andrew; Wilson, Michael; Wei, Chenyu

    Cellular membranes with their hydrophobic interior are virtually impermeable to ions. Bulk of ion transport through them is enabled through ion channels. Ion channels of contemporary cells are complex protein molecules which span the membrane creating a cylindrical pore filled with water. Protocells, which are widely regarded as precursors to modern cells, had similarly impermeable membranes, but the set of proteins in their disposal was much simpler and more limited. We have been, therefore, exploring an idea that the first ion channels in protocellular membranes were formed by much smaller peptide molecules that could spontaneously self-assemble into short-lived cylindrical bundles in a membrane. Earlier studies have shown that a group of peptides known as peptaibols is capable of forming ion channels in lipid bilayers when they are exposed to an electric field. Peptaibols are small, non-genetically encoded peptides produced by some fungi as a part of their system of defense against bacteria. They are usually only 14-20 residues long, which is just enough to span the membrane. Their sequence is characterized by the presence of non-standard amino acids which, interestingly, are also expected to have existed on the early earth. In particular, the presence of 2-aminoisobutyric acid (AIB) gives peptaibols strong helix forming propensities. Association of the helices inside membranes leads to the formation of cylindrical bundles, typically containing 4 to 10 monomers. Although peptaibols are excellent candidates for models of the earliest ion channels their struc-tures, which are stabilized only by van der Waals forces and occasional hydrogen bonds between neighboring helices, are not very stable. Although it might properly reflect protobiological real-ity, it is also a major obstacle in studying channel behavior. For this reason we focused on two members of the peptaibol family, trichotoxin and antiamoebin, which are characterized by a single conductance level. This

  3. The Earliest Ion Channels in Protocellular Membranes

    NASA Technical Reports Server (NTRS)

    Mijajlovic, Milan; Pohorille, Andrew; Wilson, Michael; Wei, Chenyu

    2010-01-01

    Cellular membranes with their hydrophobic interior are virtually impermeable to ions. Bulk of ion transport through them is enabled through ion channels. Ion channels of contemporary cells are complex protein molecules which span the membrane creating a cylindrical pore filled with water. Protocells, which are widely regarded as precursors to modern cells, had similarly impermeable membranes, but the set of proteins in their disposal was much simpler and more limited. We have been, therefore, exploring an idea that the first ion channels in protocellular membranes were formed by much smaller peptide molecules that could spontaneously selfassemble into short-lived cylindrical bundles in a membrane. Earlier studies have shown that a group of peptides known as peptaibols is capable of forming ion channels in lipid bilayers when they are exposed to an electric field. Peptaibols are small, non-genetically encoded peptides produced by some fungi as a part of their system of defense against bacteria. They are usually only 14-20 residues long, which is just enough to span the membrane. Their sequence is characterized by the presence of non-standard amino acids which, interestingly, are also expected to have existed on the early earth. In particular, the presence of 2-aminoisobutyric acid (AIB) gives peptaibols strong helix forming propensities. Association of the helices inside membranes leads to the formation of cylindrical bundles, typically containing 4 to 10 monomers. Although peptaibols are excellent candidates for models of the earliest ion channels their structures, which are stabilized only by van der Waals forces and occasional hydrogen bonds between neighboring helices, are not very stable. Although it might properly reflect protobiological reality, it is also a major obstacle in studying channel behavior. For this reason we focused on two members of the peptaibol family, trichotoxin and antiamoebin, which are characterized by a single conductance level. This

  4. The place of human psychophysics in modern neuroscience.

    PubMed

    Read, J C A

    2015-06-18

    Human psychophysics is the quantitative measurement of our own perceptions. In essence, it is simply a more sophisticated version of what humans have done since time immemorial: noticed and reflected upon what we can see, hear, and feel. In the 21st century, when hugely powerful techniques are available that enable us to probe the innermost structure and function of nervous systems, is human psychophysics still relevant? I argue that it is, and that in combination with other techniques, it will continue to be a key part of neuroscience for the foreseeable future. I discuss these points in detail using the example of binocular stereopsis, where human psychophysics in combination with physiology and computational vision, has made a substantial contribution. Copyright © 2014 The Author. Published by Elsevier Ltd.. All rights reserved.

  5. Human prehistory: Hunting for the earliest farmers.

    PubMed

    Rowley-Conwy, Peter

    2009-11-03

    The degree to which the spread of farming into Europe was accompanied by demographic shifts is subject to intense debate. Genetic evidence from Europe's first farmers and their hunter-gatherer counterparts now suggests an important role for the immigration of farmers.

  6. Understanding the emergence of modern humans and the disappearance of Neanderthals: Insights from Kaldar Cave (Khorramabad Valley, Western Iran)

    PubMed Central

    Bazgir, Behrouz; Ollé, Andreu; Tumung, Laxmi; Becerra-Valdivia, Lorena; Douka, Katerina; Higham, Thomas; van der Made, Jan; Picin, Andrea; Saladié, Palmira; López-García, Juan Manuel; Blain, Hugues-Alexandre; Allué, Ethel; Fernández-García, Mónica; Rey-Rodríguez, Iván; Arceredillo, Diego; Bahrololoumi, Faranak; Azimi, Moloudsadat; Otte, Marcel; Carbonell, Eudald

    2017-01-01

    Kaldar Cave is a key archaeological site that provides evidence of the Middle to Upper Palaeolithic transition in Iran. Excavations at the site in 2014–2015 led to the discovery of cultural remains generally associated with anatomically modern humans (AMHs) and evidence of a probable Neanderthal-made industry in the basal layers. Attempts have been made to establish a chronology for the site. These include four thermoluminescence (TL) dates for Layer 4, ranging from 23,100 ± 3300 to 29,400 ± 2300 BP, and three AMS radiocarbon dates from charcoal samples belonging to the lower part of the same layer, yielding ages of 38,650–36,750 cal BP, 44,200–42,350 cal BP, and 54,400–46,050 cal BP (all at the 95.4% confidence level). Kaldar Cave is the first well-stratified Late Palaeolithic locality to be excavated in the Zagros which is one of the earliest sites with cultural materials attributed to early AMHs in western Asia. It also offers an opportunity to study the technological differences between the Mousterian and the first Upper Palaeolithic lithic technologies as well as the human behaviour in the region. In this study, we present a detailed description of the newly excavated stratigraphy, quantified results from the lithic assemblages, preliminary faunal remains analyses, geochronologic data, taphonomic aspects, and an interpretation of the regional paleoenvironment. PMID:28252042

  7. The Role of Genetic Drift in Shaping Modern Human Cranial Evolution: A Test Using Microevolutionary Modeling

    PubMed Central

    Smith, Heather F.

    2011-01-01

    The means by which various microevolutionary processes have acted in the past to produce patterns of cranial variation that characterize modern humans is not thoroughly understood. Applying a microevolutionary framework, within- and among-population variance/covariance (V/CV) structure was compared for several functional and developmental modules of the skull across a worldwide sample of modern humans. V/CV patterns in the basicranium, temporal bone, and face are proportional within and among groups, which is consistent with a hypothesis of neutral evolution; however, mandibular morphology deviated from this pattern. Degree of intergroup similarity in facial, temporal bone, and mandibular morphology is significantly correlated with geographic distance; however, much of the variance remains unexplained. These findings provide insight into the evolutionary history of modern human cranial variation by identifying signatures of genetic drift, gene flow, and migration and set the stage for inferences regarding selective pressures that early humans encountered since their initial migrations around the world. PMID:21461369

  8. Origin of Clothing Lice Indicates Early Clothing Use by Anatomically Modern Humans in Africa

    PubMed Central

    Toups, Melissa A.; Kitchen, Andrew; Light, Jessica E.; Reed, David L.

    2011-01-01

    Clothing use is an important modern behavior that contributed to the successful expansion of humans into higher latitudes and cold climates. Previous research suggests that clothing use originated anywhere between 40,000 and 3 Ma, though there is little direct archaeological, fossil, or genetic evidence to support more specific estimates. Since clothing lice evolved from head louse ancestors once humans adopted clothing, dating the emergence of clothing lice may provide more specific estimates of the origin of clothing use. Here, we use a Bayesian coalescent modeling approach to estimate that clothing lice diverged from head louse ancestors at least by 83,000 and possibly as early as 170,000 years ago. Our analysis suggests that the use of clothing likely originated with anatomically modern humans in Africa and reinforces a broad trend of modern human developments in Africa during the Middle to Late Pleistocene. PMID:20823373

  9. The Oldest Anatomically Modern Humans from Far Southeast Europe: Direct Dating, Culture and Behavior

    PubMed Central

    Prat, Sandrine; Péan, Stéphane C.; Crépin, Laurent; Drucker, Dorothée G.; Puaud, Simon J.; Valladas, Hélène; Lázničková-Galetová, Martina; van der Plicht, Johannes; Yanevich, Alexander

    2011-01-01

    Background Anatomically Modern Humans (AMHs) are known to have spread across Europe during the period coinciding with the Middle to Upper Paleolithic transition. Whereas their dispersal into Western Europe is relatively well established, evidence of an early settlement of Eastern Europe by modern humans are comparatively scarce. Methodology/Principal Finding Based on a multidisciplinary approach for the study of human and faunal remains, we describe here the oldest AMH remains from the extreme southeast Europe, in conjunction with their associated cultural and paleoecological background. We applied taxonomy, paleoecology, and taphonomy combined with geomorphology, stratigraphy, archeology and radiocarbon dating. More than 160 human bone remains have been discovered. They originate from a well documented Upper Paleolithic archeological layer (Gravettian cultural tradition) from the site of Buran-Kaya III located in Crimea (Ukraine). The combination of non-metric dental traits and the morphology of the occipital bones allow us to attribute the human remains to Anatomically Modern Humans. A set of human and faunal remains from this layer has been radiocarbon dated by Accelerator Mass Spectrometry. The direct-dating results of human bone establish a secure presence of AMHs at 31,900+240/−220 BP in this region. They are the oldest direct evidence of the presence of AMHs in a well documented archeological context. Based on taphonomical observations (cut marks and distribution of skeletal elements), they represent the oldest Upper Paleolithic modern humans from Eastern Europe, showing post-mortem treatment of the dead as well. Conclusion/Significance These findings are essential for the debate on the spread of modern humans in Europe during the Upper Paleolithic, as well as their cultural behaviors. PMID:21698105

  10. The oldest anatomically modern humans from far southeast Europe: direct dating, culture and behavior.

    PubMed

    Prat, Sandrine; Péan, Stéphane C; Crépin, Laurent; Drucker, Dorothée G; Puaud, Simon J; Valladas, Hélène; Lázničková-Galetová, Martina; van der Plicht, Johannes; Yanevich, Alexander

    2011-01-01

    Anatomically Modern Humans (AMHs) are known to have spread across Europe during the period coinciding with the Middle to Upper Paleolithic transition. Whereas their dispersal into Western Europe is relatively well established, evidence of an early settlement of Eastern Europe by modern humans are comparatively scarce. Based on a multidisciplinary approach for the study of human and faunal remains, we describe here the oldest AMH remains from the extreme southeast Europe, in conjunction with their associated cultural and paleoecological background. We applied taxonomy, paleoecology, and taphonomy combined with geomorphology, stratigraphy, archeology and radiocarbon dating. More than 160 human bone remains have been discovered. They originate from a well documented Upper Paleolithic archeological layer (Gravettian cultural tradition) from the site of Buran-Kaya III located in Crimea (Ukraine). The combination of non-metric dental traits and the morphology of the occipital bones allow us to attribute the human remains to Anatomically Modern Humans. A set of human and faunal remains from this layer has been radiocarbon dated by Accelerator Mass Spectrometry. The direct-dating results of human bone establish a secure presence of AMHs at 31,900+240/-220 BP in this region. They are the oldest direct evidence of the presence of AMHs in a well documented archeological context. Based on taphonomical observations (cut marks and distribution of skeletal elements), they represent the oldest Upper Paleolithic modern humans from Eastern Europe, showing post-mortem treatment of the dead as well. These findings are essential for the debate on the spread of modern humans in Europe during the Upper Paleolithic, as well as their cultural behaviors.

  11. The late Pleistocene dispersal of modern humans in the Americas.

    PubMed

    Goebel, Ted; Waters, Michael R; O'Rourke, Dennis H

    2008-03-14

    When did humans colonize the Americas? From where did they come and what routes did they take? These questions have gripped scientists for decades, but until recently answers have proven difficult to find. Current genetic evidence implies dispersal from a single Siberian population toward the Bering Land Bridge no earlier than about 30,000 years ago (and possibly after 22,000 years ago), then migration from Beringia to the Americas sometime after 16,500 years ago. The archaeological records of Siberia and Beringia generally support these findings, as do archaeological sites in North and South America dating to as early as 15,000 years ago. If this is the time of colonization, geological data from western Canada suggest that humans dispersed along the recently deglaciated Pacific coastline.

  12. Genotypic analysis of the earliest known prehistoric case of tuberculosis in Britain.

    PubMed

    Taylor, G Michael; Young, Douglas B; Mays, Simon A

    2005-05-01

    The earliest known case of human tuberculosis in Britain dates to the middle period of the Iron Age, approximately 2,200 years before present. Bone lesions on the spine of a male skeleton excavated at Tarrant Hinton in Dorset, United Kingdom, show evidence of Pott's disease and are supported by molecular evidence of Mycobacterium tuberculosis complex DNA amplified by IS6110 PCR (19). In the present study, we used a further series of sensitive PCR methods to confirm the diagnosis of tuberculosis and to determine the genotype of the infecting strain. These tests demonstrated that this individual was infected with a strain of M. tuberculosis rather than Mycobacterium bovis. The strain had undergone the tuberculosis D1 deletion affecting the mmpS6 and mmpL6 genes and can therefore be identified as a member of the family of "modern" M. tuberculosis isolates. All evidence obtained was consistent with surviving mycobacterial DNA being highly fragmented in this case.

  13. Using the Neandertal genome to study the evolution of small insertions and deletions in modern humans.

    PubMed

    Chintalapati, Manjusha; Dannemann, Michael; Prüfer, Kay

    2017-08-04

    Small insertions and deletions occur in humans at a lower rate compared to nucleotide changes, but evolve under more constraint than nucleotide changes. While the evolution of insertions and deletions have been investigated using ape outgroups, the now available genome of a Neandertal can shed light on the evolution of indels in more recent times. We used the Neandertal genome together with several primate outgroup genomes to differentiate between human insertion/deletion changes that likely occurred before the split from Neandertals and those that likely arose later. Changes that pre-date the split from Neandertals show a smaller proportion of deletions than those that occurred later. The presence of a Neandertal-shared allele in Europeans or Asians but the absence in Africans was used to detect putatively introgressed indels in Europeans and Asians. A larger proportion of these variants reside in intergenic regions compared to other modern human variants, and some variants are linked to SNPs that have been associated with traits in modern humans. Our results are in agreement with earlier results that suggested that deletions evolve under more constraint than insertions. When considering Neandertal introgressed variants, we find some evidence that negative selection affected these variants more than other variants segregating in modern humans. Among introgressed variants we also identify indels that may influence the phenotype of their carriers. In particular an introgressed deletion associated with a decrease in the time to menarche may constitute an example of a former Neandertal-specific trait contributing to modern human phenotypic diversity.

  14. Genetic analysis of lice supports direct contact between modern and archaic humans.

    PubMed

    Reed, David L; Smith, Vincent S; Hammond, Shaless L; Rogers, Alan R; Clayton, Dale H

    2004-11-01

    Parasites can be used as unique markers to investigate host evolutionary history, independent of host data. Here we show that modern human head lice, Pediculus humanus, are composed of two ancient lineages, whose origin predates modern Homo sapiens by an order of magnitude (ca. 1.18 million years). One of the two louse lineages has a worldwide distribution and appears to have undergone a population bottleneck ca. 100,000 years ago along with its modern H. sapiens host. Phylogenetic and population genetic data suggest that the other lineage, found only in the New World, has remained isolated from the worldwide lineage for the last 1.18 million years. The ancient divergence between these two lice is contemporaneous with splits among early species of Homo, and cospeciation analyses suggest that the two louse lineages codiverged with a now extinct species of Homo and the lineage leading to modern H. sapiens. If these lice indeed codiverged with their hosts ca. 1.18 million years ago, then a recent host switch from an archaic species of Homo to modern H. sapiens is required to explain the occurrence of both lineages on modern H. sapiens. Such a host switch would require direct physical contact between modern and archaic forms of Homo.

  15. Genetic Analysis of Lice Supports Direct Contact between Modern and Archaic Humans

    PubMed Central

    Smith, Vincent S; Hammond, Shaless L; Rogers, Alan R; Clayton, Dale H

    2004-01-01

    Parasites can be used as unique markers to investigate host evolutionary history, independent of host data. Here we show that modern human head lice, Pediculus humanus, are composed of two ancient lineages, whose origin predates modern Homo sapiens by an order of magnitude (ca. 1.18 million years). One of the two louse lineages has a worldwide distribution and appears to have undergone a population bottleneck ca. 100,000 years ago along with its modern H. sapiens host. Phylogenetic and population genetic data suggest that the other lineage, found only in the New World, has remained isolated from the worldwide lineage for the last 1.18 million years. The ancient divergence between these two lice is contemporaneous with splits among early species of Homo, and cospeciation analyses suggest that the two louse lineages codiverged with a now extinct species of Homo and the lineage leading to modern H. sapiens. If these lice indeed codiverged with their hosts ca. 1.18 million years ago, then a recent host switch from an archaic species of Homo to modern H. sapiens is required to explain the occurrence of both lineages on modern H. sapiens. Such a host switch would require direct physical contact between modern and archaic forms of Homo. PMID:15502871

  16. Early Upper Paleolithic in Eastern Europe and implications for the dispersal of modern humans.

    PubMed

    Anikovich, M V; Sinitsyn, A A; Hoffecker, John F; Holliday, Vance T; Popov, V V; Lisitsyn, S N; Forman, Steven L; Levkovskaya, G M; Pospelova, G A; Kuz'mina, I E; Burova, N D; Goldberg, Paul; Macphail, Richard I; Giaccio, Biagio; Praslov, N D

    2007-01-12

    Radiocarbon and optically stimulated luminescence dating and magnetic stratigraphy indicate Upper Paleolithic occupation-probably representing modern humans-at archaeological sites on the Don River in Russia 45,000 to 42,000 years ago. The oldest levels at Kostenki underlie a volcanic ash horizon identified as the Campanian Ignimbrite Y5 tephra that is dated elsewhere to about 40,000 years ago. The occupation layers contain bone and ivory artifacts, including possible figurative art, and fossil shells imported more than 500 kilometers. Thus, modern humans appeared on the central plain of Eastern Europe as early as anywhere else in northern Eurasia.

  17. Tracking modern human population history from linguistic and cranial phenotype

    PubMed Central

    Reyes-Centeno, Hugo; Harvati, Katerina; Jäger, Gerhard

    2016-01-01

    Languages and genes arguably follow parallel evolutionary trajectories, descending from a common source and subsequently differentiating. However, although common ancestry is established within language families, it remains controversial whether language preserves a deep historical signal. To address this question, we evaluate the association between linguistic and geographic distances across 265 language families, as well as between linguistic, geographic, and cranial distances among eleven populations from Africa, Asia, and Australia. We take advantage of differential population history signals reflected by human cranial anatomy, where temporal bone shape reliably tracks deep population history and neutral genetic changes, while facial shape is more strongly associated with recent environmental effects. We show that linguistic distances are strongly geographically patterned, even within widely dispersed groups. However, they are correlated predominantly with facial, rather than temporal bone, morphology, suggesting that variation in vocabulary likely tracks relatively recent events and possibly population contact. PMID:27833101

  18. Ecocultural range-expansion scenarios for the replacement or assimilation of Neanderthals by modern humans.

    PubMed

    Wakano, Joe Yuichiro; Gilpin, William; Kadowaki, Seiji; Feldman, Marcus W; Aoki, Kenichi

    2018-02-01

    Recent archaeological records no longer support a simple dichotomous characterization of the cultures/behaviors of Neanderthals and modern humans, but indicate much cultural/behavioral variability over time and space. Thus, in modeling the replacement or assimilation of Neanderthals by modern humans, it is of interest to consider cultural dynamics and their relation to demographic change. The ecocultural framework for the competition between hominid species allows their carrying capacities to depend on some measure of the levels of culture they possess. In the present study both population densities and the densities of skilled individuals in Neanderthals and modern humans are spatially distributed and subject to change by spatial diffusion, ecological competition, and cultural transmission within each species. We analyze the resulting range expansions in terms of the demographic, ecological and cultural parameters that determine how the carrying capacities relate to the local densities of skilled individuals in each species. Of special interest is the case of cognitive and intrinsic-demographic equivalence of the two species. The range expansion dynamics may consist of multiple wave fronts of different speeds, each of which originates from a traveling wave solution. Properties of these traveling wave solutions are mathematically derived. Depending on the parameters, these traveling waves can result in replacement of Neanderthals by modern humans, or assimilation of the former by the latter. In both the replacement and assimilation scenarios, the first wave of intrusive modern humans is characterized by a low population density and a low density of skilled individuals, with implications for archaeological visibility. The first invasion is due to weak interspecific competition. A second wave of invasion may be induced by cultural differences between moderns and Neanderthals. Spatially and temporally extended coexistence of the two species, which would have

  19. Do Modern Forms of Human Capital Matter in Primitive Economies? Comparative Evidence from Bolivia

    ERIC Educational Resources Information Center

    Godoy, R.; Karlan, D.S.; Rabindran, S.; Huanca, T

    2005-01-01

    We examine the correlation between modern human capital and income among adult men in four foraging-horticultural societies of Bolivia. Despite their remote location, we find results similar to those found in developed nations. We find that: (a) education correlates with 4.5% higher overall income and with 5.9% higher wages and math skills…

  20. The modernizing bias of human rights: stories of mass killings and genocide in Central America.

    PubMed

    Ekern, Stener

    2010-01-01

    This article analyses selected cases of mass killings and genocide during the civil wars in El Salvador and Guatemala in the 1980s and the way in which the truth commissions in both countries reframed locally grounded narratives to fit the state-centred language of human rights. Redefining wrongdoings as human rights violations produces stories that communicate poorly with local worldviews because the 'truths' that human rights language proposes disregard local realities and transform local conflicts into a type of 'modern', nationwide struggles. Thus, while the concept of genocide might capture well the horrendous nature of a mass killing, it will also ethnify the conflict. Comparisons between local readings and human rights-based reinterpretations reveal a 'modernizing' or 'Westernizing' bias of international law; the article argues for more awareness about such effects in analysis as well as in policy-making.

  1. Facial Morphogenesis of the Earliest Europeans

    PubMed Central

    Lacruz, Rodrigo S.; de Castro, José María Bermúdez; Martinón-Torres, María; O’Higgins, Paul; Paine, Michael L.; Carbonell, Eudald; Arsuaga, Juan Luis; Bromage, Timothy G.

    2013-01-01

    The modern human face differs from that of our early ancestors in that the facial profile is relatively retracted (orthognathic). This change in facial profile is associated with a characteristic spatial distribution of bone deposition and resorption: growth remodeling. For humans, surface resorption commonly dominates on anteriorly-facing areas of the subnasal region of the maxilla and mandible during development. We mapped the distribution of facial growth remodeling activities on the 900–800 ky maxilla ATD6-69 assigned to H. antecessor, and on the 1.5 My cranium KNM-WT 15000, part of an associated skeleton assigned to African H. erectus. We show that, as in H. sapiens, H. antecessor shows bone resorption over most of the subnasal region. This pattern contrasts with that seen in KNM-WT 15000 where evidence of bone deposition, not resorption, was identified. KNM-WT 15000 is similar to Australopithecus and the extant African apes in this localized area of bone deposition. These new data point to diversity of patterns of facial growth in fossil Homo. The similarities in facial growth in H. antecessor and H. sapiens suggest that one key developmental change responsible for the characteristic facial morphology of modern humans can be traced back at least to H. antecessor. PMID:23762314

  2. Laetoli footprints reveal bipedal gait biomechanics different from those of modern humans and chimpanzees

    PubMed Central

    Demes, Brigitte; Richmond, Brian G.

    2016-01-01

    Bipedalism is a key adaptation that shaped human evolution, yet the timing and nature of its evolution remain unclear. Here we use new experimentally based approaches to investigate the locomotor mechanics preserved by the famous Pliocene hominin footprints from Laetoli, Tanzania. We conducted footprint formation experiments with habitually barefoot humans and with chimpanzees to quantitatively compare their footprints to those preserved at Laetoli. Our results show that the Laetoli footprints are morphologically distinct from those of both chimpanzees and habitually barefoot modern humans. By analysing biomechanical data that were collected during the human experiments we, for the first time, directly link differences between the Laetoli and modern human footprints to specific biomechanical variables. We find that the Laetoli hominin probably used a more flexed limb posture at foot strike than modern humans when walking bipedally. The Laetoli footprints provide a clear snapshot of an early hominin bipedal gait that probably involved a limb posture that was slightly but significantly different from our own, and these data support the hypothesis that important evolutionary changes to hominin bipedalism occurred within the past 3.66 Myr. PMID:27488647

  3. Calcaneus length determines running economy: implications for endurance running performance in modern humans and Neandertals.

    PubMed

    Raichlen, David A; Armstrong, Hunter; Lieberman, Daniel E

    2011-03-01

    The endurance running (ER) hypothesis suggests that distance running played an important role in the evolution of the genus Homo. Most researchers have focused on ER performance in modern humans, or on reconstructing ER performance in Homo erectus, however, few studies have examined ER capabilities in other members of the genus Homo. Here, we examine skeletal correlates of ER performance in modern humans in order to evaluate the energetics of running in Neandertals and early Homo sapiens. Recent research suggests that running economy (the energy cost of running at a given speed) is strongly related to the length of the Achilles tendon moment arm. Shorter moment arms allow for greater storage and release of elastic strain energy, reducing energy costs. Here, we show that a skeletal correlate of Achilles tendon moment arm length, the length of the calcaneal tuber, does not correlate with walking economy, but correlates significantly with running economy and explains a high proportion of the variance (80%) in cost between individuals. Neandertals had relatively longer calcaneal tubers than modern humans, which would have increased their energy costs of running. Calcaneal tuber lengths in early H. sapiens do not significantly differ from those of extant modern humans, suggesting Neandertal ER economy was reduced relative to contemporaneous anatomically modern humans. Endurance running is generally thought to be beneficial for gaining access to meat in hot environments, where hominins could have used pursuit hunting to run prey taxa into hyperthermia. We hypothesize that ER performance may have been reduced in Neandertals because they lived in cold climates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Enamel thickness variation of deciduous first and second upper molars in modern humans and Neanderthals.

    PubMed

    Fornai, Cinzia; Benazzi, Stefano; Svoboda, Jiří; Pap, Ildikó; Harvati, Katerina; Weber, Gerhard W

    2014-11-01

    Enamel thickness and dental tissue proportions have been recognized as effective taxonomic discriminators between Neanderthal and modern humans teeth. However, most of the research on this topic focused on permanent teeth, and little information is available for the deciduous dentition. Moreover, although worn teeth are more frequently found than unworn teeth, published data for worn teeth are scarce and methods for the assessment of their enamel thickness need to be developed. Here, we addressed this issue by studying the 2D average enamel thickness (AET) and 2D relative enamel thickness (RET) of Neanderthal and modern humans unworn to moderately worn upper first deciduous molars (dm(1)s) and upper second deciduous molars (dm(2)s). In particular, we used 3D μCT data to investigate the mesial section for dm(1)s and both mesial and buccal sections for dm(2)s. Our results confirmed previous findings of an Neanderthal derived condition of thin enamel, and thinner enamel in dm(1)s than dm(2)s in both Neanderthal and modern humans. We demonstrated that the Neanderthal 2D RET indices are significantly lower than those of modern humans at similar wear stages in both dm(1)s and dm(2)s (p < 0.05). The discriminant analysis showed that using 2D RET from dm(1) and dm(2) sections at different wear stages up to 93% of the individuals are correctly classified. Moreover, we showed that the dm(2) buccal sections, although non-conventionally used, might have an advantage on mesial sections since they distinguish as well as mesial sections but tend to be less worn. Therefore, the 2D analysis of enamel thickness is suggested as a means for taxonomic discrimination between modern humans and Neanderthal unworn to moderately worn upper deciduous molars. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Sutural growth restriction and modern human facial evolution: an experimental study in a pig model

    PubMed Central

    Holton, Nathan E; Franciscus, Robert G; Nieves, Mary Ann; Marshall, Steven D; Reimer, Steven B; Southard, Thomas E; Keller, John C; Maddux, Scott D

    2010-01-01

    Facial size reduction and facial retraction are key features that distinguish modern humans from archaic Homo. In order to more fully understand the emergence of modern human craniofacial form, it is necessary to understand the underlying evolutionary basis for these defining characteristics. Although it is well established that the cranial base exerts considerable influence on the evolutionary and ontogenetic development of facial form, less emphasis has been placed on developmental factors intrinsic to the facial skeleton proper. The present analysis was designed to assess anteroposterior facial reduction in a pig model and to examine the potential role that this dynamic has played in the evolution of modern human facial form. Ten female sibship cohorts, each consisting of three individuals, were allocated to one of three groups. In the experimental group (n = 10), microplates were affixed bilaterally across the zygomaticomaxillary and frontonasomaxillary sutures at 2 months of age. The sham group (n = 10) received only screw implantation and the controls (n = 10) underwent no surgery. Following 4 months of post-surgical growth, we assessed variation in facial form using linear measurements and principal components analysis of Procrustes scaled landmarks. There were no differences between the control and sham groups; however, the experimental group exhibited a highly significant reduction in facial projection and overall size. These changes were associated with significant differences in the infraorbital region of the experimental group including the presence of an infraorbital depression and an inferiorly and coronally oriented infraorbital plane in contrast to a flat, superiorly and sagittally infraorbital plane in the control and sham groups. These altered configurations are markedly similar to important additional facial features that differentiate modern humans from archaic Homo, and suggest that facial length restriction via rigid plate fixation is a

  6. Rapid morphological change in living humans: implications for modern human origins.

    PubMed

    Bogin, Barry; Rios, Luis

    2003-09-01

    Human body size and body proportions are interpreted as markers of ethnicity, 'race,' adaptation to temperature, nutritional history and socioeconomic status. Some studies emphasize only one of these indicators and other studies consider combinations of indicators. To better understand the biocultural nature of human size and proportions a new study of the growth of Maya-American youngsters was undertaken in 1999 and 2000. One purpose of this research is to assess changes in body proportion between Maya growing up in the US and Maya growing up in Guatemala. Height and sitting height of 6-12-year-old boys and girls (n=360) were measured and the sitting height ratio [sitting height/height]x100, a measure of proportion, was calculated. These data are compared with a sample of Maya of the same ages living in Guatemala and measured in 1998 (n=1297). Maya-American children are currently 10.24 cm taller, on average, and have a significantly lower sitting height ratio, (i.e. relatively longer legs, averaging 7.02 cm longer) than the Guatemala Maya. Maya-American children have body proportions more like those of white children in the US than like Maya children in Guatemala. Improvements in the environment for growth, in terms of nutrition and health, seem to explain both the trends in greater stature and relatively longer legs for the Maya-Americans. These findings are applied to the problem of modern human origins as assessed from fossil skeletons. It has been proposed that heat adapted, relatively long-legged Homo sapiens from Africa replaced the cold adapted, relatively short-legged Homo neandertalensis of the Levant and Europe [J Hum Evol 32 (1997a) 423]. Skeletal samples of Maya adults from rural Guatemala have body proportions similar to adult Neandertals and to skeletal samples from Europe with evidence of nutritional and disease stress. Just as nutrition and health status explains the differences in the body proportions of living Maya children, these factors, along

  7. Genetic and archaeological perspectives on the initial modern human colonization of southern Asia.

    PubMed

    Mellars, Paul; Gori, Kevin C; Carr, Martin; Soares, Pedro A; Richards, Martin B

    2013-06-25

    It has been argued recently that the initial dispersal of anatomically modern humans from Africa to southern Asia occurred before the volcanic "supereruption" of the Mount Toba volcano (Sumatra) at ∼74,000 y before present (B.P.)-possibly as early as 120,000 y B.P. We show here that this "pre-Toba" dispersal model is in serious conflict with both the most recent genetic evidence from both Africa and Asia and the archaeological evidence from South Asian sites. We present an alternative model based on a combination of genetic analyses and recent archaeological evidence from South Asia and Africa. These data support a coastally oriented dispersal of modern humans from eastern Africa to southern Asia ∼60-50 thousand years ago (ka). This was associated with distinctively African microlithic and "backed-segment" technologies analogous to the African "Howiesons Poort" and related technologies, together with a range of distinctively "modern" cultural and symbolic features (highly shaped bone tools, personal ornaments, abstract artistic motifs, microblade technology, etc.), similar to those that accompanied the replacement of "archaic" Neanderthal by anatomically modern human populations in other regions of western Eurasia at a broadly similar date.

  8. The Driving Forces of Cultural Complexity : Neanderthals, Modern Humans, and the Question of Population Size.

    PubMed

    Fogarty, Laurel; Wakano, Joe Yuichiro; Feldman, Marcus W; Aoki, Kenichi

    2017-03-01

    The forces driving cultural accumulation in human populations, both modern and ancient, are hotly debated. Did genetic, demographic, or cognitive features of behaviorally modern humans (as opposed to, say, early modern humans or Neanderthals) allow culture to accumulate to its current, unprecedented levels of complexity? Theoretical explanations for patterns of accumulation often invoke demographic factors such as population size or density, whereas statistical analyses of variation in cultural complexity often point to the importance of environmental factors such as food stability, in determining cultural complexity. Here we use both an analytical model and an agent-based simulation model to show that a full understanding of the emergence of behavioral modernity, and the cultural evolution that has followed, depends on understanding and untangling the complex relationships among culture, genetically determined cognitive ability, and demographic history. For example, we show that a small but growing population could have a different number of cultural traits from a shrinking population with the same absolute number of individuals in some circumstances.

  9. Earliest English Definitions of Anaisthesia and Anaesthesia.

    PubMed

    Haridas, Rajesh P

    2017-11-01

    The earliest identified English definition of the word anaisthesia was discovered in the first edition (1684) of A Physical Dictionary, an English translation of Steven Blankaart's medical dictionary, Lexicon Medicum Graeco-Latinum. This definition was almost certainly the source of the definition of anaesthesia which appeared in Dictionarium Anglo-Britannicum (1708), a general-purpose English dictionary compiled by the lexicographer John Kersey. The words anaisthesia and anaesthesia have not been identified in English medical or surgical publications that antedate the earliest English dictionaries in which they are known to have been defined.

  10. Brain, calvarium, cladistics: A new approach to an old question, who are modern humans and Neandertals?

    PubMed

    Mounier, Aurélien; Balzeau, Antoine; Caparros, Miguel; Grimaud-Hervé, Dominique

    2016-03-01

    The evolutionary history of the genus Homo is the focus of major research efforts in palaeoanthropology. However, the use of palaeoneurology to infer phylogenies of our genus is rare. Here we use cladistics to test the importance of the brain in differentiating and defining Neandertals and modern humans. The analysis is based on morphological data from the calvarium and endocast of Pleistocene fossils and results in a single most parsimonious cladogram. We demonstrate that the joint use of endocranial and calvarial features with cladistics provides a unique means to understand the evolution of the genus Homo. The main results of this study indicate that: (i) the endocranial features are more phylogenetically informative than the characters from the calvarium; (ii) the specific differentiation of Neandertals and modern humans is mostly supported by well-known calvarial autapomorphies; (iii) the endocranial anatomy of modern humans and Neandertals show strong similarities, which appeared in the fossil record with the last common ancestor of both species; and (iv) apart from encephalisation, human endocranial anatomy changed tremendously during the end of the Middle Pleistocene. This may be linked to major cultural and technological novelties that had happened by the end of the Middle Pleistocene (e.g., expansion of the Middle Stone Age (MSA) in Africa and Mousterian in Europe). The combined study of endocranial and exocranial anatomy offers opportunities to further understand human evolution and the implication for the phylogeny of our genus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A HUMAN FACTORS META MODEL FOR U.S. NUCLEAR POWER PLANT CONTROL ROOM MODERNIZATION

    SciTech Connect

    Joe, Jeffrey C.

    Over the last several years, the United States (U.S.) Department of Energy (DOE) has sponsored human factors research and development (R&D) and human factors engineering (HFE) activities through its Light Water Reactor Sustainability (LWRS) program to modernize the main control rooms (MCR) of commercial nuclear power plants (NPP). Idaho National Laboratory (INL), in partnership with numerous commercial nuclear utilities, has conducted some of this R&D to enable the life extension of NPPs (i.e., provide the technical basis for the long-term reliability, productivity, safety, and security of U.S. NPPs). From these activities performed to date, a human factors meta model formore » U.S. NPP control room modernization can now be formulated. This paper discusses this emergent HFE meta model for NPP control room modernization, with the goal of providing an integrated high level roadmap and guidance on how to perform human factors R&D and HFE for those in the U.S. nuclear industry that are engaging in the process of upgrading their MCRs.« less

  13. Docosahexaenoic acid (DHA): an ancient nutrient for the modern human brain.

    PubMed

    Bradbury, Joanne

    2011-05-01

    Modern humans have evolved with a staple source of preformed docosahexaenoic acid (DHA) in the diet. An important turning point in human evolution was the discovery of high-quality, easily digested nutrients from coastal seafood and inland freshwater sources. Multi-generational exploitation of seafood by shore-based dwellers coincided with the rapid expansion of grey matter in the cerebral cortex, which characterizes the modern human brain. The DHA molecule has unique structural properties that appear to provide optimal conditions for a wide range of cell membrane functions. This has particular implications for grey matter, which is membrane-rich tissue. An important metabolic role for DHA has recently been identified as the precursor for resolvins and protectins. The rudimentary source of DHA is marine algae; therefore it is found concentrated in fish and marine oils. Unlike the photosynthetic cells in algae and higher plants, mammalian cells lack the specific enzymes required for the de novo synthesis of alpha-linolenic acid (ALA), the precursor for all omega-3 fatty acid syntheses. Endogenous synthesis of DHA from ALA in humans is much lower and more limited than previously assumed. The excessive consumption of omega-6 fatty acids in the modern Western diet further displaces DHA from membrane phospholipids. An emerging body of research is exploring a unique role for DHA in neurodevelopment and the prevention of neuropsychiatric and neurodegenerative disorders. DHA is increasingly being added back into the food supply as fish oil or algal oil supplementation.

  14. Docosahexaenoic Acid (DHA): An Ancient Nutrient for the Modern Human Brain

    PubMed Central

    Bradbury, Joanne

    2011-01-01

    Modern humans have evolved with a staple source of preformed docosahexaenoic acid (DHA) in the diet. An important turning point in human evolution was the discovery of high-quality, easily digested nutrients from coastal seafood and inland freshwater sources. Multi-generational exploitation of seafood by shore-based dwellers coincided with the rapid expansion of grey matter in the cerebral cortex, which characterizes the modern human brain. The DHA molecule has unique structural properties that appear to provide optimal conditions for a wide range of cell membrane functions. This has particular implications for grey matter, which is membrane-rich tissue. An important metabolic role for DHA has recently been identified as the precursor for resolvins and protectins. The rudimentary source of DHA is marine algae; therefore it is found concentrated in fish and marine oils. Unlike the photosynthetic cells in algae and higher plants, mammalian cells lack the specific enzymes required for the de novo synthesis of alpha-linolenic acid (ALA), the precursor for all omega-3 fatty acid syntheses. Endogenous synthesis of DHA from ALA in humans is much lower and more limited than previously assumed. The excessive consumption of omega-6 fatty acids in the modern Western diet further displaces DHA from membrane phospholipids. An emerging body of research is exploring a unique role for DHA in neurodevelopment and the prevention of neuropsychiatric and neurodegenerative disorders. DHA is increasingly being added back into the food supply as fish oil or algal oil supplementation. PMID:22254110

  15. Earliest Recollections of Childhood: A Demographic Analysis.

    ERIC Educational Resources Information Center

    Mullen, Mary K.

    1994-01-01

    Four questionnaires examined the association of demographic factors with recollection for 768 adults. Found that the age of earliest memory increased across birth order, was slightly earlier for females than for males, and was earlier for Caucasians than for Asians. (Author/BC)

  16. Implications of the behavioural immune system for social behaviour and human health in the modern world.

    PubMed

    Schaller, Mark; Murray, Damian R; Bangerter, Adrian

    2015-05-26

    The 'behavioural immune system' is composed of mechanisms that evolved as a means of facilitating behaviours that minimized infection risk and enhanced fitness. Recent empirical research on human populations suggests that these mechanisms have unique consequences for many aspects of human sociality--including sexual attitudes, gregariousness, xenophobia, conformity to majority opinion and conservative sociopolitical attitudes. Throughout much of human evolutionary history, these consequences may have had beneficial health implications; but health implications in modern human societies remain unclear. This article summarizes pertinent ways in which modern human societies are similar to and different from the ecologies within which the behavioural immune system evolved. By attending to these similarities and differences, we identify a set of plausible implications-both positive and negative-that the behavioural immune system may have on health outcomes in contemporary human contexts. We discuss both individual-level infection risk and population-level epidemiological outcomes. We also discuss a variety of additional implications, including compliance with public health policies, the adoption of novel therapeutic interventions and actual immunological functioning. Research on the behavioural immune system, and its implications in contemporary human societies, can provide unique insights into relationships between fitness, sociality and health. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  17. Emergence of modern human behavior: Middle Stone Age engravings from South Africa.

    PubMed

    Henshilwood, Christopher S; d'Errico, Francesco; Yates, Royden; Jacobs, Zenobia; Tribolo, Chantal; Duller, Geoff A T; Mercier, Norbert; Sealy, Judith C; Valladas, Helene; Watts, Ian; Wintle, Ann G

    2002-02-15

    In the Eurasian Upper Paleolithic after about 35,000 years ago, abstract or depictional images provide evidence for cognitive abilities considered integral to modern human behavior. Here we report on two abstract representations engraved on pieces of red ochre recovered from the Middle Stone Age layers at Blombos Cave in South Africa. A mean date of 77,000 years was obtained for the layers containing the engraved ochres by thermoluminescence dating of burnt lithics, and the stratigraphic integrity was confirmed by an optically stimulated luminescence age of 70,000 years on an overlying dune. These engravings support the emergence of modern human behavior in Africa at least 35,000 years before the start of the Upper Paleolithic.

  18. An ecocultural model predicts Neanderthal extinction through competition with modern humans.

    PubMed

    Gilpin, William; Feldman, Marcus W; Aoki, Kenichi

    2016-02-23

    Archaeologists argue that the replacement of Neanderthals by modern humans was driven by interspecific competition due to a difference in culture level. To assess the cogency of this argument, we construct and analyze an interspecific cultural competition model based on the Lotka-Volterra model, which is widely used in ecology, but which incorporates the culture level of a species as a variable interacting with population size. We investigate the conditions under which a difference in culture level between cognitively equivalent species, or alternatively a difference in underlying learning ability, may produce competitive exclusion of a comparatively (although not absolutely) large local Neanderthal population by an initially smaller modern human population. We find, in particular, that this competitive exclusion is more likely to occur when population growth occurs on a shorter timescale than cultural change, or when the competition coefficients of the Lotka-Volterra model depend on the difference in the culture levels of the interacting species.

  19. Neandertal Demise: An Archaeological Analysis of the Modern Human Superiority Complex

    PubMed Central

    Villa, Paola; Roebroeks, Wil

    2014-01-01

    Neandertals are the best-studied of all extinct hominins, with a rich fossil record sampling hundreds of individuals, roughly dating from between 350,000 and 40,000 years ago. Their distinct fossil remains have been retrieved from Portugal in the west to the Altai area in central Asia in the east and from below the waters of the North Sea in the north to a series of caves in Israel in the south. Having thrived in Eurasia for more than 300,000 years, Neandertals vanished from the record around 40,000 years ago, when modern humans entered Europe. Modern humans are usually seen as superior in a wide range of domains, including weaponry and subsistence strategies, which would have led to the demise of Neandertals. This systematic review of the archaeological records of Neandertals and their modern human contemporaries finds no support for such interpretations, as the Neandertal archaeological record is not different enough to explain the demise in terms of inferiority in archaeologically visible domains. Instead, current genetic data suggest that complex processes of interbreeding and assimilation may have been responsible for the disappearance of the specific Neandertal morphology from the fossil record. PMID:24789039

  20. Genomic evidence for an African expansion of anatomically modern humans by a Southern route.

    PubMed

    Ghirotto, Silvia; Penso-Dolfin, Luca; Barbujani, Guido

    2011-08-01

    There is general agreement among scientists about a recent (less than 200,000 yrs ago) African origin of anatomically modern humans, whereas there is still uncertainty about whether, and to what extent, they admixed with archaic populations, which thus may have contributed to the modern populations' gene pools. Data on cranial morphology have been interpreted as suggesting that, before the main expansion from Africa through the Near East, anatomically modern humans may also have taken a Southern route from the Horn of Africa through the Arabian peninsula to India, Melanesia and Australia, about 100,000 yrs ago. This view was recently supported by archaeological findings demonstrating human presence in Eastern Arabia >90,000 yrs ago. In this study we analyzed genetic variation at 111,197 nuclear SNPs in nine populations (Kurumba, Chenchu, Kamsali, Madiga, Mala, Irula, Dalit, Chinese, Japanese), chosen because their genealogical relationships are expected to differ under the alternative models of expansion (single vs. multiple dispersals). We calculated correlations between genomic distances, and geographic distances estimated under the alternative assumptions of a single dispersal, or multiple dispersals, and found a significantly stronger association for the multiple dispersal model. If confirmed, this result would cast doubts on the possibility that some non-African populations (i.e., those whose ancestors expanded through the Southern route) may have had any contacts with Neandertals.

  1. Neandertal demise: an archaeological analysis of the modern human superiority complex.

    PubMed

    Villa, Paola; Roebroeks, Wil

    2014-01-01

    Neandertals are the best-studied of all extinct hominins, with a rich fossil record sampling hundreds of individuals, roughly dating from between 350,000 and 40,000 years ago. Their distinct fossil remains have been retrieved from Portugal in the west to the Altai area in central Asia in the east and from below the waters of the North Sea in the north to a series of caves in Israel in the south. Having thrived in Eurasia for more than 300,000 years, Neandertals vanished from the record around 40,000 years ago, when modern humans entered Europe. Modern humans are usually seen as superior in a wide range of domains, including weaponry and subsistence strategies, which would have led to the demise of Neandertals. This systematic review of the archaeological records of Neandertals and their modern human contemporaries finds no support for such interpretations, as the Neandertal archaeological record is not different enough to explain the demise in terms of inferiority in archaeologically visible domains. Instead, current genetic data suggest that complex processes of interbreeding and assimilation may have been responsible for the disappearance of the specific Neandertal morphology from the fossil record.

  2. Genetic and archaeological perspectives on the initial modern human colonization of southern Asia

    PubMed Central

    Mellars, Paul; Gori, Kevin C.; Carr, Martin; Soares, Pedro A.; Richards, Martin B.

    2013-01-01

    It has been argued recently that the initial dispersal of anatomically modern humans from Africa to southern Asia occurred before the volcanic “supereruption” of the Mount Toba volcano (Sumatra) at ∼74,000 y before present (B.P.)—possibly as early as 120,000 y B.P. We show here that this “pre-Toba” dispersal model is in serious conflict with both the most recent genetic evidence from both Africa and Asia and the archaeological evidence from South Asian sites. We present an alternative model based on a combination of genetic analyses and recent archaeological evidence from South Asia and Africa. These data support a coastally oriented dispersal of modern humans from eastern Africa to southern Asia ∼60–50 thousand years ago (ka). This was associated with distinctively African microlithic and “backed-segment” technologies analogous to the African “Howiesons Poort” and related technologies, together with a range of distinctively “modern” cultural and symbolic features (highly shaped bone tools, personal ornaments, abstract artistic motifs, microblade technology, etc.), similar to those that accompanied the replacement of “archaic” Neanderthal by anatomically modern human populations in other regions of western Eurasia at a broadly similar date. PMID:23754394

  3. The Mitonuclear Dimension of Neanderthal and Denisovan Ancestry in Modern Human Genomes

    PubMed Central

    Sharbrough, Joel; Havird, Justin C.; Noe, Gregory R.; Warren, Jessica M.

    2017-01-01

    Abstract Some human populations interbred with Neanderthals and Denisovans, resulting in substantial contributions to modern-human genomes. Therefore, it is now possible to use genomic data to investigate mechanisms that shaped historical gene flow between humans and our closest hominin relatives. More generally, in eukaryotes, mitonuclear interactions have been argued to play a disproportionate role in generating reproductive isolation. There is no evidence of mtDNA introgression into modern human populations, which means that all introgressed nuclear alleles from archaic hominins must function on a modern-human mitochondrial background. Therefore, mitonuclear interactions are also potentially relevant to hominin evolution. We performed a detailed accounting of mtDNA divergence among hominin lineages and used population-genomic data to test the hypothesis that mitonuclear incompatibilities have preferentially restricted the introgression of nuclear genes with mitochondrial functions. We found a small but significant underrepresentation of introgressed Neanderthal alleles at such nuclear loci. Structural analyses of mitochondrial enzyme complexes revealed that these effects are unlikely to be mediated by physically interacting sites in mitochondrial and nuclear gene products. We did not detect any underrepresentation of introgressed Denisovan alleles at mitochondrial-targeted loci, but this may reflect reduced power because locus-specific estimates of Denisovan introgression are more conservative. Overall, we conclude that genes involved in mitochondrial function may have been subject to distinct selection pressures during the history of introgression from archaic hominins but that mitonuclear incompatibilities have had, at most, a small role in shaping genome-wide introgression patterns, perhaps because of limited functional divergence in mtDNA and interacting nuclear genes. PMID:28854627

  4. Manipulating the reported age in earliest memories.

    PubMed

    Wessel, Ineke; Schweig, Theresa; Huntjens, Rafaële J C

    2017-11-02

    Previous work suggests that the estimated age in adults' earliest autobiographical memories depends on age information implied by the experimental context [e.g., Kingo, O. S., Bohn, A., & Krøjgaard, P. (2013). Warm-up questions on early childhood memories affect the reported age of earliest memories in late adolescence. Memory, 21(2), 280-284. doi: 10.1080/09658211.2012.729598 ] and that the age in decontextualised snippets of memory is younger than in more complete accounts (i.e., event memories [Bruce, D., Wilcox-O'Hearn, L. A., Robinson, J. A., Phillips-Grant, K., Francis, L., & Smith, M. C. (2005). Fragment memories mark the end of childhood amnesia. Memory & Cognition, 33(4), 567-576. doi: 10.3758/BF03195324 ]). We examined the malleability of the estimated age in undergraduates' earliest memories and its relation with memory quality. In Study 1 (n = 141), vignettes referring to events happening at age 2 rendered earlier reported ages than examples referring to age 6. Exploratory analyses suggested that event memories were more sensitive to the age manipulation than memories representing a single, isolated scene (i.e., snapshots). In Study 2 (n = 162), asking self-relevant and public-event knowledge questions about participants' preschool years prior to retrieval yielded comparable average estimated ages. Both types of semantic knowledge questions rendered earlier memories than a no-age control task. Overall, the reported age in snapshots was younger than in event memories. However, age-differences between memory types across conditions were not statistically significant. Together, the results add to the growing literature indicating that the average age in earliest memories is not as fixed as previously thought.

  5. The southern route "out of Africa": evidence for an early expansion of modern humans into Arabia.

    PubMed

    Armitage, Simon J; Jasim, Sabah A; Marks, Anthony E; Parker, Adrian G; Usik, Vitaly I; Uerpmann, Hans-Peter

    2011-01-28

    The timing of the dispersal of anatomically modern humans (AMH) out of Africa is a fundamental question in human evolutionary studies. Existing data suggest a rapid coastal exodus via the Indian Ocean rim around 60,000 years ago. We present evidence from Jebel Faya, United Arab Emirates, demonstrating human presence in eastern Arabia during the last interglacial. The tool kit found at Jebel Faya has affinities to the late Middle Stone Age in northeast Africa, indicating that technological innovation was not necessary to facilitate migration into Arabia. Instead, we propose that low eustatic sea level and increased rainfall during the transition between marine isotope stages 6 and 5 allowed humans to populate Arabia. This evidence implies that AMH may have been present in South Asia before the Toba eruption.

  6. Earliest hominin occupation of Sulawesi, Indonesia

    NASA Astrophysics Data System (ADS)

    van den Bergh, Gerrit D.; Li, Bo; Brumm, Adam; Grün, Rainer; Yurnaldi, Dida; Moore, Mark W.; Kurniawan, Iwan; Setiawan, Ruly; Aziz, Fachroel; Roberts, Richard G.; Suyono; Storey, Michael; Setiabudi, Erick; Morwood, Michael J.

    2016-01-01

    Sulawesi is the largest and oldest island within Wallacea, a vast zone of oceanic islands separating continental Asia from the Pleistocene landmass of Australia and Papua (Sahul). By one million years ago an unknown hominin lineage had colonized Flores immediately to the south, and by about 50 thousand years ago, modern humans (Homo sapiens) had crossed to Sahul. On the basis of position, oceanic currents and biogeographical context, Sulawesi probably played a pivotal part in these dispersals. Uranium-series dating of speleothem deposits associated with rock art in the limestone karst region of Maros in southwest Sulawesi has revealed that humans were living on the island at least 40 thousand years ago (ref. 5). Here we report new excavations at Talepu in the Walanae Basin northeast of Maros, where in situ stone artefacts associated with fossil remains of megafauna (Bubalus sp., Stegodon and Celebochoerus) have been recovered from stratified deposits that accumulated from before 200 thousand years ago until about 100 thousand years ago. Our findings suggest that Sulawesi, like Flores, was host to a long-established population of archaic hominins, the ancestral origins and taxonomic status of which remain elusive.

  7. Diet of upper paleolithic modern humans: evidence from microwear texture analysis.

    PubMed

    El Zaatari, Sireen; Hublin, Jean-Jacques

    2014-04-01

    This article presents the results of the occlusal molar microwear texture analysis of 32 adult Upper Paleolithic modern humans from a total of 21 European sites dating to marine isotope stages 3 and 2. The occlusal molar microwear textures of these specimens were analyzed with the aim of examining the effects of the climatic, as well as the cultural, changes on the diets of the Upper Paleolithic modern humans. The results of this analysis do not reveal any environmentally driven dietary shifts for the Upper Paleolithic hominins indicating that the climatic and their associated paleoecological changes did not force these humans to significantly alter their diets in order to survive. However, the microwear texture analysis does detect culturally related changes in the Upper Paleolithic humans' diets. Specifically, significant differences in diet were found between the earlier Upper Paleolithic individuals, i.e., those belonging to the Aurignacian and Gravettian contexts, and the later Magdalenian ones, such that the diet of the latter group was more varied and included more abrasive foods compared with those of the former. Copyright © 2014 Wiley Periodicals, Inc.

  8. Chronology of Ksar Akil (Lebanon) and Implications for the Colonization of Europe by Anatomically Modern Humans

    PubMed Central

    Douka, Katerina; Bergman, Christopher A.; Hedges, Robert E. M.; Wesselingh, Frank P.; Higham, Thomas F. G.

    2013-01-01

    The Out-of-Africa model holds that anatomically modern humans (AMH) evolved and dispersed from Africa into Asia, and later Europe. Palaeoanthropological evidence from the Near East assumes great importance, but AMH remains from the region are extremely scarce. ‘Egbert’, a now-lost AMH fossil from the key site of Ksar Akil (Lebanon) and ‘Ethelruda’, a recently re-discovered fragmentary maxilla from the same site, are two rare examples where human fossils are directly linked with early Upper Palaeolithic archaeological assemblages. Here we radiocarbon date the contexts from which Egbert and Ethelruda were recovered, as well as the levels above and below the findspots. In the absence of well-preserved organic materials, we primarily used marine shell beads, often regarded as indicative of behavioural modernity. Bayesian modelling allows for the construction of a chronostratigraphic framework for Ksar Akil, which supports several conclusions. The model-generated age estimates place Egbert between 40.8–39.2 ka cal BP (68.2% prob.) and Ethelruda between 42.4–41.7 ka cal BP (68.2% prob.). This indicates that Egbert is of an age comparable to that of the oldest directly-dated European AMH (Peştera cu Oase). Ethelruda is older, but on current estimates not older than the modern human teeth from Cavallo in Italy. The dating of the so-called “transitional” or Initial Upper Palaeolithic layers of the site may indicate that the passage from the Middle to Upper Palaeolithic at Ksar Akil, and possibly in the wider northern Levant, occurred later than previously estimated, casting some doubts on the assumed singular role of the region as a locus for human dispersals into Europe. Finally, tentative interpretations of the fossil's taxonomy, combined with the chronometric dating of Ethelruda's context, provides evidence that the transitional/IUP industries of Europe and the Levant, or at least some of them, may be the result of early modern human migration(s). PMID

  9. The linguistic roots of Modern English anatomical terminology.

    PubMed

    Turmezei, Tom D

    2012-11-01

    Previous research focusing on Classical Latin and Greek roots has shown that understanding the etymology of English anatomical terms may be beneficial for students of human anatomy. However, not all anatomical terms are derived from Classical origins. This study aims to explore the linguistic roots of the Modern English terminology used in human gross anatomy. By reference to the Oxford English Dictionary, etymologies were determined for a lexicon of 798 Modern English gross anatomical terms from the 40(th) edition of Gray's Anatomy. Earliest traceable language of origin was determined for all 798 terms; language of acquisition was determined for 747 terms. Earliest traceable languages of origin were: Classical Latin (62%), Classical Greek (24%), Old English (7%), Post-Classical Latin (3%), and other (4%). Languages of acquisition were: Classical Latin (42%), Post-Classical Latin (29%), Old English (8%), Modern French (6%), Classical Greek (5%), Middle English (3%), and other (7%). While the roots of Modern English anatomical terminology mostly lie in Classical languages (accounting for the origin of 86% of terms), the anatomical lexicon of Modern English is actually much more diverse. Interesting and perhaps less familiar examples from these languages and the methods by which such terms have been created and absorbed are discussed. The author suggests that awareness of anatomical etymologies may enhance the enjoyment and understanding of human anatomy for students and teachers alike. Copyright © 2012 Wiley Periodicals, Inc.

  10. [The development of molecular human genetics and its significance for perspectives of modern medicine].

    PubMed

    Coutelle, C; Speer, A; Grade, K; Rosenthal, A; Hunger, H D

    1989-01-01

    The introduction of molecular human genetics has become a paradigma for the application of genetic engineering in medicine. The main principles of this technology are the isolation of molecular probes, their application in hybridization reactions, specific gene-amplification by the polymerase chain reaction, and DNA sequencing reactions. These methods are used for the analysis of monogenic diseases by linkage studies and the elucidation of the molecular defect causing these conditions, respectively. They are also the basis for genomic diagnosis of monogenic diseases, introduced into the health care system of the GDR by a national project on Duchenne/Becker muscular dystrophy, Cystic Fibrosis and Phenylketonuria. The rapid development of basic research on the molecular analysis of the human genome and genomic diagnosis indicates, that human molecular genetics is becoming a decisive basic discipline of modern medicine.

  11. Recent African origin of modern humans revealed by complete sequences of hominoid mitochondrial DNAs.

    PubMed Central

    Horai, S; Hayasaka, K; Kondo, R; Tsugane, K; Takahata, N

    1995-01-01

    We analyzed the complete mitochondrial DNA (mtDNA) sequences of three humans (African, European, and Japanese), three African apes (common and pygmy chimpanzees, and gorilla), and one orangutan in an attempt to estimate most accurately the substitution rates and divergence times of hominoid mtDNAs. Nonsynonymous substitutions and substitutions in RNA genes have accumulated with an approximately clock-like regularity. From these substitutions and under the assumption that the orangutan and African apes diverged 13 million years ago, we obtained a divergence time for humans and chimpanzees of 4.9 million years. This divergence time permitted calibration of the synonymous substitution rate (3.89 x 10(-8)/site per year). To obtain the substitution rate in the displacement (D)-loop region, we compared the three human mtDNAs and measured the relative abundance of substitutions in the D-loop region and at synonymous sites. The estimated substitution rate in the D-loop region was 7.00 x 10(-8)/site per year. Using both synonymous and D-loop substitutions, we inferred the age of the last common ancestor of the human mtDNAs as 143,000 +/- 18,000 years. The shallow ancestry of human mtDNAs, together with the observation that the African sequence is the most diverged among humans, strongly supports the recent African origin of modern humans, Homo sapiens sapiens. PMID:7530363

  12. A geometric morphometric study of regional differences in the ontogeny of the modern human facial skeleton.

    PubMed

    Vioarsdóttir, Una Strand; O'Higgins, Paul; Stringer, Chris

    2002-09-01

    This study examines interpopulation variations in the facial skeleton of 10 modern human populations and places these in an ontogenetic perspective. It aims to establish the extent to which the distinctive features of adult representatives of these populations are present in the early post natal period and to what extent population differences in ontogenetic scaling and allometric trajectories contribute to distinct facial forms. The analyses utilize configurations of facial landmarks and are carried out using geometric morphometric methods. The results of this study show that modern human populations can be distinguished based on facial shape alone, irrespective of age or sex, indicating the early presence of differences. Additionally, some populations have statistically distinct facial ontogenetic trajectories that lead to the development of further differences later in ontogeny. We conclude that population-specific facial morphologies develop principally through distinctions in facial shape probably already present at birth and further accentuated and modified to variable degrees during growth. These findings raise interesting questions regarding the plasticity of facial growth patterns in modern humans. Further, they have important implications in relation to the study of growth in the face of fossil hominins and in relation to the possibility of developing effective discriminant functions for the identification of population affinities of immature facial skeletal material. Such tools would be of value in archaeological, forensic and anthropological applications. The findings of this study underline the need to examine more deeply, and in more detail, the ontogenetic basis of other causes of craniometric variation, such as sexual dimorphism and hominin species differentiation.

  13. Plant foods and the dietary ecology of Neanderthals and early modern humans.

    PubMed

    Henry, Amanda G; Brooks, Alison S; Piperno, Dolores R

    2014-04-01

    One of the most important challenges in anthropology is understanding the disappearance of Neanderthals. Previous research suggests that Neanderthals had a narrower diet than early modern humans, in part because they lacked various social and technological advances that lead to greater dietary variety, such as a sexual division of labor and the use of complex projectile weapons. The wider diet of early modern humans would have provided more calories and nutrients, increasing fertility, decreasing mortality and supporting large population sizes, allowing them to out-compete Neanderthals. However, this model for Neanderthal dietary behavior is based on analysis of animal remains, stable isotopes, and other methods that provide evidence only of animal food in the diet. This model does not take into account the potential role of plant food. Here we present results from the first broad comparison of plant foods in the diets of Neanderthals and early modern humans from several populations in Europe, the Near East, and Africa. Our data comes from the analysis of plant microremains (starch grains and phytoliths) in dental calculus and on stone tools. Our results suggest that both species consumed a similarly wide array of plant foods, including foods that are often considered low-ranked, like underground storage organs and grass seeds. Plants were consumed across the entire range of individuals and sites we examined, and none of the expected predictors of variation (species, geographic region, or associated stone tool technology) had a strong influence on the number of plant species consumed. Our data suggest that Neanderthal dietary ecology was more complex than previously thought. This implies that the relationship between Neanderthal technology, social behavior, and food acquisition strategies must be better explored. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Population dynamics coded in DNA: genetic traces of the expansion of modern humans

    NASA Astrophysics Data System (ADS)

    Kimmel, Marek

    1999-12-01

    It has been proposed that modern humans evolved from a small ancestral population, which appeared several hundred thousand years ago in Africa. Descendants of the founder group migrated to Europe and then to Asia, not mixing with the pre-existing local populations but replacing them. Two demographic elements are present in this “out of Africa” hypothesis: numerical growth of the modern humans and their migration into Eurasia. Did these processes leave an imprint in our DNA? To address this question, we use the classical Fisher-Wright-Moran model of population genetics, assuming variable population size and two models of mutation: the infinite-sites model and the stepwise-mutation model. We use the coalescence theory, which amounts to tracing the common ancestors of contemporary genes. We obtain mathematical formulae expressing the distribution of alleles given the time changes of population size . In the framework of the infinite-sites model, simulations indicate that the pattern of past population size change leaves its signature on the pattern of DNA polymorphism. Application of the theory to the published mitochondrial DNA sequences indicates that the current mitochondrial DNA sequence variation is not inconsistent with the logistic growth of the modern human population. In the framework of the stepwise-mutation model, we demonstrate that population bottleneck followed by growth in size causes an imbalance between allele-size variance and heterozygosity. We analyze a set of data on tetranucleotide repeats which reveals the existence of this imbalance. The pattern of imbalance is consistent with the bottleneck being most ancient in Africans, most recent in Asians and intermediate in Europeans. These findings are consistent with the “out of Africa” hypothesis, although by no means do they constitute its proof.

  15. Genomic validation of the differential preservation of population history in modern human cranial anatomy.

    PubMed

    Reyes-Centeno, Hugo; Ghirotto, Silvia; Harvati, Katerina

    2017-01-01

    In modern humans, the significant correlation between neutral genetic loci and cranial anatomy suggests that the cranium preserves a population history signature. However, there is disagreement on whether certain parts of the cranium preserve this signature to a greater degree than other parts. It is also unclear how different quantitative measures of phenotype affect the association of genetic variation and anatomy. Here, we revisit these matters by testing the correlation of genetic distances and various phenotypic distances for ten modern human populations. Geometric morphometric shape data from the crania of adult individuals (n = 224) are used to calculate phenotypic P ST , Procrustes, and Mahalanobis distances. We calculate their correlation to neutral genetic distances, F ST , derived from single nucleotide polymorphisms (SNPs). We subset the cranial data into landmark configurations that include the neurocranium, the face, and the temporal bone in order to evaluate whether these cranial regions are differentially correlated to neutral genetic variation. Our results show that P ST , Mahalanobis, and Procrustes distances are correlated with F ST distances to varying degrees. They indicate that overall cranial shape is significantly correlated with neutral genetic variation. Of the component parts examined, P ST distances for both the temporal bone and the face have a stronger association with F ST distances than the neurocranium. When controlling for population divergence time, only the whole cranium and the temporal bone have a statistically significant association with F ST distances. Our results confirm that the cranium, as a whole, and the temporal bone can be used to reconstruct modern human population history. © 2016 Wiley Periodicals, Inc.

  16. Searching for ancient balanced polymorphisms shared between Neanderthals and Modern Humans

    PubMed Central

    Viscardi, Lucas Henriques; Paixão-Côrtes, Vanessa Rodrigues; Comas, David; Salzano, Francisco Mauro; Rovaris, Diego; Bau, Claiton Dotto; Amorim, Carlos Eduardo G.; Bortolini, Maria Cátira

    2018-01-01

    Abstract Hominin evolution is characterized by adaptive solutions often rooted in behavioral and cognitive changes. If balancing selection had an important and long-lasting impact on the evolution of these traits, it can be hypothesized that genes associated with them should carry an excess of shared polymorphisms (trans- SNPs) across recent Homo species. In this study, we investigate the role of balancing selection in human evolution using available exomes from modern (Homo sapiens) and archaic humans (H. neanderthalensis and Denisovan) for an excess of trans-SNP in two gene sets: one associated with the immune system (IMMS) and another one with behavioral system (BEHS). We identified a significant excess of trans-SNPs in IMMS (N=547), of which six of these located within genes previously associated with schizophrenia. No excess of trans-SNPs was found in BEHS, but five genes in this system harbor potential signals for balancing selection and are associated with psychiatric or neurodevelopmental disorders. Our approach evidenced recent Homo trans-SNPs that have been previously implicated in psychiatric diseases such as schizophrenia, suggesting that a genetic repertoire common to the immune and behavioral systems could have been maintained by balancing selection starting before the split between archaic and modern humans. PMID:29658973

  17. New methodology to reconstruct in 2-D the cuspal enamel of modern human lower molars.

    PubMed

    Modesto-Mata, Mario; García-Campos, Cecilia; Martín-Francés, Laura; Martínez de Pinillos, Marina; García-González, Rebeca; Quintino, Yuliet; Canals, Antoni; Lozano, Marina; Dean, M Christopher; Martinón-Torres, María; Bermúdez de Castro, José María

    2017-08-01

    In the last years different methodologies have been developed to reconstruct worn teeth. In this article, we propose a new 2-D methodology to reconstruct the worn enamel of lower molars. Our main goals are to reconstruct molars with a high level of accuracy when measuring relevant histological variables and to validate the methodology calculating the errors associated with the measurements. This methodology is based on polynomial regression equations, and has been validated using two different dental variables: cuspal enamel thickness and crown height of the protoconid. In order to perform the validation process, simulated worn modern human molars were employed. The associated errors of the measurements were also estimated applying methodologies previously proposed by other authors. The mean percentage error estimated in reconstructed molars for these two variables in comparison with their own real values is -2.17% for the cuspal enamel thickness of the protoconid and -3.18% for the crown height of the protoconid. This error significantly improves the results of other methodologies, both in the interobserver error and in the accuracy of the measurements. The new methodology based on polynomial regressions can be confidently applied to the reconstruction of cuspal enamel of lower molars, as it improves the accuracy of the measurements and reduces the interobserver error. The present study shows that it is important to validate all methodologies in order to know the associated errors. This new methodology can be easily exportable to other modern human populations, the human fossil record and forensic sciences. © 2017 Wiley Periodicals, Inc.

  18. Hunter-gatherer genomic diversity suggests a southern African origin for modern humans

    PubMed Central

    Henn, Brenna M.; Gignoux, Christopher R.; Jobin, Matthew; Granka, Julie M.; Macpherson, J. M.; Kidd, Jeffrey M.; Rodríguez-Botigué, Laura; Ramachandran, Sohini; Hon, Lawrence; Brisbin, Abra; Lin, Alice A.; Underhill, Peter A.; Comas, David; Kidd, Kenneth K.; Norman, Paul J.; Parham, Peter; Bustamante, Carlos D.; Mountain, Joanna L.; Feldman, Marcus W.

    2011-01-01

    Africa is inferred to be the continent of origin for all modern human populations, but the details of human prehistory and evolution in Africa remain largely obscure owing to the complex histories of hundreds of distinct populations. We present data for more than 580,000 SNPs for several hunter-gatherer populations: the Hadza and Sandawe of Tanzania, and the ≠Khomani Bushmen of South Africa, including speakers of the nearly extinct N|u language. We find that African hunter-gatherer populations today remain highly differentiated, encompassing major components of variation that are not found in other African populations. Hunter-gatherer populations also tend to have the lowest levels of genome-wide linkage disequilibrium among 27 African populations. We analyzed geographic patterns of linkage disequilibrium and population differentiation, as measured by FST, in Africa. The observed patterns are consistent with an origin of modern humans in southern Africa rather than eastern Africa, as is generally assumed. Additionally, genetic variation in African hunter-gatherer populations has been significantly affected by interaction with farmers and herders over the past 5,000 y, through both severe population bottlenecks and sex-biased migration. However, African hunter-gatherer populations continue to maintain the highest levels of genetic diversity in the world. PMID:21383195

  19. Modern Gemini-Approach to Technology Development for Human Space Exploration

    NASA Technical Reports Server (NTRS)

    White, Harold

    2010-01-01

    In NASA's plan to put men on the moon, there were three sequential programs: Mercury, Gemini, and Apollo. The Gemini program was used to develop and integrate the technologies that would be necessary for the Apollo program to successfully put men on the moon. We would like to present an analogous modern approach that leverages legacy ISS hardware designs, and integrates developing new technologies into a flexible architecture This new architecture is scalable, sustainable, and can be used to establish human exploration infrastructure beyond low earth orbit and into deep space.

  20. Cacao usage by the earliest Maya civilization.

    PubMed

    Hurst, W Jeffrey; Tarka, Stanley M; Powis, Terry G; Valdez, Fred; Hester, Thomas R

    2002-07-18

    The Maya archaeological site at Colha in northern Belize, Central America, has yielded several spouted ceramic vessels that contain residues from the preparation of food and beverages. Here we analyse dry residue samples by using high-performance liquid chromatography coupled to atmospheric-pressure chemical-ionization mass spectrometry, and show that chocolate (Theobroma cacao) was consumed by the Preclassic Maya as early as 600 bc, pushing back the earliest chemical evidence of cacao use by some 1,000 years. Our application of this new and highly sensitive analytical technique could be extended to the identification of other ancient foods and beverages.

  1. Earliest evidence of dental caries manipulation in the Late Upper Palaeolithic

    PubMed Central

    Oxilia, Gregorio; Peresani, Marco; Romandini, Matteo; Matteucci, Chiara; Spiteri, Cynthianne Debono; Henry, Amanda G.; Schulz, Dieter; Archer, Will; Crezzini, Jacopo; Boschin, Francesco; Boscato, Paolo; Jaouen, Klervia; Dogandzic, Tamara; Broglio, Alberto; Moggi-Cecchi, Jacopo; Fiorenza, Luca; Hublin, Jean-Jacques; Kullmer, Ottmar; Benazzi, Stefano

    2015-01-01

    Prehistoric dental treatments were extremely rare, and the few documented cases are known from the Neolithic, when the adoption of early farming culture caused an increase of carious lesions. Here we report the earliest evidence of dental caries intervention on a Late Upper Palaeolithic modern human specimen (Villabruna) from a burial in Northern Italy. Using Scanning Electron Microscopy we show the presence of striations deriving from the manipulation of a large occlusal carious cavity of the lower right third molar. The striations have a “V”-shaped transverse section and several parallel micro-scratches at their base, as typically displayed by cutmarks on teeth. Based on in vitro experimental replication and a complete functional reconstruction of the Villabruna dental arches, we confirm that the identified striations and the associated extensive enamel chipping on the mesial wall of the cavity were produced ante-mortem by pointed flint tools during scratching and levering activities. The Villabruna specimen is therefore the oldest known evidence of dental caries intervention, suggesting at least some knowledge of disease treatment well before the Neolithic. This study suggests that primitive forms of carious treatment in human evolution entail an adaptation of the well-known toothpicking for levering and scratching rather than drilling practices. PMID:26179739

  2. The earliest ossicone and post-cranial record of Giraffa

    PubMed Central

    Danowitz, Melinda; Barry, John C.

    2017-01-01

    The oldest Giraffa material presently known consists of dental specimens. The oldest post-cranial Giraffa material belongs to the Plio-Pleistocene taxon Giraffa sivalensis, where the holotype is a third cervical vertebra. We describe three non-dental specimens from the Early Late Miocene of the Potwar Plateau, including an 8.1 million year old ossicone, 9.4 million year old astragalus, and 8.9 million year old metatarsal and refer them to Giraffa. The described ossicone exhibits remarkable similarities with the ossicones of a juvenile modern giraffe, including the distribution of secondary bone growth, posterior curvature, and concave pitted undersurface where the ossicone would attach to the skull. The astragalus has a notably flat grove of the trochlea, medial twisting between the trochlea and the head, and a square-shaped sustentacular facet, all of which characterize the astragalus of Giraffa camelopardalis. The newly described astragalus is narrow and rectangular, unlike the boxy shaped bone of the modern giraffe. The metatarsal is large in size and has a shallow central trough created by thin medial and lateral ridges, a feature unique to Giraffa and Sivatherium. Our described material introduce the earliest non-dental material of Giraffa, a genus whose extinct representation is otherwise dominated by teeth, and demonstrate that the genus has been morphologically consistent over 9 million years. PMID:28926638

  3. The earliest ossicone and post-cranial record of Giraffa.

    PubMed

    Danowitz, Melinda; Barry, John C; Solounias, Nikos

    2017-01-01

    The oldest Giraffa material presently known consists of dental specimens. The oldest post-cranial Giraffa material belongs to the Plio-Pleistocene taxon Giraffa sivalensis, where the holotype is a third cervical vertebra. We describe three non-dental specimens from the Early Late Miocene of the Potwar Plateau, including an 8.1 million year old ossicone, 9.4 million year old astragalus, and 8.9 million year old metatarsal and refer them to Giraffa. The described ossicone exhibits remarkable similarities with the ossicones of a juvenile modern giraffe, including the distribution of secondary bone growth, posterior curvature, and concave pitted undersurface where the ossicone would attach to the skull. The astragalus has a notably flat grove of the trochlea, medial twisting between the trochlea and the head, and a square-shaped sustentacular facet, all of which characterize the astragalus of Giraffa camelopardalis. The newly described astragalus is narrow and rectangular, unlike the boxy shaped bone of the modern giraffe. The metatarsal is large in size and has a shallow central trough created by thin medial and lateral ridges, a feature unique to Giraffa and Sivatherium. Our described material introduce the earliest non-dental material of Giraffa, a genus whose extinct representation is otherwise dominated by teeth, and demonstrate that the genus has been morphologically consistent over 9 million years.

  4. Vertebral architecture in the earliest stem tetrapods.

    PubMed

    Pierce, Stephanie E; Ahlberg, Per E; Hutchinson, John R; Molnar, Julia L; Sanchez, Sophie; Tafforeau, Paul; Clack, Jennifer A

    2013-02-14

    The construction of the vertebral column has been used as a key anatomical character in defining and diagnosing early tetrapod groups. Rhachitomous vertebrae--in which there is a dorsally placed neural arch and spine, an anteroventrally placed intercentrum and paired, posterodorsally placed pleurocentra--have long been considered the ancestral morphology for tetrapods. Nonetheless, very little is known about vertebral anatomy in the earliest stem tetrapods, because most specimens remain trapped in surrounding matrix, obscuring important anatomical features. Here we describe the three-dimensional vertebral architecture of the Late Devonian stem tetrapod Ichthyostega using propagation phase-contrast X-ray synchrotron microtomography. Our scans reveal a diverse array of new morphological, and associated developmental and functional, characteristics, including a possible posterior-to-anterior vertebral ossification sequence and the first evolutionary appearance of ossified sternal elements. One of the most intriguing features relates to the positional relationships between the vertebral elements, with the pleurocentra being unexpectedly sutured or fused to the intercentra that directly succeed them, indicating a 'reverse' rhachitomous design. Comparison of Ichthyostega with two other stem tetrapods, Acanthostega and Pederpes, shows that reverse rhachitomous vertebrae may be the ancestral condition for limbed vertebrates. This study fundamentally revises our current understanding of vertebral column evolution in the earliest tetrapods and raises questions about the presumed vertebral architecture of tetrapodomorph fish and later, more crownward, tetrapods.

  5. Science, humanism, judgement, ethics: person-centered medicine as an emergent model of modern clinical practice.

    PubMed

    Miles, Andrew

    2013-01-01

    The Medical University of Plovdiv (MUP) has as its motto 'Committed to humanity". But what does humanity in modern medicine mean? Is it possible to practise a form of medicine that is without humanity? In the current article, it is argued that modern medicine is increasingly being practised in a de-personalised fashion, where the patient is understood not as a unique human individual, a person, but rather as a subject or an object and more in the manner of a complex biological machine. Medicine has, it is contended, become distracted from its duty to care, comfort and console as well as to ameliorate, attenuate and cure and that the rapid development of medicine's scientific knowledge is, paradoxically, principally causative. Signal occurrences in the 'patient as a person' movement are reviewed, together with the emergence of the evidence-based medicine (EBM) and patient-centered care (PCC) movements. The characteristics of a model of medicine evolving in response to medicine's current deficiencies--person-centered healthcare (PCH)--are noted and described. In seeking to apply science with humanism, via clinical judgement, within an ethical framework, it is contended that PCH will prove to be far more responsive to the needs of the individual patient and his/her personal circumstances than current models of practice, so that neither a reductive anatomico-pathological, disease-centric model of illness (EBM), nor an aggressive patient-directed, consumerist form of care (PCC) is allowed continued dominance within modern healthcare systems. In conclusion, it is argued that PCH will enable affordable advances in biomedicine and technology to be delivered to patients within a humanistic framework of clinical practice that recognises the patient as a person and which takes full account of his/her stories, values, preferences, goals, aspirations, fears, worries, hopes, cultural context and which responds to his/her psychological, emotional, spiritual and social necessities

  6. Antimicrobial Functions of Lactoferrin Promote Genetic Conflicts in Ancient Primates and Modern Humans.

    PubMed

    Barber, Matthew F; Kronenberg, Zev; Yandell, Mark; Elde, Nels C

    2016-05-01

    Lactoferrin is a multifunctional mammalian immunity protein that limits microbial growth through sequestration of nutrient iron. Additionally, lactoferrin possesses cationic protein domains that directly bind and inhibit diverse microbes. The implications for these dual functions on lactoferrin evolution and genetic conflicts with microbes remain unclear. Here we show that lactoferrin has been subject to recurrent episodes of positive selection during primate divergence predominately at antimicrobial peptide surfaces consistent with long-term antagonism by bacteria. An abundant lactoferrin polymorphism in human populations and Neanderthals also exhibits signatures of positive selection across primates, linking ancient host-microbe conflicts to modern human genetic variation. Rapidly evolving sites in lactoferrin further correspond to molecular interfaces with opportunistic bacterial pathogens causing meningitis, pneumonia, and sepsis. Because microbes actively target lactoferrin to acquire iron, we propose that the emergence of antimicrobial activity provided a pivotal mechanism of adaptation sparking evolutionary conflicts via acquisition of new protein functions.

  7. The human obesity epidemic, the mismatch paradigm, and our modern "captive" environment.

    PubMed

    Power, Michael L

    2012-01-01

    In the distant past obesity in humans was rare and likely caused by metabolic dysregulation due to genetic or disease-related pathology. External factors precluded the ability of most people to overeat or under exert. Socio-cultural obesity came about due to the rareness of obesity and its difficulty to achieve. What is rare becomes valuable and what is difficult to achieve becomes a badge of prestige. The modern human obesity epidemic would appear to represent a third class of obesity: environmental obesity. Much like the captive environments which humans construct for the captive/companion animals in our care, the modern human environment has greatly decreased the challenges of life that would restrict food intake and enforce exertion. And like us, our captive/companion animal populations are also experiencing obesity epidemics. A further concern is that maternal obesity alters maternal signaling to offspring, in utero through the placenta and after birth through breast milk, in ways that perpetuate an enhanced vulnerability to obesity. Molecules such as leptin, produced by adipose tissue and placenta, have significant developmental effects on brain areas associated with feeding behavior. Leptin and other cytokines and growth factors are found in breast milk. These molecules have positive effects on gut maturation; their effects on metabolism and brain development are unclear. Placenta and brain also are hotspots for epigenetic regulation, and epigenetic changes may play significant roles in the later vulnerability to obesity and to the development of a diverse array of diseases, including heart disease, hypertension, and noninsulin-dependent diabetes. Copyright © 2012 Wiley Periodicals, Inc.

  8. AFRICAN GENETIC DIVERSITY: Implications for Human Demographic History, Modern Human Origins, and Complex Disease Mapping

    PubMed Central

    Campbell, Michael C.; Tishkoff, Sarah A.

    2010-01-01

    Comparative studies of ethnically diverse human populations, particularly in Africa, are important for reconstructing human evolutionary history and for understanding the genetic basis of phenotypic adaptation and complex disease. African populations are characterized by greater levels of genetic diversity, extensive population substructure, and less linkage disequilibrium (LD) among loci compared to non-African populations. Africans also possess a number of genetic adaptations that have evolved in response to diverse climates and diets, as well as exposure to infectious disease. This review summarizes patterns and the evolutionary origins of genetic diversity present in African populations, as well as their implications for the mapping of complex traits, including disease susceptibility. PMID:18593304

  9. Earliest evidence for commensal processes of cat domestication.

    PubMed

    Hu, Yaowu; Hu, Songmei; Wang, Weilin; Wu, Xiaohong; Marshall, Fiona B; Chen, Xianglong; Hou, Liangliang; Wang, Changsui

    2014-01-07

    Domestic cats are one of the most popular pets globally, but the process of their domestication is not well understood. Near Eastern wildcats are thought to have been attracted to food sources in early agricultural settlements, following a commensal pathway to domestication. Early evidence for close human-cat relationships comes from a wildcat interred near a human on Cyprus ca. 9,500 y ago, but the earliest domestic cats are known only from Egyptian art dating to 4,000 y ago. Evidence is lacking from the key period of cat domestication 9,500-4,000 y ago. We report on the presence of cats directly dated between 5560-5280 cal B.P. in the early agricultural village of Quanhucun in Shaanxi, China. These cats were outside the wild range of Near Eastern wildcats and biometrically smaller, but within the size-range of domestic cats. The δ(13)C and δ(15)N values of human and animal bone collagen revealed substantial consumption of millet-based foods by humans, rodents, and cats. Ceramic storage containers designed to exclude rodents indicated a threat to stored grain in Yangshao villages. Taken together, isotopic and archaeological data demonstrate that cats were advantageous for ancient farmers. Isotopic data also show that one cat ate less meat and consumed more millet-based foods than expected, indicating that it scavenged among or was fed by people. This study offers fresh perspectives on cat domestication, providing the earliest known evidence for commensal relationships between people and cats.

  10. 3D enamel thickness in Neandertal and modern human permanent canines.

    PubMed

    Buti, Laura; Le Cabec, Adeline; Panetta, Daniele; Tripodi, Maria; Salvadori, Piero A; Hublin, Jean-Jacques; Feeney, Robin N M; Benazzi, Stefano

    2017-12-01

    Enamel thickness figures prominently in studies of human evolution, particularly for taxonomy, phylogeny, and paleodietary reconstruction. Attention has focused on molar teeth, through the use of advanced imaging technologies and novel protocols. Despite the important results achieved thus far, further work is needed to investigate all tooth classes. We apply a recent approach developed for anterior teeth to investigate the 3D enamel thickness of Neandertal and modern human (MH) canines. In terms of crown size, the values obtained for both upper and lower unworn/slightly worn canines are significantly greater in Neandertals than in Upper Paleolithic and recent MH. The 3D relative enamel thickness (RET) is significantly lower in Neandertals than in MH. Moreover, differences in 3D RET values between the two groups appear to decrease in worn canines beginning from wear stage 3, suggesting that both the pattern and the stage of wear may have important effects on the 3D RET value. Nevertheless, the 3D average enamel thickness (AET) does not differ between the two groups. In both groups, 3D AET and 3D RET indices are greater in upper canines than in lower canines, and overall the enamel is thicker on the occlusal half of the labial aspect of the crown, particularly in MH. By contrast, the few early modern humans investigated show the highest volumes of enamel while for all other components of 3D enamel, thickness this group holds an intermediate position between Neandertals and recent MH. Overall, our study supports the general findings that Neandertals have relatively thinner enamel than MH (as also observed in molars), indicating that unworn/slightly worn canines can be successfully used to discriminate between the two groups. Further studies, however, are needed to understand whether these differences are functionally related or are the result of pleiotropic or genetic drift effects. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Technical note: comparing von Luschan skin color tiles and modern spectrophotometry for measuring human skin pigmentation.

    PubMed

    Swiatoniowski, Anna K; Quillen, Ellen E; Shriver, Mark D; Jablonski, Nina G

    2013-06-01

    Prior to the introduction of reflectance spectrophotometry into anthropological field research during the 1950s, human skin color was most commonly classified by visual skin color matching using the von Luschan tiles, a set of 36 standardized, opaque glass tiles arranged in a chromatic scale. Our goal was to establish a conversion formula between the tile-based color matching method and modern reflectance spectrophotometry to make historical and contemporary data comparable. Skin pigmentation measurements were taken on the forehead, inner upper arms, and backs of the hands using both the tiles and a spectrophotometer on 246 participants showing a broad range of skin pigmentation. From these data, a second-order polynomial conversion formula was derived by jackknife analysis to estimate melanin index (M-index) based on tile values. This conversion formula provides a means for comparing modern data to von Luschan tile measurements recorded in historical reports. This is particularly important for populations now extinct, extirpated, or admixed for which tile-based measures of skin pigmentation are the only data available. Copyright © 2013 Wiley Periodicals, Inc.

  12. Testing the Hypothesis of Fire Use for Ecosystem Management by Neanderthal and Upper Palaeolithic Modern Human Populations

    PubMed Central

    Daniau, Anne-Laure; d'Errico, Francesco; Sánchez Goñi, Maria Fernanda

    2010-01-01

    Background It has been proposed that a greater control and more extensive use of fire was one of the behavioral innovations that emerged in Africa among early Modern Humans, favouring their spread throughout the world and determining their eventual evolutionary success. We would expect, if extensive fire use for ecosystem management were a component of the modern human technical and cognitive package, as suggested for Australia, to find major disturbances in the natural biomass burning variability associated with the colonisation of Europe by Modern Humans. Methodology/Principal Findings Analyses of microcharcoal preserved in two deep-sea cores located off Iberia and France were used to reconstruct changes in biomass burning between 70 and 10 kyr cal BP. Results indicate that fire regime follows the Dansgaard-Oeschger climatic variability and its impacts on fuel load. No major disturbance in natural fire regime variability is observed at the time of the arrival of Modern Humans in Europe or during the remainder of the Upper Palaeolithic (40–10 kyr cal BP). Conclusions/Significance Results indicate that either Neanderthals and Modern humans did not influence fire regime or that, if they did, their respective influence was comparable at a regional scale, and not as pronounced as that observed in the biomass burning history of Southeast Asia. PMID:20161786

  13. Earliest evidence for commensal processes of cat domestication

    PubMed Central

    Hu, Yaowu; Hu, Songmei; Wang, Weilin; Wu, Xiaohong; Marshall, Fiona B.; Chen, Xianglong; Hou, Liangliang; Wang, Changsui

    2014-01-01

    Domestic cats are one of the most popular pets globally, but the process of their domestication is not well understood. Near Eastern wildcats are thought to have been attracted to food sources in early agricultural settlements, following a commensal pathway to domestication. Early evidence for close human–cat relationships comes from a wildcat interred near a human on Cyprus ca. 9,500 y ago, but the earliest domestic cats are known only from Egyptian art dating to 4,000 y ago. Evidence is lacking from the key period of cat domestication 9,500–4,000 y ago. We report on the presence of cats directly dated between 5560–5280 cal B.P. in the early agricultural village of Quanhucun in Shaanxi, China. These cats were outside the wild range of Near Eastern wildcats and biometrically smaller, but within the size-range of domestic cats. The δ13C and δ15N values of human and animal bone collagen revealed substantial consumption of millet-based foods by humans, rodents, and cats. Ceramic storage containers designed to exclude rodents indicated a threat to stored grain in Yangshao villages. Taken together, isotopic and archaeological data demonstrate that cats were advantageous for ancient farmers. Isotopic data also show that one cat ate less meat and consumed more millet-based foods than expected, indicating that it scavenged among or was fed by people. This study offers fresh perspectives on cat domestication, providing the earliest known evidence for commensal relationships between people and cats. PMID:24344279

  14. 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.

  15. Morphology of muscle attachment sites in the modern human hand does not reflect muscle architecture

    PubMed Central

    Williams-Hatala, E. M.; Hatala, K. G.; Hiles, S.; Rabey, K. N.

    2016-01-01

    Muscle attachment sites (entheses) on dry bones are regularly used by paleontologists to infer soft tissue anatomy and to reconstruct behaviors of extinct organisms. This method is commonly applied to fossil hominin hand bones to assess their abilities to participate in Paleolithic stone tool behaviors. Little is known, however, about how or even whether muscle anatomy and activity regimes influence the morphologies of their entheses, especially in the hand. Using the opponens muscles from a sample of modern humans, we tested the hypothesis that aspects of hand muscle architecture that are known to be influenced by behavior correlate with the size and shape of their associated entheses. Results show no consistent relationships between these behaviorally-influenced aspects of muscle architecture and entheseal morphology. Consequently, it is likely premature to infer patterns of behavior, such as stone tool making in fossil hominins, from these same entheses. PMID:27334440

  16. Morphology of muscle attachment sites in the modern human hand does not reflect muscle architecture.

    PubMed

    Williams-Hatala, E M; Hatala, K G; Hiles, S; Rabey, K N

    2016-06-23

    Muscle attachment sites (entheses) on dry bones are regularly used by paleontologists to infer soft tissue anatomy and to reconstruct behaviors of extinct organisms. This method is commonly applied to fossil hominin hand bones to assess their abilities to participate in Paleolithic stone tool behaviors. Little is known, however, about how or even whether muscle anatomy and activity regimes influence the morphologies of their entheses, especially in the hand. Using the opponens muscles from a sample of modern humans, we tested the hypothesis that aspects of hand muscle architecture that are known to be influenced by behavior correlate with the size and shape of their associated entheses. Results show no consistent relationships between these behaviorally-influenced aspects of muscle architecture and entheseal morphology. Consequently, it is likely premature to infer patterns of behavior, such as stone tool making in fossil hominins, from these same entheses.

  17. Diversity and Relationships of Cocirculating Modern Human Rotaviruses Revealed Using Large-Scale Comparative Genomics

    PubMed Central

    McKell, Allison O.; Rippinger, Christine M.; McAllen, John K.; Akopov, Asmik; Kirkness, Ewen F.; Payne, Daniel C.; Edwards, Kathryn M.; Chappell, James D.; Patton, John T.

    2012-01-01

    Group A rotaviruses (RVs) are 11-segmented, double-stranded RNA viruses and are primary causes of gastroenteritis in young children. Despite their medical relevance, the genetic diversity of modern human RVs is poorly understood, and the impact of vaccine use on circulating strains remains unknown. In this study, we report the complete genome sequence analysis of 58 RVs isolated from children with severe diarrhea and/or vomiting at Vanderbilt University Medical Center (VUMC) in Nashville, TN, during the years spanning community vaccine implementation (2005 to 2009). The RVs analyzed include 36 G1P[8], 18 G3P[8], and 4 G12P[8] Wa-like genogroup 1 strains with VP6-VP1-VP2-VP3-NSP1-NSP2-NSP3-NSP4-NSP5/6 genotype constellations of I1-R1-C1-M1-A1-N1-T1-E1-H1. By constructing phylogenetic trees, we identified 2 to 5 subgenotype alleles for each gene. The results show evidence of intragenogroup gene reassortment among the cocirculating strains. However, several isolates from different seasons maintained identical allele constellations, consistent with the notion that certain RV clades persisted in the community. By comparing the genes of VUMC RVs to those of other archival and contemporary RV strains for which sequences are available, we defined phylogenetic lineages and verified that the diversity of the strains analyzed in this study reflects that seen in other regions of the world. Importantly, the VP4 and VP7 proteins encoded by VUMC RVs and other contemporary strains show amino acid changes in or near neutralization domains, which might reflect antigenic drift of the virus. Thus, this large-scale, comparative genomic study of modern human RVs provides significant insight into how this pathogen evolves during its spread in the community. PMID:22696651

  18. 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. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  19. Local extinction and recolonization, species effective population size, and modern human origins.

    PubMed

    Eller, Elise; Hawks, John; Relethford, John H

    2004-10-01

    A primary objection from a population genetics perspective to a multiregional model of modern human origins is that the model posits a large census size, whereas genetic data suggest a small effective population size. The relationship between census size and effective size is complex, but arguments based on an island model of migration show that if the effective population size reflects the number of breeding individuals and the effects of population subdivision, then an effective population size of 10,000 is inconsistent with the census size of 500,000 to 1,000,000 that has been suggested by archeological evidence. However, these models have ignored the effects of population extinction and recolonization, which increase the expected variance among demes and reduce the inbreeding effective population size. Using models developed for population extinction and recolonization, we show that a large census size consistent with the multiregional model can be reconciled with an effective population size of 10,000, but genetic variation among demes must be high, reflecting low interdeme migration rates and a colonization process that involves a small number of colonists or kin-structured colonization. Ethnographic and archeological evidence is insufficient to determine whether such demographic conditions existed among Pleistocene human populations, and further work needs to be done. More realistic models that incorporate isolation by distance and heterogeneity in extinction rates and effective deme sizes also need to be developed. However, if true, a process of population extinction and recolonization has interesting implications for human demographic history.

  20. APPLICATION OF EYE TRACKING FOR MEASUREMENT AND EVALUATION IN HUMAN FACTORS STUDIES IN CONTROL ROOM MODERNIZATION

    SciTech Connect

    Kovesdi, C.; Spielman, Z.; LeBlanc, K.

    An important element of human factors engineering (HFE) pertains to measurement and evaluation (M&E). The role of HFE-M&E should be integrated throughout the entire control room modernization (CRM) process and be used for human-system performance evaluation and diagnostic purposes with resolving potential human engineering deficiencies (HEDs) and other human machine interface (HMI) design issues. NUREG-0711 describes how HFE in CRM should employ a hierarchical set of measures, particularly during integrated system validation (ISV), including plant performance, personnel task performance, situation awareness, cognitive workload, and anthropometric/ physiological factors. Historically, subjective measures have been primarily used since they are easier to collectmore » and do not require specialized equipment. However, there are pitfalls with relying solely on subjective measures in M&E such that negatively impact reliability, sensitivity, and objectivity. As part of comprehensively capturing a diverse set of measures that strengthen findings and inferences made of the benefits from emerging technologies like advanced displays, this paper discusses the value of using eye tracking as an objective method that can be used in M&E. A brief description of eye tracking technology and relevant eye tracking measures is provided. Additionally, technical considerations and the unique challenges with using eye tracking in full-scaled simulations are addressed. Finally, this paper shares preliminary findings regarding the use of a wearable eye tracking system in a full-scale simulator study. These findings should help guide future full-scale simulator studies using eye tracking as a methodology to evaluate human-system performance.« less

  1. OH 83: A new early modern human fossil cranium from the Ndutu beds of Olduvai Gorge, Tanzania.

    PubMed

    Reiner, Whitney B; Masao, Fidelis; Sholts, Sabrina B; Songita, Agustino Venance; Stanistreet, Ian; Stollhofen, Harald; Taylor, R E; Hlusko, Leslea J

    2017-11-01

    Herein we introduce a newly recovered partial calvaria, OH 83, from the upper Ndutu Beds of Olduvai Gorge, Tanzania. We present the geological context of its discovery and a comparative analysis of its morphology, placing OH 83 within the context of our current understanding of the origins and evolution of Homo sapiens. We comparatively assessed the morphology of OH 83 using quantitative and qualitative data from penecontemporaneous fossils and the W.W. Howells modern human craniometric dataset. OH 83 is geologically dated to ca. 60-32 ka. Its morphology is indicative of an early modern human, falling at the low end of the range of variation for post-orbital cranial breadth, the high end of the range for bifrontal breadth, and near average in frontal length. There have been numerous attempts to use cranial anatomy to define the species Homo sapiens and identify it in the fossil record. These efforts have not met wide agreement by the scientific community due, in part, to the mosaic patterns of cranial variation represented by the fossils. The variable, mosaic pattern of trait expression in the crania of Middle and Late Pleistocene fossils implies that morphological modernity did not occur at once. However, OH 83 demonstrates that by ca. 60-32 ka modern humans in Africa included individuals that are at the fairly small and gracile range of modern human cranial variation. © 2017 Wiley Periodicals, Inc.

  2. Using the neanderthal and denisova genetic data to understand the common MAPT 17q21 inversion in modern humans.

    PubMed

    Setó-Salvia, Núria; Sánchez-Quinto, Federico; Carbonell, Eudald; Lorenzo, Carlos; Comas, David; Clarimón, Jordi

    2012-12-01

    The polymorphic inversion on 17q21, that includes the MAPT gene, represents a unique locus in the human genome characterized by a large region with strong linkage disequilibrium. Two distinct haplotypes, H1 and H2, exist in modern humans, and H1 has been unequivocally related to several neurodegenerative disorders. Recent data indicate that recurrent inversions of this genomic region have occurred through primate evolution, with the H2 haplotype being the ancestral state. Neandertals harbored the H1 haplotype; however, until now, no data were available for the Denisova hominin. Neandertals and Denisovans are sister groups that share a common ancestor with modern humans. We analyzed the MAPT sequence and assessed the differences between modern humans, Neandertals, Denisovans, and great apes. Our analysis indicated that the Denisova hominin carried the H1 haplotype, and the Neandertal and Denisova common ancestor probably shared the same subhaplotype (H1j). We also found 68 intronic variants within the MAPT gene, 23 exclusive to Denisova hominin, 6 limited to Neandertals, and 24 exclusive to present-day humans. Our results reinforce previous data; this suggests that the 17q21 inversion arose within the modern human lineage. The data also indicate that archaic hominins that coexisted in Eurasia probably shared the same MAPT subhaplotype, and this can be found in almost 2% of chromosomes from European ancestry. Copyright © 2013 Wayne State University Press, Detroit, Michigan 48201-1309.

  3. The Influence of Life History and Sexual Dimorphism on Entheseal Changes in Modern Humans and African Great Apes

    PubMed Central

    Milella, Marco

    2014-01-01

    Entheseal changes have been widely studied with regard to their correlation to biomechanical stress and their usefulness for biocultural reconstructions. However, anthropological and medical studies have demonstrated the marked influence of both age and sex on the development of these features. Studies of entheseal changes are mostly aimed in testing functional hypotheses and are mostly focused on modern humans, with few data available for non-human primates. The lack of comparative studies on the effect of age and sex on entheseal changes represent a gap in our understanding of the evolutionary basis of both development and degeneration of the human musculoskeletal system. The aim of the present work is to compare age trajectories and patterns of sexual dimorphism in entheseal changes between modern humans and African great apes. To this end we analyzed 23 postcranial entheses in a human contemporary identified skeletal collection (N = 484) and compared the results with those obtained from the analysis of Pan (N = 50) and Gorilla (N = 47) skeletal specimens. Results highlight taxon-specific age trajectories possibly linked to differences in life history schedules and phyletic relationships. Robusticity trajectories separate Pan and modern humans from Gorilla, whereas enthesopathic patterns are unique in modern humans and possibly linked to their extended potential lifespan. Comparisons between sexes evidence a decreasing dimorphism in robusticity from Gorilla, to modern humans to Pan, which is likely linked to the role played by size, lifespan and physical activity on robusticity development. The present study confirms previous hypotheses on the possible relevance of EC in the study of life history, pointing moreover to their usefulness in evolutionary studies. PMID:25251439

  4. The influence of life history and sexual dimorphism on entheseal changes in modern humans and African great apes.

    PubMed

    Milella, Marco

    2014-01-01

    Entheseal changes have been widely studied with regard to their correlation to biomechanical stress and their usefulness for biocultural reconstructions. However, anthropological and medical studies have demonstrated the marked influence of both age and sex on the development of these features. Studies of entheseal changes are mostly aimed in testing functional hypotheses and are mostly focused on modern humans, with few data available for non-human primates. The lack of comparative studies on the effect of age and sex on entheseal changes represent a gap in our understanding of the evolutionary basis of both development and degeneration of the human musculoskeletal system. The aim of the present work is to compare age trajectories and patterns of sexual dimorphism in entheseal changes between modern humans and African great apes. To this end we analyzed 23 postcranial entheses in a human contemporary identified skeletal collection (N = 484) and compared the results with those obtained from the analysis of Pan (N = 50) and Gorilla (N = 47) skeletal specimens. Results highlight taxon-specific age trajectories possibly linked to differences in life history schedules and phyletic relationships. Robusticity trajectories separate Pan and modern humans from Gorilla, whereas enthesopathic patterns are unique in modern humans and possibly linked to their extended potential lifespan. Comparisons between sexes evidence a decreasing dimorphism in robusticity from Gorilla, to modern humans to Pan, which is likely linked to the role played by size, lifespan and physical activity on robusticity development. The present study confirms previous hypotheses on the possible relevance of EC in the study of life history, pointing moreover to their usefulness in evolutionary studies.

  5. Chromosomal Rearrangements as Barriers to Genetic Homogenization between Archaic and Modern Humans

    PubMed Central

    Rogers, Rebekah L.

    2015-01-01

    Chromosomal rearrangements, which shuffle DNA throughout the genome, are an important source of divergence across taxa. Using a paired-end read approach with Illumina sequence data for archaic humans, I identify changes in genome structure that occurred recently in human evolution. Hundreds of rearrangements indicate genomic trafficking between the sex chromosomes and autosomes, raising the possibility of sex-specific changes. Additionally, genes adjacent to genome structure changes in Neanderthals are associated with testis-specific expression, consistent with evolutionary theory that new genes commonly form with expression in the testes. I identify one case of new-gene creation through transposition from the Y chromosome to chromosome 10 that combines the 5′-end of the testis-specific gene Fank1 with previously untranscribed sequence. This new transcript experienced copy number expansion in archaic genomes, indicating rapid genomic change. Among rearrangements identified in Neanderthals, 13% are transposition of selfish genetic elements, whereas 32% appear to be ectopic exchange between repeats. In Denisovan, the pattern is similar but numbers are significantly higher with 18% of rearrangements reflecting transposition and 40% ectopic exchange between distantly related repeats. There is an excess of divergent rearrangements relative to polymorphism in Denisovan, which might result from nonuniform rates of mutation, possibly reflecting a burst of transposable element activity in the lineage that led to Denisovan. Finally, loci containing genome structure changes show diminished rates of introgression from Neanderthals into modern humans, consistent with the hypothesis that rearrangements serve as barriers to gene flow during hybridization. Together, these results suggest that this previously unidentified source of genomic variation has important biological consequences in human evolution. PMID:26399483

  6. Earliest Archaeological Evidence of Persistent Hominin Carnivory

    PubMed Central

    Ferraro, Joseph V.; Plummer, Thomas W.; Pobiner, Briana L.; Oliver, James S.; Bishop, Laura C.; Braun, David R.; Ditchfield, Peter W.; Seaman, John W.; Binetti, Katie M.; Seaman, John W.; Hertel, Fritz; Potts, Richard

    2013-01-01

    The emergence of lithic technology by ∼2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ∼1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ∼2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence – spanning hundreds to thousands of years – and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution. PMID:23637995

  7. The earliest history of diaphragm physiology.

    PubMed

    Derenne, J P; Debru, A; Grassino, A E; Whitelaw, W A

    1994-12-01

    The diaphragm was recognized as a distinct anatomical structure in the earliest Greek writings. However, the precise description of wounds suffered by warriors during the Trojan war by Homer was not tied to any particular function. The diaphragm was assimilated to the region that harbours thought. The first physiologic explanations of respiration by Empedocles in the 5th century BC and the concepts introduced by Plato and Hippocrates did not include a significant participation of the diaphragm. Aristole was the first to link respiration to a particular organ and a specific movement of the thorax. However, he considered that it was the heart which caused the lungs to expand by heating them, and the lungs in turn forced the thorax to dilate, a concept which was to survive until the 17th century. As in Aristole's theory the diaphragm played no role in respiration and was just a fence separating the thorax from the abdomen. A major break through occurred in Alexandria in the 4th and 3rd century BC: Herophilus was the first to recognize that muscles were the agents of movement and Erasistratus performed animal experiments which showed that the respiratory muscles were the agents of respiratory movements, thus opening the way to the later discoveries of Galen.

  8. Skeletal development of hallucal tarsometatarsal joint curvature and angulation in extant apes and modern humans.

    PubMed

    Gill, Corey M; Bredella, Miriam A; DeSilva, Jeremy M

    2015-11-01

    The medial cuneiform, namely the curvature and angulation of its distal facet with metatarsal 1, is crucial as a stabilizer in bipedal locomotion and an axis upon which the great toe medially deviates during arboreal locomotion in extant apes. Previous work has shown that facet curvature and angulation in adult dry-bone specimens can distinguish African apes from Homo, and can even distinguish among species of Gorilla. This study provides the first ontogenetic assessment of medial cuneiform curvature and angulation in juvenile (n = 68) and adult specimens (n = 102) using computed tomography in humans and extant ape specimens, including Pongo. Our data find that modern human juveniles initially have a convex and slightly medially oriented osseous surface of the developing medial cuneiform distal facet that flattens and becomes more distally oriented with age. The same pattern (though of a different magnitude) occurs developmentally in the chimpanzee medial cuneiform, but not in Gorilla or Pongo, whose medial cuneiform facet angulation remains unchanged ontogenetically. These data suggest that the medial cuneiform ossifies in a distinguishable pattern between Pongo, Gorilla, Pan, and Homo, which may in part be due to subtle differences in the loading environment at the hallucal tarsometatarsal joint-a finding that has important implications for interpreting fossil medial cuneiforms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. The deep human prehistory of global tropical forests and its relevance for modern conservation.

    PubMed

    Roberts, Patrick; Hunt, Chris; Arroyo-Kalin, Manuel; Evans, Damian; Boivin, Nicole

    2017-08-03

    Significant human impacts on tropical forests have been considered the preserve of recent societies, linked to large-scale deforestation, extensive and intensive agriculture, resource mining, livestock grazing and urban settlement. Cumulative archaeological evidence now demonstrates, however, that Homo sapiens has actively manipulated tropical forest ecologies for at least 45,000 years. It is clear that these millennia of impacts need to be taken into account when studying and conserving tropical forest ecosystems today. Nevertheless, archaeology has so far provided only limited practical insight into contemporary human-tropical forest interactions. Here, we review significant archaeological evidence for the impacts of past hunter-gatherers, agriculturalists and urban settlements on global tropical forests. We compare the challenges faced, as well as the solutions adopted, by these groups with those confronting present-day societies, which also rely on tropical forests for a variety of ecosystem services. We emphasize archaeology's importance not only in promoting natural and cultural heritage in tropical forests, but also in taking an active role to inform modern conservation and policy-making.

  10. Traditional and Modern Uses of Natural Honey in Human Diseases: A Review

    PubMed Central

    Eteraf-Oskouei, Tahereh; Najafi, Moslem

    2013-01-01

    Honey is a by-product of flower nectar and the upper aero-digestive tract of the honey bee, which is concentrated through a dehydration process inside the bee hive. Honey has a very complex chemical composition that varies depending on the botanical source. It has been used both as food and medicine since ancient times. Human use of honey is traced to some 8000 years ago as depicted by Stone Age paintings. In addition to important role of natural honey in the traditional medicine, during the past few decades, it was subjected to laboratory and clinical investigations by several research groups and it has found a place in modern medicine. Honey has been reported to have an inhibitory effect on around 60 species of bacteria, some species of fungi and viruses. Antioxidant capacity of honey is important in many disease conditions and is due to a wide range of compounds including phenolics, peptides, organic acids, enzymes, and Maillard reaction products. Honey has also been used in some gastrointestinal, cardiovascular, inflammatory and neoplastic states. This review covers the composition, physico-chemical properties and the most important uses of natural honey in human diseases. PMID:23997898

  11. Ancient cellular structures and modern humans: change of survival strategies before prolonged low solar activity period

    NASA Astrophysics Data System (ADS)

    Ragulskaya, Mariya; Rudenchik, Evgeniy; Gromozova, Elena; Voychuk, Sergei; Kachur, Tatiana

    The study of biotropic effects of modern space weather carries the information about the rhythms and features of adaptation of early biological systems to the outer space influence. The influence of cosmic rays, ultraviolet waves and geomagnetic field on early life has its signs in modern biosphere processes. These phenomena could be experimentally studied on present-day biological objects. Particularly inorganic polyphosphates, so-called "fossil molecules", attracts special attention as the most ancient molecules which arose in inanimate nature and have been accompanying biological objects at all stages of evolution. Polyphosphates-containing graves of yeast's cells of Saccharomyces cerevisiae strain Y-517, , from the Ukrainian Collection of Microorganisms was studied by daily measurements during 2000-2013 years. The IZMIRAN daily data base of physiological parameters dynamics during 2000-2013 years were analyzed simultaneously (25 people). The analysis showed significant simultaneous changes of the statistical parameters of the studied biological systems in 2004 -2006. The similarity of simultaneous changes of adaptation strategies of human organism and the cell structures of Saccharomyces cerevisiae during the 23-24 cycles of solar activity are discussed. This phenomenon could be due to a replacement of bio-effective parameters of space weather during the change from 23rd to 24th solar activity cycle and nonstandard geophysical peculiarities of the 24th solar activity cycle. It could be suggested that the observed similarity arose as the optimization of evolution selection of the living systems in expectation of probable prolonged period of low solar activity (4-6 cycles of solar activity).

  12. Quantifying long-term human impact in contrasting environments: Statistical analysis of modern and fossil pollen records

    NASA Astrophysics Data System (ADS)

    Broothaerts, Nils; López-Sáez, José Antonio; Verstraeten, Gert

    2017-04-01

    Reconstructing and quantifying human impact is an important step to understand human-environment interactions in the past. Quantitative measures of human impact on the landscape are needed to fully understand long-term influence of anthropogenic land cover changes on the global climate, ecosystems and geomorphic processes. Nevertheless, quantifying past human impact is not straightforward. Recently, multivariate statistical analysis of fossil pollen records have been proposed to characterize vegetation changes and to get insights in past human impact. Although statistical analysis of fossil pollen data can provide useful insights in anthropogenic driven vegetation changes, still it cannot be used as an absolute quantification of past human impact. To overcome this shortcoming, in this study fossil pollen records were included in a multivariate statistical analysis (cluster analysis and non-metric multidimensional scaling (NMDS)) together with modern pollen data and modern vegetation data. The information on the modern pollen and vegetation dataset can be used to get a better interpretation of the representativeness of the fossil pollen records, and can result in a full quantification of human impact in the past. This methodology was applied in two contrasting environments: SW Turkey and Central Spain. For each region, fossil pollen data from different study sites were integrated, together with modern pollen data and information on modern vegetation. In this way, arboreal cover, grazing pressure and agricultural activities in the past were reconstructed and quantified. The data from SW Turkey provides new integrated information on changing human impact through time in the Sagalassos territory, and shows that human impact was most intense during the Hellenistic and Roman Period (ca. 2200-1750 cal a BP) and decreased and changed in nature afterwards. The data from central Spain shows for several sites that arboreal cover decreases bellow 5% from the Feudal period

  13. The human dimensions of climate change: A micro-level assessment of views from the ecological modernization, political economy and human ecology perspectives.

    PubMed

    Adua, Lazarus; York, Richard; Schuelke-Leech, Beth-Anne

    2016-03-01

    Understanding the manifold human and physical dimensions of climate change has become an area of great interest to researchers in recent decades. Using a U.S. nationally-representative data set and drawing on the ecological modernization, political economy, and human ecology perspectives, this study examines the impacts of energy efficiency technologies, affluence, household demographics, and biophysical characteristics on residential CO2 emissions. Overall, the study provides mixed support for the ecological modernization perspective. While several findings are consistent with the theory's expectation that modern societies can harness technology to mitigate human impacts on the environment, others directly contradict it. Also, the theory's prediction of an inverted U-shaped relationship between affluence and environmental impacts is contradicted. The evidence is somewhat more supportive of the political economy and human ecology perspectives, with affluence, some indicators of technology, household demographics, and biophysical characteristics emerging as important drivers of residential CO2 emissions. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Testing the equivalence of modern human cranial covariance structure: Implications for bioarchaeological applications.

    PubMed

    von Cramon-Taubadel, Noreen; Schroeder, Lauren

    2016-10-01

    Estimation of the variance-covariance (V/CV) structure of fragmentary bioarchaeological populations requires the use of proxy extant V/CV parameters. However, it is currently unclear whether extant human populations exhibit equivalent V/CV structures. Random skewers (RS) and hierarchical analyses of common principal components (CPC) were applied to a modern human cranial dataset. Cranial V/CV similarity was assessed globally for samples of individual populations (jackknifed method) and for pairwise population sample contrasts. The results were examined in light of potential explanatory factors for covariance difference, such as geographic region, among-group distance, and sample size. RS analyses showed that population samples exhibited highly correlated multivariate responses to selection, and that differences in RS results were primarily a consequence of differences in sample size. The CPC method yielded mixed results, depending upon the statistical criterion used to evaluate the hierarchy. The hypothesis-testing (step-up) approach was deemed problematic due to sensitivity to low statistical power and elevated Type I errors. In contrast, the model-fitting (lowest AIC) approach suggested that V/CV matrices were proportional and/or shared a large number of CPCs. Pairwise population sample CPC results were correlated with cranial distance, suggesting that population history explains some of the variability in V/CV structure among groups. The results indicate that patterns of covariance in human craniometric samples are broadly similar but not identical. These findings have important implications for choosing extant covariance matrices to use as proxy V/CV parameters in evolutionary analyses of past populations. © 2016 Wiley Periodicals, Inc.

  15. From fish to modern humans--comparative anatomy, homologies and evolution of the head and neck musculature.

    PubMed

    Diogo, R; Abdala, V; Lonergan, N; Wood, B A

    2008-10-01

    In a recent paper Diogo (2008) reported the results of the first part of an investigation of the comparative anatomy, homologies and evolution of the head and neck muscles of osteichthyans (bony fish + tetrapods). That report mainly focused on actinopterygian fish, but also compared these fish with certain non-mammalian sarcopterygians. The present paper focuses mainly on sarcopterygians, and particularly on how the head and neck muscles have evolved during the transitions from sarcopterygian fish and non-mammalian tetrapods to monotreme and therian mammals, including modern humans. The data obtained from our dissections of the head and neck muscles of representative members of sarcopterygian fish, amphibians, reptiles, monotremes and therian mammals, such as rodents, tree-shrews, colugos and primates, including modern humans, are compared with the information available in the literature. Our observations and comparisons indicate that the number of mandibular and true branchial muscles (sensu this work) present in modern humans is smaller than that found in mammals such as tree-shrews, rats and monotremes, as well as in reptiles such as lizards. Regarding the pharyngeal musculature, there is an increase in the number of muscles at the time of the evolutionary transition leading to therian mammals, but there was no significant increase during the transition leading to the emergence of higher primates and modern humans. The number of hypobranchial muscles is relatively constant within the therian mammals we examined, although in this case modern humans have more muscles than other mammals. The number of laryngeal and facial muscles in modern humans is greater than that found in most other therian taxa. Interestingly, modern humans possess peculiar laryngeal and facial muscles that are not present in the majority of the other mammalian taxa; this seems to corroborate the crucial role played by vocal communication and by facial expressions in primate and especially in

  16. Tracing the route of modern humans out of Africa by using 225 human genome sequences from Ethiopians and Egyptians.

    PubMed

    Pagani, Luca; Schiffels, Stephan; Gurdasani, Deepti; Danecek, Petr; Scally, Aylwyn; Chen, Yuan; Xue, Yali; Haber, Marc; Ekong, Rosemary; Oljira, Tamiru; Mekonnen, Ephrem; Luiselli, Donata; Bradman, Neil; Bekele, Endashaw; Zalloua, Pierre; Durbin, Richard; Kivisild, Toomas; Tyler-Smith, Chris

    2015-06-04

    The predominantly African origin of all modern human populations is well established, but the route taken out of Africa is still unclear. Two alternative routes, via Egypt and Sinai or across the Bab el Mandeb strait into Arabia, have traditionally been proposed as feasible gateways in light of geographic, paleoclimatic, archaeological, and genetic evidence. Distinguishing among these alternatives has been difficult. We generated 225 whole-genome sequences (225 at 8× depth, of which 8 were increased to 30×; Illumina HiSeq 2000) from six modern Northeast African populations (100 Egyptians and five Ethiopian populations each represented by 25 individuals). West Eurasian components were masked out, and the remaining African haplotypes were compared with a panel of sub-Saharan African and non-African genomes. We showed that masked Northeast African haplotypes overall were more similar to non-African haplotypes and more frequently present outside Africa than were any sets of haplotypes derived from a West African population. Furthermore, the masked Egyptian haplotypes showed these properties more markedly than the masked Ethiopian haplotypes, pointing to Egypt as the more likely gateway in the exodus to the rest of the world. Using five Ethiopian and three Egyptian high-coverage masked genomes and the multiple sequentially Markovian coalescent (MSMC) approach, we estimated the genetic split times of Egyptians and Ethiopians from non-African populations at 55,000 and 65,000 years ago, respectively, whereas that of West Africans was estimated to be 75,000 years ago. Both the haplotype and MSMC analyses thus suggest a predominant northern route out of Africa via Egypt. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. [Using some modern mathematical models of postmortem cooling of the human body for the time of death determination].

    PubMed

    Vavilov, A Iu; Viter, V I

    2007-01-01

    Mathematical questions of data errors of modern thermometrical models of postmortem cooling of the human body are considered. The main diagnostic areas used for thermometry are analyzed to minimize these data errors. The authors propose practical recommendations to decrease data errors of determination of prescription of death coming.

  18. Modern Functions of a Textbook on Social Sciences and Humanities as an Informational Management Tool of University Education

    ERIC Educational Resources Information Center

    Nikonova, Elina I.; Sharonov, Ivan A.; Sorokoumova, Svetlana N.; Suvorova, Olga V.; Sorokoumova, Elena A.

    2016-01-01

    The relevance of the study is conditioned by the changes in the content of socio-humanitarian education, aimed at the acquisition of knowledge, the development of tolerance, civic and moral education. The purpose of the paper is to identify the modern functions of a textbook on social sciences and humanities as an informational management tool of…

  19. Southern African ancient genomes estimate modern human divergence to 350,000 to 260,000 years ago.

    PubMed

    Schlebusch, Carina M; Malmström, Helena; Günther, Torsten; Sjödin, Per; Coutinho, Alexandra; Edlund, Hanna; Munters, Arielle R; Vicente, Mário; Steyn, Maryna; Soodyall, Himla; Lombard, Marlize; Jakobsson, Mattias

    2017-11-03

    Southern Africa is consistently placed as a potential region for the evolution of Homo sapiens We present genome sequences, up to 13x coverage, from seven ancient individuals from KwaZulu-Natal, South Africa. The remains of three Stone Age hunter-gatherers (about 2000 years old) were genetically similar to current-day southern San groups, and those of four Iron Age farmers (300 to 500 years old) were genetically similar to present-day Bantu-language speakers. We estimate that all modern-day Khoe-San groups have been influenced by 9 to 30% genetic admixture from East Africans/Eurasians. Using traditional and new approaches, we estimate the first modern human population divergence time to between 350,000 and 260,000 years ago. This estimate increases the deepest divergence among modern humans, coinciding with anatomical developments of archaic humans into modern humans, as represented in the local fossil record. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  20. 29 CFR 4022.10 - Earliest PBGC Retirement Date.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... after the date the participant reaches age 55, the Earliest PBGC Retirement Date for the participant is... reaches age 55, the Earliest PBGC Retirement Date for the participant is the date the participant reaches... participant reaches age 55, the PBGC will make a determination, under the facts and circumstances, as to...

  1. 29 CFR 4022.10 - Earliest PBGC Retirement Date.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... after the date the participant reaches age 55, the Earliest PBGC Retirement Date for the participant is... reaches age 55, the Earliest PBGC Retirement Date for the participant is the date the participant reaches... participant reaches age 55, the PBGC will make a determination, under the facts and circumstances, as to...

  2. New insights into differences in brain organization between Neanderthals and anatomically modern humans

    PubMed Central

    Pearce, Eiluned; Stringer, Chris; Dunbar, R. I. M.

    2013-01-01

    Previous research has identified morphological differences between the brains of Neanderthals and anatomically modern humans (AMHs). However, studies using endocasts or the cranium itself are limited to investigating external surface features and the overall size and shape of the brain. A complementary approach uses comparative primate data to estimate the size of internal brain areas. Previous attempts to do this have generally assumed that identical total brain volumes imply identical internal organization. Here, we argue that, in the case of Neanderthals and AMHs, differences in the size of the body and visual system imply differences in organization between the same-sized brains of these two taxa. We show that Neanderthals had significantly larger visual systems than contemporary AMHs (indexed by orbital volume) and that when this, along with their greater body mass, is taken into account, Neanderthals have significantly smaller adjusted endocranial capacities than contemporary AMHs. We discuss possible implications of differing brain organization in terms of social cognition, and consider these in the context of differing abilities to cope with fluctuating resources and cultural maintenance. PMID:23486442

  3. Ca Isotopes Fingerprinting the Earliest Crustal Evolution

    NASA Astrophysics Data System (ADS)

    Kreissig, K.; Elliott, T. R.

    2001-12-01

    The mechanisms of continent formation remain unclear and can be explained in two contrasting ways, using either a steady state crustal growth model involving massive crustal recycling or continuous crustal growth models. Recent developments in mass spectrometry manifest in the new Finnigan-Triton allow Ca isotopic measurements precise enough to use the K-Ca isotope system to address the problem of early Archaean crustal evolution. Due to a strong fractionation of 40K and 40Ca during continent formation and a non-linear growth of 40Ca, Archaean continental crust should show radiogenic initial Ca isotopic composition if large volumes of it have already been existed 3.6 Ga ago. Simple 15-step calculations predict a difference in 40Ca /44Ca of 9 epsilon units at 3.6 Ga between the two crustal growth models. To test this, as well as to study the earliest crust formation processes, plagioclase separates from Archaean provinces reflecting the initial Ca isotopic composition and a range of different whole rock samples have been analysed. Preliminary data for ~ 3.6 Ga old TTGs from Zimbabwe show 40Ca /44Ca indistinguishable from the mantle. This is in agreement with rather chondritic initial Sr and Nd data and might reflect a short residence time of the juvenile mafic oceanic crust before partial melting forming the first continental crust. In contrast, the first results for 3.65 Ga old samples from the Itsaq Gneiss Complex of southern West Greenland yield a more evolved radiogenic Ca signature. This can be interpreted in two different ways. Either as partial melting of juvenile mafic crust shortly after its formation but incorporating already existing crust as also suggested by the existence of older inherited zircons in these rocks and negative ɛ Hf values. Partial melting of mafic oceanic crust long after its formation so that 40K and 40Ca had time to evolve would be an alternative explanation. Importantly, there is no evidence so far for high growth and recycling rates

  4. The Flynn Effect: A Quantitative Commentary on Modernity and Human Intelligence

    ERIC Educational Resources Information Center

    Clark, Cameron M.; Lawlor-Savage, Linette; Goghari, Vina M.

    2016-01-01

    Average intelligence quotient (IQ) scores have been rising throughout the 20th century and likely before--a pattern now known as the Flynn effect. The central thesis of this paper is that the Flynn effect does not represent genuine increases in general intelligence but rather an increasing aptitude for the types of modern thinking that modern life…

  5. Earliest colobine skeletons from Nakali, Kenya.

    PubMed

    Nakatsukasa, Masato; Mbua, Emma; Sawada, Yoshihiro; Sakai, Tetsuya; Nakaya, Hideo; Yano, Wataru; Kunimatsu, Yutaka

    2010-11-01

    Old World monkeys represent one of the most successful adaptive radiations of modern primates, but a sparse fossil record has limited our knowledge about the early evolution of this clade. We report the discovery of two partial skeletons of an early colobine monkey (Microcolobus) from the Nakali Formation (9.8-9.9 Ma) in Kenya that share postcranial synapomorphies with extant colobines in relation to arboreality such as mediolaterally wide distal humeral joint, globular humeral capitulum, distinctly angled zona conoidea, reduced medial trochlear keel, long medial epicondyle with weak retroflexion, narrow and tall olecranon, posteriorly dislocated fovea on the radial head, low projection of the femoral greater trochanter, wide talar head with a greater rotation, and proximodistally short cuboid and ectocuneiform. Microcolobus in Nakali clearly differs from the stem cercopithecoid Victoriapithecus regarding these features, as Victoriapithecus is postcranially similar to extant small-sized terrestrial cercopithecines. However, degeneration of the thumb, a hallmark of modern colobines, is not observed, suggesting that this was a late event in colobine evolution. This discovery contradicts the prevailing hypothesis that the forest invasion by cercopithecids first occurred in the Plio-Pleistocene, and shows that this event occurred by the late Miocene at a time when ape diversity declined. © 2010 Wiley-Liss, Inc.

  6. Fractal dimension of the middle meningeal vessels: variation and evolution in Homo erectus, Neanderthals, and modern humans.

    PubMed

    Bruner, Emiliano; Mantini, Simone; Perna, Agostino; Maffei, Carlotta; Manzi, Giorgio

    2005-01-01

    The middle meningeal vascular network leaves its traces on the endocranial surface because of the tight relationship between neurocranial development and brain growth. Analysing the endocast of fossil specimens, it is therefore possible to describe the morphology of these structures, leading inferences on the cerebral physiology and metabolism in extinct human groups. In this paper, general features of the meningeal vascular traces are described for specimens included in the Homo erectus, Homo neanderthalensis, and Homo sapiens hypodigms. The complexity of the arterial network is quantified by its fractal dimension, calculated through the box-counting method. Modern humans show significant differences from the other two taxa because of the anterior vascular dominance and the larger fractal dimension. Neither the fractal dimension nor the anterior development are merely associated with cranial size increase. Considering the differences between Neanderthals and modern humans, these results may be interpreted in terms of phylogeny, cerebral functions, or cranial structural network.

  7. Earliest evidence of pollution by heavy metals in archaeological sites

    PubMed Central

    Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-01-01

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence. PMID:26388184

  8. Earliest evidence of pollution by heavy metals in archaeological sites.

    PubMed

    Monge, Guadalupe; Jimenez-Espejo, Francisco J; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-09-21

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called "Anthropocene". According to its heavy metal concentration, these sediments meet the present-day standards of "contaminated soil". Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

  9. Earliest evidence of pollution by heavy metals in archaeological sites

    NASA Astrophysics Data System (ADS)

    Monge, Guadalupe; Jimenez-Espejo, Francisco J.; García-Alix, Antonio; Martínez-Ruiz, Francisca; Mattielli, Nadine; Finlayson, Clive; Ohkouchi, Naohiko; Sánchez, Miguel Cortés; de Castro, Jose María Bermúdez; Blasco, Ruth; Rosell, Jordi; Carrión, José; Rodríguez-Vidal, Joaquín; Finlayson, Geraldine

    2015-09-01

    Homo species were exposed to a new biogeochemical environment when they began to occupy caves. Here we report the first evidence of palaeopollution through geochemical analyses of heavy metals in four renowned archaeological caves of the Iberian Peninsula spanning the last million years of human evolution. Heavy metal contents reached high values due to natural (guano deposition) and anthropogenic factors (e.g. combustion) in restricted cave environments. The earliest anthropogenic pollution evidence is related to Neanderthal hearths from Gorham's Cave (Gibraltar), being one of the first milestones in the so-called “Anthropocene”. According to its heavy metal concentration, these sediments meet the present-day standards of “contaminated soil”. Together with the former, the Gibraltar Vanguard Cave, shows Zn and Cu pollution ubiquitous across highly anthropic levels pointing to these elements as potential proxies for human activities. Pb concentrations in Magdalenian and Bronze age levels at El Pirulejo site can be similarly interpreted. Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo populations. Altogether, the data presented here indicate a long-term exposure of Homo to these elements, via fires, fumes and their ashes, which could have played certain role in environmental-pollution tolerance, a hitherto neglected influence.

  10. The earliest evidence of true lambdoid craniosynostosis: the case of "Benjamina", a Homo heidelbergensis child.

    PubMed

    Gracia, Ana; Martínez-Lage, Juan F; Arsuaga, Juan-Luis; Martínez, Ignacio; Lorenzo, Carlos; Pérez-Espejo, Miguel-Angel

    2010-06-01

    The authors report the morphological and neuroimaging findings of an immature human fossil (Cranium 14) diagnosed with left lambdoid synostosis. The skull was recovered at the Sima de los Huesos site in Atapuerca (Burgos, Spain). Since the human fossil remains from this site have been dated to a minimum age of 530,000 years, this skull represents the earliest evidence of craniosynostosis occurring in a hominid. A brief historical review of craniosynostosis and cranial deformation is provided.

  11. Ontogenetic changes in the internal and external morphology of the ilium in modern humans

    PubMed Central

    Abel, Richard; Macho, Gabriele A

    2011-01-01

    Trabecular architecture forms an important structural component of bone and, depending on the loading conditions encountered during life, is organised in a systematic, bone- and species-specific manner. However, recent studies suggested that gross trabecular arrangement (e.g. density distribution), like overall bone shape, is predetermined and/or affected by factors other than loading and perhaps less plastic than commonly assumed. To explore this issue further, the present cross-sectional ontogenetic study investigated morphological changes in external bone shape in relation to changes in trabecular bundle orientation and anisotropy. Radiographs of 73 modern human ilia were assessed using radiographic and Geometric Morphometric techniques. The study confirmed the apparently strong predetermination of trabecular bundle development, i.e. prior to external loading, although loading clearly also had an effect on overall morphology. For example, the sacro-pubic bundle, which follows the path of load transmission from the auricular surface to the acetabulum, is well defined and shows relatively high levels of anisotropy from early stages of development; the situation for the ischio-iliac strut is similar. However, while the sacro-pubic strut retains a constant relationship with the external landmarks defining the joint surfaces, the ischio-iliac bundle changes its relationship with the external landmarks and becomes aligned with the iliac tubercle only during late adolescence/early adulthood. It is tentatively proposed that the rearrangement of the ischio-iliac strut may reflect a change in locomotor pattern and/or a shift in positional behavior with increasing mass after growth of external bone dimensions has slowed/ceased. PMID:21323915

  12. Nasal airflow simulations suggest convergent adaptation in Neanderthals and modern humans.

    PubMed

    de Azevedo, S; González, M F; Cintas, C; Ramallo, V; Quinto-Sánchez, M; Márquez, F; Hünemeier, T; Paschetta, C; Ruderman, A; Navarro, P; Pazos, B A; Silva de Cerqueira, C C; Velan, O; Ramírez-Rozzi, F; Calvo, N; Castro, H G; Paz, R R; González-José, R

    2017-11-21

    Both modern humans (MHs) and Neanderthals successfully settled across western Eurasian cold-climate landscapes. Among the many adaptations considered as essential to survival in such landscapes, changes in the nasal morphology and/or function aimed to humidify and warm the air before it reaches the lungs are of key importance. Unfortunately, the lack of soft-tissue evidence in the fossil record turns difficult any comparative study of respiratory performance. Here, we reconstruct the internal nasal cavity of a Neanderthal plus two representatives of climatically divergent MH populations (southwestern Europeans and northeastern Asians). The reconstruction includes mucosa distribution enabling a realistic simulation of the breathing cycle in different climatic conditions via computational fluid dynamics. Striking across-specimens differences in fluid residence times affecting humidification and warming performance at the anterior tract were found under cold/dry climate simulations. Specifically, the Asian model achieves a rapid air conditioning, followed by the Neanderthals, whereas the European model attains a proper conditioning only around the medium-posterior tract. In addition, quantitative-genetic evolutionary analyses of nasal morphology provided signals of stabilizing selection for MH populations, with the removal of Arctic populations turning covariation patterns compatible with evolution by genetic drift. Both results indicate that, departing from important craniofacial differences existing among Neanderthals and MHs, an advantageous species-specific respiratory performance in cold climates may have occurred in both species. Fluid dynamics and evolutionary biology independently provided evidence of nasal evolution, suggesting that adaptive explanations regarding complex functional phenotypes require interdisciplinary approaches aimed to quantify both performance and evolutionary signals on covariation patterns.

  13. Femoral curvature variability in modern humans using three-dimensional quadric surface fitting.

    PubMed

    Chapman, Tara; Sholukha, Victor; Semal, Patrick; Louryan, Stéphane; Rooze, Marcel; Van Sint Jan, Serge

    2015-12-01

    This study analysed femoral curvature in a population from Belgium in conjunction with other morphological characteristics by the use of three-dimensional (3D) quadric surfaces (QS) modelled from the bone surface. 3D models were created from computed tomography data of 75 femoral modern human bones. Anatomical landmarks (ALs) were palpated in specific bony areas of the femur (shaft, condyles, neck and head). QS were then created from the surface vertices which enclose these ALs. The diaphyseal shaft was divided into five QS shapes to analyse curvature in different parts of the shaft. Femoral bending differs in different parts of the diaphyseal shaft. The greatest degree of curvature was found in the distal shaft (mean 4.5° range 0.2°-10°) followed by the proximal (mean 4.4° range 1.5°-10.2°), proximal intermediate (mean 3.7° range 0.9°-7.9°) and distal intermediate (mean 1.8° range 0.2°-5.6°) shaft sections. The proximal and distal angles were significantly more bowed than the intermediate proximal and the intermediate distal angle. There was no significant difference between the proximal and distal angle. No significant correlations were found between morphological characteristics and femoral curvature. An extremely large variability of femoral curvature with several bones displaying very high or low degrees of femoral curvature was also found. 3D QS fitting enables the creation of accurate models which can discriminate between different patterns in similar curvatures and demonstrates there is a clear difference between curvature in different parts of the shaft.

  14. Using modern human cortical bone distribution to test the systemic robusticity hypothesis.

    PubMed

    Baab, Karen L; Copes, Lynn E; Ward, Devin L; Wells, Nora; Grine, Frederick E

    2018-06-01

    The systemic robusticity hypothesis links the thickness of cortical bone in both the cranium and limb bones. This hypothesis posits that thick cortical bone is in part a systemic response to circulating hormones, such as growth hormone and thyroid hormone, possibly related to physical activity or cold climates. Although this hypothesis has gained popular traction, only rarely has robusticity of the cranium and postcranial skeleton been considered jointly. We acquired computed tomographic scans from associated crania, femora and humeri from single individuals representing 11 populations in Africa and North America (n = 228). Cortical thickness in the parietal, frontal and occipital bones and cortical bone area in limb bone diaphyses were analyzed using correlation, multiple regression and general linear models to test the hypothesis. Absolute thickness values from the crania were not correlated with cortical bone area of the femur or humerus, which is at odds with the systemic robusticity hypothesis. However, measures of cortical bone scaled by total vault thickness and limb cross-sectional area were positively correlated between the cranium and postcranium. When accounting for a range of potential confounding variables, including sex, age and body mass, variation in relative postcranial cortical bone area explained ∼20% of variation in the proportion of cortical cranial bone thickness. While these findings provide limited support for the systemic robusticity hypothesis, cranial cortical thickness did not track climate or physical activity across populations. Thus, some of the variation in cranial cortical bone thickness in modern humans is attributable to systemic effects, but the driving force behind this effect remains obscure. Moreover, neither absolute nor proportional measures of cranial cortical bone thickness are positively correlated with total cranial bone thickness, complicating the extrapolation of these findings to extinct species where only cranial

  15. The Red Queen Model of Recombination Hotspots Evolution in the Light of Archaic and Modern Human Genomes

    PubMed Central

    Lesecque, Yann; Glémin, Sylvain; Lartillot, Nicolas; Mouchiroud, Dominique; Duret, Laurent

    2014-01-01

    Recombination is an essential process in eukaryotes, which increases diversity by disrupting genetic linkage between loci and ensures the proper segregation of chromosomes during meiosis. In the human genome, recombination events are clustered in hotspots, whose location is determined by the PRDM9 protein. There is evidence that the location of hotspots evolves rapidly, as a consequence of changes in PRDM9 DNA-binding domain. However, the reasons for these changes and the rate at which they occur are not known. In this study, we investigated the evolution of human hotspot loci and of PRDM9 target motifs, both in modern and archaic human lineages (Denisovan) to quantify the dynamic of hotspot turnover during the recent period of human evolution. We show that present-day human hotspots are young: they have been active only during the last 10% of the time since the divergence from chimpanzee, starting to be operating shortly before the split between Denisovans and modern humans. Surprisingly, however, our analyses indicate that Denisovan recombination hotspots did not overlap with modern human ones, despite sharing similar PRDM9 target motifs. We further show that high-affinity PRDM9 target motifs are subject to a strong self-destructive drive, known as biased gene conversion (BGC), which should lead to the loss of the majority of them in the next 3 MYR. This depletion of PRDM9 genomic targets is expected to decrease fitness, and thereby to favor new PRDM9 alleles binding different motifs. Our refined estimates of the age and life expectancy of human hotspots provide empirical evidence in support of the Red Queen hypothesis of recombination hotspots evolution. PMID:25393762

  16. The red queen model of recombination hotspots evolution in the light of archaic and modern human genomes.

    PubMed

    Lesecque, Yann; Glémin, Sylvain; Lartillot, Nicolas; Mouchiroud, Dominique; Duret, Laurent

    2014-11-01

    Recombination is an essential process in eukaryotes, which increases diversity by disrupting genetic linkage between loci and ensures the proper segregation of chromosomes during meiosis. In the human genome, recombination events are clustered in hotspots, whose location is determined by the PRDM9 protein. There is evidence that the location of hotspots evolves rapidly, as a consequence of changes in PRDM9 DNA-binding domain. However, the reasons for these changes and the rate at which they occur are not known. In this study, we investigated the evolution of human hotspot loci and of PRDM9 target motifs, both in modern and archaic human lineages (Denisovan) to quantify the dynamic of hotspot turnover during the recent period of human evolution. We show that present-day human hotspots are young: they have been active only during the last 10% of the time since the divergence from chimpanzee, starting to be operating shortly before the split between Denisovans and modern humans. Surprisingly, however, our analyses indicate that Denisovan recombination hotspots did not overlap with modern human ones, despite sharing similar PRDM9 target motifs. We further show that high-affinity PRDM9 target motifs are subject to a strong self-destructive drive, known as biased gene conversion (BGC), which should lead to the loss of the majority of them in the next 3 MYR. This depletion of PRDM9 genomic targets is expected to decrease fitness, and thereby to favor new PRDM9 alleles binding different motifs. Our refined estimates of the age and life expectancy of human hotspots provide empirical evidence in support of the Red Queen hypothesis of recombination hotspots evolution.

  17. Testing the hypothesis on cognitive evolution of modern humans' learning ability: current status of past-climatic approaches.

    NASA Astrophysics Data System (ADS)

    Yoneda, Minoru; Abe-Ouchi, Ayako; Kawahata, Hodaka; Yokoyama, Yusuke; Oguchi, Takashi

    2014-05-01

    The impact of climate change on human evolution is important and debating topic for many years. Since 2010, we have involved in a general joint project entitled "Replacement of Neanderthal by Modern Humans: Testing Evolutional Models of Learning", which based on a theoretical prediction that the cognitive ability related to individual and social learning divide fates of ancient humans in very unstable Late Pleistocene climate. This model predicts that the human populations which experienced a series of environmental changes would have higher rate of individual learners, while detailed reconstructions of global climate change have reported fluent and drastic change based on ice cores and stalagmites. However, we want to understand the difference between anatomically modern human which survived and the other archaic extinct humans including European Neanderthals and Asian Denisovans. For this purpose the global synchronized change is not useful for understanding but the regional difference in the amplitude and impact of climate change is the information required. Hence, we invited a geophysicist busing Global Circulation Model to reconstruct the climatic distribution and temporal change in a continental scale. At the same time, some geochemists and geographers construct a database of local climate changes recorded in different proxies. At last, archaeologists and anthropologists tried to interpret the emergence and disappearance of human species in Europe and Asia on the reconstructed past climate maps using some tools, such as Eco-cultural niche model. Our project will show the regional difference in climate change and related archaeological events and its impact on the evolution of learning ability of modern humans.

  18. 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

  19. Genomic and cranial phenotype data support multiple modern human dispersals from Africa and a southern route into Asia

    PubMed Central

    Reyes-Centeno, Hugo; Ghirotto, Silvia; Détroit, Florent; Grimaud-Hervé, Dominique; Barbujani, Guido; Harvati, Katerina

    2014-01-01

    Despite broad consensus on Africa as the main place of origin for anatomically modern humans, their dispersal pattern out of the continent continues to be intensely debated. In extant human populations, the observation of decreasing genetic and phenotypic diversity at increasing distances from sub-Saharan Africa has been interpreted as evidence for a single dispersal, accompanied by a series of founder effects. In such a scenario, modern human genetic and phenotypic variation was primarily generated through successive population bottlenecks and drift during a rapid worldwide expansion out of Africa in the Late Pleistocene. However, recent genetic studies, as well as accumulating archaeological and paleoanthropological evidence, challenge this parsimonious model. They suggest instead a “southern route” dispersal into Asia as early as the late Middle Pleistocene, followed by a separate dispersal into northern Eurasia. Here we test these competing out-of-Africa scenarios by modeling hypothetical geographical migration routes and assessing their correlation with neutral population differentiation, as measured by genetic polymorphisms and cranial shape variables of modern human populations from Africa and Asia. We show that both lines of evidence support a multiple-dispersals model in which Australo-Melanesian populations are relatively isolated descendants of an early dispersal, whereas other Asian populations are descended from, or highly admixed with, members of a subsequent migration event. PMID:24753576

  20. A model for the induction of autism in the ecosystem of the human body: the anatomy of a modern pandemic?

    PubMed Central

    Bilbo, Staci D.; Nevison, Cynthia D.; Parker, William

    2015-01-01

    Background The field of autism research is currently divided based on a fundamental question regarding the nature of autism: Some are convinced that autism is a pandemic of modern culture, with environmental factors at the roots. Others are convinced that the disease is not pandemic in nature, but rather that it has been with humanity for millennia, with its biological and neurological underpinnings just now being understood. Objective In this review, two lines of reasoning are examined which suggest that autism is indeed a pandemic of modern culture. First, given the widely appreciated derailment of immune function by modern culture, evidence that autism is strongly associated with aberrant immune function is examined. Second, evidence is reviewed indicating that autism is associated with ‘triggers’ that are, for the most part, a construct of modern culture. In light of this reasoning, current epidemiological evidence regarding the incidence of autism, including the role of changing awareness and diagnostic criteria, is examined. Finally, the potential role of the microbial flora (the microbiome) in the pathogenesis of autism is discussed, with the view that the microbial flora is a subset of the life associated with the human body, and that the entire human biome, including both the microbial flora and the fauna, has been radically destabilized by modern culture. Conclusions It is suggested that the unequivocal way to resolve the debate regarding the pandemic nature of autism is to perform an experiment: monitor the prevalence of autism after normalizing immune function in a Western population using readily available approaches that address the well-known factors underlying the immune dysfunction in that population. PMID:25634608

  1. A model for the induction of autism in the ecosystem of the human body: the anatomy of a modern pandemic?

    PubMed

    Bilbo, Staci D; Nevison, Cynthia D; Parker, William

    2015-01-01

    The field of autism research is currently divided based on a fundamental question regarding the nature of autism: Some are convinced that autism is a pandemic of modern culture, with environmental factors at the roots. Others are convinced that the disease is not pandemic in nature, but rather that it has been with humanity for millennia, with its biological and neurological underpinnings just now being understood. In this review, two lines of reasoning are examined which suggest that autism is indeed a pandemic of modern culture. First, given the widely appreciated derailment of immune function by modern culture, evidence that autism is strongly associated with aberrant immune function is examined. Second, evidence is reviewed indicating that autism is associated with 'triggers' that are, for the most part, a construct of modern culture. In light of this reasoning, current epidemiological evidence regarding the incidence of autism, including the role of changing awareness and diagnostic criteria, is examined. Finally, the potential role of the microbial flora (the microbiome) in the pathogenesis of autism is discussed, with the view that the microbial flora is a subset of the life associated with the human body, and that the entire human biome, including both the microbial flora and the fauna, has been radically destabilized by modern culture. It is suggested that the unequivocal way to resolve the debate regarding the pandemic nature of autism is to perform an experiment: monitor the prevalence of autism after normalizing immune function in a Western population using readily available approaches that address the well-known factors underlying the immune dysfunction in that population.

  2. Earliest Marker for Autism Found in Young Infants

    MedlinePlus

    ... Release Wednesday, November 6, 2013 Earliest marker for autism found in young infants NIH-funded study finds ... to 6-month-old infants later diagnosed with autism. Decline in eye fixation reveals signs of autism ...

  3. The Earliest Electrophysiological Correlate of Visual Awareness?

    ERIC Educational Resources Information Center

    Koivisto, Mika; Lahteenmaki, Mikko; Sorensen, Thomas Alrik; Vangkilde, Signe; Overgaard, Morten; Revonsuo, Antti

    2008-01-01

    To examine the neural correlates and timing of human visual awareness, we recorded event-related potentials (ERPs) in two experiments while the observers were detecting a grey dot that was presented near subjective threshold. ERPs were averaged for conscious detections of the stimulus (hits) and nondetections (misses) separately. Our results…

  4. On the ecological context of the earliest human settlements in Europe: Resource availability and competition intensity in the carnivore guild of Barranco León-D and Fuente Nueva-3 (Orce, Baza Basin, SE Spain)

    NASA Astrophysics Data System (ADS)

    Rodríguez-Gómez, Guillermo; Palmqvist, Paul; Rodríguez, Jesús; Mateos, Ana; Martín-González, Jesús A.; Espigares, M. Patrocinio; Ros-Montoya, Sergio; Martínez-Navarro, Bienvenido

    2016-07-01

    With an age of ∼1.4 Ma, the Early Pleistocene archaeopaleontological sites of Barranco León and Fuente Nueva-3 (Orce, Baza Basin, SE Spain) provide the oldest evidence on human presence in Western Europe, including the finding of a deciduous tooth of Homo sp., huge lithic assemblages of Oldowan tradition and abundant cut-marks on large mammal bones. Here we use a mathematical approach based on Leslie matrices to quantify for the large mammal species preserved at the sites the biomass of primary consumers available, the distribution of meat resources among the secondary consumers and the competition intensity within the carnivore guild. The results obtained show a community of large mammals with a high diversity of secondary consumers that would satisfy slightly less than half of their dietary requirements under optimal ecological conditions. In the case of Homo sp., and considering that flesh resources were obtained through the scavenging of ungulate carcasses, the model indicates that the ecosystems of the basin could hold 10-14 individuals per 100 km2 during a year, a value that is close to the mean population density of recent hunter-gatherers. These density estimates decrease slightly when a mixed hunting-scavenging strategy is considered and even more in the case of a strict hunting behavior. In addition, the value of the species competition index obtained for Homo sp. is among the lowest of the carnivore guild. These results suggest that the hominin populations that inhabited Southeast Spain during the Early Pleistocene behaved more as opportunistic scavengers than as active predators.

  5. Radiocarbon dating the appearance of modern humans and timing of cultural innovations in Europe: new results and new challenges.

    PubMed

    Conard, Nicholas J; Bolus, Michael

    2003-03-01

    New radiocarbon dates from the sites of Bockstein-Törle, Geissenklösterle, Hohle Fels, Hohlenstein-Stadel, Sirgenstein, and Vogelherd in the Swabian Jura of southwestern Germany indicate that the Aurignacian of the region spans the period from ca. 40-30ka BP. If the situation at Vogelherd, in which skeletal remains from modern humans underlie an entire Aurignacian sequence, is viewed as representative for the region, the dates from the Swabian Jura support the hypothesis that populations of modern humans entered the region by way of the "Danube Corridor." The lithic technology from the lower Aurignacian of Geissenklösterle III is fully developed, and classic Aurignacian forms are well represented. During the course of the Aurignacian, numerous assemblages rich in art works, jewelry, and musical instruments are documented. By no later than 29ka BP the Gravettian was well established in the region. These dates are consistent with the "Kulturpumpe" hypothesis that important cultural innovations of the Aurignacian and Gravettian in Swabia predate similar developments in other regions of Europe. The radiocarbon dates from Geissenklösterle corroborate observations from other non-archaeological data sets indicating large global fluctuations in the atmospheric concentrations of radiocarbon between 30 and 50ka calendar years ago. These fluctuations lead to complications in building reliable chronologies during this period and cause the "Middle Paleolithic Dating Anomaly" and the "Coexistence Effect," which tend to exaggerate the temporal overlap between Neanderthals and modern humans.

  6. Effect of ancient population structure on the degree of polymorphism shared between modern human populations and ancient hominins.

    PubMed

    Eriksson, Anders; Manica, Andrea

    2012-08-28

    Recent comparisons between anatomically modern humans and ancient genomes of other hominins have raised the tantalizing, and hotly debated, possibility of hybridization. Although several tests of hybridization have been devised, they all rely on the degree to which different modern populations share genetic polymorphisms with the ancient genomes of other hominins. However, spatial population structure is expected to generate genetic patterns similar to those that might be attributed to hybridization. To investigate this problem, we take Neanderthals as a case study, and build a spatially explicit model of the shared history of anatomically modern humans and this hominin. We show that the excess polymorphism shared between Eurasians and Neanderthals is compatible with scenarios in which no hybridization occurred, and is strongly linked to the strength of population structure in ancient populations. Thus, we recommend caution in inferring admixture from geographic patterns of shared polymorphisms, and argue that future attempts to investigate ancient hybridization between humans and other hominins should explicitly account for population structure.

  7. The transition to foraging for dense and predictable resources and its impact on the evolution of modern humans

    PubMed Central

    Marean, Curtis W.

    2016-01-01

    Scientists have identified a series of milestones in the evolution of the human food quest that are anticipated to have had far-reaching impacts on biological, behavioural and cultural evolution: the inclusion of substantial portions of meat, the broad spectrum revolution and the transition to food production. The foraging shift to dense and predictable resources is another key milestone that had consequential impacts on the later part of human evolution. The theory of economic defendability predicts that this shift had an important consequence—elevated levels of intergroup territoriality and conflict. In this paper, this theory is integrated with a well-established general theory of hunter–gatherer adaptations and is used to make predictions for the sequence of appearance of several evolved traits of modern humans. The distribution of dense and predictable resources in Africa is reviewed and found to occur only in aquatic contexts (coasts, rivers and lakes). The palaeoanthropological empirical record contains recurrent evidence for a shift to the exploitation of dense and predictable resources by 110 000 years ago, and the first known occurrence is in a marine coastal context in South Africa. Some theory predicts that this elevated conflict would have provided the conditions for selection for the hyperprosocial behaviours unique to modern humans. This article is part of the themed issue ‘Major transitions in human evolution’. PMID:27298470

  8. The transition to foraging for dense and predictable resources and its impact on the evolution of modern humans.

    PubMed

    Marean, Curtis W

    2016-07-05

    Scientists have identified a series of milestones in the evolution of the human food quest that are anticipated to have had far-reaching impacts on biological, behavioural and cultural evolution: the inclusion of substantial portions of meat, the broad spectrum revolution and the transition to food production. The foraging shift to dense and predictable resources is another key milestone that had consequential impacts on the later part of human evolution. The theory of economic defendability predicts that this shift had an important consequence-elevated levels of intergroup territoriality and conflict. In this paper, this theory is integrated with a well-established general theory of hunter-gatherer adaptations and is used to make predictions for the sequence of appearance of several evolved traits of modern humans. The distribution of dense and predictable resources in Africa is reviewed and found to occur only in aquatic contexts (coasts, rivers and lakes). The palaeoanthropological empirical record contains recurrent evidence for a shift to the exploitation of dense and predictable resources by 110 000 years ago, and the first known occurrence is in a marine coastal context in South Africa. Some theory predicts that this elevated conflict would have provided the conditions for selection for the hyperprosocial behaviours unique to modern humans.This article is part of the themed issue 'Major transitions in human evolution'. © 2016 The Author(s).

  9. "Being a Decent Human Being Is a Modern Way To Be a Warrior."

    ERIC Educational Resources Information Center

    Blanc, Darlita J.

    As the Navajo nation undergoes rapid assimilation and modernization, counseling needs of the Navajo children have changed in ways similar to counseling needs in developing or "Eastern Block" nations. An adolescent sub-culture, full of at-risk behaviors, is epidemic worldwide. The paper states that a multicultural perspective can provide…

  10. Palaeoenvironmental reconstructions on the Mozambique coast as a tool to understand human evolution: from modern analogues to borehole interpretation

    NASA Astrophysics Data System (ADS)

    Gomes, Ana; Skosey-LaLonde, Elena; Zinsious, Brandon; Gonçalves, Célia; Bicho, Nuno; Raja, Mussa; Cascalheira, João; Haws, Jonathan

    2017-04-01

    In the framework of the project "Stone Age Vilankulos: Modern Human Origins Research South of the Rio Save, Mozambique" a geoarchaeological survey was conducted in 2016 aiming to better understand the environmental history and landscape evolution of the study area including the environmental context of human occupation. During the survey, 23 sediment surface samples were collected across a variety of environments, namely: freshwater environment - Elephant River basin in Southwestern Mozambique - and brackish and marine tidal environments - Inhambane coastal area, Southeastern Mozambique. These samples will be used as modern analogues to interpret the sedimentological and paleontological record of 4 cores collected in a mangrove area of the Inhambane estuary and then reconstruct its palaeoenvironmental evolution. All the sampling points were georeferenced and the study area was overflown with a drone to collect photogrammetric data. Both surface and core samples were used for diatom, texture and geochemical analysis. Diatoms will be used as the main palaeontological proxy, because they are unicellular algae with a short-live cycle and largely sensible to environmental variables such as salinity, sediment texture and duration of the tidal inundation. Preliminary data on the modern diatoms analysis showed that diatom diversity is high and the equitability is low in all environments. Cores sedimentological description and dating are also presented. The work was supported by the project PTDC/EPHARQ/4168/2014, funded by the Portuguese Foundation for Science and Technology.

  11. Incorporation of Trace Elements in Ancient and Modern Human Bone: An X-Ray Absorption Spectroscopy Study

    NASA Astrophysics Data System (ADS)

    Pingitore, N. E.; Cruz-Jimenez, G.; Price, T. D.

    2001-12-01

    X-ray absorption spectroscopy (XAS) affords the opportunity to probe the atomic environment of trace elements in human bone. We are using XAS to investigate the mode(s) of incorporation of Sr, Zn, Pb, and Ba in both modern and ancient (and thus possibly altered) human and animal bone. Because burial and diagenesis may add trace elements to bone, we performed XAS analysis on samples of pristine contemporary and ancient, buried human and animal bone. We assume that deposition of these elements during burial occurs by processes distinct from those in vivo, and this will be reflected in their atomic environments. Archaeologists measure strontium in human and animal bone as a guide to diet. Carnivores show lower Sr/Ca ratios than their herbivore prey due to discrimination against Sr relative to Ca up the food chain. In an initial sample suite no difference was observed between modern and buried bone. Analysis of additional buried samples, using a more sensitive detector, revealed significant differences in the distance to the second and third neighbors of the Sr in some of the buried samples. Distances to the first neighbor, oxygen, were similar in all samples. Zinc is also used in paleo-diet studies. Initial x-ray absorption spectroscopy of a limited suite of bones did not reveal any differences between modern and buried samples. This may reflect the limited number of samples examined or the low levels of Zn in typical aqueous solutions in soils. Signals from barium and lead were too low to record useful XAS spectra. Additional samples will be studied for Zn, Ba, and Pb. We conducted our XAS experiments on beam lines 4-1 and 4-3 at the Stanford Synchrotron Radiation Laboratory. Data were collected in the fluorescence mode, using a Lytle detector and appropriate filter, and a solid state, 13-element Ge-detector.

  12. Earliest evidence for caries and exploitation of starchy plant foods in Pleistocene hunter-gatherers from Morocco

    PubMed Central

    Humphrey, Louise T.; De Groote, Isabelle; Morales, Jacob; Barton, Nick; Collcutt, Simon; Bronk Ramsey, Christopher; Bouzouggar, Abdeljalil

    2014-01-01

    Dental caries is an infectious disease that causes tooth decay. The high prevalence of dental caries in recent humans is attributed to more frequent consumption of plant foods rich in fermentable carbohydrates in food-producing societies. The transition from hunting and gathering to food production is associated with a change in the composition of the oral microbiota and broadly coincides with the estimated timing of a demographic expansion in Streptococcus mutans, a causative agent of human dental caries. Here we present evidence linking a high prevalence of caries to reliance on highly cariogenic wild plant foods in Pleistocene hunter-gatherers from North Africa, predating other high caries populations and the first signs of food production by several thousand years. Archaeological deposits at Grotte des Pigeons in Morocco document extensive evidence for human occupation during the Middle Stone Age and Later Stone Age (Iberomaurusian), and incorporate numerous human burials representing the earliest known cemetery in the Maghreb. Macrobotanical remains from occupational deposits dated between 15,000 and 13,700 cal B.P. provide evidence for systematic harvesting and processing of edible wild plants, including acorns and pine nuts. Analysis of oral pathology reveals an exceptionally high prevalence of caries (51.2% of teeth in adult dentitions), comparable to modern industrialized populations with a diet high in refined sugars and processed cereals. We infer that increased reliance on wild plants rich in fermentable carbohydrates and changes in food processing caused an early shift toward a disease-associated oral microbiota in this population. PMID:24395774

  13. The impact of MIS-3 climate events at the transition from Neanderthals to modern humans in Europe

    NASA Astrophysics Data System (ADS)

    Staubwasser, M.; Dragusin, V.; Assonov, S.; Ersek, V.; Hoffmann, D.; Veres, D.; Onac, B. P.

    2017-12-01

    We report on last glacial stable C and O isotope records from two U-Th dated speleothems from Romania. The southerly record (Ascunsa Cave, South Carpathians) from the Danube region matches the pacing and relative change in amplitude of the Greenland ice temperature record at 30-50 ka BP as well as the abundance of coastal winter sea ice in the Black Sea. The northerly record (Tausoare Cave, East Carpathians) in parts shares the pacing of events with the Greenland or the southern Romanian record, but best matches northern Black Sea summer season temperature change. Heinrich events do not stand out in either record, but the temperature amplitudes of Greenland stadials and Black Sea records are generally reproduced. Based on similarity with the Black Sea we interpret the combined two speleothem records in terms of seasonal temperature change in central Eastern Europe. A climatic influence on the transition from Neanderthals to modern humans has long been suspected. However, the diachronous and spatially complex archaeologic succession across the Middle-Upper Paleolithic (MUPL) in Europe ( 38 - 48 ka) is difficult to reconcile with the millennial-scale pacing of northern hemisphere paleoclimate. Two extreme cold events at 44.0-43.3 recorded and 40.7-39.8 ka in the speleothems bracket the dates of the first known appearance of modern humans - the Aurignacian complex - and the disappearance of Neanderthals from most of Europe. These cold events are coeval with Greenland Stadials GS-12 and GS-10. The speleothem records generally match the paleosol/loess succession from central Europe across the MUPL. The combined record suggests that permafrost advance may have made central Europe uninhabitable at least during winter. The combined paleoclimate and archaeologic records suggest that depopulation-repopulation cycles may have occurred during and after each cold event. Repopulation of central Europe geographically favored the modern human Aurignacians from SE Europe.

  14. What Is Humane Education and Why It Should Be Included in Modern Education

    ERIC Educational Resources Information Center

    Jacobs, G. M.

    2016-01-01

    Humane education has existed since at least the 18th century (Unti & DeRosa, 2003). This brief chapter begins with a brief definition of humane education and examples of how it can be incorporated in linguistics, cross cultural studies and foreign language education. Next, the chapter discusses why humane education constitutes an important…

  15. Human and biophysical factors influencing modern fire disturbance in northern Wisconsin

    Treesearch

    Brian R. Sturtevant; David T. Cleland

    2007-01-01

    Humans cause most wildfires in northern Wisconsin, but interactions between human and biophysical variables affecting fire starts and size are not well understood. We applied classification tree analyses to a 16-year fire database from northern Wisconsin to evaluate the relative importance of human v. biophysical variables affecting fire occurrence within (1) all cover...

  16. Human cadaveric dissection: a historical account from ancient Greece to the modern era

    PubMed Central

    2015-01-01

    The review article attempts to focus on the practice of human cadaveric dissection during its inception in ancient Greece in 3rd century BC, revival in medieval Italy at the beginning of 14th century and subsequent evolution in Europe and the United States of America over the centuries. The article highlights on the gradual change in attitude of religious authorities towards human dissection, the shift in the practice of human dissection being performed by barber surgeons to the anatomist himself dissecting the human body and the enactment of prominent legislations which proved to be crucial milestones during the course of the history of human cadaveric dissection. It particularly emphasizes on the different means of procuring human bodies which changed over the centuries in accordance with the increasing demand due to the rise in popularity of human dissection as a tool for teaching anatomy. Finally, it documents the rise of body donation programs as the source of human cadavers for anatomical dissection from the second half of the 20th century. Presently innovative measures are being introduced within the body donation programs by medical schools across the world to sensitize medical students such that they maintain a respectful, compassionate and empathetic attitude towards the human cadaver while dissecting the same. Human dissection is indispensable for a sound knowledge in anatomy which can ensure safe as well as efficient clinical practice and the human dissection lab could possibly be the ideal place to cultivate humanistic qualities among future physicians in the 21st century. PMID:26417475

  17. Human factor engineering based design and modernization of control rooms with new I and C systems

    SciTech Connect

    Larraz, J.; Rejas, L.; Ortega, F.

    2012-07-01

    Instrumentation and Control (I and C) systems of the latest nuclear power plants are based on the use of digital technology, distributed control systems and the integration of information in data networks (Distributed Control and Instrumentation Systems). This has a repercussion on Control Rooms (CRs), where the operations and monitoring interfaces correspond to these systems. These technologies are also used in modernizing I and C systems in currently operative nuclear power plants. The new interfaces provide additional capabilities for operation and supervision, as well as a high degree of flexibility, versatility and reliability. An example of this is the implementationmore » of solutions such as compact stations, high level supervision screens, overview displays, computerized procedures, new operational support systems or intelligent alarms processing systems in the modernized Man-Machine Interface (MMI). These changes in the MMI are accompanied by newly added Software (SW) controls and new solutions in automation. Tecnatom has been leading various projects in this area for several years, both in Asian countries and in the United States, using in all cases international standards from which Tecnatom own methodologies have been developed and optimized. The experience acquired in applying this methodology to the design of new control rooms is to a large extent applicable also to the modernization of current control rooms. An adequate design of the interface between the operator and the systems will facilitate safe operation, contribute to the prompt identification of problems and help in the distribution of tasks and communications between the different members of the operating shift. Based on Tecnatom experience in the field, this article presents the methodological approach used as well as the most relevant aspects of this kind of project. (authors)« less

  18. Earliest Recollections and Birth Order: Two Adlerian Exercises.

    ERIC Educational Resources Information Center

    Parrott, Les

    1992-01-01

    Presents two exercises designed to demonstrate the influence of two Adlerian principles on personality. Includes exercises dealing with birth order and earliest recollection. Concludes that the exercises actively demonstrate major concepts for counseling courses in Adlerian psychotherapy. Reports that students rated both exercises highly, with…

  19. No known hominin species matches the expected dental morphology of the last common ancestor of Neanderthals and modern humans

    PubMed Central

    Gómez-Robles, Aida; Bermúdez de Castro, José María; Arsuaga, Juan-Luis; Carbonell, Eudald; Polly, P. David

    2013-01-01

    A central problem in paleoanthropology is the identity of the last common ancestor of Neanderthals and modern humans ([N-MH]LCA). Recently developed analytical techniques now allow this problem to be addressed using a probabilistic morphological framework. This study provides a quantitative reconstruction of the expected dental morphology of the [N-MH]LCA and an assessment of whether known fossil species are compatible with this ancestral position. We show that no known fossil species is a suitable candidate for being the [N-MH]LCA and that all late Early and Middle Pleistocene taxa from Europe have Neanderthal dental affinities, pointing to the existence of a European clade originated around 1 Ma. These results are incongruent with younger molecular divergence estimates and suggest at least one of the following must be true: (i) European fossils and the [N-MH]LCA selectively retained primitive dental traits; (ii) molecular estimates of the divergence between Neanderthals and modern humans are underestimated; or (iii) phenotypic divergence and speciation between both species were decoupled such that phenotypic differentiation, at least in dental morphology, predated speciation. PMID:24145426

  20. A 3D quantitative comparison of trapezium and trapezoid relative articular and nonarticular surface areas in modern humans and great apes.

    PubMed

    Tocheri, M W; Razdan, A; Williams, R C; Marzke, M W

    2005-11-01

    The structure and functions of the modern human hand are critical components of what distinguishes Homo sapiens from the great apes (Gorilla, Pan, and Pongo). In this study, attention is focused on the trapezium and trapezoid, the two most lateral bones of the distal carpal row, in the four extant hominid genera, representing the first time they have been quantified and analyzed together as a morphological-functional complex. Our objective is to quantify the relative articular and nonarticular surface areas of these two bones and to test whether modern humans exhibit significant shape differences from the great apes, as predicted by previous qualitative analyses and the functional demands of differing manipulative and locomotor strategies. Modern humans were predicted to show larger relative first metacarpal and scaphoid surfaces on the trapezium because of the regular recruitment of the thumb during manipulative behaviors; alternatively, great apes were predicted to show larger relative second metacarpal and scaphoid surfaces on the trapezoid because of the functional demands on the hands during locomotor behaviors. Modern humans were also expected to exhibit larger relative mutual joint surfaces between the trapezoid and adjacent carpals than do the great apes because of assumed transverse loads generated by the functional demands of the modern human power grip. Using 3D bone models acquired through laser digitizing, the relative articular and nonarticular areas on each bone are quantified and compared. Multivariate analyses of these data clearly distinguish modern humans from the great apes. In total, the observed differences between modern humans and the great apes support morphological predictions based on the fact that this region of the human wrist is no longer involved in weight-bearing during locomotor behavior and is instead recruited solely for manipulative behaviors. The results provide the beginnings of a 3D comparative standard against which further

  1. Out of Africa: modern human origins special feature: explaining worldwide patterns of human genetic variation using a coalescent-based serial founder model of migration outward from Africa.

    PubMed

    DeGiorgio, Michael; Jakobsson, Mattias; Rosenberg, Noah A

    2009-09-22

    Studies of worldwide human variation have discovered three trends in summary statistics as a function of increasing geographic distance from East Africa: a decrease in heterozygosity, an increase in linkage disequilibrium (LD), and a decrease in the slope of the ancestral allele frequency spectrum. Forward simulations of unlinked loci have shown that the decline in heterozygosity can be described by a serial founder model, in which populations migrate outward from Africa through a process where each of a series of populations is formed from a subset of the previous population in the outward expansion. Here, we extend this approach by developing a retrospective coalescent-based serial founder model that incorporates linked loci. Our model both recovers the observed decline in heterozygosity with increasing distance from Africa and produces the patterns observed in LD and the ancestral allele frequency spectrum. Surprisingly, although migration between neighboring populations and limited admixture between modern and archaic humans can be accommodated in the model while continuing to explain the three trends, a competing model in which a wave of outward modern human migration expands into a series of preexisting archaic populations produces nearly opposite patterns to those observed in the data. We conclude by developing a simpler model to illustrate that the feature that permits the serial founder model but not the archaic persistence model to explain the three trends observed with increasing distance from Africa is its incorporation of a cumulative effect of genetic drift as humans colonized the world.

  2. Ethical Issues Surrounding the Use of Modern Human Remains for Research in South Africa.

    PubMed

    Briers, N; Dempers, J J

    2017-02-01

    Chapter 8 of the South African National Health Act 61 of 2003 (NHA) that deals with the donation of human tissue was promulgated in 2012. The new Act is perceived to impose restrictions on low-risk research involving human remains. This study aimed to identify the issues raised by a research ethics committee (REC) when reviewing protocols where human remains are used as data source. REC minutes from 2009 to 2014 were reviewed, and issues raised by the committee were categorized. In total, 127 protocols submitted to the committee over 6 years involved human remains. Queries relating to science (22.2%) and administration (18.9%) were the most common, whereas queries relating to legal issues constituted only 10.2%. Ethical issues centered on informed consent regarding sensitive topics such as HIV, DNA, and deceased children. The change in legislation did not change the number or type of legal issues identified by the REC.

  3. Your Earliest Memory May Be Earlier than You Think: Prospective Studies of Children's Dating of Earliest Childhood Memories

    ERIC Educational Resources Information Center

    Wang, Qi; Peterson, Carole

    2014-01-01

    Theories of childhood amnesia and autobiographical memory development have been based on the assumption that the age estimates of earliest childhood memories are generally accurate, with an average age of 3.5 years among adults. It is also commonly believed that early memories will by default become inaccessible later on and this eventually…

  4. Ancient Levantine Arabic: A Reconstruction Based on the Earliest Sources and the Modern Dialects

    ERIC Educational Resources Information Center

    Al-Jallad, Ahmad

    2012-01-01

    Our understanding of the history and development of Arabic is greatly challenged by the dearth of sources. Most scholars who have undertaken this task in the past have relied almost exclusively on data from the Arabic grammatical tradition. These sources claimed that Arabic originated as the language of the Bedouin of the central and southern…

  5. Early modern human settlement of Europe north of the Alps occurred 43,500 years ago in a cold steppe-type environment

    PubMed Central

    Nigst, Philip R.; Haesaerts, Paul; Damblon, Freddy; Frank-Fellner, Christa; Mallol, Carolina; Viola, Bence; Götzinger, Michael; Niven, Laura; Trnka, Gerhard; Hublin, Jean-Jacques

    2014-01-01

    The first settlement of Europe by modern humans is thought to have occurred between 50,000 and 40,000 calendar years ago (cal B.P.). In Europe, modern human remains of this time period are scarce and often are not associated with archaeology or originate from old excavations with no contextual information. Hence, the behavior of the first modern humans in Europe is still unknown. Aurignacian assemblages—demonstrably made by modern humans—are commonly used as proxies for the presence of fully behaviorally and anatomically modern humans. The site of Willendorf II (Austria) is well known for its Early Upper Paleolithic horizons, which are among the oldest in Europe. However, their age and attribution to the Aurignacian remain an issue of debate. Here, we show that archaeological horizon 3 (AH 3) consists of faunal remains and Early Aurignacian lithic artifacts. By using stratigraphic, paleoenvironmental, and chronological data, AH 3 is ascribed to the onset of Greenland Interstadial 11, around 43,500 cal B.P., and thus is older than any other Aurignacian assemblage. Furthermore, the AH 3 assemblage overlaps with the latest directly radiocarbon-dated Neanderthal remains, suggesting that Neanderthal and modern human presence overlapped in Europe for some millennia, possibly at rather close geographical range. Most importantly, for the first time to our knowledge, we have a high-resolution environmental context for an Early Aurignacian site in Central Europe, demonstrating an early appearance of behaviorally modern humans in a medium-cold steppe-type environment with some boreal trees along valleys around 43,500 cal B.P. PMID:25246543

  6. Intra-individual metameric variation expressed at the enamel-dentine junction of lower post-canine dentition of South African fossil hominins and modern humans.

    PubMed

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

    2017-08-01

    The aim of this study is to compare the degree and patterning of inter- and intra-individual metameric variation in South African australopiths, early Homo and modern humans. Metameric variation likely reflects developmental and taxonomical issues, and could also be used to infer ecological and functional adaptations. However, its patterning along the early hominin postcanine dentition, particularly among South African fossil hominins, remains unexplored. Using microfocus X-ray computed tomography (µXCT) and geometric morphometric tools, we studied the enamel-dentine junction (EDJ) morphology and we investigated the intra- and inter-individual EDJ metameric variation among eight australopiths and two early Homo specimens from South Africa, as well as 32 modern humans. Along post-canine dentition, shape changes between metameres represented by relative positions and height of dentine horns, outlines of the EDJ occlusal table are reported in modern and fossil taxa. Comparisons of EDJ mean shapes and multivariate analyses reveal substantial variation in the direction and magnitude of metameric shape changes among taxa, but some common trends can be found. In modern humans, both the direction and magnitude of metameric shape change show increased variability in M 2 -M 3 compared to M 1 -M 2 . Fossil specimens are clustered together showing similar magnitudes of shape change. Along M 2 -M 3 , the lengths of their metameric vectors are not as variable as those of modern humans, but they display considerable variability in the direction of shape change. The distalward increase of metameric variation along the modern human molar row is consistent with the odontogenetic models of molar row structure (inhibitory cascade model). Though much remains to be tested, the variable trends and magnitudes in metamerism in fossil hominins reported here, together with differences in the scale of shape change between modern humans and fossil hominins may provide valuable information

  7. Fragile external phenotype of modern human proximal femur in comparison with medieval bone.

    PubMed

    Sievänen, Harri; Józsa, László; Pap, Ildiko; Järvinen, Markku; Järvinen, Tero A; Kannus, Pekka; Järvinen, Teppo L

    2007-04-01

    Proximal femur macroanatomy of 118 medieval and 67 contemporary adults, 84 contemporary elderly, and 48 contemporary hip fracture cases was evaluated. Within approximately 1000 years, the femoral neck axis has become longer, and its cross-section has become proportionally smaller and more oval in shape. These changes in the present external phenotype alone account for approximately 50% higher fall-induced stress compared with the medieval situation. Bones, as whole skeletal structures, adapt to mechanical stresses they customarily experience. Because the present, mechanized lifestyle apparently deprives our skeletons of vigorous, habitual physical exertion, we studied whether the proximal femur phenotype has evolved vulnerable to fragility fractures by time. Proximal femur macroanatomy of 118 medieval and 67 contemporary adults, 84 contemporary elderly, and 48 contemporary hip fracture cases was evaluated. Using direct measurements of external bone dimensions and geometric properties, we estimated the fall-induced stress as an index of hip fragility. Within approximately 1000 years, the femoral axis length has become substantially longer (analysis of covariance, body height adjusted, p < 0.001), whereas the neck circumference has not increased. The macroanatomy was found similar between the contemporary adult and elderly groups. In hip fracture cases, however, the femoral axis length was further lengthened (p < 0.001), but the circumference was somewhat smaller (p = 0.001). Consequently, the estimated fall-induced stress can be approximately 1.5-fold today compared with the medieval times (p < 0.001), and the secular trend seemed to be worse in women (sex-time interaction, p = 0.001). The modern, relatively slender phenotype of the proximal femur alone seems to increase the fall-induced stress considerably, and when this phenotype coincides the osteoporotic, internally deteriorated femoral neck structure, fracture risk is imminent. This mechanically compromised

  8. Chemical and archaeological evidence for the earliest cacao beverages

    PubMed Central

    Henderson, John S.; Joyce, Rosemary A.; Hall, Gretchen R.; Hurst, W. Jeffrey; McGovern, Patrick E.

    2007-01-01

    Chemical analyses of residues extracted from pottery vessels from Puerto Escondido in what is now Honduras show that cacao beverages were being made there before 1000 B.C., extending the confirmed use of cacao back at least 500 years. The famous chocolate beverage served on special occasions in later times in Mesoamerica, especially by elites, was made from cacao seeds. The earliest cacao beverages consumed at Puerto Escondido were likely produced by fermenting the sweet pulp surrounding the seeds. PMID:18024588

  9. Earliest evidence for arthrogryposis multiplex congenita or Larsen syndrome?

    PubMed

    Anderson, T

    1997-08-08

    A sixteenth-century illustrated pamphlet from Great Britain suggests that documentary evidence may permit accurate diagnosis of pathological conditions in earlier societies. The document is of particular importance, since the presented congenital abnormalities, including cleft lip, spina bifida cystica, genu recurvatum, and talipes deformity are reported rarely in archaeological skeletal material. It is suggested that the combination of abnormalities may represent the earliest case of arthrogryposis multiplex congenita or Larsen syndrome.

  10. Chemical and archaeological evidence for the earliest cacao beverages.

    PubMed

    Henderson, John S; Joyce, Rosemary A; Hall, Gretchen R; Hurst, W Jeffrey; McGovern, Patrick E

    2007-11-27

    Chemical analyses of residues extracted from pottery vessels from Puerto Escondido in what is now Honduras show that cacao beverages were being made there before 1000 B.C., extending the confirmed use of cacao back at least 500 years. The famous chocolate beverage served on special occasions in later times in Mesoamerica, especially by elites, was made from cacao seeds. The earliest cacao beverages consumed at Puerto Escondido were likely produced by fermenting the sweet pulp surrounding the seeds.

  11. The initial (earliest) report of polymorphous ventricular tachycardia.

    PubMed

    Jani, Sonal; Schweitzer, Paul

    2006-07-01

    In these short historical notes, we describe the early history of polymorphic ventricular tachycardia. Polymorphous ventricular tachycardia was probably first noted in 1918 by Wilson and Robinson. In a publication describing complete heart block and ventriculophasic arrhythmia, they noted a tachyarrhythmia characterized by multiple extrasystoles of different types at a rapid rate. Also, we briefly discuss the earliest recognized torsades de pointes by Dessertenes in 1966 and the first description of catecholaminergic polymorphic ventricular tachycardia, by Reid in 1977.

  12. The history of scabies in veterinary and human medicine from biblical to modern times.

    PubMed

    Roncalli, R A

    1987-07-01

    For many centuries a host of naturalists, savants, physicians and veterinarians have tried to unravel the etiology of scabies in humans and animals and to discover effective remedies to control it. After many attempts, success was achieved in the discovery of the parasitic etiology of the disease in the 15th century. Also, major advances with regard to the treatment of the disease were made during the 19th and 20th centuries. Today the prevalence of epidemic scabies in humans has diminished; on the other hand, good progress in the control of mange of livestock has been made only in a few countries including Australia, New Zealand and the U.S.A.

  13. Laterality and grip strength influence hand bone micro-architecture in modern humans, an HRpQCT study.

    PubMed

    Reina, Nicolas; Cavaignac, Etienne; Trousdale, William H; Laffosse, Jean-Michel; Braga, José

    2017-06-01

    It is widely hypothesized that mechanical loading, specifically repetitive low-intensity tasks, influences the inner structure of cancellous bone. As such, there is likely a relationship between handedness and bone morphology. The aim of this study is to determine patterns in trabecular bone between dominant and non-dominant hands in modern humans. Seventeen healthy patients between 22 and 32 years old were included in the study. Radial carpal bones (lunate, capitate, scaphoid, trapezium, trapezoid, 1st, 2nd and 3rd metacarpals) were analyzed with high-resolution micro-computed tomography. Additionally, crush and pinch grip were recorded. Factorial analysis indicated that bone volume ratio, trabeculae number (Tb.N), bone surface to volume ratio (BS.BV), body weight, stature and crush grip were all positively correlated with principal components 1 and 2 explaining 78.7% of the variance. Volumetric and trabecular endostructural parameters (BV/TV, BS/BV or Tb.Th, Tb.N) explain the observed inter-individual variability better than anthropometric or clinical parameters. Factors analysis regressions showed correlations between these parameters and the dominant side for crush strength for the lunate (r 2 = 0.640, P < 0.0001), trapezium (r 2 = 0.836, P < 0.0001) and third metacarpal (r 2 = 0.763). However, despite a significant lateralization in grip strength for all patients, the endostructural variability between dominant and non-dominant sides was limited in perspective to inter-individual differences. In conclusion, handedness is unlikely to generate trabecular patterns of asymmetry. It appears, however, that crush strength can be considered for endostructural analysis in the modern human wrist. © 2017 Anatomical Society.

  14. Civilian Workforce 2020: Strategies for Modernizing Human Resources Management in the Department of the Navy

    DTIC Science & Technology

    2000-08-18

    heavy reliance on contractors to perform much of the work performed by civilian employees . While this trend is expected to continue, a critical mass...manage, and, if necessary, terminate non- performing employees . Accountability measures should be clear and have consequences. ◆ Investments in human...complexity of work increas- es and the performance of industrial-type functions is shifted to contractors. The impact of this shift on the occupational

  15. Historical Human Footprint on Modern Tree Species Composition in the Purus-Madeira Interfluve, Central Amazonia

    PubMed Central

    Levis, Carolina; de Souza, Priscila Figueira; Schietti, Juliana; Emilio, Thaise; Pinto, José Luiz Purri da Veiga; Clement, Charles R.; Costa, Flavia R. C.

    2012-01-01

    Background Native Amazonian populations managed forest resources in numerous ways, often creating oligarchic forests dominated by useful trees. The scale and spatial distribution of forest modification beyond pre-Columbian settlements is still unknown, although recent studies propose that human impact away from rivers was minimal. We tested the hypothesis that past human management of the useful tree community decreases with distance from rivers. Methodology/Principal Findings In six sites, we inventoried trees and palms with DBH≥10 cm and collected soil for charcoal analysis; we also mapped archaeological evidence around the sites. To quantify forest manipulation, we measured the relative abundance, richness and basal area of useful trees and palms. We found a strong negative exponential relationship between forest manipulation and distance to large rivers. Plots located from 10 to 20 km from a main river had 20–40% useful arboreal species, plots between 20 and 40 km had 12–23%, plots more than 40 km had less than 15%. Soil charcoal abundance was high in the two sites closest to secondary rivers, suggesting past agricultural practices. The shortest distance between archaeological evidence and plots was found in sites near rivers. Conclusions/Significance These results strongly suggest that past forest manipulation was not limited to the pre-Columbian settlements along major rivers, but extended over interfluvial areas considered to be primary forest today. The sustainable use of Amazonian forests will be most effective if it considers the degree of past landscape domestication, as human-modified landscapes concentrate useful plants for human sustainable use and management today. PMID:23185264

  16. Phytoliths as an indicator of early modern humans plant gathering strategies, fire fuel and site occupation intensity during the Middle Stone Age at Pinnacle Point 5-6 (south coast, South Africa).

    PubMed

    Esteban, Irene; Marean, Curtis W; Fisher, Erich C; Karkanas, Panagiotis; Cabanes, Dan; Albert, Rosa M

    2018-01-01

    The study of plant remains in archaeological sites, along with a better understanding of the use of plants by prehistoric populations, can help us shed light on changes in survival strategies of hunter-gatherers and consequent impacts on modern human cognition, social organization, and technology. The archaeological locality of Pinnacle Point (Mossel Bay, South Africa) includes a series of coastal caves, rock-shelters, and open-air sites with human occupations spanning the Acheulian through Middle Stone Age (MSA) and Later Stone Age (LSA). These sites have provided some of the earliest evidence for complex human behaviour and technology during the MSA. We used phytoliths-amorphous silica particles that are deposited in cells of plants-as a proxy for the reconstruction of past human plant foraging strategies on the south coast of South Africa during the Middle and Late Pleistocene, emphasizing the use and control of fire as well as other possible plant uses. We analysed sediment samples from the different occupation periods at the rock shelter Pinnacle Point 5-6 North (PP5-6N). We also present an overview of the taphonomic processes affecting phytolith preservation in this site that will be critical to conduct a more reliable interpretation of the original plant use in the rock shelter. Our study reports the first evidence of the intentional gathering and introduction into living areas of plants from the Restionaceae family by MSA hunter-gatherers inhabiting the south coast of South Africa. We suggest that humans inhabiting Pinnacle Point during short-term occupation events during Marine Isotope Stage (MIS) 5 built fast fires using mainly grasses with some wood from trees and/or shrubs for specific purposes, perhaps for shellfish cooking. With the onset of MIS 4 we observed a change in the plant gathering strategies towards the intentional and intensive exploitation of dry wood to improve, we hypothesise, combustion for heating silcrete. This human behaviour is

  17. Phytoliths as an indicator of early modern humans plant gathering strategies, fire fuel and site occupation intensity during the Middle Stone Age at Pinnacle Point 5-6 (south coast, South Africa)

    PubMed Central

    Marean, Curtis W.; Fisher, Erich C.; Karkanas, Panagiotis; Albert, Rosa M.

    2018-01-01

    The study of plant remains in archaeological sites, along with a better understanding of the use of plants by prehistoric populations, can help us shed light on changes in survival strategies of hunter-gatherers and consequent impacts on modern human cognition, social organization, and technology. The archaeological locality of Pinnacle Point (Mossel Bay, South Africa) includes a series of coastal caves, rock-shelters, and open-air sites with human occupations spanning the Acheulian through Middle Stone Age (MSA) and Later Stone Age (LSA). These sites have provided some of the earliest evidence for complex human behaviour and technology during the MSA. We used phytoliths—amorphous silica particles that are deposited in cells of plants—as a proxy for the reconstruction of past human plant foraging strategies on the south coast of South Africa during the Middle and Late Pleistocene, emphasizing the use and control of fire as well as other possible plant uses. We analysed sediment samples from the different occupation periods at the rock shelter Pinnacle Point 5–6 North (PP5-6N). We also present an overview of the taphonomic processes affecting phytolith preservation in this site that will be critical to conduct a more reliable interpretation of the original plant use in the rock shelter. Our study reports the first evidence of the intentional gathering and introduction into living areas of plants from the Restionaceae family by MSA hunter-gatherers inhabiting the south coast of South Africa. We suggest that humans inhabiting Pinnacle Point during short-term occupation events during Marine Isotope Stage (MIS) 5 built fast fires using mainly grasses with some wood from trees and/or shrubs for specific purposes, perhaps for shellfish cooking. With the onset of MIS 4 we observed a change in the plant gathering strategies towards the intentional and intensive exploitation of dry wood to improve, we hypothesise, combustion for heating silcrete. This human behaviour

  18. Intricacies in arrangement of SNP haplotypes suggest "Great Admixture" that created modern humans.

    PubMed

    Dutta, Rajib; Mainsah, Joseph; Yatskiv, Yuriy; Chakrabortty, Sharmistha; Brennan, Patrick; Khuder, Basil; Qiu, Shuhao; Fedorova, Larisa; Fedorov, Alexei

    2017-06-05

    Inferring history from genomic sequences is challenging and problematic because chromosomes are mosaics of thousands of small Identicalby-descent (IBD) fragments, each of them having their own unique story. However, the main events in recent evolution might be deciphered from comparative analysis of numerous loci. A paradox of why humans, whose effective population size is only 10 4 , have nearly three million frequent SNPs is formulated and examined. We studied 5398 loci evenly covering all human autosomes. Common haplotypes built from frequent SNPs that are present in people from various populations have been examined. We demonstrated highly non-random arrangement of alleles in common haplotypes. Abundance of mutually exclusive pairs of common haplotypes that have different alleles at every polymorphic position (so-called Yin/Yang haplotypes) was found in 56% of loci. A novel widely spread category of common haplotypes named Mosaic has been described. Mosaic consists of numerous pieces of Yin/Yang haplotypes and represents an ancestral stage of one of them. Scenarios of possible appearance of large number of frequent human SNPs and their habitual arrangement in Yin/Yang common haplotypes have been evaluated with an advanced genomic simulation algorithm. Computer modeling demonstrated that the observed arrangement of 2.9 million frequent SNPs could not originate from a sole stand-alone population. A "Great Admixture" event has been proposed that can explain peculiarities with frequent SNP distributions. This Great Admixture presumably occurred 100-300 thousand years ago between two ancestral populations that had been separated from each other about a million years ago. Our programs and algorithms can be applied to other species to perform evolutionary and comparative genomics.

  19. A neuropsychological perspective on the link between language and praxis in modern humans

    PubMed Central

    Roby-Brami, Agnes; Hermsdörfer, Joachim; Roy, Alice C.; Jacobs, Stéphane

    2012-01-01

    Hypotheses about the emergence of human cognitive abilities postulate strong evolutionary links between language and praxis, including the possibility that language was originally gestural. The present review considers functional and neuroanatomical links between language and praxis in brain-damaged patients with aphasia and/or apraxia. The neural systems supporting these functions are predominantly located in the left hemisphere. There are many parallels between action and language for recognition, imitation and gestural communication suggesting that they rely partially on large, common networks, differentially recruited depending on the nature of the task. However, this relationship is not unequivocal and the production and understanding of gestural communication are dependent on the context in apraxic patients and remains to be clarified in aphasic patients. The phonological, semantic and syntactic levels of language seem to share some common cognitive resources with the praxic system. In conclusion, neuropsychological observations do not allow support or rejection of the hypothesis that gestural communication may have constituted an evolutionary link between tool use and language. Rather they suggest that the complexity of human behaviour is based on large interconnected networks and on the evolution of specific properties within strategic areas of the left cerebral hemisphere. PMID:22106433

  20. A philosophical theory on human communication and modern physics: e(,2)c(,2)H('2)T energy-exchange and consciousness-change toward humanism, healing, and transformation

    NASA Astrophysics Data System (ADS)

    Jenkins-Tate, Marnishia Laverne

    This dissertation addresses the need for a body of human communication theory that can be useful toward advancing personal and social transformation. Of the humanistic genre, it suggests that there is a need to promote humanism, healing, and personal transformation in the non-clinical settings of everyday living. Three questions guide the effort. First, it asks: what kind of human communication theory might describe some of the underlying dynamics of human interaction, while also suggesting ways to improve the quality of interactions of any related philosophical theory be grounded by some scientific discipline? Then finally, it asks: how might these proposed concepts be captured in a manner that can be useful to human beings in everyday human interaction? Extending the work of modern physics to the realm of human communication, the theory integrates conceptual aspects of quantum theory, relativity theory, communication accommodation theory, and various nonverbal communication theory. Then, it proposes the philosophical framework for a new body of theory which it calls the energy-exchange theory of human communication. Treating human beings as living forms of matter, it suggests that ``energy'' is the life-force that sustains all human beings, and that ``consciousness'' is that qualitative level of development at which energy manifests itself in the human experience. It proposes that human beings have the capacity to exchange energy and influence consciousness during the human communication process, and that these interactions can advance humanism, healing, and transformation-which it proposes are the higher states and levels of human consciousness. Thus, this research effort sought to know and to describe a phenomenon that is the interactive human being; and to suggest useful ways that this volitional being can know and transform itself through human interaction. With verisimilitude as a driving factor in describing human beings as communicators, the research is

  1. Scabies in animals and humans: history, evolutionary perspectives, and modern clinical management.

    PubMed

    Currier, Russell W; Walton, Shelley F; Currie, Bart J

    2011-08-01

    Scabies, a mite infestation frequently sexually transmitted, dates back to antiquity but remains a challenging parasite for study in clinical practice and community settings. Its history is one of centuries of slow progress to recognize the mite and to finally establish its nexus to the clinical syndrome of pruritis with several protean manifestations and different epidemiological patterns. Contemporary methods of management are briefly reviewed, with the future promise of improved evolutionary knowledge associated with the advent of molecular and genetic technology. Current information indicates that humans and earlier protohumans were most likely the source of animal scabies, first of dogs, and later of other species with subsequent spread to wildlife. Morphologically identical variants of Sarcoptes scabiei are nonetheless host specific, as determined by recent DNA studies, and invite future investigations into the dynamics of this troublesome sexually transmissible agent, with the goal of improved recognition and control. © 2012 New York Academy of Sciences.

  2. Contribution of dental tissues to sex determination in modern human populations.

    PubMed

    García-Campos, Cecilia; Martinón-Torres, María; Martín-Francés, Laura; Martínez de Pinillos, Marina; Modesto-Mata, Mario; Perea-Pérez, Bernardo; Zanolli, Clément; Labajo González, Elena; Sánchez Sánchez, José Antonio; Ruiz Mediavilla, Elena; Tuniz, Claudio; Bermúdez de Castro, José María

    2018-02-20

    Accurate sex estimation is an essential step for the reconstruction of the biological profile of human remains. Earlier studies have shown that elements of the human permanent dentition are sexually dimorphic. The aims of this study are to determine the degree of sexual dimorphism in the dental tissue volumes and surface areas of mandibular canines and to explore its potential for reliable sex determination. The teeth included in this study (n = 69) were selected from anthropological collections from Spain, South Africa and Sudan. In all cases, the sex of the individuals was known. The teeth were scanned and three-dimensional (3D) measurements (volumes and surfaces areas) were obtained. Finally, a dsicriminant function analysis was applied. Our results showed that sexual dimorphism in canine size is due to males having greater amounts of dentine, whereas enamel volume does not contribute significantly to overall tooth size dimorphism. Classification accuracy of the multivariable equations tested on slightly worn teeth ranged from 78 to 90.2% for the crossvalidation, and from 71.43 to 84.62% for the hold-out sample validation. When all functions were applied together, the sex was correctly assigned 92.30% of the time. Our results suggest that the 3D variables from mandibular canine dental tissues are useful for sex determination as they present a high degree of dimorphism. The results obtained show the importance of 3D dental tissue measurements as a methodology in sex determination, which application should be considered as a supplemental method to others. © 2018 Wiley Periodicals, Inc.

  3. Adolescent archaics or adult moderns? Le Moustier 1 as a model for estimating the age at death of fragmentary supraorbital fossils in the modern human origins debate.

    PubMed

    Ahern, J C M; Smith, F H

    2004-01-01

    This study documents and examines selected implications of the adolescent supraorbital anatomy of the Le Moustier 1 Neandertal. Le Moustier's supraorbital morphology conforms to that expected of an adolescent Neandertal but indicates that significant development of the adult Neandertal torus occurs late in ontogeny. As the best preserved adolescent from the Late Pleistocene, Le Moustier 1's anatomy is used to help distinguish adolescent from adult anatomy in two cases of fragmentary supraorbital fossils, the Vindija late Neandertals and KRM 16425 from Klasies River Mouth (South Africa). It has been suggested that the modern-like aspects of the Vindija and Klasies supraorbital fossils are a function of developmental age rather than evolution. Although Le Moustier 1's anatomy does indicate that two of the Vindija fossils are adolescent; these two fossils have already been excluded from studies that demonstrate transitional aspects of the Vindija adult supraorbitals. Results of an analysis of KRM 16425 in light of Le Moustier 1 are more ambiguous. KRM 16425 is clearly not a Neandertal, but its morphology suggests that it may be an adolescent form of such late archaic Africans like Florisbad or Ngaloba. Both the Vindija and Klasies River Mouth cases highlight the need to be wary of confusing adolescent anatomy with modernity.

  4. Oceanic dispersal, vicariance and human introduction shaped the modern distribution of the termites Reticulitermes, Heterotermes and Coptotermes.

    PubMed

    Bourguignon, Thomas; Lo, Nathan; Šobotník, Jan; Sillam-Dussès, David; Roisin, Yves; Evans, Theodore A

    2016-03-30

    Reticulitermes, Heterotermes and Coptotermes form a small termite clade with partly overlapping distributions. Although native species occur across all continents, the factors influencing their distribution are poorly known. Here, we reconstructed the historical biogeography of these termites using mitochondrial genomes of species collected on six continents. Our analyses showed that Reticulitermes split from Heterotermes + Coptotermesat 59.5 Ma (49.9-69.5 Ma 95% CI), yet the oldest split within Reticulitermes(Eurasia and North America) is 16.1 Ma (13.4-19.5 Ma) and the oldest split within Heterotermes + Coptotermesis 36.0 Ma (33.9-40.5 Ma). We detected 14 disjunctions between biogeographical realms, all of which occurred within the last 34 Ma, not only after the break-up of Pangaea, but also with the continents in similar to current positions. Land dispersal over land bridges explained four disjunctions, oceanic dispersal by wood rafting explained eight disjunctions, and human introduction was the source of two recent disjunctions. These wood-eating termites, therefore, appear to have acquired their modern worldwide distribution through multiple dispersal processes, with oceanic dispersal and human introduction favoured by the ecological traits of nesting in wood and producing replacement reproductives. © 2016 The Author(s).

  5. Oceanic dispersal, vicariance and human introduction shaped the modern distribution of the termites Reticulitermes, Heterotermes and Coptotermes

    PubMed Central

    Bourguignon, Thomas; Lo, Nathan; Šobotník, Jan; Sillam-Dussès, David; Roisin, Yves; Evans, Theodore A.

    2016-01-01

    Reticulitermes, Heterotermes and Coptotermes form a small termite clade with partly overlapping distributions. Although native species occur across all continents, the factors influencing their distribution are poorly known. Here, we reconstructed the historical biogeography of these termites using mitochondrial genomes of species collected on six continents. Our analyses showed that Reticulitermes split from Heterotermes + Coptotermes at 59.5 Ma (49.9–69.5 Ma 95% CI), yet the oldest split within Reticulitermes (Eurasia and North America) is 16.1 Ma (13.4–19.5 Ma) and the oldest split within Heterotermes + Coptotermes is 36.0 Ma (33.9–40.5 Ma). We detected 14 disjunctions between biogeographical realms, all of which occurred within the last 34 Ma, not only after the break-up of Pangaea, but also with the continents in similar to current positions. Land dispersal over land bridges explained four disjunctions, oceanic dispersal by wood rafting explained eight disjunctions, and human introduction was the source of two recent disjunctions. These wood-eating termites, therefore, appear to have acquired their modern worldwide distribution through multiple dispersal processes, with oceanic dispersal and human introduction favoured by the ecological traits of nesting in wood and producing replacement reproductives. PMID:27030416

  6. Out of Africa: modern human origins special feature: middle and later Pleistocene hominins in Africa and Southwest Asia.

    PubMed

    Rightmire, G Philip

    2009-09-22

    Approximately 700,000 years ago, Homo erectus in Africa was giving way to populations with larger brains accompanied by structural adjustments to the vault, cranial base, and face. Such early Middle Pleistocene hominins were not anatomically modern. Their skulls display strong supraorbital tori above projecting faces, flattened frontals, and less parietal expansion than is the case for Homo sapiens. Postcranial remains seem also to have archaic features. Subsequently, some groups evolved advanced skeletal morphology, and by ca. 200,000 years ago, individuals more similar to recent humans are present in the African record. These fossils are associated with Middle Stone Age lithic assemblages and, in some cases, Acheulean tools. Crania from Herto in Ethiopia carry defleshing cutmarks and superficial scoring that may be indicative of mortuary practices. Despite these signs of behavioral innovation, neither the Herto hominins, nor others from Late Pleistocene sites such as Klasies River in southern Africa and Skhūl/Qafzeh in Israel, can be matched in living populations. Skulls are quite robust, and it is only after approximately 35,000 years ago that people with more gracile, fully modern morphology make their appearance. Not surprisingly, many questions concerning this evolutionary history have been raised. Attention has centered on systematics of the mid-Pleistocene hominins, their paleobiology, and the timing of dispersals that spread H. sapiens out of Africa and across the Old World. In this report, I discuss structural changes characterizing the skulls from different time periods, possible regional differences in morphology, and the bearing of this evidence on recognizing distinct species.

  7. A pulse of mid-Pleistocene rift volcanism in Ethiopia at the dawn of modern humans.

    PubMed

    Hutchison, William; Fusillo, Raffaella; Pyle, David M; Mather, Tamsin A; Blundy, Jon D; Biggs, Juliet; Yirgu, Gezahegn; Cohen, Benjamin E; Brooker, Richard A; Barfod, Dan N; Calvert, Andrew T

    2016-10-18

    The Ethiopian Rift Valley hosts the longest record of human co-existence with volcanoes on Earth, however, current understanding of the magnitude and timing of large explosive eruptions in this region is poor. Detailed records of volcanism are essential for interpreting the palaeoenvironments occupied by our hominin ancestors; and also for evaluating the volcanic hazards posed to the 10 million people currently living within this active rift zone. Here we use new geochronological evidence to suggest that a 200 km-long segment of rift experienced a major pulse of explosive volcanic activity between 320 and 170 ka. During this period, at least four distinct volcanic centres underwent large-volume (>10 km 3 ) caldera-forming eruptions, and eruptive fluxes were elevated five times above the average eruption rate for the past 700 ka. We propose that such pulses of episodic silicic volcanism would have drastically remodelled landscapes and ecosystems occupied by early hominin populations.

  8. Modern approaches to the treatment of human infertility through assisted reproduction.

    PubMed

    Fernández Pelegrina, R; Kessler, A G; Rawlins, R G

    1991-08-01

    Medical statistics from the United States show approximately 15 percent of all couples of reproductive age are unable to conceive naturally. In recent years, the numbers of couples with reproductive problems has increased, principally due to changes in life style and delayed childbearing. Only 13 years after the birth of the first "test tube baby", advances in the field of human reproduction have created a wide range of alternatives to help infertile couples conceive a healthy infant. Together, these techniques are called Assisted Reproductive Technology (ART) and include: in vitro fertilization (IVF), intratubal transfer of gametes (GIFT), intratubal transfer of zygotes (ZIFT), tubal transfer of preimplantation embryos (TET), gamete or embryo donation, cryopreservtion, and micromanipulation. The application of these techniques is presented here. While much remains to be learned, the ability to fertilize ova in vitro and sustain early embryonic life outside the body is now a reality. Contrary to the idea that these techniques create life in vitro, they simply remove barriers caused by different forms of infertility which impede the creation of life. More than 30,000 infants have now been produced world-wide through ART. In the future, new developments in the field of assisted reproduction promise to bring new hope to the growing numbers of infertile couples around the world.

  9. A pulse of mid-Pleistocene rift volcanism in Ethiopia at the dawn of modern humans

    PubMed Central

    Hutchison, William; Fusillo, Raffaella; Pyle, David M.; Mather, Tamsin A.; Blundy, Jon D.; Biggs, Juliet; Yirgu, Gezahegn; Cohen, Benjamin E.; Brooker, Richard A.; Barfod, Dan N.; Calvert, Andrew T.

    2016-01-01

    The Ethiopian Rift Valley hosts the longest record of human co-existence with volcanoes on Earth, however, current understanding of the magnitude and timing of large explosive eruptions in this region is poor. Detailed records of volcanism are essential for interpreting the palaeoenvironments occupied by our hominin ancestors; and also for evaluating the volcanic hazards posed to the 10 million people currently living within this active rift zone. Here we use new geochronological evidence to suggest that a 200 km-long segment of rift experienced a major pulse of explosive volcanic activity between 320 and 170 ka. During this period, at least four distinct volcanic centres underwent large-volume (>10 km3) caldera-forming eruptions, and eruptive fluxes were elevated five times above the average eruption rate for the past 700 ka. We propose that such pulses of episodic silicic volcanism would have drastically remodelled landscapes and ecosystems occupied by early hominin populations. PMID:27754479

  10. Accelerated modern human-induced species losses: Entering the sixth mass extinction.

    PubMed

    Ceballos, Gerardo; Ehrlich, Paul R; Barnosky, Anthony D; García, Andrés; Pringle, Robert M; Palmer, Todd M

    2015-06-01

    The oft-repeated claim that Earth's biota is entering a sixth "mass extinction" depends on clearly demonstrating that current extinction rates are far above the "background" rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing.

  11. Bridging burn care education with modern technology, an integration with high fidelity human patient simulation.

    PubMed

    Reeves, Patrick T; Borgman, Matthew A; Caldwell, Nicole W; Patel, Leela; Aden, James; Duggan, John P; Serio-Melvin, Maria L; Mann-Salinas, Elizabeth A

    2018-08-01

    The Advanced Burn Life Support (ABLS) program is a burn-education curriculum nearly 30 years in the making, focusing on the unique challenges of the first 24h of care after burn injury. Our team applied high fidelity human patient simulation (HFHPS) to the established ABLS curriculum. Our hypothesis was that HFHPS would be a feasible, easily replicable, and valuable adjunct to the current curriculum that would enhance learner experience. This prospective, evidenced-based practice project was conducted in a single simulation center employing the American Burn Association's ABLS curriculum using HFHPS. Participants managed 7 separate simulated polytrauma and burn scenarios with resultant clinical complications. After training, participants completed written and practical examinations as well as satisfaction surveys. From 2012 to 2013, 71 students participated in this training. Simulation (ABLS-Sim) participants demonstrated a 2.5% increase in written post-test scores compared to traditional ABLS Provider Course (ABLS Live) (p=0.0016). There was no difference in the practical examination when comparing ABLS-Sim versus ABLS Live. Subjectively, 60 (85%) participants completed surveys. The Educational Practice Questionnaire showed best practices rating of 4.5±0.7; with importance of learning rated at 4.4±0.8. The Simulation Design Scale rating for design was 4.6±0.6 with an importance rating of 4.4±0.8. Overall Satisfaction and Self-Confidence with Learning were 4.4±0.7 and 4.5±0.7, respectfully. Integrating HFHPS with the current ABLS curriculum led to higher written exam scores, high levels of confidence, satisfaction, and active learning, and presented an evidenced-based model for education that is easily employable for other facilities nationwide. Copyright © 2018 Elsevier Ltd and ISBI. All rights reserved.

  12. Archaeometallurgical characterization of the earliest European metal helmets

    PubMed Central

    Mödlinger, Marianne; Piccardo, Paolo; Kasztovszky, Zsolt; Kovács, Imre; Szőkefalvi-Nagy, Zoltán; Káli, György; Szilágyi, Veronika

    2013-01-01

    Archaeometric analyses on conical and decorated cap helmets from the Bronze Age are presented. The helmets are dated to the 14–12th century BC according to associated finds in hoards. Alloy composition, material structure and manufacturing processes are determined and shed light on the earliest development of weaponry production in Central and Eastern Europe. Analyses were carried out using light and dark field microscopy, SEM–EDXS, PIXE, TOF-ND and PGAA. The results allowed reconstructing the manufacturing process, the differences between the cap of the helmets and their knobs (i.e. alloy composition) and the joining technique of the two parts. PMID:26523114

  13. The relationships among jaw-muscle fiber architecture, jaw morphology, and feeding behavior in extant apes and modern humans.

    PubMed

    Taylor, Andrea B; Vinyard, Christopher J

    2013-05-01

    The jaw-closing muscles are responsible for generating many of the forces and movements associated with feeding. Muscle physiologic cross-sectional area (PCSA) and fiber length are two architectural parameters that heavily influence muscle function. While there have been numerous comparative studies of hominoid and hominin craniodental and mandibular morphology, little is known about hominoid jaw-muscle fiber architecture. We present novel data on masseter and temporalis internal muscle architecture for small- and large-bodied hominoids. Hominoid scaling patterns are evaluated and compared with representative New- (Cebus) and Old-World (Macaca) monkeys. Variation in hominoid jaw-muscle fiber architecture is related to both absolute size and allometry. PCSAs scale close to isometry relative to jaw length in anthropoids, but likely with positive allometry in hominoids. Thus, large-bodied apes may be capable of generating both absolutely and relatively greater muscle forces compared with smaller-bodied apes and monkeys. Compared with extant apes, modern humans exhibit a reduction in masseter PCSA relative to condyle-M1 length but retain relatively long fibers, suggesting humans may have sacrificed relative masseter muscle force during chewing without appreciably altering muscle excursion/contraction velocity. Lastly, craniometric estimates of PCSAs underestimate hominoid masseter and temporalis PCSAs by more than 50% in gorillas, and overestimate masseter PCSA by as much as 30% in humans. These findings underscore the difficulty of accurately estimating jaw-muscle fiber architecture from craniometric measures and suggest models of fossil hominin and hominoid bite forces will be improved by incorporating architectural data in estimating jaw-muscle forces. Copyright © 2013 Wiley Periodicals, Inc.

  14. Role of the Information Professional in the Development and Promotion of Digital Humanities Content for Research, Teaching, and Learning in the Modern Academic Library: An Irish Case Study

    ERIC Educational Resources Information Center

    Burns, Jane A.

    2016-01-01

    The Internet has been the catalyst for the convergence of many subject areas and online platforms. Information professionals such as Archivists, IT developers and especially Librarians have been impacted in the development and promotion of digital humanities content for research, teaching, and learning in the modern academic library. In this case…

  15. Maximizing Modern Distribution of Complex Anatomical Spatial Information: 3D Reconstruction and Rapid Prototype Production of Anatomical Corrosion Casts of Human Specimens

    ERIC Educational Resources Information Center

    Li, Jianyi; Nie, Lanying; Li, Zeyu; Lin, Lijun; Tang, Lei; Ouyang, Jun

    2012-01-01

    Anatomical corrosion casts of human specimens are useful teaching aids. However, their use is limited due to ethical dilemmas associated with their production, their lack of perfect reproducibility, and their consumption of original specimens in the process of casting. In this study, new approaches with modern distribution of complex anatomical…

  16. Ontogenetic study of the skull in modern humans and the common chimpanzees: neotenic hypothesis reconsidered with a tridimensional Procrustes analysis.

    PubMed

    Penin, Xavier; Berge, Christine; Baylac, Michel

    2002-05-01

    Heterochronic studies compare ontogenetic trajectories of an organ in different species: here, the skulls of common chimpanzees and modern humans. A growth trajectory requires three parameters: size, shape, and ontogenetic age. One of the great advantages of the Procrustes method is the precise definition of size and shape for whole organs such as the skull. The estimated ontogenetic age (dental stages) is added to the plot to give a graphical representation to compare growth trajectories. We used the skulls of 41 Homo sapiens and 50 Pan troglodytes at various stages of growth. The Procrustes superimposition of all specimens was completed by statistical procedures (principal component analysis, multivariate regression, and discriminant function) to calculate separately size-related shape changes (allometry common to chimpanzees and humans), and interspecific shape differences (discriminant function). The results confirm the neotenic theory of the human skull (sensu Gould [1977] Ontogeny and Phylogeny, Cambridge: Harvard University Press; Alberch et al. [1979] Paleobiology 5:296-317), but modify it slightly. Human growth is clearly retarded in terms of both the magnitude of changes (size-shape covariation) and shape alone (size-shape dissociation) with respect to the chimpanzees. At the end of growth, the adult skull in humans reaches an allometric shape (size-related shape) which is equivalent to that of juvenile chimpanzees with no permanent teeth, and a size which is equivalent to that of adult chimpanzees. Our results show that human neoteny involves not only shape retardation (paedomorphosis), but also changes in relative growth velocity. Before the eruption of the first molar, human growth is accelerated, and then strongly decelerated, relative to the growth of the chimpanzee as a reference. This entails a complex process, which explains why these species reach the same overall (i.e., brain + face) size in adult stage. The neotenic traits seem to concern

  17. Shift of large-scale atmospheric systems over Europe during late MIS 3 and implications for Modern Human dispersal.

    PubMed

    Obreht, Igor; Hambach, Ulrich; Veres, Daniel; Zeeden, Christian; Bösken, Janina; Stevens, Thomas; Marković, Slobodan B; Klasen, Nicole; Brill, Dominik; Burow, Christoph; Lehmkuhl, Frank

    2017-07-19

    Understanding the past dynamics of large-scale atmospheric systems is crucial for our knowledge of the palaeoclimate conditions in Europe. Southeastern Europe currently lies at the border between Atlantic, Mediterranean, and continental climate zones. Past changes in the relative influence of associated atmospheric systems must have been recorded in the region's palaeoarchives. By comparing high-resolution grain-size, environmental magnetic and geochemical data from two loess-palaeosol sequences in the Lower Danube Basin with other Eurasian palaeorecords, we reconstructed past climatic patterns over Southeastern Europe and the related interaction of the prevailing large-scale circulation modes over Europe, especially during late Marine Isotope Stage 3 (40,000-27,000 years ago). We demonstrate that during this time interval, the intensification of the Siberian High had a crucial influence on European climate causing the more continental conditions over major parts of Europe, and a southwards shift of the Westerlies. Such a climatic and environmental change, combined with the Campanian Ignimbrite/Y-5 volcanic eruption, may have driven the Anatomically Modern Human dispersal towards Central and Western Europe, pointing to a corridor over the Eastern European Plain as an important pathway in their dispersal.

  18. Evolution of the human diet: linking our ancestral diet to modern functional foods as a means of chronic disease prevention.

    PubMed

    Jew, Stephanie; AbuMweis, Suhad S; Jones, Peter J H

    2009-10-01

    The evolution of the human diet over the past 10,000 years from a Paleolithic diet to our current modern pattern of intake has resulted in profound changes in feeding behavior. Shifts have occurred from diets high in fruits, vegetables, lean meats, and seafood to processed foods high in sodium and hydrogenated fats and low in fiber. These dietary changes have adversely affected dietary parameters known to be related to health, resulting in an increase in obesity and chronic disease, including cardiovascular disease (CVD), diabetes, and cancer. Some intervention trials using Paleolithic dietary patterns have shown promising results with favorable changes in CVD and diabetes risk factors. However, such benefits may be offset by disadvantages of the Paleolithic diet, which is low in vitamin D and calcium and high in fish potentially containing environmental toxins. More advantageous would be promotion of foods and food ingredients from our ancestral era that have been shown to possess health benefits in the form of functional foods. Many studies have investigated the health benefits of various functional food ingredients, including omega-3 fatty acids, polyphenols, fiber, and plant sterols. These bioactive compounds may help to prevent and reduce incidence of chronic diseases, which in turn could lead to health cost savings ranging from $2 to $3 billion per year as estimated by case studies using omega-3 and plant sterols as examples. Thus, public health benefits should result from promotion of the positive components of Paleolithic diets as functional foods.

  19. Earliest economic exploitation of chicken outside East Asia: Evidence from the Hellenistic Southern Levant

    PubMed Central

    Perry-Gal, Lee; Erlich, Adi; Gilboa, Ayelet; Bar-Oz, Guy

    2015-01-01

    Chicken (Gallus gallus domesticus) is today one of the most widespread domesticated species and is a main source of protein in the human diet. However, for thousands of years exploitation of chickens was confined to symbolic and social domains such as cockfighting. The question of when and where chickens were first used for economic purposes remains unresolved. The results of our faunal analysis demonstrate that the Hellenistic (fourth–second centuries B.C.E.) site of Maresha, Israel, is the earliest site known today where economic exploitation of chickens was widely practiced. We base our claim on the exceptionally high frequency of chicken bones at that site, the majority of which belong to adult individuals, and on the observed 2:1 ratio of female to male bones. These results are supported further by an extensive survey of faunal remains from 234 sites in the Southern Levant, spanning more than three millennia, which shows a sharp increase in the frequency of chicken during the Hellenistic period. We further argue that the earliest secure evidence for economic exploitation of chickens in Europe dates to the first century B.C.E. and therefore is predated by the finds in the Southern Levant by at least a century. We suggest that the gradual acclimatization of chickens in the Southern Levant and its gradual integration into the local economy, the latter fully accomplished in the Hellenistic period, was a crucial step in the adoption of this species in European husbandry some 100 y later. PMID:26195775

  20. Ornaments of the earliest Upper Paleolithic: New insights from the Levant

    PubMed Central

    Kuhn, Steven L.; Stiner, Mary C.; Reese, David S.; Güleç, Erksin

    2001-01-01

    Two sites located on the northern Levantine coast, Üçağızlı Cave (Turkey) and Ksar 'Akil (Lebanon) have yielded numerous marine shell beads in association with early Upper Paleolithic stone tools. Accelerator mass spectrometry (AMS) radiocarbon dates indicate ages between 39,000 and 41,000 radiocarbon years (roughly 41,000–43,000 calendar years) for the oldest ornament-bearing levels in Üçağızlı Cave. Based on stratigraphic evidence, the earliest shell beads from Ksar 'Akil may be even older. These artifacts provide some of the earliest evidence for traditions of personal ornament manufacture by Upper Paleolithic humans in western Asia, comparable in age to similar objects from Eastern Europe and Africa. The new data show that the initial appearance of Upper Paleolithic ornament technologies was essentially simultaneous on three continents. The early appearance and proliferation of ornament technologies appears to have been contingent on variable demographic or social conditions. PMID:11390976

  1. The earliest fossil evidence for sexual dimorphism in primates

    NASA Technical Reports Server (NTRS)

    Krishtalka, Leonard; Stucky, Richard K.; Beard, K. C.

    1990-01-01

    Recently obtained material of the early Eocene primate Notharctus venticolus, including two partial skulls from a single stratigraphic horizon, provides the geologically earliest evidence of sexual dimorphism in canine size and shape in primates and the only unequivocal evidence for such dimorphism in strepsirhines. By analogy with living platyrrhines, these data suggest that Notharctus venticolus may have lived in polygynous social groups characterized by a relatively high level of intermale competition for mates and other limited resources. The anatomy of the upper incisors and related evidence imply that Notharctus is not as closely related to extant lemuriform primates as has been recently proposed. The early Eocene evidence for canine sexual dimorphism reported here, and its occurrence in a nonanthropoid, indicates that in the order Primates such a condition is either primitive or evolved independently more than once.

  2. Origin and radiation of the earliest vascular land plants.

    PubMed

    Steemans, Philippe; Hérissé, Alain Le; Melvin, John; Miller, Merrell A; Paris, Florentin; Verniers, Jacques; Wellman, Charles H

    2009-04-17

    Colonization of the land by plants most likely occurred in a stepwise fashion starting in the Mid-Ordovician. The earliest flora of bryophyte-like plants appears to have been cosmopolitan and dominated the planet, relatively unchanged, for some 30 million years. It is represented by fossilized dispersed cryptospores and fragmentary plant remains. In the Early Silurian, cryptospore abundance and diversity diminished abruptly as trilete spores appeared, became abundant, and underwent rapid diversification. This change coincides approximately with the appearance of vascular plant megafossils and probably represents the origin and adaptive radiation of vascular plants. We have obtained a diverse trilete spore occurrence from the Late Ordovician that suggests that vascular plants originated and diversified earlier than previously hypothesized, in Gondwana, before migrating elsewhere and secondarily diversifying.

  3. Ultrasonic hearing and echolocation in the earliest toothed whales.

    PubMed

    Park, Travis; Fitzgerald, Erich M G; Evans, Alistair R

    2016-04-01

    The evolution of biosonar (production of high-frequency sound and reception of its echo) was a key innovation of toothed whales and dolphins (Odontoceti) that facilitated phylogenetic diversification and rise to ecological predominance. Yet exactly when high-frequency hearing first evolved in odontocete history remains a fundamental question in cetacean biology. Here, we show that archaic odontocetes had a cochlea specialized for sensing high-frequency sound, as exemplified by an Oligocene xenorophid, one of the earliest diverging stem groups. This specialization is not as extreme as that seen in the crown clade. Paired with anatomical correlates for high-frequency signal production in Xenorophidae, this is strong evidence that the most archaic toothed whales possessed a functional biosonar system, and that this signature adaptation of odontocetes was acquired at or soon after their origin. © 2016 The Author(s).

  4. Observing the Earliest Galaxies: Looking for the Sources of Reionization

    NASA Astrophysics Data System (ADS)

    Illingworth, Garth

    2015-04-01

    Systematic searches for the earliest galaxies in the reionization epoch finally became possible in 2009 when the Hubble Space Telescope was updated with a powerful new infrared camera during the final Shuttle servicing mission SM4 to Hubble. The reionization epoch represents the last major phase transition of the universe and was a major event in cosmic history. The intense ultraviolet radiation from young star-forming galaxies is increasingly considered to be the source of the photons that reionized intergalactic hydrogen in the period between the ``dark ages'' (the time before the first stars and galaxies at about 100-200 million years after the Big Bang) and the end of reionization around 800-900 million years. Yet finding and measuring the earliest galaxies in this era of cosmic dawn has proven to a challenging task, even with Hubble's new infrared camera. I will discuss the deep imaging undertaken by Hubble and the remarkable insights that have accrued from the imaging datasets taken over the last decade on the Hubble Ultra-Deep Field (HUDF, HUDF09/12) and other regions. The HUDF datasets are central to the story and have been assembled into the eXtreme Deep Field (XDF), the deepest image ever from Hubble data. The XDF, when combined with results from shallower wide-area imaging surveys (e.g., GOODS, CANDELS) and with detections of galaxies from the Frontier Fields, has provided significant insights into the role of galaxies in reionization. Yet many questions remain. The puzzle is far from being fully solved and, while much will done over the next few years, the solution likely awaits the launch of JWST. NASA/STScI Grant HST-GO-11563.

  5. Origin and earliest state of the earth's hydrosphere

    SciTech Connect

    Cogley, J.G.; Henderson-Sellers, A.

    1984-05-01

    The origin and earliest history of the earth's hydrosphere, the inventory of excess volatiles defined by Rubey in 1951, can be constrained within wide but useful limits by a consideration of empirical and theoretical evidence from astrophysics and geology. Models for the evolution of the solar system from the protoplanetary nebula and for the growth of the earth to its present dimensions suggest quite strongly that the hydrosphere came into being during accretion. Its format, with H/sub 2/O mostly in the oceans, CO/sub 2/ mostly in sediments, and a residual atmosphere dominated by N/sub 2/, CO/sub 2/, and H/sub 2/Omore » was established at a very early data and has persisted without large, destabilizing climatic excursions until the present day. Alternative accounts of early history, in which the earth either loses a massive primordial atmosphere or acquires its secondary atmosphere by gradual degassing, seem improbable on the basis of a series of circumstantial but cumulatively persuasive arguments. The difficulty of dissipating a massive atmosphere of solar composition in reasonable times, the likelihood that accretion was a highly energetic process and that it triggered early segregation of the core, and the tendency of the planet to accumulate volatiles preferentially in the later stages of accretion are examples of arguments favoring an early origin for the hydrosphere. Several geological isotope systems which can be sampled today require early separation of the atmosphere and probably the hydrosphere ass a whole; these systems recorrd radiogenic enrichment patterns in the noble gases and stable isotope fractionations which suggest an early origin of the biosphere. Certain geological indicators of atmsopheric composition. and the broadly equable character of the rock record, are also consistent with a hydrosphere established in the earliest stages of history and having an initial neutral or weakly reduced composition.« less

  6. Considerations on Terrestrial Iron Depositing Analogs to Earliest Mars

    NASA Technical Reports Server (NTRS)

    Brown, Igor I.; Allen, Carlton C.; Sarkisova, S. A.; Garrison, D. H.; McKay, D. S.

    2007-01-01

    Iron oxide and hydroxide minerals, including hematite, can mineralize and preservemicrofossils and physical biomarkers (Allen at al., 2004). Preserved remnants of phototrophic microorganisms are recognized as biosignatures of past life on Earth (Schopf, 2006). To date, two types of surface iron depositing environments have been studied as analogs to possible habitable environments on earliest Mars: the highly acidified Rio Tinto River (Iberian Belt, Spain) [Gomez Ortis et al., 2007], and the nearneutral iron depositing Chocolate Pots Hot Spring (Yellowstone National Park, US) [Parenteau at al., 2005]. While phototrophs in the Rio Tinto are only represented by eukaryotic algae (Amaral Zettler et all., 2002), Chocolate Pots is mainly populated with cyanobacteria (Pierson et all., 2000; Brown et all., 2007). Which of these environments is the closer analog to a potentially habitable early Mars? Paleobiological data, combined with recent "tree of life" interpretations, suggest that phototrophic eukaryotes evolved not earlier than 2.5 - 2.8 b.y. after Earth s accretion (4.6 b.y.), while cyanobacteria and /or their iron-tolerant predecessors evolved between 1 - 1.5 b.y. after accretion (Brown et al., 2007). Lindsay and Brasier (2002) postulated that microbial life on Mars surface could have lasted no more than 1-1.5 b.y. after Mars accretion (also 4.6 b.y.). Recent multispectral mapping of Mars suggests that near-neutral wet environments prevailed at approximately this time (Bibring, et al., 2006). Thus, near-neutral iron depositing hot springs such as Chocolate Pots Hot Spring seem to be the more likely habitable analogs for earliest Mars.

  7. The earliest drawings of datable auroras and a two-tail comet from the Syriac Chronicle of Zūqnīn

    NASA Astrophysics Data System (ADS)

    Hayakawa, Hisashi; Mitsuma, Yasuyuki; Fujiwara, Yasunori; Kawamura, Akito Davis; Kataoka, Ryuho; Ebihara, Yusuke; Kosaka, Shunsuke; Iwahashi, Kiyomi; Tamazawa, Harufumi; Isobe, Hiroaki

    2017-04-01

    People have probably been watching the sky since the beginning of human history. Observers in pre-telescopic ages recorded anomalous events, which now provide uniquely valuable information for modern scientists. Records that include drawings are particularly useful, since the verbal expressions recorded by pre-telescopic observers, who did not know the physical nature of the phenomena, are often ambiguous. However, drawings concerning specific datable events in the historical documents are far fewer than the verbal records. Therefore, in this paper we show the possible earliest drawings of datable auroras and a two-tail comet included in a manuscript of the Chronicle of Zūqnīn, a Syriac chronicle up to 775/776 CE, to interpret their nature. Careful perusing the original Syriac autograph manuscript, MS Vat.Sir.162, provide not only historical facts in the realm around Amida, but also information concerning low-latitude aurora observations due to extreme space weather events and the existence of sun-grazing comets.

  8. Aurorae: The earliest datable observation of the aurora borealis

    NASA Astrophysics Data System (ADS)

    Stephenson, F. Richard; Willis, David M.; Hallinan, Thomas J.

    2004-12-01

    The Late Babylonian astronomical texts, discovered at the site of Babylon (32.5°N, 44.4°E) more than a century ago, contain what is probably the earliest reliable account of the aurora borealis. A clay tablet recording numerous celestial observations made by the official astronomers during the 37th year of King Nebuchadnezzar II (568/567 BC) describes an unusual ``red glow'' in the sky at night; the exact date of this observation corresponds to the night of 12/13 March in 567 BC. The most likely interpretation of the phenomenon is an auroral display. This event occurred several centuries before the first clearly identifiable observation of the aurora from elsewhere in the world, namely China in 193 BC. The Babylonian auroral observation is remarkable in the sense that it is one of a series of carefully recorded astronomical observations, for each of which the year, month and day are known precisely. This observation occurred at a time when the geomagnetic (dipole) latitude of Babylon was about 41°N compared with the present value of 27.5°N, suggesting a higher auroral incidence at Babylon in 567 BC than at present.

  9. The first skull of the earliest giant panda

    PubMed Central

    Jin, Changzhu; Ciochon, Russell L.; Dong, Wei; Hunt, Robert M.; Liu, Jinyi; Jaeger, Marc; Zhu, Qizhi

    2007-01-01

    Fossils of the giant panda Ailuropoda (Order Carnivora, Family Ursidae) are largely isolated teeth, mandibles, and a few rare skulls, known from the late Pliocene to late Pleistocene in China and Southeast Asia. Much of this material represents a Pleistocene chronospecies, Ailuropoda baconi, an animal larger than the living giant panda, Ailuropoda melanoleuca. The earliest certain record of Ailuropoda is the late Pliocene chronospecies, Ailuropoda microta, smaller than either A. baconi or A. melanoleuca, and previously known only from teeth and a few mandibles from karst caves in south China. Here, we report the discovery of the first skull of A. microta, establishing its cranial anatomy and demonstrating that the specialized cranial and dental adaptations of Ailuropoda for durophagous feeding behavior centered on bamboo were already evident in this late Pliocene species. The skull from Jinyin cave (Guangxi) and dental remains from other karst localities in southeastern China show that Ailuropoda microta occupied south China from ≈2 to 2.4 Myr ago after a marked global climatic deterioration. Dental and basicranial anatomy indicate a less specialized morphology early in the history of the lineage and support derivation of the giant panda from the Miocene Asian ursid Ailurarctos PMID:17578912

  10. Fixational Eye Movements in the Earliest Stage of Metazoan Evolution

    PubMed Central

    Bielecki, Jan; Høeg, Jens T.; Garm, Anders

    2013-01-01

    All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur. PMID:23776673

  11. Buried Impact Basins and the Earliest History of Mars

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    2003-01-01

    The "Quasi-Circular Depressions" (QCDs) seen in MOLA data which have little or no visible appearance in image data have been interpreted as buried impact basins on Mars. These have important implications for the age of the lowland crust, what mechanisms could produce the crustal dichotomy, and the existence of crust older than the oldest observed surface units on Mars. A global survey of large QCDs using high resolution MOLA data now available has provided further details of the earliest history of Mars. The lowlands are of Early Noachian age, slightly younger than the buried highlands and definitely older than the exposed highland surface. A depopulation of large visible basins at diameters 800 to 1300 km suggests some global scale event early in martian history, maybe related to the formation of the lowlands and/or the development of Tharsis. A suggested early disappearance of the global magnetic field can be placed within a temporal sequence of formation of the very largest impact basins.

  12. Computer Modeling of the Earliest Cellular Structures and Functions

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Chipot, Christophe; Schweighofer, Karl

    2000-01-01

    In the absence of extinct or extant record of protocells (the earliest ancestors of contemporary cells). the most direct way to test our understanding of the origin of cellular life is to construct laboratory models of protocells. Such efforts are currently underway in the NASA Astrobiology Program. They are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs for molecules that perform proto-cellular functions. Many of these functions, such as import of nutrients, capture and storage of energy. and response to changes in the environment are carried out by proteins bound to membrane< We will discuss a series of large-scale, molecular-level computer simulations which demonstrate (a) how small proteins (peptides) organize themselves into ordered structures at water-membrane interfaces and insert into membranes, (b) how these peptides aggregate to form membrane-spanning structures (eg. channels), and (c) by what mechanisms such aggregates perform essential proto-cellular functions, such as proton transport of protons across cell walls, a key step in cellular bioenergetics. The simulations were performed using the molecular dynamics method, in which Newton's equations of motion for each item in the system are solved iteratively. The problems of interest required simulations on multi-nanosecond time scales, which corresponded to 10(exp 6)-10(exp 8) time steps.

  13. Technological variation in the earliest Oldowan from Gona, Afar, Ethiopia.

    PubMed

    Stout, Dietrich; Semaw, Sileshi; Rogers, Michael J; Cauche, Dominique

    2010-06-01

    Inter-site technological variation in the archaeological record is one of the richest potential sources of information about Plio-Pleistocene hominid behavior and evolution. However, appropriate methods for describing and comparing Oldowan assemblages have yet to be agreed upon, and interpretation of the early record remains highly controversial. Particularly salient is disagreement over whether the Oldowan is a single technological phenomenon or is more accurately divided into multiple regional and/or chronological traditions, perhaps including a less developed Pre-Oldowan phase in the late Pliocene. Some of this disagreement reflects theoretical and methodological differences between research traditions and some is more directly evidential. Here we present a framework for describing and interpreting Oldowan variation and apply it to three Pliocene assemblages (EG-10, EG-12, and OGS-7) from Gona, all dated to c. 2.6 million years (Ma). Results indicate proficient knapping and a full range of Oldowan reduction strategies in these earliest known occurrences, consistent with the idea of an Oldowan "technological stasis" from 2.6-1.6 Ma. Patterns of variation in raw material selection and predominant reduction strategy at each site clearly indicate the importance of cultural transmission in the Oldowan, but confounding ecological and economic variation continue to render interpretation in terms of multiple tool making traditions or species inappropriate. We propose that cultural transmission and ecological adaptation should be recognized as complementary, rather than mutually exclusive, mechanisms in future attempts to explain Oldowan technological variation. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Fixational eye movements in the earliest stage of metazoan evolution.

    PubMed

    Bielecki, Jan; Høeg, Jens T; Garm, Anders

    2013-01-01

    All known photoreceptor cells adapt to constant light stimuli, fading the retinal image when exposed to an immobile visual scene. Counter strategies are therefore necessary to prevent blindness, and in mammals this is accomplished by fixational eye movements. Cubomedusae occupy a key position for understanding the evolution of complex visual systems and their eyes are assumedly subject to the same adaptive problems as the vertebrate eye, but lack motor control of their visual system. The morphology of the visual system of cubomedusae ensures a constant orientation of the eyes and a clear division of the visual field, but thereby also a constant retinal image when exposed to stationary visual scenes. Here we show that bell contractions used for swimming in the medusae refresh the retinal image in the upper lens eye of Tripedalia cystophora. This strongly suggests that strategies comparable to fixational eye movements have evolved at the earliest metazoan stage to compensate for the intrinsic property of the photoreceptors. Since the timing and amplitude of the rhopalial movements concur with the spatial and temporal resolution of the eye it circumvents the need for post processing in the central nervous system to remove image blur.

  15. The Earliest Post-Paleozoic Freshwater Bivalves Preserved in Coprolites from the Karoo Basin, South Africa

    PubMed Central

    Yates, Adam M.; Neumann, Frank H.; Hancox, P. John

    2012-01-01

    Background Several clades of bivalve molluscs have invaded freshwaters at various times throughout Phanerozoic history. The most successful freshwater clade in the modern world is the Unionoida. Unionoids arose in the Triassic Period, sometime after the major extinction event at the End-Permian boundary and are now widely distributed across all continents except Antarctica. Until now, no freshwater bivalves of any kind were known to exist in the Early Triassic. Principal Findings Here we report on a faunule of two small freshwater bivalve species preserved in vertebrate coprolites from the Olenekian (Lower Triassic) of the Burgersdorp Formation of the Karoo Basin, South Africa. Positive identification of these bivalves is not possible due to the limited material. Nevertheless they do show similarities with Unionoida although they fall below the size range of extant unionoids. Phylogenetic analysis is not possible with such limited material and consequently the assignment remains somewhat speculative. Conclusions Bivalve molluscs re-invaded freshwaters soon after the End-Permian extinction event, during the earliest part of the recovery phase during the Olenekian Stage of the Early Triassic. If the specimens do represent unionoids then these Early Triassic examples may be an example of the Lilliput effect. Since the oldest incontrovertible freshwater unionoids are also from sub-Saharan Africa, it is possible that this subcontinent hosted the initial freshwater radiation of the Unionoida. This find also demonstrates the importance of coprolites as microenvironments of exceptional preservation that contain fossils of organisms that would otherwise have left no trace. PMID:22319562

  16. The earliest mollusc dominated seep fauna from the Early Jurassic of Argentina

    NASA Astrophysics Data System (ADS)

    Kaim, Andrzej; Jenkins, Robert; Parent, Horacio; Garrido, Alberto; Moriya, Kazuhiro

    2015-04-01

    The earliest mollusc dominated seep fauna from the Early Jurassic of Argentina Andrzej Kaim, Robert G. Jenkins, Horacio Parent, Alberto C. Garrido The hydrocarbon seep deposits are known from Early Jurassic of Argentina since the report of Gomez-Perez (2003). The latter author identified very negative δ13C values (down to -33) and several fabrics typical for seep carbonates. Nevertheless she identified no macrofaunal assemblages apart from worm tubes. We re-visited the locality of Gomez-Perez (named here La Elina) and we were able to collect several molluscs associated with the seep carbonate. The most common and diversified are molluscs and worm tubes. We identified at least three species of gastropods, including the oldest-known species of neomphalids, lucinid and protobranch bivalves and numerous ammonoids. Unlike another known Early Jurassic seep from Oregon and the only Late Triassic seep (also from Oregon) there are no brachiopods associated with this seep. Therefore we consider the seep at La Elina as the oldest seep of modern aspect where the fauna is dominated by molluscs and not brachiopods.

  17. The Culture Integration in The Context of National Art Schools--Prioritized Direction of Development of the Modern Humanities

    ERIC Educational Resources Information Center

    Melekhova, Ksenia Alexandrovna; Lichman, Yelena Yurievna

    2016-01-01

    The modern picture of the world is experiencing a permanent transformation, adapting to the influence of various globalization factors, the dominance of information technology, dynamic development of a material environment, etc. In these circumstances, the society faces a problem of a technocratic knowledge domination without attention to…

  18. Microbiology of ancient and modern hydrothermal systems.

    PubMed

    Reysenbach, A L; Cady, S L

    2001-02-01

    Hydrothermal systems have prevailed throughout geological history on earth, and ancient ARCHAEAN hydrothermal deposits could provide clues to understanding earth's earliest biosphere. Modern hydrothermal systems support a plethora of microorganisms and macroorganisms, and provide good comparisons for paleontological interpretation of ancient hydrothermal systems. However, all of the microfossils associated with ancient hydrothermal deposits reported to date are filamentous, and limited STABLE ISOTOPE analysis suggests that these microfossils were probably autotrophs. Therefore, the morphology and mode of carbon metabolism are attributes of microorganisms from modern hydrothermal systems that provide valuable information for interpreting the geological record using morphological and isotopic signatures.

  19. Earliest example of a giant monitor lizard (Varanus, Varanidae, Squamata).

    PubMed

    Conrad, Jack L; Balcarcel, Ana M; Mehling, Carl M

    2012-01-01

    Varanidae is a clade of tiny (<20 mm pre-caudal length [PCL]) to giant (>600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors.

  20. The earliest Lunar Magma Ocean differentiation recorded in Fe isotopes

    NASA Astrophysics Data System (ADS)

    Wang, Kun; Jacobsen, Stein B.; Sedaghatpour, Fatemeh; Chen, Heng; Korotev, Randy L.

    2015-11-01

    Recent high-precision isotopic measurements show that the isotopic similarity of Earth and Moon is unique among all known planetary bodies in our Solar System. These observations provide fundamental constraints on the origin of Earth-Moon system, likely a catastrophic Giant Impact event. However, in contrast to the isotopic composition of many elements (e.g., O, Mg, Si, K, Ti, Cr, and W), the Fe isotopic compositions of all lunar samples are significantly different from those of the bulk silicate Earth. Such a global Fe isotopic difference between the Moon and Earth provides an important constraint on the lunar formation - such as the amount of Fe evaporation as a result of a Giant Impact origin of the Moon. Here, we show through high-precision Fe isotopic measurements of one of the oldest lunar rocks (4.51 ± 0.10 Gyr dunite 72 415), compared with Fe isotope results of other lunar samples from the Apollo program, and lunar meteorites, that the lunar dunite is enriched in light Fe isotopes, complementing the heavy Fe isotope enrichment in other lunar samples. Thus, the earliest olivine accumulation in the Lunar Magma Ocean may have been enriched in light Fe isotopes. This new observation allows the Fe isotopic composition of the bulk silicate Moon to be identical to that of the bulk silicate Earth, by balancing light Fe in the deep Moon with heavy Fe in the shallow Moon rather than the Moon having a heavier Fe isotope composition than Earth as a result of Giant Impact vaporization.

  1. Revisiting the earliest electrophysiological correlate of familiar face recognition.

    PubMed

    Huang, Wanyi; Wu, Xia; Hu, Liping; Wang, Lei; Ding, Yulong; Qu, Zhe

    2017-10-01

    The present study used event-related potentials (ERPs) to reinvestigate the earliest face familiarity effect (FFE: ERP differences between familiar and unfamiliar faces) that genuinely reflects cognitive processes underlying recognition of familiar faces in long-term memory. To trigger relatively early FFEs, participants were required to categorize upright and inverted famous faces and unknown faces in a task that placed high demand on face recognition. More importantly, to determine whether an observed FFE was linked to on-line face recognition, systematical investigation about the relationship between the FFE and behavioral performance of face recognition was conducted. The results showed significant FFEs on P1, N170, N250, and P300 waves. The FFEs on occipital P1 and N170 (<200ms) showed reversed polarities for upright and inverted faces, and were not correlated with any behavioral measure (accuracy, response time) or modulated by learning, indicating that they might merely reflect low-level visual differences between face sets. In contrast, the later FFEs on occipito-temporal N250 (~230ms) and centro-parietal P300 (~350ms) showed consistent polarities for upright and inverted faces. The N250 FFE was individually correlated with recognition speed for upright faces, and could be obtained for inverted faces through learning. The P300 FFE was also related to behavior in many aspects. These findings provide novel evidence supporting that cognitive discrimination of familiar and unfamiliar faces starts no less than 200ms after stimulus onset, and the familiarity effect on N250 may be the first electrophysiological correlate underlying recognition of familiar faces in long-term memory. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. The earliest mantle fabrics formed during subduction zone infancy

    NASA Astrophysics Data System (ADS)

    Harigane, Y.; Michibayashi, K.; Morishita, T.; Tani, K.; Dick, H. J.; Ishizuka, O.

    2013-12-01

    Harzburgites obtained from the oldest crust-mantle section in the Philippine Sea plate along the landward slope of the southern Izu-Ogasawara Trench in Izu-Bonin-Mariana arc, that explored by Dive 7K417 of the ROV Kaiko 7000II during R/V Kairei cruise KR08-07, and Dredge 31 of R/V Hakuho-Maru cruise KH07-02, operated by the Japan Agency for Marine-Earth Science and Technology. Harzburgites preserve mantle fabrics formed during the infancy of the subduction zone; that is during the initial stages of Pacific plate subduction beneath the Philippine Sea plate. The main constituent minerals of harzburgites are olivine (15.6%), orthopyroxene (Opx; 13.1%) and spinel (0.5%), along with serpentine (70.8%) as a secondary mineral. Microstructure shows inequigranular interlobate (or protogranular) textures. There is no secondary deformation such as porphyroclastic or fine-grained textures. The secondary serpentine shows undeformed mesh texture in the harzburgites. Harzburgites have crystal preferred orientation patterns in olivine (001)[100] and Opx (100)[001]. The mineral chemistry in harzburgites have high olivine forsterite (90.6-92.1 mol.%) and NiO (~0.4 wt%) contents, low Opx Al2O3 (<~1.5 wt%) and Na2O (<0.03 wt%), and high spinel Cr# (65-67). This has the characteristics of residual peridotites, whereas the dunites, obtained from the same location as the harzburgites, provide evidence for the earliest stages of arc volcanism during the inception of subduction. Therefore, we propose that the (001)[100] olivine patterns began forming in immature fore-arc mantle with an increase in slab-derived hydrous fluids during the initial stages of subduction in in situ oceanic island arc.

  3. Magnetic Reconnection at the Earliest Stage of Solar Flux Emergence

    NASA Astrophysics Data System (ADS)

    Tian, Hui; Zhu, Xiaoshuai; Peter, Hardi; Zhao, Jie; Samanta, Tanmoy; Chen, Yajie

    2018-02-01

    On 2016 September 20, the Interface Region Imaging Spectrograph observed an active region during its earliest emerging phase for almost 7 hr. The Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory observed continuous emergence of small-scale magnetic bipoles with a rate of ∼1016 Mx s‑1. The emergence of magnetic fluxes and interactions between different polarities lead to the frequent occurrence of ultraviolet (UV) bursts, which exhibit as intense transient brightenings in the 1400 Å images. In the meantime, discrete small patches with the same magnetic polarity tend to move together and merge, leading to the enhancement of the magnetic fields and thus the formation of pores (small sunspots) at some locations. The spectra of these UV bursts are characterized by the superposition of several chromospheric absorption lines on the greatly broadened profiles of some emission lines formed at typical transition region temperatures, suggesting heating of the local materials to a few tens of thousands of kelvin in the lower atmosphere by magnetic reconnection. Some bursts reveal blue- and redshifts of ∼100 km s‑1 at neighboring pixels, indicating the spatially resolved bidirectional reconnection outflows. Many such bursts appear to be associated with the cancellation of magnetic fluxes with a rate of the order of ∼1015 Mx s‑1. We also investigate the three-dimensional magnetic field topology through a magnetohydrostatic model and find that a small fraction of the bursts are associated with bald patches (magnetic dips). Finally, we find that almost all bursts are located in regions of large squashing factor at the height of ∼1 Mm, reinforcing our conclusion that these bursts are produced through reconnection in the lower atmosphere.

  4. Earliest Example of a Giant Monitor Lizard (Varanus, Varanidae, Squamata)

    PubMed Central

    Conrad, Jack L.; Balcarcel, Ana M.; Mehling, Carl M.

    2012-01-01

    Background Varanidae is a clade of tiny (<20 mm pre-caudal length [PCL]) to giant (>600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. Methodology/Principal Findings A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. Conclusions/Significance The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors. PMID:22900001

  5. The earliest maize from San Marcos Tehuacán is a partial domesticate with genomic evidence of inbreeding

    PubMed Central

    Vallebueno-Estrada, Miguel; Rodríguez-Arévalo, Isaac; Rougon-Cardoso, Alejandra; Martínez González, Javier; García Cook, Angel; Vielle-Calzada, Jean-Philippe

    2016-01-01

    Pioneering archaeological expeditions lead by Richard MacNeish in the 1960s identified the valley of Tehuacán as an important center of early Mesoamerican agriculture, providing by far the widest collection of ancient crop remains, including maize. In 2012, a new exploration of San Marcos cave (Tehuacán, Mexico) yielded nonmanipulated maize specimens dating at a similar age of 5,300–4,970 calibrated y B.P. On the basis of shotgun sequencing and genomic comparisons to Balsas teosinte and modern maize, we show herein that the earliest maize from San Marcos cave was a partial domesticate diverging from the landraces and containing ancestral allelic variants that are absent from extant maize populations. Whereas some domestication loci, such as teosinte branched1 (tb1) and brittle endosperm2 (bt2), had already lost most of the nucleotide variability present in Balsas teosinte, others, such as teosinte glume architecture1 (tga1) and sugary1 (su1), conserved partial levels of nucleotide variability that are absent from extant maize. Genetic comparisons among three temporally convergent samples revealed that they were homozygous and identical by descent across their genome. Our results indicate that the earliest maize from San Marcos was already inbred, opening the possibility for Tehuacán maize cultivation evolving from reduced founder populations of isolated and perhaps self-pollinated individuals. PMID:27872313

  6. The earliest maize from San Marcos Tehuacán is a partial domesticate with genomic evidence of inbreeding.

    PubMed

    Vallebueno-Estrada, Miguel; Rodríguez-Arévalo, Isaac; Rougon-Cardoso, Alejandra; Martínez González, Javier; García Cook, Angel; Montiel, Rafael; Vielle-Calzada, Jean-Philippe

    2016-12-06

    Pioneering archaeological expeditions lead by Richard MacNeish in the 1960s identified the valley of Tehuacán as an important center of early Mesoamerican agriculture, providing by far the widest collection of ancient crop remains, including maize. In 2012, a new exploration of San Marcos cave (Tehuacán, Mexico) yielded nonmanipulated maize specimens dating at a similar age of 5,300-4,970 calibrated y B.P. On the basis of shotgun sequencing and genomic comparisons to Balsas teosinte and modern maize, we show herein that the earliest maize from San Marcos cave was a partial domesticate diverging from the landraces and containing ancestral allelic variants that are absent from extant maize populations. Whereas some domestication loci, such as teosinte branched1 (tb1) and brittle endosperm2 (bt2), had already lost most of the nucleotide variability present in Balsas teosinte, others, such as teosinte glume architecture1 (tga1) and sugary1 (su1), conserved partial levels of nucleotide variability that are absent from extant maize. Genetic comparisons among three temporally convergent samples revealed that they were homozygous and identical by descent across their genome. Our results indicate that the earliest maize from San Marcos was already inbred, opening the possibility for Tehuacán maize cultivation evolving from reduced founder populations of isolated and perhaps self-pollinated individuals.

  7. The earliest archaeological maize (Zea mays L.) from highland Mexico: New accelerator mass spectrometry dates and their implications

    PubMed Central

    Piperno, D. R.; Flannery, K. V.

    2001-01-01

    Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from older strata from the site, although Zea pollen has previously been identified from those levels. These results, together with the modern geographical distribution of wild Zea mays, suggest that the cultural practices that led to Zea domestication probably occurred elsewhere in Mexico. Guilá Naquitz Cave has now yielded the earliest macrofossil evidence for the domestication of two major American crop plants, squash (Cucurbita pepo) and maize. PMID:11172082

  8. The earliest archaeological maize (Zea mays L.) from highland Mexico: new accelerator mass spectrometry dates and their implications.

    PubMed

    Piperno, D R; Flannery, K V

    2001-02-13

    Accelerator mass spectrometry age determinations of maize cobs (Zea mays L.) from Guilá Naquitz Cave in Oaxaca, Mexico, produced dates of 5,400 carbon-14 years before the present (about 6,250 calendar years ago), making those cobs the oldest in the Americas. Macrofossils and phytoliths characteristic of wild and domesticated Zea fruits are absent from older strata from the site, although Zea pollen has previously been identified from those levels. These results, together with the modern geographical distribution of wild Zea mays, suggest that the cultural practices that led to Zea domestication probably occurred elsewhere in Mexico. Guilá Naquitz Cave has now yielded the earliest macrofossil evidence for the domestication of two major American crop plants, squash (Cucurbita pepo) and maize.

  9. Evaluating College Students' Conceptual Knowledge of Modern Physics: Test of Understanding on Concepts of Modern Physics (TUCO-MP)

    ERIC Educational Resources Information Center

    Akarsu, Bayram

    2011-01-01

    In present paper, we propose a new diagnostic test to measure students' conceptual knowledge of principles of modern physics topics. Over few decades since born of physics education research (PER), many diagnostic instruments that measure students' conceptual understanding of various topics in physics, the earliest tests developed in PER are Force…

  10. Philipp Bozzini (1773-1809): The earliest description of endoscopy.

    PubMed

    Ramai, Daryl; Zakhia, Karl; Etienne, Denzil; Reddy, Madhavi

    2018-05-01

    The widespread use of endoscopy in today's clinical arena underscores its utility and growing significance within the field of medicine. Primitive forms of endoscopy have existed for hundreds of years, but it was not until the early 19th century that Dr Philipp Bozzini invented an endoscope that would form the basis of modern endoscopy. Born into an influential Italian family, Bozzini practiced medicine in a time and place of conflict and political unrest. His passion, ingenuity, and important social connections allowed him to create and introduce to the medical profession the Lichtleiter (light-conductor), which overcame two key issues plaguing endoscopy: inadequate lighting and poor penetration. A combination of professional rivalry and his premature passing stifled enthusiasm and further work on the Lichtleiter, but its value would not be lost forever. The advancements in the field of endoscopy that have come since the time of the Lichtleiter all build upon the principles of Bozzini, who became widely acknowledged as the father of modern endoscopy.

  11. The Earliest Evidence of Holometabolan Insect Pupation in Conifer Wood

    PubMed Central

    Tapanila, Leif; Roberts, Eric M.

    2012-01-01

    Background The pre-Jurassic record of terrestrial wood borings is poorly resolved, despite body fossil evidence of insect diversification among xylophilic clades starting in the late Paleozoic. Detailed analysis of borings in petrified wood provides direct evidence of wood utilization by invertebrate animals, which typically comprises feeding behaviors. Methodology/Principal Findings We describe a U-shaped boring in petrified wood from the Late Triassic Chinle Formation of southern Utah that demonstrates a strong linkage between insect ontogeny and conifer wood resources. Xylokrypta durossi new ichnogenus and ichnospecies is a large excavation in wood that is backfilled with partially digested xylem, creating a secluded chamber. The tracemaker exited the chamber by way of a small vertical shaft. This sequence of behaviors is most consistent with the entrance of a larva followed by pupal quiescence and adult emergence — hallmarks of holometabolous insect ontogeny. Among the known body fossil record of Triassic insects, cupedid beetles (Coleoptera: Archostemata) are deemed the most plausible tracemakers of Xylokrypta, based on their body size and modern xylobiotic lifestyle. Conclusions/Significance This oldest record of pupation in fossil wood provides an alternative interpretation to borings once regarded as evidence for Triassic bees. Instead Xylokrypta suggests that early archostematan beetles were leaders in exploiting wood substrates well before modern clades of xylophages arose in the late Mesozoic. PMID:22355387

  12. Tracing Life in the Earliest Terrestrial Rock Record

    NASA Astrophysics Data System (ADS)

    Lepland, A.; van Zuilen, M.; Arrhenius, G.

    2001-12-01

    The principal method for studying the earliest traces of life in the metamorphosed, oldest (> 3.5 Ga) terrestrial rocks involves determination of isotopic composition of carbon, mainly prevailing as graphite. It is generally believed that this measure can distinguish biogenic graphite from abiogenic varieties. However, the interpretation of life from carbon isotope ratios has to be assessed within the context of specific geologic circumstances requiring (i) reliable protolith interpretation (ii) control of secondary, metasomatic processes, and (iii) understanding of different graphite producing mechanisms and related carbon isotopic systematics. We have carried out a systematic study of abundance, isotopic composition and petrographic associations of graphite in rocks from the ca. 3.8 Ga Isua Supracrustal Belt (ISB) in southern West Greenland. Our study indicates that most of the graphite in ISB occurs in carbonate-rich metasomatic rocks (metacarbonates) while sedimentary units, including banded iron formations (BIFs) and metacherts, have exceedingly low graphite concentrations. Regardless of isotopic composition of graphite in metacarbonate rocks, their secondary origin disqualifies them from providing evidence for traces of life stemming from 3.8 Ga. Recognition of the secondary origin of Isua metacarbonates thus calls for reevaluation of biologic interpretations by Schidlowski et al. (1979) and Mojzsis et al. (1996) that suggested the occurrence of 3.8 Ga biogenic graphite in these rocks. The origin of minute quantities of reduced carbon, released from sedimentary BIFs and metacherts at combustion steps > 700 C remains to be clarified. Its isotopic composition (d13C from -18 to -25%) may hint at a biogenic origin. However, such isotopically light carbon was also found in Proterozoic mafic dykes cross-cutting the metasedimentary units in the ISB. The occurrence of isotopically light, reduced carbon in biologically irrelevant dykes may indicate secondary graphite

  13. Modern Spectroscopy

    ERIC Educational Resources Information Center

    Barrow, Gordon M.

    1970-01-01

    Presents the basic ideas of modern spectroscopy. Both the angular momenta and wave-nature approaches to the determination of energy level patterns for atomic and molecular systems are discussed. The interpretation of spectra, based on atomic and molecular models, is considered. (LC)

  14. Japan 1945-1989: Re-Creating a Modern Nation. A Humanities Approach to Japanese History, Part IV.

    ERIC Educational Resources Information Center

    Parisi, Lynn; Masalski, Kathleen Woods

    This curriculum unit is the final volume of a four-part series. Noting that the humanities reveal the values and beliefs that underlie social, political, and economic institutions, the unit contends that the study of other countries and their histories may be greatly enriched by a humanities approach that draws on the fields of literature,…

  15. Initiation of clement surface conditions on the earliest Earth

    PubMed Central

    Sleep, N. H.; Zahnle, K.; Neuhoff, P. S.

    2001-01-01

    In the beginning the surface of the Earth was extremely hot, because the Earth as we know it is the product of a collision between two planets, a collision that also created the Moon. Most of the heat within the very young Earth was lost quickly to space while the surface was still quite hot. As it cooled, the Earth's surface passed monotonically through every temperature regime between silicate vapor to liquid water and perhaps even to ice, eventually reaching an equilibrium with sunlight. Inevitably the surface passed through a time when the temperature was around 100°C at which modern thermophile organisms live. How long this warm epoch lasted depends on how long a thick greenhouse atmosphere can be maintained by heat flow from the Earth's interior, either directly as a supplement to insolation, or indirectly through its influence on the nascent carbonate cycle. In both cases, the duration of the warm epoch would have been controlled by processes within the Earth's interior where buffering by surface conditions played little part. A potentially evolutionarily significant warm period of between 105 and 107 years seems likely, which nonetheless was brief compared to the vast expanse of geological time. PMID:11259665

  16. Initiation of clement surface conditions on the earliest Earth.

    PubMed

    Sleep, N H; Zahnle, K; Neuhoff, P S

    2001-03-27

    In the beginning the surface of the Earth was extremely hot, because the Earth as we know it is the product of a collision between two planets, a collision that also created the Moon. Most of the heat within the very young Earth was lost quickly to space while the surface was still quite hot. As it cooled, the Earth's surface passed monotonically through every temperature regime between silicate vapor to liquid water and perhaps even to ice, eventually reaching an equilibrium with sunlight. Inevitably the surface passed through a time when the temperature was around 100 degrees C at which modern thermophile organisms live. How long this warm epoch lasted depends on how long a thick greenhouse atmosphere can be maintained by heat flow from the Earth's interior, either directly as a supplement to insolation, or indirectly through its influence on the nascent carbonate cycle. In both cases, the duration of the warm epoch would have been controlled by processes within the Earth's interior where buffering by surface conditions played little part. A potentially evolutionarily significant warm period of between 10(5) and 10(7) years seems likely, which nonetheless was brief compared to the vast expanse of geological time.

  17. Modern carbonate mound systems

    NASA Astrophysics Data System (ADS)

    Henriet, J. P.; Dullo, C.

    2003-04-01

    Carbonate mounds are prominent features throughout the geological record. In many hydrocarbon provinces, they form prime reservoir structures. But recent investigations have increasingly reported occurrences of large mound clusters at the surface of the seabed, or buried at shallow depth on modern ocean margins, and in particular in basins rich in hydrocarbons. Such exciting new observations along the West-European margin are promising for elucidating the setting and environment of modern carbonate mounds, but at the same time they confront us with puzzling or sometimes contradictory observations in the quest for their genesis. Spectacular cold-water coral communities have colonized such mounds, but convincing arguments for recognizing them as prime builders are still lacking. The geological record provides ample evidence of microbial mediation in mound build-up and stabilisation, but as long as mound drilling is lacking, we have no opportunity to verify the role of such processes and identify the key actors in the earliest stage of onset and development of modern mounds. Some evidence from the past record and from present very-high resolution observations in the shallow seabed suggest an initial control by fluid venting, and fluid migration pathways have been imaged or are tentatively reconstructed by modelling in the concerned basins, but the ultimate link in the shallow subsurface seems still to elude a large part of our efforts. Surface sampling and analyses of both corals and surface sediments have largely failed in giving any conclusive evidence of present-day or recent venting in the considered basins. But on the other hand, applying rigourously the interpretational keys derived from e.g. Porcupine Seabight settings off NW Ireland on brand new prospective settings e.g. on the Moroccan margin have resulted in the discovery of totally new mound settings, in the middle of a field of giant, active mud volcanoes. Keys are apparently working, but we still do not

  18. Shape of the orbital opening: individual characterization and analysis of variability in modern humans, Gorilla gorilla, and Pan troglodytes.

    PubMed

    Schmittbuhl, M; Le Minor, J M; Allenbach, B; Schaaf, A

    1999-05-01

    The description of the human orbital shape is principally qualitative in the classical literature, and characterised by adjectives such as circular, rectangular or quadrangular. In order to provide a precise quantification and interpretation of this shape, a study based on automatic image analysis and Fourier analysis was carried out on 45 human skulls (30 males, 15 females), and for comparison on 61 skulls of Gorilla gorilla (40 males, 21 females), and 34 skulls of Pan troglodytes (20 males, 14 females). Sexual dimorphism in the shape of the orbital opening was not demonstrated. Its dominant morphological features could be characterized by Fourier analysis; elliptical elongation and quadrangularity were dominant morphological features of the shape of the orbital opening in the three species. Elliptical elongation was more marked in humans and Pan, whereas quadrangularity was particularly emphasized in Gorilla. An intraspecific variability of the shape of the orbital opening existed in humans, Gorilla and Pan, and seemed close in the three species. Interspecific partition between humans, Gorilla and Pan was demonstrated despite the variability observed in the three species studied. Interspecific differences between Gorilla and the Pan-humans group were principally explained by the differences in quadrangularity, and by differences in orientation of triangularity and pentagonality. Differences in the shape of the orbital opening between humans and Pan were principally explained by differences in hexagonality, and by differences in orientation of quadrangularity. A closeness of shape between some humans and some individuals in Pan and, to a lesser degree, with some individuals in Gorilla was observed, demonstrating the existence of a morphological continuum of the shape of the orbital opening in hominoids.

  19. The Comoros Show the Earliest Austronesian Gene Flow into the Swahili Corridor.

    PubMed

    Brucato, Nicolas; Fernandes, Veronica; Mazières, Stéphane; Kusuma, Pradiptajati; Cox, Murray P; Ng'ang'a, Joseph Wainaina; Omar, Mohammed; Simeone-Senelle, Marie-Claude; Frassati, Coralie; Alshamali, Farida; Fin, Bertrand; Boland, Anne; Deleuze, Jean-Francois; Stoneking, Mark; Adelaar, Alexander; Crowther, Alison; Boivin, Nicole; Pereira, Luisa; Bailly, Pascal; Chiaroni, Jacques; Ricaut, François-Xavier

    2018-01-04

    At the dawn of the second millennium, the expansion of the Indian Ocean trading network aligned with the emergence of an outward-oriented community along the East African coast to create a cosmopolitan cultural and trading zone known as the Swahili Corridor. On the basis of analyses of new genome-wide genotyping data and uniparental data in 276 individuals from coastal Kenya and the Comoros islands, along with large-scale genetic datasets from the Indian Ocean rim, we reconstruct historical population dynamics to show that the Swahili Corridor is largely an eastern Bantu genetic continuum. Limited gene flows from the Middle East can be seen in Swahili and Comorian populations at dates corresponding to historically documented contacts. However, the main admixture event in southern insular populations, particularly Comorian and Malagasy groups, occurred with individuals from Island Southeast Asia as early as the 8 th century, reflecting an earlier dispersal from this region. Remarkably, our results support recent archaeological and linguistic evidence-based suggestions that the Comoros archipelago was the earliest location of contact between Austronesian and African populations in the Swahili Corridor. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  20. Origin and timing of New Zealand's earliest domestic chickens: Polynesian commensals or European introductions?

    PubMed Central

    Wood, Jamie R.; Herrera, Michael J. B.; Wilmshurst, Janet M.

    2016-01-01

    Human settlers transported chickens (Gallus gallus domesticus) to most East Polynesian archipelagos between AD 1000 and 1300; however, it has long been assumed that New Zealand was an exception. Despite the fact that chicken bones have been recovered from localities of early archaeological middens in New Zealand, their age and genetic relationships have never been critically assessed. Here, we test the assumption that chickens were not introduced to New Zealand during prehistory through ancient DNA and radiocarbon analyses of chicken bones from sites of Māori middens containing prehistoric material. The chickens belong to the widespread mitochondrial control region haplogroup E. Radiocarbon dating reveals that the bones are not prehistoric, but are still the earliest chicken remains known from New Zealand. Two of the bones pre-date permanent European settlement (ca 1803s onwards) but overlap with the arrival of James Cook's second voyage (1773–1774), and, therefore, they are likely to be chickens, or progeny thereof, liberated during that voyage. Our results support the idea that chickens were first introduced to New Zealand by Europeans, and provide new insights into Māori uptake and integration of resources introduced during the early post-European period. PMID:27853601

  1. Perceptual learning increases the strength of the earliest signals in visual cortex.

    PubMed

    Bao, Min; Yang, Lin; Rios, Cristina; He, Bin; Engel, Stephen A

    2010-11-10

    Training improves performance on most visual tasks. Such perceptual learning can modify how information is read out from, and represented in, later visual areas, but effects on early visual cortex are controversial. In particular, it remains unknown whether learning can reshape neural response properties in early visual areas independent from feedback arising in later cortical areas. Here, we tested whether learning can modify feedforward signals in early visual cortex as measured by the human electroencephalogram. Fourteen subjects were trained for >24 d to detect a diagonal grating pattern in one quadrant of the visual field. Training improved performance, reducing the contrast needed for reliable detection, and also reliably increased the amplitude of the earliest component of the visual evoked potential, the C1. Control orientations and locations showed smaller effects of training. Because the C1 arises rapidly and has a source in early visual cortex, our results suggest that learning can increase early visual area response through local receptive field changes without feedback from later areas.

  2. Origin and timing of New Zealand's earliest domestic chickens: Polynesian commensals or European introductions?

    NASA Astrophysics Data System (ADS)

    Wood, Jamie R.; Herrera, Michael J. B.; Scofield, R. Paul; Wilmshurst, Janet M.

    2016-08-01

    Human settlers transported chickens (Gallus gallus domesticus) to most East Polynesian archipelagos between AD 1000 and 1300; however, it has long been assumed that New Zealand was an exception. Despite the fact that chicken bones have been recovered from localities of early archaeological middens in New Zealand, their age and genetic relationships have never been critically assessed. Here, we test the assumption that chickens were not introduced to New Zealand during prehistory through ancient DNA and radiocarbon analyses of chicken bones from sites of Māori middens containing prehistoric material. The chickens belong to the widespread mitochondrial control region haplogroup E. Radiocarbon dating reveals that the bones are not prehistoric, but are still the earliest chicken remains known from New Zealand. Two of the bones pre-date permanent European settlement (ca 1803s onwards) but overlap with the arrival of James Cook's second voyage (1773-1774), and, therefore, they are likely to be chickens, or progeny thereof, liberated during that voyage. Our results support the idea that chickens were first introduced to New Zealand by Europeans, and provide new insights into Māori uptake and integration of resources introduced during the early post-European period.

  3. Earliest Phanerozoic or latest Proterozoic fossils from the Arabian Shield

    USGS Publications Warehouse

    Cloud, P.; Awramik, S.M.; Morrison, K.; Hadley, D.G.

    1979-01-01

    We report here the first biologically definable fossils from pre-Saq (pre-Middle Cambrian) rocks of the Arabian Shield. They include the distinctive helically coiled tubular filaments of the oscillatorialean blue-green alga Obruchevella parva as well as two size classes of spheroidal unicells of uncertain affinity. Also present is the conical stromatolite Conophyton and unidentified stromatolites. All occur in cherty limestones of the Jubaylah Group, northern Saudi Arabia, a nonmarine to locally marine taphrogeosynclinal sequence that fills depressions along the northwest-trending Najd faults. Conophyton has heretofore been found only in strata older than about 680 Ma (except for puzzling records in modern hot springs) while Obruchevella is so far known only from rocks between about 680 and 470 Ma old. Thus it appears that the Jubaylah Group is close to the Proterozoic-Phanerozoic transition. The simple spheroidal nanno-fossils are not diagnostic as to age. Their relationships within what appears to be early diagenetic chert suggest a classical algal-mat association. The brecciated and microchanneled appearance of much of the fossiliferous rock, its locally dolomitic nature, and the prevalence of cryptalgalaminate favors a very shallow, locally turbulent, and perhaps episodically exposed marine or marginal marine setting. The Jubaylah Group lies unconformably beneath the Siq Sandstone (basal member of the Saq Sandstone) of medial Cambrian age, rests nonconformably on crystalline basement, and has yielded a K-Ar whole-rock age (on andesitic basalt) of ???540 Ma. To judge from the fossils, however, that age may be as much as 100 Ma or more too young. ?? 1979.

  4. Stable Isotopes and Zooarchaeology at Teotihuacan, Mexico Reveal Earliest Evidence of Wild Carnivore Management in Mesoamerica.

    PubMed

    Sugiyama, Nawa; Somerville, Andrew D; Schoeninger, Margaret J

    2015-01-01

    From Roman gladiatorial combat to Egyptian animal mummies, the capture and manipulation of carnivores was instrumental in helping to shape social hierarchies throughout the ancient world. This paper investigates the historical inflection point when humans began to control animals not only as alimental resources but as ritual symbols and social actors in the New World. At Teotihuacan (A.D. 1-550), one of the largest pre-Hispanic cities, animal remains were integral components of ritual caches expressing state ideology and militarism during the construction of the Moon and the Sun Pyramids. The caches contain the remains of nearly 200 carnivorous animals, human sacrificial victims and other symbolic artifacts. This paper argues the presence of skeletal pathologies of infectious disease and injuries manifest on the carnivore remains show direct evidence of captivity. Stable isotope analysis (δ13C and δ15N) of bones and teeth confirms that some of these carnivores were consuming high levels of C4 foods, likely reflecting a maize-based anthropocentric food chain. These results push back the antiquity of keeping captive carnivores for ritualistic purposes nearly 1000 years before the Spanish conquistadors described Moctezuma's zoo at the Aztec capital. Mirroring these documents the results indicate a select group of carnivores at Teotihuacan may have been fed maize-eating omnivores, such as dogs and humans. Unlike historical records, the present study provides the earliest and direct archaeological evidence for this practice in Mesoamerica. It also represents the first systematic isotopic exploration of a population of archaeological eagles (n = 24) and felids (n = 29).

  5. Stable Isotopes and Zooarchaeology at Teotihuacan, Mexico Reveal Earliest Evidence of Wild Carnivore Management in Mesoamerica

    PubMed Central

    Sugiyama, Nawa; Somerville, Andrew D.; Schoeninger, Margaret J.

    2015-01-01

    From Roman gladiatorial combat to Egyptian animal mummies, the capture and manipulation of carnivores was instrumental in helping to shape social hierarchies throughout the ancient world. This paper investigates the historical inflection point when humans began to control animals not only as alimental resources but as ritual symbols and social actors in the New World. At Teotihuacan (A.D. 1–550), one of the largest pre-Hispanic cities, animal remains were integral components of ritual caches expressing state ideology and militarism during the construction of the Moon and the Sun Pyramids. The caches contain the remains of nearly 200 carnivorous animals, human sacrificial victims and other symbolic artifacts. This paper argues the presence of skeletal pathologies of infectious disease and injuries manifest on the carnivore remains show direct evidence of captivity. Stable isotope analysis (δ13C and δ15N) of bones and teeth confirms that some of these carnivores were consuming high levels of C4 foods, likely reflecting a maize-based anthropocentric food chain. These results push back the antiquity of keeping captive carnivores for ritualistic purposes nearly 1000 years before the Spanish conquistadors described Moctezuma’s zoo at the Aztec capital. Mirroring these documents the results indicate a select group of carnivores at Teotihuacan may have been fed maize-eating omnivores, such as dogs and humans. Unlike historical records, the present study provides the earliest and direct archaeological evidence for this practice in Mesoamerica. It also represents the first systematic isotopic exploration of a population of archaeological eagles (n = 24) and felids (n = 29). PMID:26332042

  6. Analysis of Site Formation and Assemblage Integrity Does Not Support Attribution of the Uluzzian to Modern Humans at Grotta del Cavallo

    PubMed Central

    Zilhão, João; Banks, William E.; d’Errico, Francesco; Gioia, Patrizia

    2015-01-01

    Based on the morphology of two deciduous molars and radiocarbon ages from layers D and E of the Grotta del Cavallo (Lecce, Italy), assigned to the Uluzzian, it has been proposed that modern humans were the makers of this Early Upper Paleolithic culture and that this finding considerably weakens the case for an independent emergence of symbolism among western European Neandertals. Reappraisal of the new dating evidence, of the finds curated in the Taranto Antiquities depot, and of coeval publications detailing the site’s 1963–66 excavations shows that (a) Protoaurignacian, Aurignacian and Early Epigravettian lithics exist in the assemblages from layers D and E, (b) even though it contains both inherited and intrusive items, the formation of layer D began during Protoaurignacian times, and (c) the composition of the extant Cavallo assemblages is influenced in a non-negligible manner by the post-hoc assignment of items to stratigraphic units distinct from that of original discovery. In addition, a major disturbance feature affected the 1960s excavation trench down to Mousterian layer F, this feature went unrecognized until 1964, the human remains assigned to the Uluzzian were discovered that year and/or the previous year, and there are contradictions between field reports and the primary anthropological description of the remains as to their morphology and level of provenience. Given these major contextual uncertainties, the Cavallo teeth cannot be used to establish the authorship of the Uluzzian. Since this technocomplex’s start date is ca. 45,000 calendar years ago, a number of Neandertal fossils are dated to this period, and the oldest diagnostic European modern human fossil is the <41,400 year-old Oase 1 mandible, Neandertal authorship of the Uluzzian remains the parsimonious reading of the evidence. PMID:26154139

  7. Assessing the accuracy of cranial and pelvic ageing methods on human skeletal remains from a modern Greek assemblage.

    PubMed

    Xanthopoulou, Panagiota; Valakos, Efstratios; Youlatos, Dionisios; Nikita, Efthymia

    2018-05-01

    The present study tests the accuracy of commonly adopted ageing methods based on the morphology of the pubic symphysis, auricular surface and cranial sutures. These methods are examined both in their traditional form as well as in the context of transition analysis using the ADBOU software in a modern Greek documented collection consisting of 140 individuals who lived mainly in the second half of the twentieth century and come from cemeteries in the area of Athens. The auricular surface overall produced the most accurate age estimates in our material, with different methods based on this anatomical area showing varying degrees of success for different age groups. The pubic symphysis produced accurate results primarily for young adults and the same applied to cranial sutures but the latter appeared completely inappropriate for older individuals. The use of transition analysis through the ADBOU software provided less accurate results than the corresponding traditional ageing methods in our sample. Our results are in agreement with those obtained from validation studies based on material from across the world, but certain differences identified with other studies on Greek material highlight the importance of taking into account intra- and inter-population variability in age estimation. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Health benefits of ancient grains. Comparison among bread made with ancient, heritage and modern grain flours in human cultured cells.

    PubMed

    Valli, Veronica; Taccari, Annalisa; Di Nunzio, Mattia; Danesi, Francesca; Bordoni, Alessandra

    2018-05-01

    Nowadays the higher nutritional value of whole grains compared to refined grains is recognized. In the last decade, there has been a renewed interest in the ancient wheat varieties for producing high-value food products with enhanced health benefits. This study compared two ancient grains, two heritage grains, and four modern grains grown in the same agronomic conditions considering not only their chemical characteristics, but also their biological effects. Whole grain flours were obtained and used to make bread. Bread was in vitro digested, the digesta were supplemented to HepG2 cells, and the biological effects of supplementation were evaluated. In addition, cells previously supplemented with the different digested bread types were then exposed to inflammatory agents to evidence possible protective effects of the pre-treatments. Despite the impossibility to discriminate bread made with different grains based on their chemical composition, results herein reported evidence that their supplementation to cultured cells exerts different effects, confirming the potential health benefits of ancient grains. This research represents an advancement for the evaluation of the apparent positive effects of ancient grains and the formulation of cereal-based products with added nutritional value. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. The Modern Primitives: Applying New Technological Approaches to Explore the Biology of the Earliest Red Blood Cells

    PubMed Central

    Fraser, Stuart T.

    2013-01-01

    One of the most critical stages in mammalian embryogenesis is the independent production of the embryo's own circulating, functional red blood cells. Correspondingly, erythrocytes are the first cell type to become functionally mature during embryogenesis. Failure to achieve this invariably leads to in utero lethality. The recent application of technologies such as transcriptome analysis, flow cytometry, mutant embryo analysis, and transgenic fluorescent gene expression reporter systems has shed new light on the distinct erythroid lineages that arise early in development. Here, I will describe the similarities and differences between the distinct erythroid populations that must form for the embryo to survive. While much of the focus of this review will be the poorly understood primitive erythroid lineage, a discussion of other erythroid and hematopoietic lineages, as well as the cell types making up the different niches that give rise to these lineages, is essential for presenting an appropriate developmental context of these cells. PMID:24222861

  10. Implications of Nubian-Like Core Reduction Systems in Southern Africa for the Identification of Early Modern Human Dispersals

    PubMed Central

    Phillips, Natasha

    2015-01-01

    Lithic technologies have been used to trace dispersals of early human populations within and beyond Africa. Convergence in lithic systems has the potential to confound such interpretations, implying connections between unrelated groups. Due to their reductive nature, stone artefacts are unusually prone to this chance appearance of similar forms in unrelated populations. Here we present data from the South African Middle Stone Age sites Uitpanskraal 7 and Mertenhof suggesting that Nubian core reduction systems associated with Late Pleistocene populations in North Africa and potentially with early human migrations out of Africa in MIS 5 also occur in southern Africa during early MIS 3 and with no clear connection to the North African occurrence. The timing and spatial distribution of their appearance in southern and northern Africa implies technological convergence, rather than diffusion or dispersal. While lithic technologies can be a critical guide to human population flux, their utility in tracing early human dispersals at large spatial and temporal scales with stone artefact types remains questionable. PMID:26125972

  11. The first modern Europeans.

    PubMed

    Benazzi, Stefano

    2012-01-01

    The discovery of new human fossil remains is one of the most obvious ways to improve our understanding of the dynamics of human evolution. The reanalysis of existing fossils using newer methods is also crucial, and may lead to a reconsideration of the biological and taxonomical status of some specimens, and improve our understanding of highly debated periods in human prehistory. This is particularly true for those remains that have previously been studied using traditional approaches, with only morphological descriptions and standard calliper measurements available. My own interest in the Uluzzian, and its associated human remains grew from my interest in applying recently developed analytical techniques to quantify morphological variation. Discovered more than 40 years ago, the two deciduous molars from Grotta del Cavallo (Apulia, Italy) are the only human remains associated with the Uluzzian culture (one of the main three European "transitional" cultures). These teeth were previously attributed to Neanderthals. This attribution contributed to a consensus view that the Uluzzian, with its associated ornament and tool complexes, was produced by Neanderthals. A reassessment of these deciduous teeth by means of digital morphometric analysis revealed that these remains belong to anatomically modern humans (AMHs). This finding contradicts previous assumptions and suggests that modern humans, and not Neanderthals, created the Uluzzian culture. Of equal importance, new chronometric analyses date these dental remains to 43,000-45,000 cal BP. Thus, the teeth from Grotta del Cavallo represent the oldest European AMH currently known.

  12. Were inefficient mitochondrial haplogroups selected during migrations of modern humans? A test using modular kinetic analysis of coupling in mitochondria from cybrid cell lines

    PubMed Central

    Amo, Taku; Brand, Martin D.

    2007-01-01

    We introduce a general test of the bioenergetic importance of mtDNA (mitochondrial DNA) variants: modular kinetic analysis of oxidative phosphorylation in mitochondria from cybrid cells with constant nuclear DNA but different mtDNA. We have applied this test to the hypothesis [Ruiz-Pesini, Mishmar, Brandon, Procaccio and Wallace (2004) Science 303, 223–226] that particular mtDNA haplogroups (specific combinations of polymorphisms) that cause lowered coupling efficiency, leading to generation of less ATP and more heat, were positively selected during radiations of modern humans into colder climates. Contrary to the predictions of this hypothesis, mitochondria from Arctic haplogroups had similar or even greater coupling efficiency than mitochondria from tropical haplogroups. PMID:17355224

  13. Modern embalming, circulation of fluids, and the voyage through the human arterial system: Carl L. Barnes and the culture of immortality in America.

    PubMed

    Podgorny, Irina

    2011-01-01

    By considering the work of American embalmer, lawyer, and physician Carl Lewis Barnes (1872-1927), this paper analyzes the emergence of modern embalming in America. Barnes experimented with and exhibited the techniques by which embalming fluids travelled into the most remote cavities of the human body. In this sense, modem embalmers based their skills and methods on experimental medicine, turning the anatomy of blood vessels, physiology of circulation, and composition of blood into a circuit that allowed embalming fluids to move throughout the corpse. Embalmers in the late 19th century took ownership of the laws of hydrodynamics and the physiology of blood circulation to market their fluids and equipment, thus playing the role of physiologists of death, performing and demonstrating physiological experiments with dead bodies.

  14. Were inefficient mitochondrial haplogroups selected during migrations of modern humans? A test using modular kinetic analysis of coupling in mitochondria from cybrid cell lines.

    PubMed

    Amo, Taku; Brand, Martin D

    2007-06-01

    We introduce a general test of the bioenergetic importance of mtDNA (mitochondrial DNA) variants: modular kinetic analysis of oxidative phosphorylation in mitochondria from cybrid cells with constant nuclear DNA but different mtDNA. We have applied this test to the hypothesis [Ruiz-Pesini, Mishmar, Brandon, Procaccio and Wallace (2004) Science 303, 223-226] that particular mtDNA haplogroups (specific combinations of polymorphisms) that cause lowered coupling efficiency, leading to generation of less ATP and more heat, were positively selected during radiations of modern humans into colder climates. Contrary to the predictions of this hypothesis, mitochondria from Arctic haplogroups had similar or even greater coupling efficiency than mitochondria from tropical haplogroups.

  15. Ford and Edison in a modern regulatory environment: the first-in-human trial of night-work and artificial light.

    PubMed

    Erren, Thomas C; Shaw, David M; Wild, Ursula; Groß, J Valérie

    2017-01-01

    A thought experiment places Henry Ford and Thomas Alva Edison in a modern regulatory environment. In a utopian occupational world devoid of night-shifts or artificial light, Ford wants to experiment with "working through the night". To support Ford's project, Edison offers his patented electric lamps to "turn nights into days". An ethics committee [EC] does not approve the night-work experiment and Utopia's Food and Drug Administration [FDA] does not approve the potential medical device as safe for use by humans. According to the EC and FDA, complex effects on circadian biology and thus safety of work and light at night are not understood. The thought experiment conveys that we should pay more attention to possible risks of work and light at chronobiologically unusual times.

  16. [The international network and Italian modernization. Ruggero Ceppellini, genetics, and HLA].

    PubMed

    Capocci, Mauro

    2014-01-01

    The paper reconstructs the scientific career of Ruggero Ceppellini, focusing especially on his role in the discovery of the genetic system underlying the Human Leucocyte Antigen. From his earliest investigations in blood group genetics, Ceppellini quickly became an internationally acknowledged authority in the field of immunogenetics--the study of genetics by means of immunological tools--and participated to the endeavor that ultimately yelded a new meaning for the word: thanks to the pioneering research in the HLA field, immunogenetics became the study of the genetic control of immune system. The paper will also place Ceppellini's scientific work against the backdrop of the modernization of Italian genetics after WWII, resulting from the efforts of a handful of scientists to connect to international networks and adopting new methodologies in life sciences.

  17. Most of the extant mtDNA boundaries in South and Southwest Asia were likely shaped during the initial settlement of Eurasia by anatomically modern humans

    PubMed Central

    Metspalu, Mait; Kivisild, Toomas; Metspalu, Ene; Parik, Jüri; Hudjashov, Georgi; Kaldma, Katrin; Serk, Piia; Karmin, Monika; Behar, Doron M; Gilbert, M Thomas P; Endicott, Phillip; Mastana, Sarabjit; Papiha, Surinder S; Skorecki, Karl; Torroni, Antonio; Villems, Richard

    2004-01-01

    Background Recent advances in the understanding of the maternal and paternal heritage of south and southwest Asian populations have highlighted their role in the colonization of Eurasia by anatomically modern humans. Further understanding requires a deeper insight into the topology of the branches of the Indian mtDNA phylogenetic tree, which should be contextualized within the phylogeography of the neighboring regional mtDNA variation. Accordingly, we have analyzed mtDNA control and coding region variation in 796 Indian (including both tribal and caste populations from different parts of India) and 436 Iranian mtDNAs. The results were integrated and analyzed together with published data from South, Southeast Asia and West Eurasia. Results Four new Indian-specific haplogroup M sub-clades were defined. These, in combination with two previously described haplogroups, encompass approximately one third of the haplogroup M mtDNAs in India. Their phylogeography and spread among different linguistic phyla and social strata was investigated in detail. Furthermore, the analysis of the Iranian mtDNA pool revealed patterns of limited reciprocal gene flow between Iran and the Indian sub-continent and allowed the identification of different assemblies of shared mtDNA sub-clades. Conclusions Since the initial peopling of South and West Asia by anatomically modern humans, when this region may well have provided the initial settlers who colonized much of the rest of Eurasia, the gene flow in and out of India of the maternally transmitted mtDNA has been surprisingly limited. Specifically, our analysis of the mtDNA haplogroups, which are shared between Indian and Iranian populations and exhibit coalescence ages corresponding to around the early Upper Paleolithic, indicates that they are present in India largely as Indian-specific sub-lineages. In contrast, other ancient Indian-specific variants of M and R are very rare outside the sub-continent. PMID:15339343

  18. From fish to modern humans--comparative anatomy, homologies and evolution of the pectoral and forelimb musculature.

    PubMed

    Diogo, R; Abdala, V; Aziz, M A; Lonergan, N; Wood, B A

    2009-05-01

    In a recent study Diogo & Abdala [(2007) J Morphol 268, 504-517] reported the results of the first part of a research project on the comparative anatomy, homologies and evolution of the pectoral muscles of osteichthyans (bony fish and tetrapods). That report mainly focused on actinopterygian fish but also compared these fish with certain non-mammalian sarcopterygians. This study, which reports the second part of the research project, focuses mainly on sarcopterygians and particularly on how the pectoral and forelimb muscles have evolved during the transitions from sarcopterygian fish and non-mammalian tetrapods to monotreme and therian mammals and humans. The data obtained by our own dissections of all the pectoral and forelimb muscles of representative members of groups as diverse as sarcopterygian fish, amphibians, reptiles, monotremes and therian mammals such as rodents, tree-shrews, colugos and primates, including humans, are compared with the information available in the literature. Our observations and comparisons clearly stress that, with regard to the number of pectoral and forelimb muscles, the most striking transition within sarcopterygian evolutionary history was that leading to the origin of tetrapods. Whereas extant sarcopterygian fish have an abductor and adductor of the fin and a largely undifferentiated hypaxial and epaxial musculature, extant salamanders such as Ambystoma have more than 40 pectoral and forelimb muscles. There is no clear increase in the number of pectoral and forelimb muscles within the evolutionary transition that led to the origin of mammals and surely not to that leading to the origin of primates and humans.

  19. The oldest Stone Age occupation of coastal West Africa and its implications for modern human dispersals: New insight from Tiémassas

    NASA Astrophysics Data System (ADS)

    Niang, Khady; Blinkhorn, James; Ndiaye, Matar

    2018-05-01

    Examinations of modern human dispersals are typically focused on expansions from South, East or North Africa into Eurasia, with more limited attention paid to dispersals within Africa. The paucity of the West African fossil record means it has typically been overlooked in appraisals of human expansions in the Late Pleistocene, yet regions such as Senegal occur in key biogeographic transitional zones that may offer significant corridors for human occupation and expansion. Here, we report the first evidence for Middle Stone Age occupation of the West African littoral from Tiémassas, dating to ∼44 thousand years ago, coinciding with a period of enhanced humidity across the region. Prehistoric populations mainly procured raw material from exposed Ypresian limestone horizons with Levallois, discoidal and informal reduction sequences producing flake blanks for retouched tools. We discuss this mid-Marine Isotope Stage 3 occupation in the context of the site's unique, ecotonal position amongst Middle Stone Age sites across West Africa, and its significance for Later Stone Age colonization of near coastal forests in the region. The results also support previous suggestions for connections between Middle Stone Age populations in West Africa and the Maghreb, for which the coastline may also have played a significant role.

  20. From fish to modern humans – comparative anatomy, homologies and evolution of the pectoral and forelimb musculature

    PubMed Central

    Diogo, R; Abdala, V; Aziz, M A; Lonergan, N; Wood, B A

    2009-01-01

    In a recent study Diogo & Abdala [(2007) JMorphol268, 504–517] reported the results of the first part of a research project on the comparative anatomy, homologies and evolution of the pectoral muscles of osteichthyans (bony fish and tetrapods). That report mainly focused on actinopterygian fish but also compared these fish with certain non-mammalian sarcopterygians. This study, which reports the second part of the research project, focuses mainly on sarcopterygians and particularly on how the pectoral and forelimb muscles have evolved during the transitions from sarcopterygian fish and non-mammalian tetrapods to monotreme and therian mammals and humans. The data obtained by our own dissections of all the pectoral and forelimb muscles of representative members of groups as diverse as sarcopterygian fish, amphibians, reptiles, monotremes and therian mammals such as rodents, tree-shrews, colugos and primates, including humans, are compared with the information available in the literature. Our observations and comparisons clearly stress that, with regard to the number of pectoral and forelimb muscles, the most striking transition within sarcopterygian evolutionary history was that leading to the origin of tetrapods. Whereas extant sarcopterygian fish have an abductor and adductor of the fin and a largely undifferentiated hypaxial and epaxial musculature, extant salamanders such as Ambystoma have more than 40 pectoral and forelimb muscles. There is no clear increase in the number of pectoral and forelimb muscles within the evolutionary transition that led to the origin of mammals and surely not to that leading to the origin of primates and humans. PMID:19438764

  1. Human mining activity across the ages determines the genetic structure of modern brown trout (Salmo trutta L.) populations

    PubMed Central

    Paris, Josephine R; King, R Andrew; Stevens, Jamie R

    2015-01-01

    Humans have exploited the earth's metal resources for thousands of years leaving behind a legacy of toxic metal contamination and poor water quality. The southwest of England provides a well-defined example, with a rich history of metal mining dating to the Bronze Age. Mine water washout continues to negatively impact water quality across the region where brown trout (Salmo trutta L.) populations exist in both metal-impacted and relatively clean rivers. We used microsatellites to assess the genetic impact of mining practices on trout populations in this region. Our analyses demonstrated that metal-impacted trout populations have low genetic diversity and have experienced severe population declines. Metal-river trout populations are genetically distinct from clean-river populations, and also from one another, despite being geographically proximate. Using approximate Bayesian computation (ABC), we dated the origins of these genetic patterns to periods of intensive mining activity. The historical split of contemporary metal-impacted populations from clean-river fish dated to the Medieval period. Moreover, we observed two distinct genetic populations of trout within a single catchment and dated their divergence to the Industrial Revolution. Our investigation thus provides an evaluation of contemporary population genetics in showing how human-altered landscapes can change the genetic makeup of a species. PMID:26136823

  2. Size variation in early human mandibles and molars from Klasies River, South Africa: comparison with other middle and late Pleistocene assemblages and with modern humans.

    PubMed

    Royer, Danielle F; Lockwood, Charles A; Scott, Jeremiah E; Grine, Frederick E

    2009-10-01

    Previous studies of the Middle Stone Age human remains from Klasies River have concluded that they exhibited more sexual dimorphism than extant populations, but these claims have not been assessed statistically. We evaluate these claims by comparing size variation in the best-represented elements at the site, namely the mandibular corpora and M(2)s, to that in samples from three recent human populations using resampling methods. We also examine size variation in these same elements from seven additional middle and late Pleistocene sites: Skhūl, Dolní Vestonice, Sima de los Huesos, Arago, Krapina, Shanidar, and Vindija. Our results demonstrate that size variation in the Klasies assemblage was greater than in recent humans, consistent with arguments that the Klasies people were more dimorphic than living humans. Variation in the Skhūl, Dolní Vestonice, and Sima de los Huesos mandibular samples is also higher than in the recent human samples, indicating that the Klasies sample was not unusual among middle and late Pleistocene hominins. In contrast, the Neandertal samples (Krapina, Shanidar, and Vindija) do not evince relatively high mandibular and molar variation, which may indicate that the level of dimorphism in Neandertals was similar to that observed in extant humans. These results suggest that the reduced levels of dimorphism in Neandertals and living humans may have developed independently, though larger fossil samples are needed to test this hypothesis.

  3. Age at earliest reported memory: associations with personality traits, behavioral health, and repression.

    PubMed

    Spirrison, C L; McCarley, N G

    2001-09-01

    The present study examined relationships between the age at earliest memory and the personality traits and behavioral health of 107 undergraduates. Participants answered questions on their earliest memory and completed the Myers-Briggs Type Indicator (MBTI) and a medical history form. Analyses indicated that continuous scores on two MBTI scales (Sensing-Intuition and Judging-Perceiving) were inversely related to age at earliest memory as were participant's self-reported drug and alcohol problems, emotional and psychological symptoms, accident rates, physical symptoms, and satisfaction with health. Respondents who reported first memories at or after 7 years of age (i.e., approximately 1 SD above the mean age at recalled memory) were classified as repressors. Repressors scored in the Sensing and Judging directions on the MBTI and reported significantly fewer emotional symptoms, accidents, psychological symptoms, and less health satisfaction than nonrepressors. Results are consistent with the age at earliest memory and repression literature and support the use of earliest memory age as an index of repression.

  4. Microbiological Safety of Animal Wastes Processed by Physical Heat Treatment: An Alternative To Eliminate Human Pathogens in Biological Soil Amendments as Recommended by the Food Safety Modernization Act.

    PubMed

    Chen, Zhao; Jiang, Xiuping

    2017-03-01

    Animal wastes have high nutritional value as biological soil amendments of animal origin for plant cultivation in sustainable agriculture; however, they can be sources of some human pathogens. Although composting is an effective way to reduce pathogen levels in animal wastes, pathogens may still survive under certain conditions and persist in the composted products, which potentially could lead to fresh produce contamination. According to the U.S. Food and Drug Administration Food Safety Modernization Act, alternative treatments are recommended for reducing or eliminating human pathogens in raw animal manure. Physical heat treatments can be considered an effective method to inactivate pathogens in animal wastes. However, microbial inactivation in animal wastes can be affected by many factors, such as composition of animal wastes, type and physiological stage of the tested microorganism, and heat source. Following some current processing guidelines for physical heat treatments may not be adequate for completely eliminating pathogens from animal wastes. Therefore, this article primarily reviews the microbiological safety and economic value of physically heat-treated animal wastes as biological soil amendments.

  5. Indigenous Arabs are descendants of the earliest split from ancient Eurasian populations

    PubMed Central

    Rodriguez-Flores, Juan L.; Fakhro, Khalid; Agosto-Perez, Francisco; Ramstetter, Monica D.; Arbiza, Leonardo; Vincent, Thomas L.; Robay, Amal; Malek, Joel A.; Suhre, Karsten; Chouchane, Lotfi; Badii, Ramin; Al-Nabet Al-Marri, Ajayeb; Abi Khalil, Charbel; Zirie, Mahmoud; Jayyousi, Amin; Salit, Jacqueline; Keinan, Alon; Clark, Andrew G.; Crystal, Ronald G.; Mezey, Jason G.

    2016-01-01

    An open question in the history of human migration is the identity of the earliest Eurasian populations that have left contemporary descendants. The Arabian Peninsula was the initial site of the out-of-Africa migrations that occurred between 125,000 and 60,000 yr ago, leading to the hypothesis that the first Eurasian populations were established on the Peninsula and that contemporary indigenous Arabs are direct descendants of these ancient peoples. To assess this hypothesis, we sequenced the entire genomes of 104 unrelated natives of the Arabian Peninsula at high coverage, including 56 of indigenous Arab ancestry. The indigenous Arab genomes defined a cluster distinct from other ancestral groups, and these genomes showed clear hallmarks of an ancient out-of-Africa bottleneck. Similar to other Middle Eastern populations, the indigenous Arabs had higher levels of Neanderthal admixture compared to Africans but had lower levels than Europeans and Asians. These levels of Neanderthal admixture are consistent with an early divergence of Arab ancestors after the out-of-Africa bottleneck but before the major Neanderthal admixture events in Europe and other regions of Eurasia. When compared to worldwide populations sampled in the 1000 Genomes Project, although the indigenous Arabs had a signal of admixture with Europeans, they clustered in a basal, outgroup position to all 1000 Genomes non-Africans when considering pairwise similarity across the entire genome. These results place indigenous Arabs as the most distant relatives of all other contemporary non-Africans and identify these people as direct descendants of the first Eurasian populations established by the out-of-Africa migrations. PMID:26728717

  6. Indigenous Arabs are descendants of the earliest split from ancient Eurasian populations.

    PubMed

    Rodriguez-Flores, Juan L; Fakhro, Khalid; Agosto-Perez, Francisco; Ramstetter, Monica D; Arbiza, Leonardo; Vincent, Thomas L; Robay, Amal; Malek, Joel A; Suhre, Karsten; Chouchane, Lotfi; Badii, Ramin; Al-Nabet Al-Marri, Ajayeb; Abi Khalil, Charbel; Zirie, Mahmoud; Jayyousi, Amin; Salit, Jacqueline; Keinan, Alon; Clark, Andrew G; Crystal, Ronald G; Mezey, Jason G

    2016-02-01

    An open question in the history of human migration is the identity of the earliest Eurasian populations that have left contemporary descendants. The Arabian Peninsula was the initial site of the out-of-Africa migrations that occurred between 125,000 and 60,000 yr ago, leading to the hypothesis that the first Eurasian populations were established on the Peninsula and that contemporary indigenous Arabs are direct descendants of these ancient peoples. To assess this hypothesis, we sequenced the entire genomes of 104 unrelated natives of the Arabian Peninsula at high coverage, including 56 of indigenous Arab ancestry. The indigenous Arab genomes defined a cluster distinct from other ancestral groups, and these genomes showed clear hallmarks of an ancient out-of-Africa bottleneck. Similar to other Middle Eastern populations, the indigenous Arabs had higher levels of Neanderthal admixture compared to Africans but had lower levels than Europeans and Asians. These levels of Neanderthal admixture are consistent with an early divergence of Arab ancestors after the out-of-Africa bottleneck but before the major Neanderthal admixture events in Europe and other regions of Eurasia. When compared to worldwide populations sampled in the 1000 Genomes Project, although the indigenous Arabs had a signal of admixture with Europeans, they clustered in a basal, outgroup position to all 1000 Genomes non-Africans when considering pairwise similarity across the entire genome. These results place indigenous Arabs as the most distant relatives of all other contemporary non-Africans and identify these people as direct descendants of the first Eurasian populations established by the out-of-Africa migrations. © 2016 Rodriguez-Flores et al.; Published by Cold Spring Harbor Laboratory Press.

  7. Patterns of East Asian pig domestication, migration, and turnover revealed by modern and ancient DNA

    PubMed Central

    Larson, Greger; Liu, Ranran; Zhao, Xingbo; Yuan, Jing; Fuller, Dorian; Barton, Loukas; Dobney, Keith; Fan, Qipeng; Gu, Zhiliang; Liu, Xiao-Hui; Luo, Yunbing; Lv, Peng; Andersson, Leif; Li, Ning

    2010-01-01

    The establishment of agricultural economies based upon domestic animals began independently in many parts of the world and led to both increases in human population size and the migration of people carrying domestic plants and animals. The precise circumstances of the earliest phases of these events remain mysterious given their antiquity and the fact that subsequent waves of migrants have often replaced the first. Through the use of more than 1,500 modern (including 151 previously uncharacterized specimens) and 18 ancient (representing six East Asian archeological sites) pig (Sus scrofa) DNA sequences sampled across East Asia, we provide evidence for the long-term genetic continuity between modern and ancient Chinese domestic pigs. Although the Chinese case for independent pig domestication is supported by both genetic and archaeological evidence, we discuss five additional (and possibly) independent domestications of indigenous wild boar populations: one in India, three in peninsular Southeast Asia, and one off the coast of Taiwan. Collectively, we refer to these instances as “cryptic domestication,” given the current lack of corroborating archaeological evidence. In addition, we demonstrate the existence of numerous populations of genetically distinct and widespread wild boar populations that have not contributed maternal genetic material to modern domestic stocks. The overall findings provide the most complete picture yet of pig evolution and domestication in East Asia, and generate testable hypotheses regarding the development and spread of early farmers in the Far East. PMID:20404179

  8. The second modern condition? Compressed modernity as internalized reflexive cosmopolitization.

    PubMed

    Kyung-Sup, Chang

    2010-09-01

    Compressed modernity is a civilizational condition in which economic, political, social and/or cultural changes occur in an extremely condensed manner in respect to both time and space, and in which the dynamic coexistence of mutually disparate historical and social elements leads to the construction and reconstruction of a highly complex and fluid social system. During what Beck considers the second modern stage of humanity, every society reflexively internalizes cosmopolitanized risks. Societies (or their civilizational conditions) are thereby being internalized into each other, making compressed modernity a universal feature of contemporary societies. This paper theoretically discusses compressed modernity as nationally ramified from reflexive cosmopolitization, and, then, comparatively illustrates varying instances of compressed modernity in advanced capitalist societies, un(der)developed capitalist societies, and system transition societies. In lieu of a conclusion, I point out the declining status of national societies as the dominant unit of (compressed) modernity and the interactive acceleration of compressed modernity among different levels of human life ranging from individuals to the global community. © London School of Economics and Political Science 2010.

  9. Structural and molecular study of the supraspinatus muscle of modern humans (Homo sapiens) and common chimpanzees (Pan troglodytes).

    PubMed

    Potau, J M; Casado, A; de Diego, M; Ciurana, N; Arias-Martorell, J; Bello-Hellegouarch, G; Barbosa, M; de Paz, F J; Pastor, J F; Pérez-Pérez, A

    2018-04-21

    To analyze the muscle architecture and the expression pattern of the myosin heavy chain (MyHC) isoforms in the supraspinatus of Pan troglodytes and Homo sapiens in order to identify differences related to their different types of locomotion. We have analyzed nine supraspinatus muscles of Pan troglodytes and ten of Homo sapiens. For each sample, we have recorded the muscle fascicle length (MFL), the pennation angle, and the physiological cross-sectional area (PCSA). In the same samples, by real-time quantitative polymerase chain reaction, we have assessed the percentages of expression of the MyHC-I, MyHC-IIa, and MyHC-IIx isoforms. The mean MFL of the supraspinatus was longer (p = 0.001) and the PCSA was lower (p < 0.001) in Homo sapiens than in Pan troglodytes. Although the percentage of expression of MyHC-IIa was lower in Homo sapiens than in Pan troglodytes (p = 0.035), the combination of MyHC-IIa and MyHC-IIx was expressed at a similar percentage in the two species. The longer MFL in the human supraspinatus is associated with a faster contractile velocity, which reflects the primary function of the upper limbs in Homo sapiens-the precise manipulation of objects-an adaptation to bipedal locomotion. In contrast, the larger PCSA in Pan troglodytes is related to the important role of the supraspinatus in stabilizing the glenohumeral joint during the support phase of knuckle-walking. These functional differences of the supraspinatus in the two species are not reflected in differences in the expression of the MyHC isoforms. © 2018 Wiley Periodicals, Inc.

  10. Archaeological support for the three-stage expansion of modern humans across northeastern Eurasia and into the Americas.

    PubMed

    Hamilton, Marcus J; Buchanan, Briggs

    2010-08-30

    Understanding the dynamics of the human range expansion across northeastern Eurasia during the late Pleistocene is central to establishing empirical temporal constraints on the colonization of the Americas. Opinions vary widely on how and when the Americas were colonized, with advocates supporting either a pre- or post- last glacial maximum (LGM) colonization, via either a land bridge across Beringia, a sea-faring Pacific Rim coastal route, a trans-Arctic route, or a trans-Atlantic oceanic route. Here we analyze a large sample of radiocarbon dates from the northeast Eurasian Upper Paleolithic to identify the origin of this expansion, and estimate the velocity of colonization wave as it moved across northern Eurasia and into the Americas. We use diffusion models to quantify these dynamics. Our results show the expansion originated in the Altai region of southern Siberia approximately 46kBP , and from there expanded across northern Eurasia at an average velocity of 0.16 km per year. However, the movement of the colonizing wave was not continuous but underwent three distinct phases: 1) an initial expansion from 47-32k calBP; 2) a hiatus from approximately 32-16k calBP, and 3) a second expansion after the LGM approximately 16k calBP. These results provide archaeological support for the recently proposed three-stage model of the colonization of the Americas. Our results falsify the hypothesis of a pre-LGM terrestrial colonization of the Americas and we discuss the importance of these empirical results in the light of alternative models. Our results demonstrate that the radiocarbon record of Upper Paleolithic northeastern Eurasia supports a post-LGM terrestrial colonization of the Americas falsifying the proposed pre-LGM terrestrial colonization of the Americas. We show that this expansion was not a simple process, but proceeded in three phases, consistent with genetic data, largely in response to the variable climatic conditions of late Pleistocene northeast Eurasia

  11. Archaeological Support for the Three-Stage Expansion of Modern Humans across Northeastern Eurasia and into the Americas

    PubMed Central

    Hamilton, Marcus J.; Buchanan, Briggs

    2010-01-01

    Background Understanding the dynamics of the human range expansion across northeastern Eurasia during the late Pleistocene is central to establishing empirical temporal constraints on the colonization of the Americas [1]. Opinions vary widely on how and when the Americas were colonized, with advocates supporting either a pre-[2] or post-[1], [3], [4], [5], [6] last glacial maximum (LGM) colonization, via either a land bridge across Beringia [3], [4], [5], a sea-faring Pacific Rim coastal route [1], [3], a trans-Arctic route [4], or a trans-Atlantic oceanic route [5]. Here we analyze a large sample of radiocarbon dates from the northeast Eurasian Upper Paleolithic to identify the origin of this expansion, and estimate the velocity of colonization wave as it moved across northern Eurasia and into the Americas. Methodology/Principal Findings We use diffusion models [6], [7] to quantify these dynamics. Our results show the expansion originated in the Altai region of southern Siberia ∼46kBP , and from there expanded across northern Eurasia at an average velocity of 0.16 km per year. However, the movement of the colonizing wave was not continuous but underwent three distinct phases: 1) an initial expansion from 47-32k calBP; 2) a hiatus from ∼32-16k calBP, and 3) a second expansion after the LGM ∼16k calBP. These results provide archaeological support for the recently proposed three-stage model of the colonization of the Americas [8], [9]. Our results falsify the hypothesis of a pre-LGM terrestrial colonization of the Americas and we discuss the importance of these empirical results in the light of alternative models. Conclusions/Significance Our results demonstrate that the radiocarbon record of Upper Paleolithic northeastern Eurasia supports a post-LGM terrestrial colonization of the Americas falsifying the proposed pre-LGM terrestrial colonization of the Americas. We show that this expansion was not a simple process, but proceeded in three phases, consistent

  12. "Democratic and Humanistic/Humane Paideia in the Euro-Cypriot Polity--Prospects for Reconstruction and Modernization": A Biographical Sociological Analysis of A Reform Initiative in a (De-)Globalizing World

    ERIC Educational Resources Information Center

    Klerides, Eleftherios

    2018-01-01

    In 2004, a reform report entitled "Democratic and Humanistic/ Humane Paideia in the Euro-Cypriot Polity: Prospects for Reconstruction and Modernization" was published by the Ministry of Education and Culture in the Republic of Cyprus. Professor Andreas M. Kazamias is held to have been the driving force behind this initiative, shaping…

  13. Earliest Mysticete from the Late Eocene of Peru Sheds New Light on the Origin of Baleen Whales.

    PubMed

    Lambert, Olivier; Martínez-Cáceres, Manuel; Bianucci, Giovanni; Di Celma, Claudio; Salas-Gismondi, Rodolfo; Steurbaut, Etienne; Urbina, Mario; de Muizon, Christian

    2017-05-22

    Although combined molecular and morphological analyses point to a late middle Eocene (38-39 million years ago) origin for the clade Neoceti (Odontoceti, echolocating toothed whales plus Mysticeti, baleen whales, and relatives), the oldest known mysticete fossil dates from the latest Eocene (about 34 million years ago) of Antarctica [1, 2]. Considering that the latter is not the most stemward mysticete in recent phylogenies and that Oligocene toothed mysticetes display a broad morphological disparity most likely corresponding to contrasted ecological niches, the origin of mysticetes from a basilosaurid ancestor and its drivers are currently poorly understood [1, 3-8]. Based on an articulated cetacean skeleton from the early late Eocene (Priabonian, around 36.4 million years ago) of the Pisco Basin, Peru, we describe a new archaic tooth-bearing mysticete, Mystacodon selenensis gen. et sp. nov. Being the geologically oldest neocete (crown group cetacean) and the earliest mysticete to branch off described so far, the new taxon is interpreted as morphologically intermediate between basilosaurids and later toothed mysticetes, providing thus crucial information about the anatomy of the skull, forelimb, and innominate at these critical initial stages of mysticete evolution. Major changes in the morphology of the oral apparatus (including tooth wear) and flipper compared to basilosaurids suggest that suction and possibly benthic feeding represented key, early ecological traits accompanying the emergence of modern filter-feeding baleen whales' ancestors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Birth to Three Matters: A Framework to Support Children in Their Earliest Years

    ERIC Educational Resources Information Center

    Abbott, Lesley; Langston, Ann

    2005-01-01

    Government commitment to the care and education of children from birth to three years in England led to the commissioning in 2001 of "a framework of best practice" (DfEE, 2001:24) to support children in their earliest years. The resulting framework of "effective" practice, together with supporting materials, was developed by a…

  15. Gathering Together: A View of the Earliest Student Affairs Professional Organizations

    ERIC Educational Resources Information Center

    Gerda, Janice J.

    2006-01-01

    In November 1903, 18 women gathered together for the Conference of Deans of Women of the Middle West. Variations of this conference were held over the following 20 years, constituting the earliest period of professional association in what was to become known as student affairs. When creating their associations, the early deans needed to consider…

  16. Earliest Memories and Recent Memories of Highly Salient Events--Are They Similar?

    ERIC Educational Resources Information Center

    Peterson, Carole; Fowler, Tania; Brandeau, Katherine M.

    2015-01-01

    Four- to 11-year-old children were interviewed about 2 different sorts of memories in the same home visit: recent memories of highly salient and stressful events--namely, injuries serious enough to require hospital emergency room treatment--and their earliest memories. Injury memories were scored for amount of unique information, completeness…

  17. Maternal Reminiscing Style during Early Childhood Predicts the Age of Adolescents' Earliest Memories

    ERIC Educational Resources Information Center

    Jack, Fiona; MacDonald, Shelley; Reese, Elaine; Hayne, Harlene

    2009-01-01

    Individual differences in parental reminiscing style are hypothesized to have long-lasting effects on children's autobiographical memory development, including the age of their earliest memories. This study represents the first prospective test of this hypothesis. Conversations about past events between 17 mother-child dyads were recorded on…

  18. Infantile Amnesia across the Years: A 2-Year Follow-Up of Children's Earliest Memories

    ERIC Educational Resources Information Center

    Peterson, Carole; Warren, Kelly L.; Short, Megan M.

    2011-01-01

    Although infantile amnesia has been investigated for many years in adults, only recently has it been investigated in children. This study was a 2-year follow-up and extension of an earlier study. Children (4-13 years old) were asked initially and 2 years later for their earliest 3 memories. At follow-up, their age at the time of these memories…

  19. Interspecies difference in placement of developing teeth and its relationship with cross-sectional geometry of the mandibular symphysis in four primate species including modern humans.

    PubMed

    Fukase, Hitoshi

    2012-02-01

    The form of the anthropoid mandibular symphysis has recently been addressed in association with spatial requirements for the forming anterior teeth. To evaluate potential relationships between the symphyseal shape and teeth further, the growth patterns of the symphyseal region and the positioning of the tooth crypts were examined using CT data, comparing four primate species (modern humans, chimpanzees, Japanese monkeys, and hamadryas baboons) with varied symphyseal curvature and tooth size. First, results showed that interspecies differences in overall mandibular shape including symphyseal inclination and bicanine width are consistently expressed throughout postnatal ontogeny, although local symphyseal configurations related to the superior transverse torus (STT) tended to change considerably during growth in chimpanzees. Second, the four species were found to exhibit differentiated formation positions of the incisor and canine crypts. In particular, I2 developed between I1 and C in humans with a broad bicanine space and small teeth, whereas it was positioned posterior to I1 and above C in the cercopithecines with an extremely narrow bicanine space. In chimpanzees, despite the large bicanine width, I1 and I2 grew with a large antero-posterior overlap owing to their large size. These results indicate that the dental positioning is determined in concert with the size balance of the available mandibular space and forming teeth. Finally, the positions/contours of I2 crypt were shown to correspond strongly with the STT across the taxa. This suggests that interspecies differences in symphyseal shape should be interpreted partially by the species-specific positional relationships of the developing anterior teeth. Copyright © 2011 Wiley Periodicals, Inc.

  20. The Emergence of Modern Humans.

    ERIC Educational Resources Information Center

    Stringer, Christopher B.

    1990-01-01

    Presented are the three main theories that describe the pattern of evolution of geographic variants of H. sapiens--the multiregional model, the out-of-Africa model, and the gene-flow or hybridization model. The contributions of geneticists, paleoanthropologists, and the history of fossils are included. (KR)

  1. An Aboriginal Australian genome reveals separate human dispersals into Asia.

    PubMed

    Rasmussen, Morten; Guo, Xiaosen; Wang, Yong; Lohmueller, Kirk E; Rasmussen, Simon; Albrechtsen, Anders; Skotte, Line; Lindgreen, Stinus; Metspalu, Mait; Jombart, Thibaut; Kivisild, Toomas; Zhai, Weiwei; Eriksson, Anders; Manica, Andrea; Orlando, Ludovic; De La Vega, Francisco M; Tridico, Silvana; Metspalu, Ene; Nielsen, Kasper; Ávila-Arcos, María C; Moreno-Mayar, J Víctor; Muller, Craig; Dortch, Joe; Gilbert, M Thomas P; Lund, Ole; Wesolowska, Agata; Karmin, Monika; Weinert, Lucy A; Wang, Bo; Li, Jun; Tai, Shuaishuai; Xiao, Fei; Hanihara, Tsunehiko; van Driem, George; Jha, Aashish R; Ricaut, François-Xavier; de Knijff, Peter; Migliano, Andrea B; Gallego Romero, Irene; Kristiansen, Karsten; Lambert, David M; Brunak, Søren; Forster, Peter; Brinkmann, Bernd; Nehlich, Olaf; Bunce, Michael; Richards, Michael; Gupta, Ramneek; Bustamante, Carlos D; Krogh, Anders; Foley, Robert A; Lahr, Marta M; Balloux, Francois; Sicheritz-Pontén, Thomas; Villems, Richard; Nielsen, Rasmus; Wang, Jun; Willerslev, Eske

    2011-10-07

    We present an Aboriginal Australian genomic sequence obtained from a 100-year-old lock of hair donated by an Aboriginal man from southern Western Australia in the early 20th century. We detect no evidence of European admixture and estimate contamination levels to be below 0.5%. We show that Aboriginal Australians are descendants of an early human dispersal into eastern Asia, possibly 62,000 to 75,000 years ago. This dispersal is separate from the one that gave rise to modern Asians 25,000 to 38,000 years ago. We also find evidence of gene flow between populations of the two dispersal waves prior to the divergence of Native Americans from modern Asian ancestors. Our findings support the hypothesis that present-day Aboriginal Australians descend from the earliest humans to occupy Australia, likely representing one of the oldest continuous populations outside Africa.

  2. An Aboriginal Australian Genome Reveals Separate Human Dispersals into Asia

    PubMed Central

    Rasmussen, Morten; Guo, Xiaosen; Wang, Yong; Lohmueller, Kirk E.; Rasmussen, Simon; Albrechtsen, Anders; Skotte, Line; Lindgreen, Stinus; Metspalu, Mait; Jombart, Thibaut; Kivisild, Toomas; Zhai, Weiwei; Eriksson, Anders; Manica, Andrea; Orlando, Ludovic; De La Vega, Francisco M.; Tridico, Silvana; Metspalu, Ene; Nielsen, Kasper; Ávila-Arcos, María C.; Moreno-Mayar, J. Víctor; Muller, Craig; Dortch, Joe; Gilbert, M. Thomas P.; Lund, Ole; Wesolowska, Agata; Karmin, Monika; Weinert, Lucy A.; Wang, Bo; Li, Jun; Tai, Shuaishuai; Xiao, Fei; Hanihara, Tsunehiko; van Driem, George; Jha, Aashish R.; Ricaut, François-Xavier; de Knijff, Peter; Migliano, Andrea B; Romero, Irene Gallego; Kristiansen, Karsten; Lambert, David M.; Brunak, Søren; Forster, Peter; Brinkmann, Bernd; Nehlich, Olaf; Bunce, Michael; Richards, Michael; Gupta, Ramneek; Bustamante, Carlos D.; Krogh, Anders; Foley, Robert A.; Lahr, Marta M.; Balloux, Francois; Sicheritz-Pontén, Thomas; Villems, Richard; Nielsen, Rasmus; Wang, Jun; Willerslev, Eske

    2013-01-01

    We present an Aboriginal Australian genomic sequence obtained from a 100-year-old lock of hair donated by an Aboriginal man from southern Western Australia in the early 20th century. We detect no evidence of European admixture and estimate contamination levels to be below 0.5%. We show that Aboriginal Australians are descendants of an early human dispersal into eastern Asia, possibly 62,000 to 75,000 years ago. This dispersal is separate from the one that gave rise to modern Asians 25,000 to 38,000 years ago. We also find evidence of gene flow between populations of the two dispersal waves prior to the divergence of Native Americans from modern Asian ancestors. Our findings support the hypothesis that present-day Aboriginal Australians descend from the earliest humans to occupy Australia, likely representing one of the oldest continuous populations outside Africa. PMID:21940856

  3. The Earliest Fossil Evidence for Life on Land and the Freshwater Origin of Algae?

    NASA Astrophysics Data System (ADS)

    Battison, L.; Brasier, M. D.; Antcliffe, J. B.

    2009-04-01

    Some 150 years ago, in 1859, Charles Darwin was greatly puzzled by a seeming absence of fossils in rocks older than the Cambrian period. He drew attention to a veritable Lost World that it is now known to have spanned more than 80 per cent of Earth History. And he made a prediction that we here bring again into focus: 'The presence of phosphate nodules and bituminous matter in some of the lowest azoic rocks probably indicates the former existence of life at these periods (Darwin 1859, p.307). His prediction came to fruition in 1899, when Sir Archibald Geikie announced to the world the first discovery of genuine microfossils in Precambrian phosphatic rocks, made by Jephro Teall, Ben Peach and John Horne within the Torridonian rocks of Scotland. The Torridonian phosphate of NW Scotland has, however, been rather little studied until recently. It is remarkable for its fidelity of fossil preservation, and also for its non-marine depositional setting. Dating to the end of the Mesoproterozoic Era around 1Ga ago, thick packages of fluvial sandstones are found to serve the remains of very ancient intermontane lake ecosystems. Fossil assemblages from terrestrial settings are rarely seen before the Devonian ~ 350 Ma ago. Evidence for freshwater and terrestrial life in the Precambrian has therefore been circumstantial rather than detailed and none has yet come from freshwater phosphate. We here demonstrate that phosphate from ~ 1200-1000 Ma Mesoproterozoic lake sediments of the Torridon Group preserve a remarkable suite of organisms forming a freshwater, terrestrial, phototrophic ecosystem. Ephemeral lakes and streams developed in intermontane basins within the interior of the supercontinent of Rodinia and periodically experienced prolonged desiccation allowing phosphate precipitation. The microbiology of these lake sediments is being studied in detail, where they are yielding - with the aid of Automontage - fresh evidence for the earliest known terrestrial ecology and

  4. Homo sapiens in the Americas. Overview of the earliest human expansion in the New World.

    PubMed

    Marangoni, Aurelio; Caramelli, David; Manzi, Giorgio

    2014-01-01

    Although it is widely recognised that America was the last continent to be populated by our species, researchers' views on various aspects of this process (e.g. the period in which it occurred, the area from which the colonizing populations came, the number of dispersal waves and the routes taken by these migrations) differ significantly. In this paper, we review both classical data and more recent findings from various research fields - including geology, paleoecology, archaeology, skeletal biology, and genetics - that may shed light on the dynamics of the colonization of the American continent, according to a critical reappraisal of the various hypotheses and models that have been advanced over time to explain this process.

  5. The earliest direct evidence of frogs in wet tropical forests from Cretaceous Burmese amber.

    PubMed

    Xing, Lida; Stanley, Edward L; Bai, Ming; Blackburn, David C

    2018-06-14

    Frogs are a familiar and diverse component of tropical forests around the world. Yet there is little direct evidence from the fossil record for the antiquity of this association. We describe four fossil frog specimens from mid-Cretaceous (~99 mya) amber deposits from Kachin State, Myanmar for which the associated fauna provides rich paleoenvironmental context. Microcomputed tomographic analysis provides detailed three-dimensional anatomy for these small frogs, which is generally unavailable for articulated anurans in the Mesozoic. These crown-group anuran specimens provide the earliest direct evidence for anurans in a wet tropical forest. Based on a distinct combination of skeletal characters, at least one specimen has clear similarities to living alytoid frogs as well as several Mesozoic taxa known from the Jehol Biota in China. Whereas many Mesozoic frogs are from seasonal and mesic paleoenvironments, these fossils provide the earliest direct evidence of anurans in wet tropical forests.

  6. Dietary specializations and diversity in feeding ecology of the earliest stem mammals.

    PubMed

    Gill, Pamela G; Purnell, Mark A; Crumpton, Nick; Brown, Kate Robson; Gostling, Neil J; Stampanoni, M; Rayfield, Emily J

    2014-08-21

    The origin and radiation of mammals are key events in the history of life, with fossils placing the origin at 220 million years ago, in the Late Triassic period. The earliest mammals, representing the first 50 million years of their evolution and including the most basal taxa, are widely considered to be generalized insectivores. This implies that the first phase of the mammalian radiation--associated with the appearance in the fossil record of important innovations such as heterodont dentition, diphyodonty and the dentary-squamosal jaw joint--was decoupled from ecomorphological diversification. Finds of exceptionally complete specimens of later Mesozoic mammals have revealed greater ecomorphological diversity than previously suspected, including adaptations for swimming, burrowing, digging and even gliding, but such well-preserved fossils of earlier mammals do not exist, and robust analysis of their ecomorphological diversity has previously been lacking. Here we present the results of an integrated analysis, using synchrotron X-ray tomography and analyses of biomechanics, finite element models and tooth microwear textures. We find significant differences in function and dietary ecology between two of the earliest mammaliaform taxa, Morganucodon and Kuehneotherium--taxa that are central to the debate on mammalian evolution. Morganucodon possessed comparatively more forceful and robust jaws and consumed 'harder' prey, comparable to extant small-bodied mammals that eat considerable amounts of coleopterans. Kuehneotherium ingested a diet comparable to extant mixed feeders and specialists on 'soft' prey such as lepidopterans. Our results reveal previously hidden trophic specialization at the base of the mammalian radiation; hence even the earliest mammaliaforms were beginning to diversify--morphologically, functionally and ecologically. In contrast to the prevailing view, this pattern suggests that lineage splitting during the earliest stages of mammalian evolution was

  7. The characteristics and chronology of the earliest Acheulean at Konso, Ethiopia

    PubMed Central

    Beyene, Yonas; Katoh, Shigehiro; WoldeGabriel, Giday; Hart, William K.; Uto, Kozo; Sudo, Masafumi; Kondo, Megumi; Hyodo, Masayuki; Renne, Paul R.; Suwa, Gen; Asfaw, Berhane

    2013-01-01

    The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6–1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period ∼1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world’s earliest with an age of ∼1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at ∼1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology. PMID:23359714

  8. Virtual endocranial cast of earliest Eocene Diacodexis (Artiodactyla, Mammalia) and morphological diversity of early artiodactyl brains

    PubMed Central

    Orliac, M. J.; Gilissen, E.

    2012-01-01

    The study of brain evolution, particularly that of the neocortex, is of primary interest because it directly relates to how behavioural variations arose both between and within mammalian groups. Artiodactyla is one of the most diverse mammalian clades. However, the first 10 Myr of their brain evolution has remained undocumented so far. Here, we used high-resolution X-ray computed tomography to investigate the endocranial cast of Diacodexis ilicis of earliest Eocene age. Its virtual reconstruction provides unprecedented access to both metric parameters and fine anatomy of the most complete endocast of the earliest artiodactyl. This picture is assessed in a broad comparative context by reconstructing endocasts of 14 other Early and Middle Eocene representatives of basal artiodactyls, allowing the tracking of the neocortical structure of artiodactyls back to its simplest pattern. We show that the earliest artiodactyls share a simple neocortical pattern, so far never observed in other ungulates, with an almond-shaped gyrus instead of parallel sulci as previously hypothesized. Our results demonstrate that artiodactyls experienced a tardy pulse of encephalization during the Late Neogene, well after the onset of cortical complexity increase. Comparisons with Eocene perissodactyls show that the latter reached a high level of cortical complexity earlier than the artiodactyls. PMID:22764165

  9. Experiencing patient death in clinical practice: nurses' recollections of their earliest memorable patient death.

    PubMed

    Anderson, Natalie Elizabeth; Kent, Bridie; Owens, R Glynn

    2015-03-01

    Death and dying are inevitable life encounters, but a nurse's first experience with patient death may pose considerable cognitive, emotional and clinical challenges. This paper reports the findings of the second phase of a study; the first has been reported elsewhere. This phase explored the earliest memorable patient death experiences of New Zealand registered nurses. A purposeful, self-selected sub-sample of a larger study of New Zealand registered nurses, took part in individual face-to-face semi-structured interviews. Interpretative phenomenological analysis was utilised to seek to understand participants' experiences. Thematic analysis was undertaken to identify emerging themes, with participants' own words used as theme headings, where their phrases provided succinct or powerful descriptors. A diverse participant group of twenty, currently practising, New Zealand registered nurses provided rich and detailed descriptions of their earliest memorable experience with patient death. Participants from a variety of training backgrounds described patient deaths, which occurred in a range of settings - some only a few months prior, others - more than thirty years ago. Seven emergent themes, and features of more positive, or negative experiences were identified: Event Significance; Emotional Challenges; Sharing the Experience; Learning; Feeling Unprepared, Responses to Death and Finding Benefits. For participants in this study, there was considerable evidence that their earliest memorable patient death was a significant event. Furthermore, although most participants' experiences were characterised by emphatic or poignant description, there was most often a balance of challenges and rewards. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. A Modern Aristotelian Rhetorical Theory.

    ERIC Educational Resources Information Center

    Douglass, Rodney Blaine

    This study proposes a modern Aristotelian rhetorical theory--that rhetorical communication is that human communication within which persons deliberatively interact. A number of corollaries follow from the fundamental postulate and include: (1) persons function as the essential agents of the rhetorical communicative process; (2) a person's…

  11. The Modernization of Pedagogical Education

    ERIC Educational Resources Information Center

    Zasypkin, V. P.; Zborovskii, G. E.

    2012-01-01

    In the social, political, and social humanities lexicon of today's Russia there is probably no word that is in wider and more common use than modernization. What this refers to is the profound and systematic transformation of all the main structures and sub-systems of the social organism, including "education"--one of the most important,…

  12. Identification of the earliest collagen- and plant-based coatings from Neolithic artefacts (Nahal Hemar cave, Israel)

    PubMed Central

    Solazzo, Caroline; Courel, Blandine; Connan, Jacques; van Dongen, Bart E.; Barden, Holly; Penkman, Kirsty; Taylor, Sheila; Demarchi, Beatrice; Adam, Pierre; Schaeffer, Philippe; Nissenbaum, Arie; Bar-Yosef, Ofer; Buckley, Michael

    2016-01-01

    Mortuary practices in human evolution record cognitive, social changes and technological innovations. The Neolithic Revolution in the Levant was a watershed in this domain that has long fascinated the archaeological community. Plaster modelled skulls are well known at Jericho and several other Neolithic sites, and in Nahal Hemar cave (Israel, ca. 8200 −7300 cal. BC) excavations yielded six unique human skulls covered with a black organic coating applied in a net pattern evoking a headdress. This small cave was used as storage for paraphernalia in the semi-arid area of the Judean desert and the dry conditions preserved other artefacts such as baskets coated with a similar dark substance. While previous analysis had revealed the presence of amino acids consistent with a collagen signature, in the present report, specific biomarkers were characterised using combined proteomic and lipid approaches. Basket samples yielded collagen and blood proteins of bovine origin (Bos genus) and a large sequence coverage of a plant protein charybdin (Charybdis genus). The skull residue samples were dominated by benzoate and cinnamate derivatives and triterpenes consistent with a styrax-type resin (Styrax officinalis), thus providing the earliest known evidence of an odoriferous plant resin used in combination with an animal product. PMID:27503740

  13. Identification of the earliest collagen- and plant-based coatings from Neolithic artefacts (Nahal Hemar cave, Israel).

    PubMed

    Solazzo, Caroline; Courel, Blandine; Connan, Jacques; van Dongen, Bart E; Barden, Holly; Penkman, Kirsty; Taylor, Sheila; Demarchi, Beatrice; Adam, Pierre; Schaeffer, Philippe; Nissenbaum, Arie; Bar-Yosef, Ofer; Buckley, Michael

    2016-08-09

    Mortuary practices in human evolution record cognitive, social changes and technological innovations. The Neolithic Revolution in the Levant was a watershed in this domain that has long fascinated the archaeological community. Plaster modelled skulls are well known at Jericho and several other Neolithic sites, and in Nahal Hemar cave (Israel, ca. 8200 -7300 cal. BC) excavations yielded six unique human skulls covered with a black organic coating applied in a net pattern evoking a headdress. This small cave was used as storage for paraphernalia in the semi-arid area of the Judean desert and the dry conditions preserved other artefacts such as baskets coated with a similar dark substance. While previous analysis had revealed the presence of amino acids consistent with a collagen signature, in the present report, specific biomarkers were characterised using combined proteomic and lipid approaches. Basket samples yielded collagen and blood proteins of bovine origin (Bos genus) and a large sequence coverage of a plant protein charybdin (Charybdis genus). The skull residue samples were dominated by benzoate and cinnamate derivatives and triterpenes consistent with a styrax-type resin (Styrax officinalis), thus providing the earliest known evidence of an odoriferous plant resin used in combination with an animal product.

  14. Intrafamilial similarities and cross-generational differences in the earliest childhood memories of daughters, mothers, and grandmothers.

    PubMed

    Sahin-Acar, Basak; Bakir, Tugce; Kus, Elif Gizem

    2017-09-01

    This study aimed to examine how daughters, mothers, and grandmothers from the same families resembled each other and how these three generations differed from each other in narrating their earliest childhood memories. Fifty-nine triads from the same families filled out a memory questionnaire and were asked to narrate their earliest childhood memories. Results revealed both intrafamilial similarities and cross-generational difference on characteristics of triads' earliest childhood memories. After earliest childhood memories were coded for memory characteristics, we measured intrafamilial similarities using intra-class correlation coefficients across three generations for each memory characteristic. Results revealed that the earliest childhood memories of members of the same family were significantly similar in terms of level of detail and volume. Although similar patterns among members of the same families were observed in self-related and other-related words, the other/self ratio did not display an intrafamilial similarity. We also measured cross-generational differences and found that daughters' reported age of their earliest childhood memories was dated significantly earlier compared to their grandmothers. Results revealed predominant intrafamilial similarities among the members of the same family and cross-generational differences in terms of the age of the earliest childhood memory.

  15. Late Paleocene fossils from the Cerrejón Formation, Colombia, are the earliest record of Neotropical rainforest

    PubMed Central

    Wing, Scott L.; Herrera, Fabiany; Jaramillo, Carlos A.; Gómez-Navarro, Carolina; Wilf, Peter; Labandeira, Conrad C.

    2009-01-01

    Neotropical rainforests have a very poor fossil record, making hypotheses concerning their origins difficult to evaluate. Nevertheless, some of their most important characteristics can be preserved in the fossil record: high plant diversity, dominance by a distinctive combination of angiosperm families, a preponderance of plant species with large, smooth-margined leaves, and evidence for a high diversity of herbivorous insects. Here, we report on an ≈58-my-old flora from the Cerrejón Formation of Colombia (paleolatitude ≈5 °N) that is the earliest megafossil record of Neotropical rainforest. The flora has abundant, diverse palms and legumes and similar family composition to extant Neotropical rainforest. Three-quarters of the leaf types are large and entire-margined, indicating rainfall >2,500 mm/year and mean annual temperature >25 °C. Despite modern family composition and tropical paleoclimate, the diversity of fossil pollen and leaf samples is 60–80% that of comparable samples from extant and Quaternary Neotropical rainforest from similar climates. Insect feeding damage on Cerrejón fossil leaves, representing primary consumers, is abundant, but also of low diversity, and overwhelmingly made by generalist feeders rather than specialized herbivores. Cerrejón megafossils provide strong evidence that the same Neotropical rainforest families have characterized the biome since the Paleocene, maintaining their importance through climatic phases warmer and cooler than present. The low diversity of both plants and herbivorous insects in this Paleocene Neotropical rainforest may reflect an early stage in the diversification of the lineages that inhabit this biome, and/or a long recovery period from the terminal Cretaceous extinction. PMID:19833876

  16. Studying Innovation Technologies in Modern Education

    ERIC Educational Resources Information Center

    Stukalenko, Nina M.; Zhakhina, Bariya B.; Kukubaeva, Asiya K.; Smagulova, Nurgul K.; Kazhibaeva, Gulden K.

    2016-01-01

    In modern society, innovation technologies expand to almost every field of human activity, including such wide field as education. Due to integrating innovation technologies into the educational process practice, this phenomenon gained special significance within improvement and modernization of the established educational system. Currently, the…

  17. Modern problems of thermodynamics

    NASA Astrophysics Data System (ADS)

    Novikov, I. I.

    2012-12-01

    The role of energy and methods of its saving for the development of human society and life are analyzed. The importance of future use of space energy flows and energy of water and air oceans is emphasized. The authors consider the idea of the unit for production of electric energy and pure substances using sodium chloride which reserves are limitless on the planet. Looking retrospectively at the development of power engineering from the elementary fire to modern electric power station, we see that the used method of heat production, namely by direct interaction of fuel and oxidizer, is the simplest. However, it may be possible to combust coal, i.e., carbon in salt melt, for instance, sodium chloride that would be more rational and efficient. If the stated problems are solved positively, we would master all energy properties of the substance; and this is the main problem of thermodynamics being one of the sciences on energy.

  18. Neanderthal and Anatomically Modern Human interaction with Abrupt Late Pleistocene Environments - the data is finally good enough to talk about climate change!

    NASA Astrophysics Data System (ADS)

    Blockley, Simon; Schreve, Danielle

    2015-04-01

    The timing and nature of the appearance of Anatomically Modern Humans (AMH) in Europe, their interaction with, and eventual morphological replacement of Neanderthals (despite some shared genetic heritage) has been a matter of intense debate within archaeology for a generation. This period, often termed the Middle to Upper Palaeolithic transition occurs in the latter part of Marine Isotope Stage Three and in recent decades archaeological interest has been complemented by the input of palaeoclimate scientists, over the role of abrupt climate change in this process. This was due to the recognition from ice core and marine proxy archives, in particular, of periods if intense cooling, correlated to the marine record of Heinrich ice rafted debris layers from the Atlantic. As a result of these collaborations between the archaeological and palaeoenvironmental communities various drivers have been proposed for the Middle to Upper Palaeolithic Transition that include: (1) resource competition between two species occupying similar niches; (2) the impact of repeated cycles of Heinrich event cooling, leading to the decline and eventual disappearance of the Neanderthal populations, leaving a new region open for AMH exploitation; and (3) catastrophic impacts of large volcanic eruptions on Neanderthal populations. Attempts to address the above hypotheses have been dogged by the chronological precision available for a number of key archives. The accuracy of many of the radiocarbon ages that underpin the chronology for both Neanderthal and AMH archaeological sites has been questioned1. This has been exacerbated by uncertainties over the influence of variability in the radiocarbon marine reservoir effect on marine palaeoclimate records and a marine dominated radiocarbon calibration curve. Additionally, the counting uncertainties of the master Greenland palaeoclimate archives are also large by this time, meaning palaeoclimate interpretation can be equivocal. However, several research

  19. Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

    PubMed Central

    Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

    2016-01-01

    Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE. PMID:26738699

  20. Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

    2016-01-01

    Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

  1. Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau.

    PubMed

    Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

    2016-01-07

    Phytoliths and biomolecular components extracted from ancient plant remains from Chang'an (Xi'an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang'an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

  2. New evidence on the anatomy and phylogeny of the earliest vertebrates.

    PubMed Central

    Xian-guang, Hou; Aldridge, Richard J; Siveter, David J; Siveter, Derek J; Xiang-hong, Feng

    2002-01-01

    We report the discovery of a new agnathan specimen from the Lower Cambrian Chengjiang Lagerstätte of China and thereby provide new evidence on the myomeres (V-shaped), the branchial apparatus (gill filaments and arches), the dorsal fin and the gonads (24-26) of the earliest vertebrates. The new specimen and the co-occurring Myllokunmingia fengjiaoa and Haikouichthys ercaicunensis represent a single species, which is a primitive member of the crown group craniates (vertebrates) and post-dates the origin of the myxinoids (hagfish). The origin of the vertebrate clade is at least as old as Early Cambrian. PMID:12350247

  3. Pulses of middle Eocene to earliest Oligocene climatic deterioration in southern California and the Gulf Coast

    USGS Publications Warehouse

    Frederiksen, N.O.

    1991-01-01

    A general deterioration of terrestrial climate took place during middle Eocene to earliest Oligocene time in southern California and in the Gulf Coast. Pollen data, calibrated by calcareous nannofossil ages, indicate four events of rapid floral and/or vegetational change among angiosperms during this time interval. The events can be correlated between the two regions even though these regions lay within different floristic provinces, and each event of angiosperm change is interpreted to indicate a pulse of rapid climatic shift. The most distinct of these events is the Middle Eocene Diversity Decline, which resulted from a peak in last appearances (extinctions, emigrations) centered in the early Bartonian. -from Author

  4. The breath of life: an essay on the earliest history of respiration: part ii.

    PubMed

    Gandevia, B

    1970-06-01

    It is to ancient Greek civilization that we must look for the first groping steps towards a naturalistic concept of respiration, although we shall not, of course, expect to find one which is consistent with modern views. Nearly a millennium before Christ, Homer wrote of the gods as more less predictable and very human beings, deserving more of admiration and emulation than worship; they took a fairly commonsense view of man's earthly pursuits, and left him a measure of control over his own destiny. From this relatively disrespectful state-by comparison with primitive or Old Testament views-it is but a stage to a rationalistic view of the universe, that is, to science, and this step was taken about three centuries later (6th century B.C.) by Thales, Anaximander and Anaximenes. We cannot pause to consider their views in detail, nor can we digress, as strictly we should, to consider the emerging relationship between philosophy and science. Suffice it to say that these first philosopher-scientists sought to explain the universe and life in rational terms, basing their rationalizations-we might say extrapolations-on certain specific observations of natural phenomena. The latter were concerned, in the main, with the interrelationships of basic substances (ultimately regarded as the four elements) such as fire, earth, air and water. Water, for example, could be condensed to form earth, or rarefied to form mist and vapour. Copyright © 1970 Australian Physiotherapy Association. Published by . All rights reserved.

  5. Middle Palaeolithic occupation in the Thar Desert during the Upper Pleistocene: the signature of a modern human exit out of Africa?

    NASA Astrophysics Data System (ADS)

    Blinkhorn, James; Achyuthan, Hema; Petraglia, Michael; Ditchfield, Peter

    2013-10-01

    The Thar Desert marks the transition from the Saharo-Arabian deserts to the Oriental biogeographical zone and is therefore an important location in understanding hominin occupation and dispersal during the Upper Pleistocene. Here, we report the discovery of stratified Middle Palaeolithic assemblages at Katoati in the north-eastern Thar Desert, dating to Marine Isotope Stages (MIS) 5 and the MIS 4-3 boundary, during periods of enhanced humidity. Hominins procured cobbles from gravels at the site as evidenced by early stages of stone tool reduction, with a component of more formalised point production. The MIS 5c assemblages at Katoati represent the earliest securely dated Middle Palaeolithic occupation of South Asia. Distinctive artefacts identified in both MIS 5 and MIS 4-3 boundary horizons match technological entities observed in Middle Palaeolithic assemblages in South Asia, Arabia and Middle Stone Age sites in the Sahara. The evidence from Katoati is consistent with arguments for the dispersal of Homo sapiens populations from Africa across southern Asia using Middle Palaeolithic technologies.

  6. Development of modern human subadult age and sex estimation standards using multi-slice computed tomography images from medical examiner's offices

    NASA Astrophysics Data System (ADS)

    Stock, Michala K.; Stull, Kyra E.; Garvin, Heather M.; Klales, Alexandra R.

    2016-10-01

    Forensic anthropologists are routinely asked to estimate a biological profile (i.e., age, sex, ancestry and stature) from a set of unidentified remains. In contrast to the abundance of collections and techniques associated with adult skeletons, there is a paucity of modern, documented subadult skeletal material, which limits the creation and validation of appropriate forensic standards. Many are forced to use antiquated methods derived from small sample sizes, which given documented secular changes in the growth and development of children, are not appropriate for application in the medico-legal setting. Therefore, the aim of this project is to use multi-slice computed tomography (MSCT) data from a large, diverse sample of modern subadults to develop new methods to estimate subadult age and sex for practical forensic applications. The research sample will consist of over 1,500 full-body MSCT scans of modern subadult individuals (aged birth to 20 years) obtained from two U.S. medical examiner's offices. Statistical analysis of epiphyseal union scores, long bone osteometrics, and os coxae landmark data will be used to develop modern subadult age and sex estimation standards. This project will result in a database of information gathered from the MSCT scans, as well as the creation of modern, statistically rigorous standards for skeletal age and sex estimation in subadults. Furthermore, the research and methods developed in this project will be applicable to dry bone specimens, MSCT scans, and radiographic images, thus providing both tools and continued access to data for forensic practitioners in a variety of settings.

  7. Dental remains of cebid platyrrhines from the earliest late Miocene of Western Amazonia, Peru: Macroevolutionary implications on the extant capuchin and marmoset lineages.

    PubMed

    Marivaux, Laurent; Adnet, Sylvain; Altamirano-Sierra, Ali J; Pujos, François; Ramdarshan, Anusha; Salas-Gismondi, Rodolfo; Tejada-Lara, Julia V; Antoine, Pierre-Olivier

    2016-11-01

    Undoubted fossil Cebidae have so far been primarily documented from the late middle Miocene of Colombia, the late Miocene of Brazilian Amazonia, the early Miocene of Peruvian Amazonia, and very recently from the earliest Miocene of Panama. The evolutionary history of cebids is far from being well-documented, with notably a complete blank in the record of callitrichine stem lineages until and after the late middle Miocene (Laventan SALMA). Further documenting their evolutionary history is therefore of primary importance. Recent field efforts in Peruvian Amazonia (Contamana area, Loreto Department) have allowed for the discovery of an early late Miocene (ca. 11 Ma; Mayoan SALMA) fossil primate-bearing locality (CTA-43; Pebas Formation). In this study, we analyze the primate material, which consists of five isolated teeth documenting two distinct Cebidae: Cebus sp., a medium-sized capuchin (Cebinae), and Cebuella sp., a tiny marmoset (Callitrichinae). Although limited, this new fossil material of platyrrhines contributes to documenting the post-Laventan evolutionary history of cebids, and besides testifies to the earliest occurrences of the modern Cebuella and Cebus/Sapajus lineages in the Neotropics. Regarding the evolutionary history of callitrichine marmosets, the discovery of an 11 Ma-old fossil representative of the modern Cebuella pushes back by at least 6 Ma the age of the Mico/Cebuella divergence currently proposed by molecular biologists (i.e., ca. 4.5 Ma). This also extends back to > 11 Ma BP the divergence between Callithrix and the common ancestor (CA) of Mico/Cebuella, as well as the divergence between the CA of marmosets and Callimico (Goeldi's callitrichine). This discovery from Peruvian Amazonia implies a deep evolutionary root of the Cebuella lineage in the northwestern part of South America (the modern western Amazon basin), slightly before the recession of the Pebas mega-wetland system (PMWS), ca. 10.5 Ma, and well-before the subsequent

  8. The earliest bird-line archosaurs and the assembly of the dinosaur body plan.

    PubMed

    Nesbitt, Sterling J; Butler, Richard J; Ezcurra, Martín D; Barrett, Paul M; Stocker, Michelle R; Angielczyk, Kenneth D; Smith, Roger M H; Sidor, Christian A; Niedźwiedzki, Grzegorz; Sennikov, Andrey G; Charig, Alan J

    2017-04-27

    The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology.

  9. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

    NASA Astrophysics Data System (ADS)

    Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

    2017-01-01

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

  10. A structural intermediate between triisodontids and mesonychians (Mammalia, Acreodi) from the earliest Eocene of Portugal.

    PubMed

    Tabuce, Rodolphe; Clavel, Julien; Antunes, Miguel Telles

    2011-02-01

    A new mammal, Mondegodon eutrigonus gen. et sp. nov., is described from the earliest Eocene locality of Silveirinha, Portugal. This species shows dental adaptations indicative of a carnivorous diet. M. eutrigonus is referred to the order Acreodi and considered, along with the early Paleocene North American species Oxyclaenus cuspidatus, as a morphological intermediate between two groups of ungulate-like mammals, namely, the triisodontids and mesonychians. Considering that triisodontids are early to early-late Paleocene North American taxa, Mondegodon probably belongs to a group that migrated from North America towards Europe during the first part of the Paleocene. Mondegodon could represent thus a relict genus, belonging to the ante-Eocene European mammalian fauna. The occurrence of such a taxon in Southern Europe may reflect a period of isolation of this continental area during the Paleocene/Eocene transition. In this context, the non-occurrence of closely allied forms of Mondegodon in the Eocene North European mammalian faunas is significant. This strengthens the hypothesis that the mammalian fauna from Southern Europe is characterized by a certain degree of endemism during the earliest Eocene. Mondegodon also presents some striking similarities with an unnamed genus from the early Eocene of India which could represent the first Asian known transitional form between the triisodontids and mesonychians.

  11. Equatorial Precession Drove Mid-Latitude Changes in ENSO-Scale Variation in the Earliest Miocene

    NASA Astrophysics Data System (ADS)

    Fox, B.; D'Andrea, W. J.; Lee, D. E.; Wilson, G. S.

    2014-12-01

    Foulden Maar is an annually laminated lacustrine diatomite deposit from the South Island of New Zealand. The deposit was laid down over ~100 kyr of the latest Oligocene and earliest Miocene, during the peak and deglaciation phase of the Mi-1 Antarctic glaciation event. At this time, New Zealand was located at approximately the same latitude as today (~45°S). Evidence from organic geochemical proxies (δD, δ13C) and physical properties (density, colour) indicates the presence of an 11-kyr cycle at the site. Although it is known that 11-kyr insolation (half-precession) cycles occur between the Tropics, this cycle is rarely seen in sedimentary archives deposited outside the immediate vicinity of the Equator. Records from Foulden Maar correlate well with the amplitude and phase of the modelled equatorial half-precession cycle for the earliest Miocene. High-resolution (50 µm) colour intensity measurements and lamina thickness measurements both indicate the presence of significant ENSO-like (2-8 year) variation in the Foulden Maar sediments. Early results from targeted lamina thickness measurements suggest that ENSO-band variation is modulated by the 11-kyr cycle, with power in the ENSO band increasing during periods of increased insolation at the Equator. This implies that equatorial half-precession had a significant effect on ENSO-like variation in the early Miocene, and that this effect was felt as far afield as the mid-latitudes of the Southern Hemisphere.

  12. History and contemporary significance of the Rhynie cherts-our earliest preserved terrestrial ecosystem.

    PubMed

    Edwards, Dianne; Kenrick, Paul; Dolan, Liam

    2018-02-05

    The Rhynie cherts Unit is a 407 million-year old geological site in Scotland that preserves the most ancient known land plant ecosystem, including associated animals, fungi, algae and bacteria. The quality of preservation is astonishing, and the initial description of several plants 100 years ago had a huge impact on botany. Subsequent discoveries provided unparalleled insights into early life on land. These include the earliest records of plant life cycles and fungal symbioses, the nature of soil microorganisms and the diversity of arthropods. Today the Rhynie chert (here including the Rhynie and Windyfield cherts) takes on new relevance, especially in relation to advances in the fields of developmental genetics and Earth systems science. New methods and analytical techniques also contribute to a better understanding of the environment and its organisms. Key discoveries are reviewed, focusing on the geology of the site, the organisms and the palaeoenvironments. The plants and their symbionts are of particular relevance to understanding the early evolution of the plant life cycle and the origins of fundamental organs and tissue systems. The Rhynie chert provides remarkable insights into the structure and interactions of early terrestrial communities, and it has a significant role to play in developing our understanding of their broader impact on Earth systems.This article is part of a discussion meeting issue 'The Rhynie cherts: our earliest terrestrial ecosystem revisited'. © 2017 The Author(s).

  13. Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits

    PubMed Central

    Djokic, Tara; Van Kranendonk, Martin J.; Campbell, Kathleen A.; Walter, Malcolm R.; Ward, Colin R.

    2017-01-01

    The ca. 3.48 Ga Dresser Formation, Pilbara Craton, Western Australia, is well known for hosting some of Earth’s earliest convincing evidence of life (stromatolites, fractionated sulfur/carbon isotopes, microfossils) within a dynamic, low-eruptive volcanic caldera affected by voluminous hydrothermal fluid circulation. However, missing from the caldera model were surface manifestations of the volcanic-hydrothermal system (hot springs, geysers) and their unequivocal link with life. Here we present new discoveries of hot spring deposits including geyserite, sinter terracettes and mineralized remnants of hot spring pools/vents, all of which preserve a suite of microbial biosignatures indicative of the earliest life on land. These include stromatolites, newly observed microbial palisade fabric and gas bubbles preserved in inferred mineralized, exopolymeric substance. These findings extend the known geological record of inhabited terrestrial hot springs on Earth by ∼3 billion years and offer an analogue in the search for potential fossil life in ancient Martian hot springs. PMID:28486437

  14. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago.

    PubMed

    Eichler, A; Gramlich, G; Kellerhals, T; Tobler, L; Rehren, Th; Schwikowski, M

    2017-01-31

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

  15. Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

    PubMed Central

    Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

    2017-01-01

    The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200–800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700–50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures. PMID:28139760

  16. Earliest floral grave lining from 13,700-11,700-y-old Natufian burials at Raqefet Cave, Mt. Carmel, Israel.

    PubMed

    Nadel, Dani; Danin, Avinoam; Power, Robert C; Rosen, Arlene M; Bocquentin, Fanny; Tsatskin, Alexander; Rosenberg, Danny; Yeshurun, Reuven; Weissbrod, Lior; Rebollo, Noemi R; Barzilai, Omry; Boaretto, Elisabetta

    2013-07-16

    Flowering plants possess mechanisms that stimulate positive emotional and social responses in humans. It is difficult to establish when people started to use flowers in public and ceremonial events because of the scarcity of relevant evidence in the archaeological record. We report on uniquely preserved 13,700-11,700-y-old grave linings made of flowers, suggesting that such use began much earlier than previously thought. The only potentially older instance is the questionable use of flowers in the Shanidar IV Neanderthal grave. The earliest cemeteries (ca. 15,000-11,500 y ago) in the Levant are known from Natufian sites in northern Israel, where dozens of burials reflect a wide range of inhumation practices. The newly discovered flower linings were found in four Natufian graves at the burial site of Raqefet Cave, Mt. Carmel, Israel. Large identified plant impressions in the graves include stems of sage and other Lamiaceae (Labiatae; mint family) or Scrophulariaceae (figwort family) species; accompanied by a plethora of phytoliths, they provide the earliest direct evidence now known for such preparation and decoration of graves. Some of the plant species attest to spring burials with a strong emphasis on colorful and aromatic flowers. Cave floor chiseling to accommodate the desired grave location and depth is also evident at the site. Thus, grave preparation was a sophisticated planned process, embedded with social and spiritual meanings reflecting a complex preagricultural society undergoing profound changes at the end of the Pleistocene.

  17. The He isotope composition of the earliest picrites erupted by the Ethiopia plume, implications for mantle plume source

    NASA Astrophysics Data System (ADS)

    Stuart, Finlay; Rogers, Nick; Davies, Marc

    2016-04-01

    The earliest basalts erupted by mantle plumes are Mg-rich, and typically derived from mantle with higher potential temperature than those derived from the convecting upper mantle at mid-ocean ridges and ocean islands. The chemistry and isotopic composition of picrites from CFB provide constraints on the composition of deep Earth and thus the origin and differentiation history. We report new He-Sr-Nd-Pb isotopic composition of the picrites from the Ethiopian flood basalt province from the Dilb (Chinese Road) section. They are characterized by high Fe and Ti contents for MgO = 10-22 wt. % implying that the parent magma was derived from a high temperature low melt fraction, most probably from the Afar plume head. The picrite 3He/4He does not exceed 21 Ra, and there is a negative correlation with MgO, the highest 3He/4He corresponding to MgO = 15.4 wt. %. Age-corrected 87Sr/86Sr (0.70392-0.70408) and 143Nd/144Nd (0.512912-0.512987) display little variation and are distinct from MORB and OIB. Age-corrected Pb isotopes display a significant range (e.g. 206Pb/204Pb = 18.70-19.04) and plot above the NHRL. These values contrast with estimates of the modern Afar mantle plume which has lower 3He/4He and Sr, Nd and Pb isotope ratios that are more comparable with typical OIB. These results imply either interaction between melts derived from the Afar mantle plume and a lithospheric component, or that the original Afar mantle plume had a rather unique radiogenic isotope composition. Regardless of the details of the origins of this unusual signal, our observations place a minimum 3He/4He value of 21 Ra for the Afar mantle plume, significantly greater than the present day value of 16 Ra, implying a significant reduction over 30 Myr. In addition the Afar source was less degassed than convecting mantle but more degassed than mantle sampled by the proto-Iceland plume (3He/4He ~50 Ra). This suggests that the largest mantle plumes are not sourced in a single deep mantle domain with a

  18. The earliest document regarding the history of cranioplasty from the Ottoman era.

    PubMed

    Aciduman, Ahmet; Belen, Deniz

    2007-09-01

    Cranioplasty is one of the significant neurosurgical procedures in which the technical advances and also, by some means, drawbacks are still continuing. According to archeological findings and anthropological studies, the earliest procedures regarding cranioplasty date back to just about the same period claimed for trepanation. Ancient surgeons from different geographical sites and cultures performed both practices with remarkable survival rates. However, despite the length of the thriving past of cranioplasty, the first known written record on the topic dates back to late 16th century Europe. Further study of the Ottoman era documents revealed an intriguing text that was written about the repair of skull defects and that dates from early 16th century. This worthy discovery will add valuable contribution to the history of neurosurgery by drawing the written history of cranioplasty more than 60 years back and the use of organic grafts 160 years back. In the present study, this original text is discussed.

  19. Earliest record of the invasive Foraminifera Trochammina hadai in San Francisco Bay, California, USA

    USGS Publications Warehouse

    McGann, Mary

    2014-01-01

    In 1995, Trochammina hadai, a benthic Foraminifera prevalent in Japanese estuaries, was found in San Francisco Bay, California, USA. Subsequent field investigations determined that the species was also present in nearly all of the major ports and estuaries along the western United States. Because of its widespread colonization, it is of interest to determine when T. hadai first appeared as an invasive in the coastal regions of the North Pacific. In San Francisco Bay, the species was not found in 404 surface samples collected between 1930 and 1981. In 1983, however, a grab sediment sample from one of four sites in the southern portion of the bay contained T. hadai. This site was the most northern of the four and contained 12 specimens of the invasive, comprising 1.5% of the assemblage. This is the earliest appearance on record of T. hadai in San Francisco Bay.

  20. The termites of Early Eocene Cambay amber, with the earliest record of the Termitidae (Isoptera)

    PubMed Central

    Engel, Michael S.; Grimaldi, David A.; Nascimbene, Paul C.; Singh, Hukam

    2011-01-01

    Abstract The fauna of termites (Isoptera) preserved in Early Eocene amber from the Cambay Basin (Gujarat, India) are described and figured. Three new genera and four new species are recognized, all of them Neoisoptera – Parastylotermes krishnai Engel & Grimaldi, sp. n. (Stylotermitidae); Prostylotermes kamboja Engel & Grimaldi, gen. et sp. n. (Stylotermitidae?); Zophotermes Engel, gen. n., with Zophotermes ashoki Engel & Singh, sp. n. (Rhinotermitidae: Prorhinotermitinae); and Nanotermes isaacae Engel & Grimaldi, gen. et sp. n. (Termitidae: Termitinae?). Together these species represent the earliest Tertiary records of the Neoisoptera and the oldest definitive record of Termitidae, a family that comprises >75% of the living species of Isoptera. Interestingly, the affinities of the Cambay amber termites are with largely Laurasian lineages, in this regard paralleling relationships seen between the fauna of bees and some flies. Diversity of Neoisoptera in Indian amber may reflect origin of the amber deposit in Dipterocarpaceae forests formed at or near the paleoequator. PMID:22287892

  1. The naturalistic fallacy is modern.

    PubMed

    Daston, Lorraine

    2014-09-01

    The naturalistic fallacy appears to be ubiquitous and irresistible. The avant-garde and the rearguard, the devout and the secular, the learned elite and the lay public all seem to want to enlist nature on their side, everywhere and always. Yet a closer look at the history of the term "naturalistic fallacy" and its associated arguments suggests that this way of understanding (and criticizing) appeals to nature's authority in human affairs is of relatively modern origin. To apply this category cross-historically masks considerable variability and naturalizes our own assumptions about the natural and the human.

  2. The Modern Religious Language of Education: Rousseau's "Emile"

    ERIC Educational Resources Information Center

    Osterwalder, Fritz

    2012-01-01

    The Republican education, its concepts, theories, and form of discourse belong to the shared European heritage of the pre-modern Age. The pedagogy of humanism and its effects on the early Modern Age are represented by Republicanism. Even if Republicanism found a political continuation in liberalism and democratism of the Modern Age, the same…

  3. Volutidae (Mollusca: Gastropoda) of the Lakhra Formation (Earliest Eocene, Sindh, Pakistan): systematics, biostratigraphy and paleobiogeography.

    PubMed

    Merle, Didier; Pacaud, Jean-Michel; Métais, Grégoire; Bartolini, Annachiara; Lashari, Rafiq A; Brohi, Imdad A; Solangi, Sarfraz H; Marivaux, Laurent; Welcomme, Jean-Loup

    2014-06-27

    The paleobiodiversity of the Volutidae (Mollusca: Gastropoda) of the Ranikot Group (Sindh, Pakistan) and particularly of the Lakhra Formation (SBZ 5 biozone, Earliest Eocene), is reconsidered on the basis of new material collected during recent field trips. Ten new species are described (Mitreola brohii sp. nov., Lyrischapa vredenburgi sp. nov., L. brevispira sp. nov., Athleta (Volutopupa) citharopsis sp. nov., A. (Volutocorbis) lasharii sp. nov., Volutilithes welcommei sp. nov., V. sindhiensis sp. nov., Pseudaulicina coxi sp. nov., Sindhiluta lakhraensis sp. nov. and Pakiluta solangii sp. nov.) and one species is in open nomenclature (Lyria sp.). Three new genera are described: Lyriopsis gen. nov. [Volutinae, ?Lyriini, type species: Lyriopsis cossmanni (Vredenburg, 1923)], Sindhiluta gen. nov. [Volutilithinae, type species: Sindhiluta lakhraensis n. sp.] and Pakiluta gen. nov. [?Volutodermatinae, type species: Pakiluta solangii n. sp.]. Two new combinations are proposed: Lyriopsis cossmanni (Vredenburg, 1923) comb. nov. and Athleta (Volutopupa) intercrenatus (Cossmann & Pissarro, 1909) comb. nov. Lectotypes are designated for Lyria cossmanni Vredenburg, 1923, L. feddeni Vredenburg, 1923, Volutospina noetlingi Cossmann & Pissarro, 1909, V. intercrenata Cossmann & Pissarro, 1909 and Athleta (Volutocorbis) victoriae Vredenburg, 1923. With 21 species, this volutid fauna is the most diverse recorded from the Tethys Ocean during Earliest Eocene time. The assemblage is characterized by a strong turnover marked by regional speciation and the appearance of many western Tethyan invaders. Although at the species level, the assemblage documents a strong provincialism, at the genus level, the high number of shared genera between Eastern Tethyan and Old World Tethyan realms begins a phase of long-term homogeneity of volutid assemblages from the Tethyan paleobiogeographic province.

  4. Technique: imaging earliest tooth development in 3D using a silver-based tissue contrast agent.

    PubMed

    Raj, Muhammad T; Prusinkiewicz, Martin; Cooper, David M L; George, Belev; Webb, M Adam; Boughner, Julia C

    2014-02-01

    Looking in microscopic detail at the 3D organization of initiating teeth within the embryonic jaw has long-proved technologically challenging because of the radio-translucency of these tiny un-mineralized oral tissues. Yet 3D image data showing changes in the physical relationships among developing tooth and jaw tissues are vital to understand the coordinated morphogenesis of vertebrate teeth and jaws as an animal grows and as species evolve. Here, we present a new synchrotron-based scanning solution to image odontogenesis in 3D and in histological detail using a silver-based contrast agent. We stained fixed, intact wild-type mice aged embryonic (E) day 10 to birth with 1% Protargol-S at 37°C for 12-32 hr. Specimens were scanned at 4-10 µm pixel size at 28 keV, just above the silver K-edge, using micro-computed tomography (µCT) at the Canadian Light Source synchrotron. Synchrotron µCT scans of silver-stained embryos showed even the earliest visible stages of tooth initiation, as well as many other tissue types and structures, in histological detail. Silver stain penetration was optimal for imaging structures in intact embryos E15 and younger. This silver stain method offers a powerful yet straightforward approach to visualize at high-resolution and in 3D the earliest stages of odontogenesis in situ, and demonstrates the important of studying the tooth organ in all three planes of view. Copyright © 2013 Wiley Periodicals, Inc.

  5. Sequencing the Earliest Stages of Active Galactic Nuclei Development Using The Youngest Radio Sources

    NASA Astrophysics Data System (ADS)

    Collier, Jordan; Filipovic, Miroslav; Norris, Ray; Chow, Kate; Huynh, Minh; Banfield, Julie; Tothill, Nick; Sirothia, Sandeep Kumar; Shabala, Stanislav

    2014-04-01

    This proposal is a continuation of an extensive project (the core of Collier's PhD) to explore the earliest stages of AGN formation, using Gigahertz-Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) sources. Both are widely believed to represent the earliest stages of radio-loud AGN evolution, with GPS sources preceding CSS sources. In this project, we plan to (a) test this hypothesis, (b) place GPS and CSS sources into an evolutionary sequence with a number of other young AGN candidates, and (c) search for evidence of the evolving accretion mode. We will do this using high-resolution radio observations, with a number of other multiwavelength age indicators, of a carefully selected complete faint sample of 80 GPS/CSS sources. Analysis of the C2730 ELAIS-S1 data shows that we have so far met our goals, resolving the jets of 10/49 sources, and measuring accurate spectral indices from 0.843-10 GHz. This particular proposal is to almost triple the sample size by observing an additional 80 GPS/CSS sources in the Chandra Deep Field South (arguably the best-studied field) and allow a turnover frequency - linear size relation to be derived at >10-sigma. Sources found to be unresolved in our final sample will subsequently be observed with VLBI. Comparing those sources resolved with ATCA to the more compact sources resolved with VLBI will give a distribution of source sizes, helping to answer the question of whether all GPS/CSS sources grow to larger sizes.

  6. Nuclear weapons modernizations

    NASA Astrophysics Data System (ADS)

    Kristensen, Hans M.

    2014-05-01

    This article reviews the nuclear weapons modernization programs underway in the world's nine nuclear weapons states. It concludes that despite significant reductions in overall weapons inventories since the end of the Cold War, the pace of reductions is slowing - four of the nuclear weapons states are even increasing their arsenals, and all the nuclear weapons states are busy modernizing their remaining arsenals in what appears to be a dynamic and counterproductive nuclear competition. The author questions whether perpetual modernization combined with no specific plan for the elimination of nuclear weapons is consistent with the nuclear Non-Proliferation Treaty and concludes that new limits on nuclear modernizations are needed.

  7. Genetic Variation and Adaptation in Africa: Implications for Human Evolution and Disease

    PubMed Central

    Gomez, Felicia; Hirbo, Jibril; Tishkoff, Sarah A.

    2014-01-01

    Because modern humans originated in Africa and have adapted to diverse environments, African populations have high levels of genetic and phenotypic diversity. Thus, genomic studies of diverse African ethnic groups are essential for understanding human evolutionary history and how this leads to differential disease risk in all humans. Comparative studies of genetic diversity within and between African ethnic groups creates an opportunity to reconstruct some of the earliest events in human population history and are useful for identifying patterns of genetic variation that have been influenced by recent natural selection. Here we describe what is currently known about genetic variation and evolutionary history of diverse African ethnic groups. We also describe examples of recent natural selection in African genomes and how these data are informative for understanding the frequency of many genetic traits, including those that cause disease susceptibility in African populations and populations of recent African descent. PMID:24984772

  8. Gene Expression in Wilms’ Tumor Mimics the Earliest Committed Stage in the Metanephric Mesenchymal-Epithelial Transition

    PubMed Central

    Li, Chi-Ming; Guo, Meirong; Borczuk, Alain; Powell, Charles A.; Wei, Michelle; Thaker, Harshwardhan M.; Friedman, Richard; Klein, Ulf; Tycko, Benjamin

    2002-01-01

    Wilms’ tumor (WT) has been considered a prototype for arrested cellular differentiation in cancer, but previous studies have relied on selected markers. We have now performed an unbiased survey of gene expression in WTs using oligonucleotide microarrays. Statistical criteria identified 357 genes as differentially expressed between WTs and fetal kidneys. This set contained 124 matches to genes on a microarray used by Stuart and colleagues (Stuart RO, Bush KT, Nigam SK: Changes in global gene expression patterns during development and maturation of the rat kidney. Proc Natl Acad Sci USA 2001, 98:5649–5654) to establish genes with stage-specific expression in the developing rat kidney. Mapping between the two data sets showed that WTs systematically overexpressed genes corresponding to the earliest stage of metanephric development, and underexpressed genes corresponding to later stages. Automated clustering identified a smaller group of 27 genes that were highly expressed in WTs compared to fetal kidney and heterologous tumor and normal tissues. This signature set was enriched in genes encoding transcription factors. Four of these, PAX2, EYA1, HBF2, and HOXA11, are essential for cell survival and proliferation in early metanephric development, whereas others, including SIX1, MOX1, and SALL2, are predicted to act at this stage. SIX1 and SALL2 proteins were expressed in the condensing mesenchyme in normal human fetal kidneys, but were absent (SIX1) or reduced (SALL2) in cells at other developmental stages. These data imply that the blastema in WTs has progressed to the committed stage in the mesenchymal-epithelial transition, where it is partially arrested in differentiation. The WT-signature set also contained the Wnt receptor FZD7, the tumor antigen PRAME, the imprinted gene NNAT and the metastasis-associated transcription factor E1AF. PMID:12057921

  9. RAPTOR: Closed-Loop monitoring of the night sky and the earliest optical detection of GRB 021211

    NASA Astrophysics Data System (ADS)

    Vestrand, W. T.; Borozdin, K.; Casperson, D. J.; Fenimore, E.; Galassi, M.; McGowan, K.; Starr, D.; White, R. R.; Wozniak, P.; Wren, J.

    2004-10-01

    We discuss the RAPTOR (Rapid Telescopes for Optical Response) sky monitoring system at Los Alamos National Laboratory. RAPTOR is a fully autonomous robotic system that is designed to identify and make follow-up observations of optical transients with durations as short as one minute. The RAPTOR design is based on Biomimicry of Human Vision. The sky monitor is composed of two identical arrays of telescopes, separated by 38 kilometers, which stereoscopically monitor a field of about 1300 square-degrees for transients. Both monitoring arrays are carried on rapidly slewing mounts and are composed of an ensemble of wide-field telescopes clustered around a more powerful narrow-field telescope called the ``fovea'' telescope. All telescopes are coupled to real-time analysis pipelines that identify candidate transients and relay the information to a central decision unit that filters the candidates to find real celestial transients and command a response. When a celestial transient is found, the system can point the fovea telescopes to any position on the sky within five seconds and begin follow-up observations. RAPTOR also responds to Gamma Ray Burst (GRB) alerts generated by GRB monitoring spacecraft. Here we present RAPTOR observations of GRB 021211 that constitute the earliest detection of optical emission from that event and are the second fastest achieved for any GRB. The detection of bright optical emission from GRB021211, a burst with modest gamma-ray fluence, indicates that prompt optical emission, detectable with small robotic telescopes, is more common than previously thought. Further, the very fast decline of the optical afterglow from GRB 021211 suggests that some so-called ``optically dark'' GRBs were not detected only because of the slow response of the follow-up telescopes.

  10. Early Period of Modern Architecture in Turkey - A Case Study of Eskisehir

    NASA Astrophysics Data System (ADS)

    Karasozen, Rana

    2017-10-01

    Modern architecture in the Western World bore fruit at the beginning of the 20th Century in consequence of the process of modernity and seeking of the proper architecture for it. It was formed firstly towards the end of the 1920s. The main reason of this nonsynchronous development was the inadequacy of enlightenment and industrial revolution during the Ottoman Empire and the lack of formation of an intellectual infrastructure which provides the basis of modernity. However, the Ottoman Westernization occurring in the 19th century constituted the foundations of the Republic modernity founded in 1923. The earliest modern architectural designs in Turkey were first practised by European architects after the foundation of the Republic and internalised and practised extensively by the native architects afterwards. The early modern architecture of Turkey, named as “1930s Modernism”, continued until the beginning of the World War II. This period was formed in between the periods of first and second nationalist architecture movements. The early modern architecture period of Turkey was a period which high-quality designs were made. It was practised and internalised not only in big cities such as Ankara and in Istanbul, but also in the medium and small cities of the country. This situation was not just about a formal exception but about the internalisation of modernity by the society. Eskisehir is one of the most important pioneering cities of the Republic period in terms of industrial and educational developments. The earliest modern buildings were built as the public buildings by the state and non-citizen architects in the inadequate conditions of the country in terms of economy and professional people. The earliest modern houses of the city designed by these architects were the prototypes for the later practices which offered the citizens a new lifestyle. The modern houses were the symbols of prestige and status for the owners and the dwellers. The features of early

  11. The evolution of the human pelvis: changing adaptations to bipedalism, obstetrics and thermoregulation.

    PubMed

    Gruss, Laura Tobias; Schmitt, Daniel

    2015-03-05

    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. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  12. The evolution of the human pelvis: changing adaptations to bipedalism, obstetrics and thermoregulation

    PubMed Central

    Gruss, Laura Tobias; Schmitt, Daniel

    2015-01-01

    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. PMID:25602067

  13. 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.

  14. Infectious Disease Stigmas: Maladaptive in Modern Society

    PubMed Central

    Smith, Rachel A.; Hughes, David

    2014-01-01

    At multiple times in human history people have asked if there are good stigmas. Is there some useful function stigmas serve in the context of our evolutionary history; is stigma adaptive? This essay discusses stigmas as a group-selection strategy and the human context in which stigmas likely appeared. The next section explores how human patterns have changed in modern society and the consequences for infectious disease (ID) stigmas in the modern age. The concluding section suggests that while social-living species may be particularly apt to create and communicate ID stigmas and enact ID-related stigmatization, such stigma-related processes no longer function to protect human communities. Stigmas do not increase the ability of modern societies to survive infectious diseases, but in fact may be important drivers of problematic disease dynamics and act as catalysts for failures in protecting public health. PMID:25477728

  15. MATERIALS FOR MODERNIZATION.

    ERIC Educational Resources Information Center

    JACKSON, R. GRAHAM

    CHOICES AND ISSUES IN SELECTING MATERIALS FOR MODERNIZATION OF SCHOOL BUILDINGS ARE DISCUSSED IN THIS REPORT. BACKGROUND INFORMATION IS INTRODUCED IN TERMS OF REASONS FOR ABANDONMENT, THE CAUSES AND EFFECTS OF SCHOOL BUILDING OBSOLESCENCE, AND PROBLEMS IN THE MODERNIZATION PROCESS. INTERIOR PARTITIONS ARE DISCUSSED IN TERMS OF BUILDING MATERIALS,…

  16. Sangkulirang Mangkalihat: The Earliest Prehistoric Rock-Art in the World

    NASA Astrophysics Data System (ADS)

    Imam Gozali Sumantri, Dirga; Soeria Atmadja, Dicky A. S.; Setiawan, Pindi

    2018-05-01

    Borneo island, a part of Sundaland - a great mainland in South East Asia thousands of years ago - is the largest island in Indonesian Archipelago. In the middle-eastern of East Borneo, lies a peninsula karst region named Sangkulirang Mangkalihat. The region's biodiversity contains many species of flora and fauna which are part of karst ecosystem. Surprisingly, thousands prehistoric rock art paintings and engraving were found here, spread over 48 inland caves in seven different karst mountain areas. The rock arts are painted on the ceiling, wall, and hollow of the cave depends on the meaning. They illustrate forms such as spiritual images (zoomorphic and antropomorphic) for sacred spiritual meaning, and social phenomenon images (tools and weapons) for description of daily life. From all those rock-arts, hand paintings are the most common elements appeared. Compared to other paintings, these are the only negative images using different techniques. Radiocarbon dating indicated that the rock-arts at Tewet Cave in Sangkulirang Mangkalihat is 40,000 BP. It is much earlier compared to Lascaux Cave (35,400 BP) and Chauvet Cave (32,000) in France which were previously known as the earliest one in the world. Rock arts and some archeological findings also indicate the migration of Austronesian People. During the migration, Borneo's climate and land cover were changing from time to time. Continental climate occurred when all Sundaland was still dry (40,000-21,000 BP), followed by tropical savanna climate and archipelagic climate (12,000-7.000 BP), and then Tropical Rainforest consecutively (1,000 BP). Correlatively, geological interpretations from such areas indicate land cover changes. These changes effected Austronesian ways of living, e.g. from hunting to fishing, and were depicted clearly on their paintings. Today, - as observed from time series satellite images - industrial activities such as karst exploitation for cement production and

  17. The earliest known titanosauriform sauropod dinosaur and the evolution of Brachiosauridae

    PubMed Central

    Moine, Olivier

    2017-01-01

    Brachiosauridae is a clade of titanosauriform sauropod dinosaurs that includes the well-known Late Jurassic taxa Brachiosaurus and Giraffatitan. However, there is disagreement over the brachiosaurid affinities of most other taxa, and little consensus regarding the clade’s composition or inter-relationships. An unnamed partial sauropod skeleton was collected from middle–late Oxfordian (early Late Jurassic) deposits in Damparis, in the Jura department of eastern France, in 1934. Since its brief description in 1943, this specimen has been informally known in the literature as the ‘Damparis sauropod’ and ‘French Bothriospondylus’, and has been considered a brachiosaurid by most authors. If correctly identified, this would make the specimen the earliest known titanosauriform. Coupled with its relatively complete nature and the rarity of Oxfordian sauropod remains in general, this is an important specimen for understanding the early evolution of Titanosauriformes. Full preparation and description of this specimen, known from teeth, vertebrae and most of the appendicular skeleton of a single individual, recognises it as a distinct taxon: Vouivria damparisensis gen. et sp. nov. Phylogenetic analysis of a data matrix comprising 77 taxa (including all putative brachiosaurids) scored for 416 characters recovers a fairly well resolved Brachiosauridae. Vouivria is a basal brachiosaurid, confirming its status as the stratigraphically oldest known titanosauriform. Brachiosauridae consists of a paraphyletic array of Late Jurassic forms, with Europasaurus, Vouivria and Brachiosaurus recovered as successively more nested genera that lie outside of a clade comprising (Giraffatitan + Sonorasaurus) + (Lusotitan + (Cedarosaurus + Venenosaurus)). Abydosaurus forms an unresolved polytomy with the latter five taxa. The Early Cretaceous South American sauropod Padillasaurus was previously regarded as a brachiosaurid, but is here placed within Somphospondyli. A recent study

  18. Petrographic and C & O isotopic characteristics of the earliest stages of aqueous alteration of CM chondrites

    NASA Astrophysics Data System (ADS)

    Vacher, Lionel G.; Marrocchi, Yves; Villeneuve, Johan; Verdier-Paoletti, Maximilien J.; Gounelle, Matthieu

    2017-09-01

    CM chondrites form the largest group of hydrated meteorites and span a wide range of alteration states, with the Paris meteorite being the least altered CM described to date. Ca-Carbonates are powerful proxies for the alteration conditions of CMs because they are direct snapshots of the chemical and isotopic compositions of the parent fluids. Here, we report a petrographic and a C isotope and O isotope survey of Ca-carbonates in Paris in order to better characterize the earliest stages of aqueous alteration. Petrographic observations show that Paris contains two distinct populations of Ca-carbonates: Type 1a Ca-carbonates, which are surrounded by rims of tochilinite/cronstedtite intergrowths (TCIs), and new Type 0 Ca-carbonates, which do not exhibit the TCI rims. The TCI rims of Type 1a Ca-carbonates commonly outline euhedral crystal faces, demonstrating that these Ca-carbonates were (i) partially or totally pseudomorphosed by TCI and (ii) precipitated at the earliest stages of aqueous alteration, before Type 0 Ca-carbonates. Isotopic measurements show that Paris' Ca-carbonates have δ13C values that range from 19 to 80‰ (PDB), δ18O values that range from 29 to 41%, and δ17O values that range from 13 to 24‰ (SMOW). According to the δ13C-δ18O values of Paris' Ca-carbonates, we developed a new alteration model that involves (i) the equilibration of a primordial 17,18O-rich water (PW) with 16O-rich anhydrous silicates and (ii) varying contribution of 12C- and 13C-rich soluble organic matter (SOMs). It also suggests that many parameters control the C and O isotopic composition of Ca-carbonates, the principles being the degree of isotopic equilibration between the PW and the anhydrous silicates, the respective contribution of 12C and 13C-rich SOMs as well as the thermal evolution of CM parent bodies. Consequently, we suggest that CM Ca-carbonates could record both positive and negative δ13C-δ18O relationships, but a systematic correspondence is probably absent

  19. Precise U-Pb Zircon Constraints on the Earliest Magmatic History of the Carolina Terrane.

    PubMed

    Wortman; Samson; Hibbard

    2000-05-01

    The early magmatic and tectonic history of the Carolina terrane and its possible affinities with other Neoproterozoic circum-Atlantic arc terranes have been poorly understood, in large part because of a lack of reliable geochronological data. Precise U-Pb zircon dates for the Virgilina sequence, the oldest exposed part, constrain the timing of the earliest known stage of magmatism in the terrane and of the Virgilina orogeny. A flow-banded rhyolite sampled from a metavolcanic sequence near Chapel Hill, North Carolina, yielded a U-Pb zircon date of 632.9 +2.6/-1.9 Ma. A granitic unit of the Chapel Hill pluton, which intrudes the metavolcanic sequence, yielded a nearly identical U-Pb zircon date of 633 +2/-1.5 Ma, interpreted as its crystallization age. A felsic gneiss and a dacitic tuff from the Hyco Formation yielded U-Pb zircon dates of 619.9 +4.5/-3 Ma and 615.7 +3.7/-1.9 Ma, respectively. Diorite and granite of the Flat River complex have indistinguishable U-Pb upper-intercept dates of 613.9 +1.6/-1.5 Ma and 613.4 +2.8/-2 Ma. The Osmond biotite-granite gneiss, which intruded the Hyco Formation before the Virgilina orogeny, crystallized at 612.4 +5.2/-1.7 Ma. Granite of the Roxboro pluton, an intrusion that postdated the Virgilina orogeny, yielded a U-Pb upper intercept date of 546.5 +3.0/-2.4 Ma, interpreted as the time of its crystallization. These new dates both provide the first reliable estimates of the age of the Virgilina sequence and document that the earliest known stage of magmatism in the Carolina terrane had begun by 633 +2/-1.5 Ma and continued at least until 612.4 +5.2/-1.7 Ma, an interval of approximately 25 m.yr. Timing of the Virgilina orogeny is bracketed between 612.4 +5.2/-1.7 Ma and 586+/-10 Ma (reported age of the upper Uwharrie Formation). The U-Pb systematics of all units studied in the Virgilina sequence are simple and lack any evidence of an older xenocrystic zircon component, which would indicate the presence of a continental

  20. The thalamus and multiple sclerosis: modern views on pathologic, imaging, and clinical aspects.

    PubMed

    Minagar, Alireza; Barnett, Michael H; Benedict, Ralph H B; Pelletier, Daniel; Pirko, Istvan; Sahraian, Mohamad Ali; Frohman, Elliott; Zivadinov, Robert

    2013-01-08

    The paired thalamic nuclei are gray matter (GM) structures on both sides of the third ventricle that play major roles in cortical activation, relaying sensory information to the higher cortical centers that influence cognition. Multiple sclerosis (MS) is an immune-mediated disease of the human CNS that affects both the white matter (WM) and GM. A number of clinical observations as well as recent neuropathologic and neuroimaging studies have clearly demonstrated extensive involvement of the thalamus, basal ganglia, and neocortex in patients with MS. Modern MRI techniques permit visualization of GM lesions and measurement of atrophy. These contemporary methods have fundamentally altered our understanding of the pathophysiologic nature of MS. Evidence confirms the contention that GM injury can be detected in the earliest phases of MS, and that iron deposition and atrophy of deep gray nuclei are closely related to the magnitude of inflammation. Extensive involvement of GM, and particularly of the thalamus, is associated with a wide range of clinical manifestations including cognitive decline, motor deficits, fatigue, painful syndromes, and ocular motility disturbances in patients with MS. In this review, we characterize the neuropathologic, neuroimaging, and clinical features of thalamic involvement in MS. Further, we underscore the contention that neuropathologic and neuroimaging correlative investigations of thalamic derangements in MS may elucidate not heretofore considered pathobiological underpinnings germane to understanding the ontogeny, magnitude, and progression of the disease process.

  1. The history of gait analysis before the advent of modern computers.

    PubMed

    Baker, Richard

    2007-09-01

    Aristotle (384-322 BCE) can be attributed with the earliest recorded comments regarding the manner in which humans walk. It was not until the renaissance that further progress was made through the experiments and theorising of Giovanni Borelli (1608-1679). Although several scientists wrote about walking through the enlightenment period it was the brothers Willhelm (1804-1891) and Eduard (1806-1871) Weber, working in Leipzig who made the next major contribution based on very simple measurements. Both Jules Etienne Marey (1830-1904), working in France, and Eadweard Muybridge (1830-1904), working in America, made significant advances in measurement technology. These were developed further by Otto Fischer (1861-1917) in collaboration with Willhelm Braune (1831-1892). The major developments in the early twentieth century were in the development of force plates and the understanding of kinetics. The team headed by Verne Inman (1905-1980) and Howard Eberhart (1906-1993) made major advances in America shortly after the Second War. David Sutherland (1923-2006) and Jacquelin Perry pioneered clinical applications in America and Jurg Baumann (1926-2000) in Europe. It was not until the advent of modern computers that clinical gait analysis became widely available.

  2. Basal tissue structure in the earliest euconodonts: Testing hypotheses of developmental plasticity in euconodont phylogeny

    USGS Publications Warehouse

    Dong, X.-P.; Donoghue, P.C.J.; Repetski, J.E.

    2005-01-01

    The hypothesis that conodonts are vertebrates rests solely on evidence of soft tissue anatomy. This has been corroborated by microstructural, topological and developmental evidence of homology between conodont and vertebrate hard tissues. However, these conclusions have been reached on the basis of evidence from highly derived euconodont taxa and the degree to which they are representative of plesiomorphic euconodonts remains an open question. Furthermore, the range of variation in tissue types comprising the euconodont basal body has been used to establish a hypothesis of developmental plasticity early in the phylogeny of the clade, and a model of diminishing potentiality in the evolution of development systems. The microstructural fabrics of the basal tissues of the earliest euconodonts (presumed to be the most plesiomorphic) are examined to test these two hypotheses. It is found that the range of microstructural variation observed hitherto was already apparent among plesiomorphic euconodonts. Thus, established histological data are representative of the most plesiomorphic euconodonts. However, although there is evidence of a range in microstructural fabrics, these are compatible with the dentine tissue system alone, and the degree of variation is compatible with that seen in clades of comparable diversity. ?? The Palaeontological Association.

  3. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis

    PubMed Central

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070–c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula. PMID:26535583

  4. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis.

    PubMed

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula.

  5. Tales from the prehistory of Quantum Gravity. Léon Rosenfeld's earliest contributions

    NASA Astrophysics Data System (ADS)

    Peruzzi, Giulio; Rocci, Alessio

    2018-05-01

    The main purpose of this paper is to analyse the earliest work of Léon Rosenfeld, one of the pioneers in the search of Quantum Gravity, the supposed theory unifying quantum theory and general relativity. We describe how and why Rosenfeld tried to face this problem in 1927, analysing the role of his mentors: Oskar Klein, Louis de Broglie and Théophile De Donder. Rosenfeld asked himself how quantum mechanics should concretely modify general relativity. In the context of a five-dimensional theory, Rosenfeld tried to construct a unifying framework for the gravitational and electromagnetic interaction and wave mechanics. Using a sort of "general relativistic quantum mechanics" Rosenfeld introduced a wave equation on a curved background. He investigated the metric created by what he called `quantum phenomena', represented by wave functions. Rosenfeld integrated Einstein equations in the weak field limit, with wave functions as source of the gravitational field. The author performed a sort of semi-classical approximation obtaining at the first order the Reissner-Nordström metric. We analyse how Rosenfeld's work is part of the history of Quantum Mechanics, because in his investigation Rosenfeld was guided by Bohr's correspondence principle. Finally we briefly discuss how his contribution is connected with the task of finding out which metric can be generated by a quantum field, a problem that quantum field theory on curved backgrounds will start to address 35 years later.

  6. K-ras Mutations as the Earliest Driving Force in a Subset of Colorectal Carcinomas

    PubMed Central

    MARGETIS, NIKOLAOS; KOULOUKOUSSA, MYRSINI; PAVLOU, KYRIAKI; VRAKAS, SPYRIDON; MARIOLIS-SAPSAKOS, THEODOROS

    2017-01-01

    K-ras oncogene is a key factor in colorectal cancer. Based on published and our data we propose that K-ras could be the oncogene responsible for the inactivation of the tumor-suppressor gene APC, currently considered as the initial step in colorectal tumorigenesis. K-ras fulfills the criteria of the oncogene-induced DNA damage model, as it can provoke well- established causes for inactivating tumor-suppressors, i.e. DNA double-strand breaks (causing allele deletion) and ROS production (responsible for point mutation). The model we propose is a variation of the currently existing model and hypothesizes that, in a subgroup of colorectal carcinomas, K-ras mutation may precede APC inactivation, representing the earliest driving force and, probably, an early biomarker of colorectal carcinogenesis. This observation is clinically useful, since it may modify the preventive colorectal cancer strategy, restricting numerically patients undergoing colonoscopies to those bearing K-ras mutation in their colorectum, either in benign polyps or the normal accompanying mucosa. PMID:28652417

  7. A Swift Look at SN 2011fe: The Earliest Ultraviolet Observations of a Type Ia Supernova

    NASA Technical Reports Server (NTRS)

    Oates, Samantha; Holland, Stephen; Immler, Stefan; Brown, Peter J.; Dawson, Kyle S.; DePasquale, Massimiliano; Gronwall, Caryl; Kuin, Paul; Mazzali, Paolo; Miline, Peter; hide

    2012-01-01

    We present the earliest ultraviolet (UV) observations of the bright Type Ia supernova SN 2011fe/PTF11kly in the nearby galaxy M101 at a distance of only 6.4 Mpc. It was discovered shortly after explosion by the Palomar Transient Factory and first observed by Swift/UVOT about a day after explosion. The early UV light is well-defined, with approx. 20 data points per filter in the 5 days after explosion. With these early UV observations, we extend the near-UV template of SNe Ia to earlier times for comparison with observations at low and high redshift and report fits from semiempirical models of the explosion. We find the early UV count rates to be well fit by the superposition of two parabolic curves. Finally, we use the early UV flux measurements to examine a possible shock interaction with a non-degenerate companion. We find that even a solar mass companion at a distance of a few solar radii is unlikely at more than 95% confidence.

  8. Changes of lysosomes in the earliest stages of the development of atherosclerosis.

    PubMed

    Bobryshev, Yuri V; Shchelkunova, Tatyana A; Morozov, Ivan A; Rubtsov, Petr M; Sobenin, Igor A; Orekhov, Alexander N; Smirnov, Alexander N

    2013-05-01

    One of hypotheses of atherosclerosis is based on a presumption that the zones prone to the development of atherosclerosis contain lysosomes which are characterized by enzyme deficiency and thus, are unable to dispose of lipoproteins. The present study was undertaken to investigate the characteristics and changes of lysosomes in the earliest stages of the development of atherosclerosis. Electron microscopic immunocytochemistry revealed that there were certain changes in the distribution of CD68 antigen in lysosomes along the 'normal intima-initial lesion-fatty streak' sequence. There were no significant changes found in the key mRNAs encoding for the components of endosome/lysosome compartment in initial atherosclerotic lesions, but in fatty streaks, the contents of EEA1 and Rab5a mRNAs were found to be diminished while the contents of CD68 and p62 mRNAs were increased, compared with the intact tissue. The study reinforces a view that changes occurring in lysosomes play a role in atherogenesis from the very earlier stages of the disease. © 2013 The Authors. Published by Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  9. Starless Clumps and the Earliest Phases of High-mass Star Formation in the Milky Way

    NASA Astrophysics Data System (ADS)

    Svoboda, Brian

    2018-01-01

    High-mass stars are key to regulating the interstellar medium, star formation activity, and overall evolution of galaxies, but their formation remains an open problem in astrophysics. In order to understand the physical conditions during the earliest phases of high-mass star formation, I report on observational studies of dense starless clump candidates (SCCs) that show no signatures of star formation activity. I identify 2223 SCCs from the 1.1 mm Bolocam Galactic Plane Survey, systematically analyze their physical properties, and show that the starless phase is not represented by a single timescale, but evolves more rapidly with increasing clump mass. To investigate the sub-structure in SCCs at high spatial resolution, I study the 12 most high-mass SCCs within 5 kpc using ALMA. I report previously undetected low-luminosity protostars in 11 out of 12 SCCs, fragmentation equal to the thermal Jeans length of the clump, and no starless cores exceeding 30 solar masses. While uncertainties remain concerning the star formation effeciency in this sample, these observational facts are consistent with models where high-mass stars form from intially low- to intermediate-mass protostars that accrete most of their mass from the surrounding clump.

  10. Cranial Bosses of Choerosaurus dejageri (Therapsida, Therocephalia): Earliest Evidence of Cranial Display Structures in Eutheriodonts

    PubMed Central

    Benoit, Julien; Manger, Paul R.; Fernandez, Vincent; Rubidge, Bruce S.

    2016-01-01

    Choerosaurus dejageri, a non-mammalian eutheriodont therapsid from the South African late Permian (~259 Ma), has conspicuous hemispheric cranial bosses on the maxilla and the mandible. These bosses, the earliest of this nature in a eutheriodont, potentially make C. dejageri a key species for understanding the evolutionary origins of sexually selective behaviours (intraspecific competition, ritualized sexual and intimidation displays) associated with cranial outgrowths at the root of the clade that eventually led to extant mammals. Comparison with the tapinocephalid dinocephalian Moschops capensis, a therapsid in which head butting is strongly supported, shows that the delicate structure of the cranial bosses and the gracile structure of the skull of Choerosaurus would be more suitable for display and low energy combat than vigorous head butting. Thus, despite the fact that Choerosaurus is represented by only one skull (which makes it impossible to address the question of sexual dimorphism), its cranial bosses are better interpreted as structures involved in intraspecific selection, i.e. low-energy fighting or display. Display structures, such as enlarged canines and cranial bosses, are widespread among basal therapsid clades and are also present in the putative basal therapsid Tetraceratops insignis. This suggests that sexual selection may have played a more important role in the distant origin and evolution of mammals earlier than previously thought. Sexual selection may explain the subsequent independent evolution of cranial outgrowths and pachyostosis in different therapsid lineages (Biarmosuchia, Dinocephalia, Gorgonopsia and Dicynodontia). PMID:27548428

  11. Cranial Bosses of Choerosaurus dejageri (Therapsida, Therocephalia): Earliest Evidence of Cranial Display Structures in Eutheriodonts.

    PubMed

    Benoit, Julien; Manger, Paul R; Fernandez, Vincent; Rubidge, Bruce S

    2016-01-01

    Choerosaurus dejageri, a non-mammalian eutheriodont therapsid from the South African late Permian (~259 Ma), has conspicuous hemispheric cranial bosses on the maxilla and the mandible. These bosses, the earliest of this nature in a eutheriodont, potentially make C. dejageri a key species for understanding the evolutionary origins of sexually selective behaviours (intraspecific competition, ritualized sexual and intimidation displays) associated with cranial outgrowths at the root of the clade that eventually led to extant mammals. Comparison with the tapinocephalid dinocephalian Moschops capensis, a therapsid in which head butting is strongly supported, shows that the delicate structure of the cranial bosses and the gracile structure of the skull of Choerosaurus would be more suitable for display and low energy combat than vigorous head butting. Thus, despite the fact that Choerosaurus is represented by only one skull (which makes it impossible to address the question of sexual dimorphism), its cranial bosses are better interpreted as structures involved in intraspecific selection, i.e. low-energy fighting or display. Display structures, such as enlarged canines and cranial bosses, are widespread among basal therapsid clades and are also present in the putative basal therapsid Tetraceratops insignis. This suggests that sexual selection may have played a more important role in the distant origin and evolution of mammals earlier than previously thought. Sexual selection may explain the subsequent independent evolution of cranial outgrowths and pachyostosis in different therapsid lineages (Biarmosuchia, Dinocephalia, Gorgonopsia and Dicynodontia).

  12. Earliest date for milk use in the Near East and southeastern Europe linked to cattle herding.

    PubMed

    Evershed, Richard P; Payne, Sebastian; Sherratt, Andrew G; Copley, Mark S; Coolidge, Jennifer; Urem-Kotsu, Duska; Kotsakis, Kostas; Ozdoğan, Mehmet; Ozdoğan, Aslý E; Nieuwenhuyse, Olivier; Akkermans, Peter M M G; Bailey, Douglass; Andeescu, Radian-Romus; Campbell, Stuart; Farid, Shahina; Hodder, Ian; Yalman, Nurcan; Ozbaşaran, Mihriban; Biçakci, Erhan; Garfinkel, Yossef; Levy, Thomas; Burton, Margie M

    2008-09-25

    The domestication of cattle, sheep and goats had already taken place in the Near East by the eighth millennium bc. Although there would have been considerable economic and nutritional gains from using these animals for their milk and other products from living animals-that is, traction and wool-the first clear evidence for these appears much later, from the late fifth and fourth millennia bc. Hence, the timing and region in which milking was first practised remain unknown. Organic residues preserved in archaeological pottery have provided direct evidence for the use of milk in the fourth millennium in Britain, and in the sixth millennium in eastern Europe, based on the delta(13)C values of the major fatty acids of milk fat. Here we apply this approach to more than 2,200 pottery vessels from sites in the Near East and southeastern Europe dating from the fifth to the seventh millennia bc. We show that milk was in use by the seventh millennium; this is the earliest direct evidence to date. Milking was particularly important in northwestern Anatolia, pointing to regional differences linked with conditions more favourable to cattle compared to other regions, where sheep and goats were relatively common and milk use less important. The latter is supported by correlations between the fat type and animal bone evidence.

  13. Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts

    PubMed Central

    Brown, Amanda M. V.; Wasala, Sulochana K.; Howe, Dana K.; Peetz, Amy B.; Zasada, Inga A.; Denver, Dee R.

    2016-01-01

    Wolbachia, one of the most widespread endosymbionts, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new Wolbachia strain (wPpe) in the plant-parasitic nematode Pratylenchus penetrans. Phylogenomic analyses placed wPpe as the earliest diverging Wolbachia, suggesting two evolutionary invasions into nematodes. The next branches comprised strains in sap-feeding insects, suggesting Wolbachia may have first evolved as a nutritional mutualist. Genome size, protein content, %GC, and repetitive DNA allied wPpe with mutualistic Wolbachia, whereas gene repertoire analyses placed it between parasite (A, B) and mutualist (C, D, F) groups. Conservation of iron metabolism genes across Wolbachia suggests iron homeostasis as a potential factor in its success. This study enhances our understanding of this globally pandemic endosymbiont, highlighting genetic patterns associated with host changes. Combined with future work on this strain, these genomic data could help provide potential new targets for plant-parasitic nematode control. PMID:27734894

  14. Zebrafish monosex population reveals female dominance in sex determination and earliest events of gonad differentiation.

    PubMed

    Tong, Sok-Keng; Hsu, Hwei-Jan; Chung, Bon-chu

    2010-08-15

    The zebrafish is a popular model for genetic analysis and its sex differentiation has been the focus of attention for breeding purposes. Despite numerous efforts, very little is known about the mechanism of zebrafish sex determination. The lack of discernible sex chromosomes and the difficulty of distinguishing the sex of juvenile fish are two major obstacles that hamper the progress in such studies. To alleviate these problems, we have developed a scheme involving methyltestosterone treatment followed by natural mating to generate fish with predictable sex trait. Female F1 fish that gave rise to all-female offspring were generated. This predictable sex trait enables characterization of gonadal development in juvenile fish by histological examination and gene expression analysis. We found the first sign of zebrafish sex differentiation to be ovarian gonocyte proliferation and differentiation at 10 to 12 days post-fertilization (dpf). Somatic genes were expressed indifferently at 10 to 17 dpf, and then became sexually dimorphic at three weeks. This result indicates clear distinction of male and female gonads derived independently from primordial gonads. We classified the earliest stages of zebrafish sex determination into the initial preparation followed by female germ cell growth, oocyte differentiation, and somatic differentiation. Our genetic selection scheme matches the prediction that female-dominant genetic factors are required to determine zebrafish sex. Copyright 2010 Elsevier Inc. All rights reserved.

  15. Trauma and autobiographical memory: contents and determinants of earliest memories among war-affected Palestinian children.

    PubMed

    Peltonen, Kirsi; Kangaslampi, Samuli; Qouta, Samir; Punamäki, Raija-Leena

    2017-11-01

    The contents of earliest memories (EM), as part of autobiographical memory, continue to fascinate scientists and therapists. However, research is scarce on the determinants of EM, especially among children. This study aims, first, to identify contents of EM of children living in war conditions, and, second, to analyse child gender, traumatic events and mental health as determinants of the contents of EM. The participants were 240 Palestinian schoolchildren from the Gaza Strip (10-12 years, M = 11.35, SD = 0.57; 49.4% girls). They responded to an open-ended EM question, and reported their trauma exposures (war trauma, losses and current traumatic events), posttraumatic stress, depressive symptoms and psychosocial well-being, indicating mental health. The EM coding involved nature, social orientation, emotional tone and specificity. Results showed, first, that 43% reported playing or visiting a nice place as EM, and about a third (30%) traumatic events or accidents (30%) or miscellaneous events (27%). The individual and social orientation were almost equally common, the emotional tone mainly neutral (45.5%), and 60% remembered a specific event. Second, boys remembered more EM involving traumatic events or accidents, and girls more social events. Third, war trauma was associated with less positive emotional tone and with more specific memories.

  16. Multigene phylogeny of land plants with special reference to bryophytes and the earliest land plants.

    PubMed

    Nickrent, D L; Parkinson, C L; Palmer, J D; Duff, R J

    2000-12-01

    A widely held view of land plant relationships places liverworts as the first branch of the land plant tree, whereas some molecular analyses and a cladistic study of morphological characters indicate that hornworts are the earliest land plants. To help resolve this conflict, we used parsimony and likelihood methods to analyze a 6, 095-character data set composed of four genes (chloroplast rbcL and small-subunit rDNA from all three plant genomes) from all major land plant lineages. In all analyses, significant support was obtained for the monophyly of vascular plants, lycophytes, ferns (including PSILOTUM: and EQUISETUM:), seed plants, and angiosperms. Relationships among the three bryophyte lineages were unresolved in parsimony analyses in which all positions were included and weighted equally. However, in parsimony and likelihood analyses in which rbcL third-codon-position transitions were either excluded or downweighted (due to apparent saturation), hornworts were placed as sister to all other land plants, with mosses and liverworts jointly forming the second deepest lineage. Decay analyses and Kishino-Hasegawa tests of the third-position-excluded data set showed significant support for the hornwort-basal topology over several alternative topologies, including the commonly cited liverwort-basal topology. Among the four genes used, mitochondrial small-subunit rDNA showed the lowest homoplasy and alone recovered essentially the same topology as the multigene tree. This molecular phylogeny presents new opportunities to assess paleontological evidence and morphological innovations that occurred during the early evolution of terrestrial plants.

  17. Sodium-driven energy conversion for flagellar rotation of the earliest divergent hyperthermophilic bacterium.

    PubMed

    Takekawa, Norihiro; Nishiyama, Masayoshi; Kaneseki, Tsuyoshi; Kanai, Tamotsu; Atomi, Haruyuki; Kojima, Seiji; Homma, Michio

    2015-08-05

    Aquifex aeolicus is a hyperthermophilic, hydrogen-oxidizing and carbon-fixing bacterium that can grow at temperatures up to 95 °C. A. aeolicus has an almost complete set of flagellar genes that are conserved in bacteria. Here we observed that A. aeolicus has polar flagellum and can swim with a speed of 90 μm s(-1) at 85 °C. We expressed the A. aeolicus mot genes (motA and motB), which encode the torque generating stator proteins of the flagellar motor, in a corresponding mot nonmotile mutant of Escherichia coli. Its motility was slightly recovered by expression of A. aeolicus MotA and chimeric MotB whose periplasmic region was replaced with that of E. coli. A point mutation in the A. aeolicus MotA cytoplasmic region remarkably enhanced the motility. Using this system in E. coli, we demonstrate that the A. aeolicus motor is driven by Na(+). As motor proteins from hyperthermophilic bacteria represent the earliest motor proteins in evolution, this study strongly suggests that ancient bacteria used Na(+) for energy coupling of the flagellar motor. The Na(+)-driven flagellar genes might have been laterally transferred from early-branched bacteria into late-branched bacteria and the interaction surfaces of the stator and rotor seem not to change in evolution.

  18. Tales from the prehistory of Quantum Gravity - Léon Rosenfeld's earliest contributions

    NASA Astrophysics Data System (ADS)

    Peruzzi, Giulio; Rocci, Alessio

    2018-04-01

    The main purpose of this paper is to analyse the earliest work of Léon Rosenfeld, one of the pioneers in the search of Quantum Gravity, the supposed theory unifying quantum theory and general relativity. We describe how and why Rosenfeld tried to face this problem in 1927, analysing the role of his mentors: Oskar Klein, Louis de Broglie and Théophile De Donder. Rosenfeld asked himself how quantum mechanics should concretely modify general relativity. In the context of a five-dimensional theory, Rosenfeld tried to construct a unifying framework for the gravitational and electromagnetic interaction and wave mechanics. Using a sort of "general relativistic quantum mechanics" Rosenfeld introduced a wave equation on a curved background. He investigated the metric created by what he called `quantum phenomena', represented by wave functions. Rosenfeld integrated Einstein equations in the weak field limit, with wave functions as source of the gravitational field. The author performed a sort of semi-classical approximation obtaining at the first order the Reissner-Nordström metric. We analyse how Rosenfeld's work is part of the history of Quantum Mechanics, because in his investigation Rosenfeld was guided by Bohr's correspondence principle. Finally we briefly discuss how his contribution is connected with the task of finding out which metric can be generated by a quantum field, a problem that quantum field theory on curved backgrounds will start to address 35 years later.

  19. A 33,000-year-old incipient dog from the Altai Mountains of Siberia: evidence of the earliest domestication disrupted by the Last Glacial Maximum.

    PubMed

    Ovodov, Nikolai D; Crockford, Susan J; Kuzmin, Yaroslav V; Higham, Thomas F G; Hodgins, Gregory W L; van der Plicht, Johannes

    2011-01-01

    Virtually all well-documented remains of early domestic dog (Canis familiaris) come from the late Glacial and early Holocene periods (ca. 14,000-9000 calendar years ago, cal BP), with few putative dogs found prior to the Last Glacial Maximum (LGM, ca. 26,500-19,000 cal BP). The dearth of pre-LGM dog-like canids and incomplete state of their preservation has until now prevented an understanding of the morphological features of transitional forms between wild wolves and domesticated dogs in temporal perspective. We describe the well-preserved remains of a dog-like canid from the Razboinichya Cave (Altai Mountains of southern Siberia). Because of the extraordinary preservation of the material, including skull, mandibles (both sides) and teeth, it was possible to conduct a complete morphological description and comparison with representative examples of pre-LGM wild wolves, modern wolves, prehistoric domesticated dogs, and early dog-like canids, using morphological criteria to distinguish between wolves and dogs. It was found that the Razboinichya Cave individual is most similar to fully domesticated dogs from Greenland (about 1000 years old), and unlike ancient and modern wolves, and putative dogs from Eliseevichi I site in central Russia. Direct AMS radiocarbon dating of the skull and mandible of the Razboinichya canid conducted in three independent laboratories resulted in highly compatible ages, with average value of ca. 33,000 cal BP. The Razboinichya Cave specimen appears to be an incipient dog that did not give rise to late Glacial-early Holocene lineages and probably represents wolf domestication disrupted by the climatic and cultural changes associated with the LGM. The two earliest incipient dogs from Western Europe (Goyet, Belguim) and Siberia (Razboinichya), separated by thousands of kilometers, show that dog domestication was multiregional, and thus had no single place of origin (as some DNA data have suggested) and subsequent spread.

  20. Etymology and Modern Linguistics

    ERIC Educational Resources Information Center

    Malkiel, Yakov

    1975-01-01

    Discusses the estrangement between etymology and modern linguistics, and concludes that a reconciliation between spatio-temporal linguistics and etymology must occur, because without it, both disciplines are doomed to inanition. (Author/AM)

  1. Modernizing Electricity Delivery

    EPA Pesticide Factsheets

    Explains how modern grid, or smart grid, investments can enable grid operators to respond faster to changes in grid conditions and allow for two-way communication between utilities and electricity end-users.

  2. Nuclear weapons modernizations

    SciTech Connect

    Kristensen, Hans M.

    This article reviews the nuclear weapons modernization programs underway in the world's nine nuclear weapons states. It concludes that despite significant reductions in overall weapons inventories since the end of the Cold War, the pace of reductions is slowing - four of the nuclear weapons states are even increasing their arsenals, and all the nuclear weapons states are busy modernizing their remaining arsenals in what appears to be a dynamic and counterproductive nuclear competition. The author questions whether perpetual modernization combined with no specific plan for the elimination of nuclear weapons is consistent with the nuclear Non-Proliferation Treaty and concludesmore » that new limits on nuclear modernizations are needed.« less

  3. Modern roundabouts for Oregon

    DOT National Transportation Integrated Search

    1998-06-01

    This report reviews current research and practice on modern roundabouts, both in the US and other countries. The report compares the advantages and disadvantages of roundabouts, summarizes safety implications, and discusses pedestrian and bicyclist c...

  4. Depot Maintenance Modernization

    DTIC Science & Technology

    1988-02-01

    process. However, this mobilization-planning process has not been implemented in the shipyards. Instead, NAVSEA has announcedl that " National economic...illustrate the type of modernization planning that occurs at the ALCs, we draw upon Oklahoma City’s Technology Enhancement and Modernization of Plant ... National Product - he concluded that the inflation-adjusted rate of return in the private sector was about 10 percent in 1965 (12 percent nominal rate

  5. Telling Modernization: Three Voices. Life History, Gender and the Discourse of Modernization. Roskilde University Life History Project Paper.

    ERIC Educational Resources Information Center

    Anderson, Linda

    The relationship between life history, gender, and the discourse of modernization was examined from the perspective of a researcher with extensive experience performing evaluations about modernization within human services in Denmark. Three stories about site-based management in two human service institutionsa youth center and a boarding school…

  6. Microbial biosynthesis of wax esters during desiccation: an adaptation for colonization of the earliest terrestrial environments?

    NASA Astrophysics Data System (ADS)

    Finkelstein, D. B.; Brassell, S. C.; Pratt, L. M.

    2008-12-01

    and during dehydration or desiccation cycles. Thus, production of WE may have facilitated microbial migration to the lake environments that represented the earliest terrestrial ecosystems, and survival through the Great Oxygenation Event.

  7. Starch granule evidence for the earliest potato use in North America

    PubMed Central

    Louderback, Lisbeth A.; Pavlik, Bruce M.

    2017-01-01

    The prehistory of wild potato use, leading to its domestication and diversification, has been well-documented in, and confined to, South America. At least 20 tuber-bearing, wild species of Solanum are known from North and Central America, yet their importance in ancient diets has never been assessed from the archaeological record. Here, we report the earliest evidence of wild potato use in North America at 10,900–10,100 calendar years (cal) B.P. in the form of well-preserved starch granules extracted from ground stone tools at North Creek Shelter, southern Utah. These granules have been identified as those of Solanum jamesii Torr. (Four Corners potato), a tuber-bearing species native to the American Southwest. Identification was based on applying five strictly defined diagnostic characteristics (eccentric hilum, longitudinal fissure, lack of fissure branching, fissure ratio, and maximum granule size) to each of 323 archaeological granules. Of those, nine were definitively assigned to S. jamesii based on possession of all characteristics, and another 61 were either likely or possibly S. jamesii depending on the number of characteristics they possessed. The oldest granules were found in substratum 4k (10,900–10,100 cal B.P.). Younger deposits, dating to ∼6,900 cal B.P., also contained tools with S. jamesii granules, indicating at least 4,000 y of intermittent use. Ethnographic and historical accounts extend the period of use to more than 10,000 y. The question then arises as to whether some S. jamesii populations could have undergone transport, cultivation, and eventual domestication over such a long period of time. PMID:28673982

  8. The earliest evidence for Upper Paleolithic occupation in the Armenian Highlands at Aghitu-3 Cave.

    PubMed

    Kandel, Andrew W; Gasparyan, Boris; Allué, Ethel; Bigga, Gerlinde; Bruch, Angela A; Cullen, Victoria L; Frahm, Ellery; Ghukasyan, Robert; Gruwier, Ben; Jabbour, Firas; Miller, Christopher E; Taller, Andreas; Vardazaryan, Varduhi; Vasilyan, Davit; Weissbrod, Lior

    2017-09-01

    With its well-preserved archaeological and environmental records, Aghitu-3 Cave permits us to examine the settlement patterns of the Upper Paleolithic (UP) people who inhabited the Armenian Highlands. We also test whether settlement of the region between ∼39-24,000 cal BP relates to environmental variability. The earliest evidence occurs in archaeological horizon (AH) VII from ∼39-36,000 cal BP during a mild, moist climatic phase. AH VI shows periodic occupation as warm, humid conditions prevailed from ∼36-32,000 cal BP. As the climate becomes cooler and drier at ∼32-29,000 cal BP (AH V-IV), evidence for occupation is minimal. However, as cooling continues, the deposits of AH III demonstrate that people used the site more intensively from ∼29-24,000 cal BP, leaving behind numerous stone artifacts, faunal remains, and complex combustion features. Despite the climatic fluctuations seen across this 15,000-year sequence, lithic technology remains attuned to one pattern: unidirectional reduction of small cores geared towards the production of bladelets for tool manufacture. Subsistence patterns also remain stable, focused on medium-sized prey such as ovids and caprids, as well as equids. AH III demonstrates an expansion of social networks to the northwest and southwest, as the transport distance of obsidian used to make stone artifacts increases. We also observe the addition of bone tools, including an eyed needle, and shell beads brought from the east, suggesting that these people manufactured complex clothing and wore ornaments. Remains of micromammals, birds, charcoal, pollen, and tephra relate the story of environmental variability. We hypothesize that UP behavior was linked to shifts in demographic pressures and climatic changes. Thus, by combining archaeological and environmental data, we gain a clearer picture about the first UP inhabitants of the Armenian Highlands. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Some further observations and comments on the earliest role of the father.

    PubMed

    Abelin, E L

    1975-08-01

    The longitudinal observation in the family setting of a boy (Michael) during his first two years is used to explore further the earliest role of the father, and to refine my 'early triangulation' model. This model was meant to account for some basic phenomena of Mahler's rapprochement subphase, and was partly based on Piaget's framework. The data are presented along three developmental lines. (1) The specific relationship with father as a different person: the concepts of 'specific refuelling' and of object-specific libido are introduced; and it is suggested that during the subphase of differentiation, all of Michael's specific objects (in particular, the father) shared some 'symbiotic' quality with the mother. (2) On the other hand, qualitative differences of the father relationship were also noted; they confirmed my earlier findings and Mahler's view. (3) Very early, Michael began to acknowledge the relationship with the parents as a couple. After a fleeting indication of rivalry (with mother!), a ritual game of 'getting his parents together' developed at the onset of the rapprochement subphase. This is discussed as one of many possible compromise solutions to avoid the full achievement of the anxiety-provoking 'early triangulation' process. This process, if completed, would involve 'identification with the rival parent', formation of a mental image of the self, and the positive cathexis of neutralized intragroup relationships (which presupposes symbolization). The ubiquitous observation of 'identification with the rival baby' may represent another such compromise solution, and thus a precursor of early triangulation. It might also be a parellel process, leading to 'generational identification' as distinguished from 'gender identification'. The isomorphism of these processes with Piaget's outline of cognitive development is pointed out.

  10. Activation Of Wild-Type Hras Suppresses The Earliest Stages Of Pancreatic Cancer.

    PubMed

    Weyandt, Jamie

    2015-08-01

    The RAS family of small GTPases is comprised of HRAS, NRAS, and KRAS. KRAS is invariably oncogenically mutated in pancreatic cancers, which is known to induce this disease. Beyond oncogenic KRAS, redox-dependent reactions have been implicated in the activation of the remaining wild-type RAS proteins in pancreatic cancer cell lines. These results suggest a possible involvement of wild-type RAS proteins in pancreatic cancer. To evaluate the impact of genetically suppressing wild-type RAS expression on pancreatic cancer. Hras homozygous null mice (Hras -/- ) were crossed into a Pdx-Cre; LSL-Kras G12D/+ (KC) murine background in which oncogenic Kras is activated in the pancreas to promote preinvasive pancreatic cancer. Tumor burden was then measured at different stages of disease. HRas -/- ;KC mice exhibited more precancerous lesions in the pancreas and more off-target skin papillomas compared to their wild-type counterparts, suggesting that Hras suppresses early oncogenic Kras-driven tumorigenesis, possibly at the time of initiation. Loss of Hras also reduced the survival of mice engineered to develop aggressive pancreatic cancer by the additional disruption of one allele of the tumor suppressor p53 (Trp53 R172H/+ ). However, this survival advantage was lost when both alleles of Trp53 were mutated, suggesting that wild-type Hras inhibits tumorigenesis in a p53-dependent fashion. Loss of wild-type Hras promotes the earliest stages of pancreatic tumorigenesis, and moreover results in more rapid progression of the disease. As such, mechanisms leading to activation of wild-type Ras proteins, including but not limited to redox-dependent reactions, may influence the development of pancreatic cancer. Copyright © 2015. Published by Elsevier B.V.

  11. A Modern Update and Usage of Historical Variable Star Catalogs

    NASA Astrophysics Data System (ADS)

    Pagnotta, Ashley; Graur, Or; Murray, Zachary; Kruk, Julia; Christie-Dervaux, Lucien; Chen, Dong Yi

    2015-01-01

    One of the earliest modern variable star catalogs was constructed by Henrietta Swan Leavitt during her tenure at the Harvard College Observatory (HCO) in the early 1900s. Originally published in 1908, Leavitt's catalog listed 1777 variables in the Magellanic Clouds (MCs). The construction and analysis of this catalog allowed her to subsequently discover the Cepheid period-luminosity relationship, now known as the Leavitt Law. The MC variable star catalogs were updated and expanded by Cecilia Payne-Gaposchkin in 1966 and 1971. Although newer studies of the MC variables have been performed since then, the new information has not always been correlated with the old due to a lack of modern descriptors of the stars listed in the Harvard MC catalogs. We will discuss the history of MC variable star catalogs, especially those compiled using the HCO plates, as well as our modernized version of the Leavitt and Payne-Gaposchkin catalogs. Our modern catalog can be used in conjunction with the archival plates (primarily via the Digital Access to a Sky Century @ Harvard scanning project) to study the secular behavior of the MC variable stars over the past century.

  12. Epigenetics and child abuse: Modern-day Darwinism--The miraculous ability of the human genome to adapt, and then adapt again.

    PubMed

    Gershon, Naomi B; High, Pamela C

    2015-12-01

    It has long been recognized that early adversity can have life-long consequences, and the extent to which this is true is gaining increasing attention. A growing body of literature implicates Adverse Childhood Experiences, including physical, sexual, and emotional abuse, in a broad range of negative health consequences including adult psychopathology, cardiovascular, and immune disease. Increasing evidence from animal, clinical, and epidemiological studies highlight the critical role of epigenetic programing, such as DNA methylation and histone modification, in altering gene expression, brain structure and function, and ultimately life-course trajectories. This review outlines our developing insight into the interplay between our human biology and our changing environment, and explores the growing evidence base for how interventions may prevent and ameliorate damage inflicted by toxic stress in early life. © 2015 Wiley Periodicals, Inc.

  13. Testing for Archaic Hominin Admixture on the X Chromosome: Model Likelihoods for the Modern Human RRM2P4 Region From Summaries of Genealogical Topology Under the Structured Coalescent

    PubMed Central

    Cox, Murray P.; Mendez, Fernando L.; Karafet, Tatiana M.; Pilkington, Maya Metni; Kingan, Sarah B.; Destro-Bisol, Giovanni; Strassmann, Beverly I.; Hammer, Michael F.

    2008-01-01

    A 2.4-kb stretch within the RRM2P4 region of the X chromosome, previously sequenced in a sample of 41 globally distributed humans, displayed both an ancient time to the most recent common ancestor (e.g., a TMRCA of ∼2 million years) and a basal clade composed entirely of Asian sequences. This pattern was interpreted to reflect a history of introgressive hybridization from archaic hominins (most likely Asian Homo erectus) into the anatomically modern human genome. Here, we address this hypothesis by resequencing the 2.4-kb RRM2P4 region in 131 African and 122 non-African individuals and by extending the length of sequence in a window of 16.5 kb encompassing the RRM2P4 pseudogene in a subset of 90 individuals. We find that both the ancient TMRCA and the skew in non-African representation in one of the basal clades are essentially limited to the central 2.4-kb region. We define a new summary statistic called the minimum clade proportion (pmc), which quantifies the proportion of individuals from a specified geographic region in each of the two basal clades of a binary gene tree, and then employ coalescent simulations to assess the likelihood of the observed central RRM2P4 genealogy under two alternative views of human evolutionary history: recent African replacement (RAR) and archaic admixture (AA). A molecular-clock-based TMRCA estimate of 2.33 million years is a statistical outlier under the RAR model; however, the large variance associated with this estimate makes it difficult to distinguish the predictions of the human origins models tested here. The pmc summary statistic, which has improved power with larger samples of chromosomes, yields values that are significantly unlikely under the RAR model and fit expectations better under a range of archaic admixture scenarios. PMID:18202385

  14. Culture effects on adults' earliest childhood recollection and self-description: implications for the relation between memory and the self.

    PubMed

    Wang, Q

    2001-08-01

    American and Chinese college students (N = 256) reported their earliest childhood memory on a memory questionnaire and provided self-descriptions on a shortened 20 Statements Test (M. H. Kuhn & T. S. McPartland, 1954). The average age at earliest memory of Americans was almost 6 months earlier than that of Chinese. Americans reported lengthy, specific, self-focused, and emotionally elaborate memories; they also placed emphasis on individual attributes in describing themselves. Chinese provided brief accounts of childhood memories centering on collective activities, general routines, and emotionally neutral events; they also included a great number of social roles in their self-descriptions. Across the entire sample, individuals who described themselves in more self-focused and positive terms provided more specific and self-focused memories. Findings are discussed in light of the interactive relation between autobiographical memory and cultural self-construal.

  15. Repeated diffusion MRI reveals earliest time point for stratification of radiotherapy response in brain metastases

    NASA Astrophysics Data System (ADS)

    Mahmood, Faisal; Johannesen, Helle H.; Geertsen, Poul; Hansen, Rasmus H.

    2017-04-01

    An imaging biomarker for early prediction of treatment response potentially provides a non-invasive tool for better prognostics and individualized management of the disease. Radiotherapy (RT) response is generally related to changes in gross tumor volume manifesting months later. In this prospective study we investigated the apparent diffusion coefficient (ADC), perfusion fraction and pseudo diffusion coefficient derived from diffusion weighted MRI as potential early biomarkers for radiotherapy response of brain metastases. It was a particular aim to assess the optimal time point for acquiring the DW-MRI scan during the course of treatment, since to our knowledge this important question has not been addressed directly in previous studies. Twenty-nine metastases (N  =  29) from twenty-one patients, treated with whole-brain fractionated external beam RT were analyzed. Patients were scanned with a 1 T MRI system to acquire DW-, T2*W-, T2W- and T1W scans, before start of RT, at each fraction and at follow up two to three months after RT. The DW-MRI parameters were derived using regions of interest based on high b-value images (b  =  800 s mm-2). Both volumetric and RECIST criteria were applied for response evaluation. It was found that in non-responding metastases the mean ADC decreased and in responding metastases it increased. The volume based response proved to be far more consistently predictable by the ADC change found at fraction number 7 and later, compared to the linear response (RECIST). The perfusion fraction and pseudo diffusion coefficient did not show sufficient prognostic value with either response assessment criteria. In conclusion this study shows that the ADC derived using high b-values may be a reliable biomarker for early assessment of radiotherapy response for brain metastases patients. The earliest response stratification can be achieved using two DW-MRI scans, one pre-treatment and one at treatment day 7-9 (equivalent to 21 Gy).

  16. Comparing the composition of the earliest basalts erupted by the Iceland and Afar mantle plumes.

    NASA Astrophysics Data System (ADS)

    Stuart, Finlay M.

    2013-04-01

    The first basalts erupted by mantle plumes are typically generated by mantle melting at temperatures 200-300°C higher than average ambient mantle. This is consistent with the derivation of from a thermal boundary layer at the core-mantle boundary. Mantle plume temperatures decrease with time, likely as large plume heads give way to thin plume conduits. Consequently the early, hot plume basalts are a window into the deep mantle. At it's simplest they provide a test of whether the discrete plume source regions are primordial mantle that have been isolated since soon after Earth accretion, or have substantial contributions from subducted slabs. Here I present new isotopic and trace element determinations of the earliest picritic basalts from the ~30 Ma Afar plume in Ethiopia. They will be compared with similar material from the ~60 Ma proto-Iceland plume (PIP) in an effort to test prevailing models regarding the source of mantle plumes. The extremely primordial nature of the helium in the PIP picrites (3He/4He ~ 50 Ra) contrasts with much lower values of the Ethiopian flood basalt province (~21 Ra). The Iceland plume 3He/4He has decreased (linearly) with time, mirroring the secular cooling of the Iceland mantle plume identified by decreasing MgO and FeO in primary melts. In 60 million years the Iceland plume 3He/4He is still higher than the maximum Afar plume value. The Sr-Nd-Pb isotopic composition of the high 3He/4He Ethiopian flood basalt province picrites are remarkably homogenous (e.g. 87Sr/86Sr = 0.70396-0.70412; 206Pb/204Pb = 18.82-19.01). In comparison the PIP picrites have ranges that span nearly the global range of E-MORB and N-MORB. The Afar and proto-Iceland mantle plumes are clearly not initiated in a single deep mantle domain with the same depletion/enrichment and degassing histories, and the same scale of heterogeneity. This implies that there is more than one plume source region/mechanism that is capable of generating comparable volumes of basalt melt

  17. Mineralogical, crystallographic and redox features of the earliest stages of fluid alteration in CM chondrites

    NASA Astrophysics Data System (ADS)

    Pignatelli, Isabella; Marrocchi, Yves; Mugnaioli, Enrico; Bourdelle, Franck; Gounelle, Matthieu

    2017-07-01

    The CM chondrites represent the largest group of hydrated meteorites and span a wide range of conditions, from less altered (i.e., CM2) down to heavily altered (i.e., CM1). The Paris chondrite is considered the least altered CM and thus enables the earliest stages of aqueous alteration processes to be deciphered. Here, we report results from a nanoscale study of tochilinite/cronstedtite intergrowths (TCIs) in Paris-TCIs being the emblematic secondary mineral assemblages of CM chondrites, formed from the alteration of Fe-Ni metal beads (type-I TCIs) and anhydrous silicates (type-II TCIs). We combined high-resolution transmission electron microscopy, scanning transmission X-ray microscopy and electron diffraction tomography to characterize the crystal structure, crystal chemistry and redox state of TCIs. The data obtained are useful to reconstruct the alteration conditions of Paris and to compare them with those of other meteorites. Our results show that tochilinite in Paris is characterized by a high hydroxide layer content (n = 2.1-2.2) regardless of the silicate precursors. When examined alongside other CMs, it appears that the hydroxide layer and iron contents of tochilinites correlate with the degree of alteration experienced by the chondrites. The Fe3+/ΣFe ratios of TCIs are high: 8-15% in tochilinite, 33-60% in cronstedtite and 70-80% in hydroxides. These observations suggest that alteration of CM chondrites took place under oxidizing conditions that could have been induced by significant H2 release during serpentinization. Similar results were recently reported in CR chondrites (Le Guillou et al., 2015), suggesting that the process(es) controlling the redox state of the secondary mineral assemblages were quite similar in the CM and CR parent bodies despite the different alteration conditions. According to our mineralogical and crystallographic survey, the formation of TCIs in Paris occurred at temperatures lower than 100 °C, under neutral, slightly alkaline

  18. Modern Chinese: History and Sociolinguistics.

    ERIC Educational Resources Information Center

    Chen, Ping

    This book presents a comprehensive and up-to-date account of the development of modern Chinese from the late 19th century up to the 1990s, concentrating on three major aspects: modern spoken Chinese, modern written Chinese, and the modern Chinese writing system. It describes and analyzes in detail, from historical and sociolinguistic perspectives,…

  19. Parturition lines in modern human wisdom tooth roots: do they exist, can they be characterized and are they useful for retrospective determination of age at first reproduction and/or inter-birth intervals?

    PubMed

    Dean, M Christopher; Elamin, Fadil

    2014-01-01

    Parturition lines have been described in the teeth of a number of animals, including primates, but never in modern humans. These accentuated lines in dentine are comprised of characteristic dark and light component zones. The aim of this study was to review the physiology underlying these lines and to ask if parturition lines exist in the third molar tooth roots of mothers known to have had one or more children during their teenage years. Brief retrospective oral medical obstetric histories were taken from four mothers and compared with histological estimates for the timing of accentuated markings visible in longitudinal ground sections of their wisdom teeth. Evidence of accentuated markings in M3 root dentine matched the age of the mother at the time their first child was born reasonably well. However, the dates calculated for inter-birth intervals did not match well. Parturition lines corresponding to childbirth during the teenage years can exist in human M3 roots, but may not always do so. Without a written medical history it would not be possible to say with confidence that an accentuated line in M3 root dentine was caused by stress, illness or was a parturition line.

  20. Auxosporulation in Paralia guyana MacGillivary (Bacillariophyta) and Possible New Insights into the Habit of the Earliest Diatoms

    PubMed Central

    Kaczmarska, Irena; Ehrman, James M.

    2015-01-01

    Background Diatoms are one of the most ecologically important aquatic micro-eukaryotes. As a group unambiguously recognized as diatoms, they seem to have appeared relatively recently with a limited record of putative remains from oldest sediments. In contrast, molecular clock estimates for the earliest possible emergence of diatoms suggest a considerably older date. Depending on the analysis, Paralia and Leptocylindrus have been recovered within the basal molecular divergences of diatoms. Thus these genera may be in the position to inform on characters that the earliest diatoms possessed. Findings Here we present auxospore development and structure of initial and post-auxospore cells in a representative of the ancient non-polar centric genus Paralia. Their initial frustules showed unusual, but not unprecedented, spore-like morphology. Similarly, initial frustules of Leptocylindrus have been long considered resting spores and a unique peculiarity of this genus. However, even though spore-like in appearance, initial cells of Paralia readily resumed mitotic divisions. In addition, Paralia post-auxospore cells underwent several rounds of mitoses in a multi-step process of building a typical, “perfect” vegetative valve. This degree of heteromorphy immediately post-auxosporulation is thus far unknown among the diatoms. Implications A spore-related origin of diatoms has already been considered, most recently in the form of the “multiplate diploid cyst” hypothesis. Our discovery that the initial cells in some of the most ancient diatom lineages are structurally spore-like is consistent with that hypothesis because the earliest diatoms may be expected to look somewhat similar to their ancestors. We speculate that because the earliest diatoms may have appeared less diatom-like and more spore-like, they could have gone unrecognized as such in the Triassic/Jurassic sediments. If correct, diatoms may indeed be much older than the fossil record indicates, and possibly

  1. An early history of human breast cancer: West meets East.

    PubMed

    Yan, Shou-He

    2013-09-01

    Cancer has been increasingly recognized as a global issue. This is especially true in countries like China, where cancer incidence has increased likely because of changes in environment and lifestyle. However, cancer is not a modern disease; early cases have been recorded in ancient medical books in the West and in China. Here, we provide a brief history of cancer, focusing on cancer of the breast, and review the etymology of ai, the Chinese character for cancer. Notable findings from both Western and Chinese traditional medicine are presented to give an overview of the most important, early contributors to our evolving understanding of human breast cancer. We also discuss the earliest historical documents to record patients with breast cancer.

  2. Review series on helminths, immune modulation and the hygiene hypothesis: Immunity against helminths and immunological phenomena in modern human populations: coevolutionary legacies?

    PubMed Central

    Jackson, Joseph A; Friberg, Ida M; Little, Susan; Bradley, Janette E

    2009-01-01

    Although the molecules and cells involved in triggering immune responses against parasitic worms (helminths) remain enigmatic, research has continued to implicate expansions of T-helper type 2 (Th2) cells and regulatory T-helper (Treg) cells as a characteristic response to these organisms. An intimate association has also emerged between Th2 responses and wound-healing functions. As helminth infections in humans are associated with a strong Th2/Treg immunoregulatory footprint (often termed a ‘modified Th2’ response), plausible links have been made to increased susceptibility to microbial pathogens in helminth-infected populations in the tropics and to the breakdowns in immunological control (allergy and autoimmunity) that are increasing in frequency in helminth-free developed countries. Removal of helminths and their anti-inflammatory influence may also have hazards for populations exposed to infectious agents, such as malaria and influenza, whose worst effects are mediated by excessive inflammatory reactions. The patterns seen in the control of helminth immunity are discussed from an evolutionary perspective. Whilst an inability to correctly regulate the immune system in the absence of helminth infection might seem highly counter-adaptive, the very ancient and pervasive relationship between vertebrates and helminths supports a view that immunological control networks have been selected to function within the context of a modified Th2 environment. The absence of immunoregulatory stimuli from helminths may therefore uncover maladaptations that were not previously exposed to selection. PMID:19120495

  3. Early-Modern "Speech" Marks

    ERIC Educational Resources Information Center

    Blackburn, Nick

    2011-01-01

    This essay presents a revised history of the punctuation mark ["], drawn from the earliest communities who made it their own. By situating the development of ["] in its historical context, from first uses of the diple [diple] by the Greek scholar Aristarchus, it explains how it was the general applications which persisted into the sixteenth…

  4. Modern NMR Spectroscopy.

    ERIC Educational Resources Information Center

    Jelinski, Lynn W.

    1984-01-01

    Discusses direct chemical information that can be obtained from modern nuclear magnetic resonance (NMR) methods, concentrating on the types of problems that can be solved. Shows how selected methods provide information about polymers, bipolymers, biochemistry, small organic molecules, inorganic compounds, and compounds oriented in a magnetic…

  5. Modern Languages and Antiracism.

    ERIC Educational Resources Information Center

    O'Shaughnessy, Martin

    1988-01-01

    Discusses a school language department's antiracist/multicultural policy for modern languages. The policy stresses the need for a multicultural curriculum, exploration of racism, acceptance of all languages, recognition of specialized knowledge, and positive images of people from ethnic minority groups. (CB)

  6. [Modern magic and medicine].

    PubMed

    Prokop, O

    1975-01-01

    In a paper presented on the occasion of the 5th Congress of gynecology in the GDR the author discusses in details the phenomenon of modern occultism and quackery. Preferably he examines the so called parapsychology and declares that this is a field without any scientific value. Therefore the course of action of parapsychologists is not to be accepted without resolute reply.

  7. Modern Versus Traditional Mathematics

    ERIC Educational Resources Information Center

    Roberts, A. M.

    1974-01-01

    The effect of different secondary school mathematics syllabi on first-year performance in college-level mathematics was studied in an attempt to evaluate the syllabus change. Students with a modern mathematics background performed sigficantly better on most first-year units. A topic-by-topic analysis of results is included. (DT)

  8. Meta Modernism: An Introduction

    ERIC Educational Resources Information Center

    Snell, Joel

    2016-01-01

    The author introduces Hegel. From the triad (Hegelian Dialect), he briefly gives an overview of the history of philosophy. In true Hegelian form, it is now time to reform "Postmodernism" and replace it with "Meta modernism." Postmodern had a short life from 1950 to now and has left few adherents. It is confusing and…

  9. Modern vs. Traditional.

    ERIC Educational Resources Information Center

    Zhenhui, Rao

    1999-01-01

    This article discusses traditional methods, such as the grammar-translation, and modern methods, the communicative approach, for teaching English-as-a-foreign-language in China. The relationship between linguistic accuracy and communicative competence, student-centered orientation, and the role of the teacher are highlighted. (Author/VWL)

  10. Gnotobiology in modern medicine

    NASA Technical Reports Server (NTRS)

    Podoprigora, G. I.

    1980-01-01

    A review is given of currently accepted theories and applications of gnotobiology. A brief history of gnotobiology is supplied. Problems involved in creating germ-free gnotobiota and the use of these animals in experimental biology are cited. Examples of how gnotobiology is used in modern medical practice illustrate the future prospects for this area of science.

  11. Rail Modernization Study

    DOT National Transportation Integrated Search

    1987-04-01

    This study summarizes the results of a multi-year assessment of the rail transit and commuter rail systems. The work was based on an earlier study design effort. The purposes of the study were to determine the costs of upgrading and modernizing urban...