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1

The taxonomic implications of cranial shape variation in Homo erectus  

Microsoft Academic Search

The taxonomic status of Homo erectus sensu lato has been a source of debate since the early 1980s, when a series of publications suggested that the early African fossils may represent a separate species, H. ergaster. To gain further resolution regarding this debate, 3D geometric morphometric data were used to quantify overall shape variation in the cranial vault within H.

Karen L. Baab

2008-01-01

2

Latest Homo erectus of Java: Potential Contemporaneity with Homo sapiens in Southeast Asia  

Microsoft Academic Search

Hominid fossils from Ngandong and Sambungmacan, Central Java, are considered the most morphologically advanced representatives of Homo erectus. Electron spin resonance (ESR) and mass spectrometric U-series dating of fossil bovid teeth collected from the hominid-bearing levels at these sites gave mean ages of 27 ± 2 to 53.3 ± 4 thousand years ago; the range in ages reflects uncertainties in

C. C. Swisher III; W. J. Rink; S. C. Anton; H. P. Schwarcz; G. H. Curtis; A. Suprijo; Widiasmoro

1996-01-01

3

Three new Homo erectus mandibles from Java  

Microsoft Academic Search

There are now eleven manidublar pieces from the Lower and Middle Pleistocene of Java, all but one being from the Sangiran\\u000a site. All of these have been assigned toHomo erectus by most workers, while others have suggested as many as four different hominoid taxa. Sangiran 21 (Mandible E), Sangiran\\u000a 22 (Mandible F), and Sangiran 37 (Mandible G) are described here

D. E. Tyler

2001-01-01

4

New 1.5 million-year-old Homo erectus maxilla from Sangiran (Central Java, Indonesia)  

Microsoft Academic Search

Sangiran (Solo Basin, Central Java, Indonesia) is the singular Homo erectus fossil locale for Early Pleistocene Southeast Asia. Sangiran is the source for more than 80 specimens in deposits with 40Ar\\/39Ar ages of 1.51–0.9 Ma. In April 2001, we recovered a H. erectus left maxilla fragment (preserving P3- M2) from the Sangiran site of Bapang. The find spot lies at the base

Yahdi Zaim; Russell L. Ciochon; Joshua M. Polanski; Frederick E. Grine; E. Arthur Bettis; Yan Rizal; Robert G. Franciscus; Roy R. Larick; Matthew Heizler; Aswan; K. Lindsay Eaves; Hannah E. Marsh

2011-01-01

5

Remains of Homo erectus from Bouri, Middle Awash, Ethiopia  

Microsoft Academic Search

The genesis, evolution and fate of Homo erectus have been explored palaeontologically since the taxon's recognition in the late nineteenth century. Current debate is focused on whether early representatives from Kenya and Georgia should be classified as a separate ancestral species (`H. ergaster'), and whether H. erectus was an exclusively Asian species lineage that went extinct. Lack of resolution of

Berhane Asfaw; W. Henry Gilbert; Yonas Beyene; William K. Hart; Paul R. Renne; Giday WoldeGabriel; Elisabeth S. Vrba; Tim D. White

2002-01-01

6

New 1.5 million-year-old Homo erectus maxilla from Sangiran (Central Java, Indonesia).  

PubMed

Sangiran (Solo Basin, Central Java, Indonesia) is the singular Homo erectus fossil locale for Early Pleistocene Southeast Asia. Sangiran is the source for more than 80 specimens in deposits with (40)Ar/(39)Ar ages of 1.51-0.9 Ma. In April 2001, we recovered a H. erectus left maxilla fragment (preserving P(3)- M(2)) from the Sangiran site of Bapang. The find spot lies at the base of the Bapang Formation type section in cemented gravelly sands traditionally called the Grenzbank Zone. Two meters above the find spot, pumice hornblende has produced an (40)Ar/(39)Ar age of 1.51 ± 0.08 Ma. With the addition of Bpg 2001.04, Sangiran now has five H. erectus maxillae. We compare the new maxilla with homologs representing Sangiran H. erectus, Zhoukoudian H. erectus, Western H. erectus (pooled African and Georgian specimens), and Homo habilis. Greatest contrast is with the Zhoukoudian maxillae, which appear to exhibit a derived pattern of premolar-molar relationships compared to Western and Sangiran H. erectus. The dental patterns suggest distinct demic origins for the earlier H. erectus populations represented at Sangiran and the later population represented at Zhoukoudian. These two east Asian populations, separated by 5000 km and nearly 800 k.yr., may have had separate origins from different African/west Eurasian populations. PMID:21783226

Zaim, Yahdi; Ciochon, Russell L; Polanski, Joshua M; Grine, Frederick E; Bettis, E Arthur; Rizal, Yan; Franciscus, Robert G; Larick, Roy R; Heizler, Matthew; Aswan; Eaves, K Lindsay; Marsh, Hannah E

2011-10-01

7

A new Homo erectus cranium from Sangiran, Java  

Microsoft Academic Search

A newHomo erectus cranium was found on May 18, 1993 by Budi, a local farmer, at Sangiran. It dates from the Middle Pucangan Formation approximately\\u000a 1.6–1.8 mya. The braincase is essentially complete and as is most of the face. The vault has the typicalH. erectus gable shape. There is a clear sagittal ridge beginning below the middle of the frontal

D. E. Tyler; S. Sartono

2001-01-01

8

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

PubMed

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

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

2014-07-01

9

A neonatal perspective on Homo erectus brain growth.  

PubMed

The Mojokerto calvaria has been central to assessment of brain growth in Homo erectus, but different analytical approaches and uncertainty in the specimen's age at death have hindered consensus on the nature of H. erectus brain growth. We simulate average annual rates (AR) of absolute endocranial volume (ECV) growth and proportional size change (PSC) in H. erectus, utilizing estimates of H. erectus neonatal ECV and a range of ages for Mojokerto. These values are compared with resampled ARs and PSCs from ontogenetic series of humans, chimpanzees, and gorillas from birth to six years. Results are consistent with other studies of ECV growth in extant taxa. There is extensive overlap in PSC between all living species through the first postnatal year, with continued but lesser overlap between humans and chimpanzees to age six. Human ARs are elevated above those of apes, although there is modest overlap up to 0.50 years. Ape ARs overlap throughout the sequence, with gorillas slightly elevated over chimpanzees up to 0.50 years. Simulated H. erectus PSCs can be found in all living species by 0.50 years, and the median falls below the human and chimpanzee ranges after 2.5 years. H. erectus ARs are elevated above those of all extant taxa prior to 0.50 years, and after two years they fall out of the human range but are still above ape ranges. A review of evidence for the age at death of Mojokerto supports an estimate of around one year, indicating absolute brain growth rates in the lower half of the human range. These results point to secondary altriciality in H. erectus, implying that key human adaptations for increasing the energy budget of females may have been established by at least 1 Ma. PMID:25771994

Cofran, Zachary; DeSilva, Jeremy M

2015-04-01

10

Human taxonomic diversity in the pleistocene: does Homo erectus represent multiple hominid species?  

PubMed

Recently, nomina such as "Homo heidelbergensis" and "H. ergaster" have been resurrected to refer to fossil hominids that are perceived to be specifically distinct from Homo sapiens and Homo erectus. This results in a later human fossil record that is nearly as speciose as that documenting the earlier history of the family Hominidae. However, it is agreed that there remains only one extant hominid species: H. sapiens. Has human taxonomic diversity been significantly pruned over the last few hundred millennia, or have the number of taxa been seriously overestimated? To answer this question, the following null hypothesis is tested: polytypism was established relatively early and the species H. erectus can accommodate all spatio-temporal variation from ca. 1.7 to 0.5 Ma. A disproof of this hypothesis would suggest that modern human polytypism is a very recent phenomenon and that speciation throughout the course of human evolution was the norm and not the exception. Cranial variation in a taxonomically mixed sample of fossil hominids, and in a modern human sample, is analyzed with regard to the variation present in the fossils attributed to H. erectus. The data are examined using both univariate (coefficient of variation) and multivariate (determinant) analyses. Employing randomization methodology to offset the small size and non-normal distribution of the fossil samples, the CV and determinant results reveal a pattern and degree of variation in H. erectus that most closely approximates that of the single species H. sapiens. It is therefore concluded that the null hypothesis cannot be rejected. PMID:8317558

Kramer, A

1993-06-01

11

Palaeolithic chronology and possible coexistence of Homo erectus and Homo sapiens in China  

Microsoft Academic Search

The dating results of twenty?five Chinese palaeolithic and palaeoanthropological sites are summarized. Palaeomagnetism, Uranium?series and radiocarbon are the three main dating techniques used in establishing the chronology. The paper discusses the reliability of dating results, correlation between climate and the age distribution of sites, and the possible coexistence of Homo erectus and Homo sapiens.

Chen Tiemei; Zhang Yinyun

1991-01-01

12

Clavicle length, throwing performance and the reconstruction of the Homo erectus shoulder.  

PubMed

Powerful, accurate throwing may have been an important mode of early hunting and defense. Previous work has shown that throwing performance is functionally linked to several anatomical shifts in the upper body that occurred during human evolution. The final shift to occur is the inferior reorientation of the shoulder. Fossil scapulae show the earliest evidence of a more inferior glenoid in Homo erectus. However, where the scapula rests on the thorax is uncertain. The relative length of the clavicle, the only skeletal attachment of the scapula to the torso, is quite variable. Depending on which fossils or skeletal measures are used to reconstruct the H. erectus shoulder, either a novel, anteriorly facing shoulder configuration or a modern human-like lateral orientation is possible. These competing hypotheses have led to very different conclusions regarding the throwing ability and hunting behavior of early Homo. Here, we evaluate competing models of H. erectus shoulder morphology and examine how these models relate to throwing performance. To address these questions, we collected skeletal measures from fossil and extant taxa, as well as anthropometric (N = 36) and kinematic (N = 27) data from Daasanach throwers from northwestern Kenya. Our data show that all H. erectus fossil clavicles fall within the normal range of modern human variation. We find that a commonly used metric for normalizing clavicle length, the claviculohumeral ratio, poorly predicts shoulder position on the torso. Furthermore, no significant relationship between clavicle length and any measure of throwing performance was found. These data support reconstructing the H. erectus shoulder as modern human-like, with a laterally facing glenoid, and suggest that the capacity for high speed throwing dates back nearly two million years. PMID:25439706

Roach, Neil T; Richmond, Brian G

2015-03-01

13

Sangiran 5, (“Pithecanthropus dubius”), homo erectus, “Meganthropus,” or Pongo?  

Microsoft Academic Search

There are now eleven known mandibular remains from the Lower and Middle Pleistocene of Java, all but one being from the Sangiran\\u000a site. All of these have been assigned toHomo erectus by most workers, while others have suggested as many as four different hominoid taxa. The author finds that the jaws cannot\\u000a be a homogeneous sample. Morphologically, they are a

D. E. Tyler

2003-01-01

14

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

PubMed

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

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

2015-02-12

15

Solo man in question: Convergent views to split Indonesian Homo erectus in two categories  

Microsoft Academic Search

Between the famous Man of Java and the new star of paleoanthropology id est the Man of Flores, embedded in the bank of the river Solo or in the shadow of the volcanoes of Sangiran, Homo erectus remains apart. Driven from evolved Homo erectus to archaic Homo sapiens, for a long time Solo man did not find a real place

Valery Zeitoun; Florent Détroit; Dominique Grimaud-Hervé; Harry Widianto

2010-01-01

16

Les assemblages fauniques associés aux sites à Homo erectus du dôme de Sangiran (Pléistocène moyen, Java, Indonésie)  

Microsoft Academic Search

In the Sangiran dome (Central Java), Homo erectus and mammal fossils in fluviatile context are found in several open-air localities: Tanjung, Sendang Busik, Ngrejeng Plupuh, Grogol Plupuh, and Bukuran. Thirteen taxa of Middle Pleistocene mammals were determined. Lithic tools are rare at these sites. The origin and setting up of these mainly unpublished faunal assemblages are approached by means of

Anne Bouteaux; Anne-Marie Moigne; François Sémah; Teuku Jacob

2007-01-01

17

An examination of the taxonomic status of the fragmentary mandible Sangiran 5, ( Pithecanthropus dubius), Homo erectus, “ Meganthropus”, or Pongo?  

Microsoft Academic Search

There are 12 known mandibular fossils from the Lower and Middle Pleistocene of Java, all but two from the Sangiran Dome region. All of these have been assigned at various times to Homo erectus, but the same specimens have been said by others to represent as many as four different hominoid taxa. This is not, however, the finding of this

D. E. Tyler

2004-01-01

18

Étude taphonomique d’assemblages fauniques de sites à Homo erectus du dôme de Sangiran (Pléistocène moyen, Java central, Indonésie)  

Microsoft Academic Search

Since the sixties, the National Indonesian Center for Archaeological Research, in collaboration with the Gajah Mada University, organizes field excavations on open-air sites in the Sangiran dome, one of the most famous places of palaeoanthropological discoveries in Southeast Asia. That project led to the discovery of Homo erectus more or less fragmentary fossils, and to the collection of numerous mammal

Anne Bouteaux

2008-01-01

19

Structural analysis of the Kresna 11 Homo erectus femoral shaft (Sangiran, Java).  

PubMed

The biomechanical characterization of lower limb long bones in the chrono-ecogeographically diverse species Homo erectus is a fundamental step for assessing evolutionary changes in locomotor mode and body shape that occurred within the genus Homo. However, the samples available for the Early and earlier Middle Pleistocene are small and widely scattered in time and space, thus limiting our understanding of the nature and polarity of morphological trends. Compared to the African fossil record, loading histories based on detailed biomechanical assessment of diaphyseal strength in Indonesian H. erectus lower limb long bones have not been assessed. By using a microtomographic record (?CT), we performed a quantitative analysis of the biomechanical properties and structural organization of Kresna 11, a late Early Pleistocene adult H. erectus femoral shaft from the Sangiran Dome, Central Java. Relative to the modern human condition, Kresna 11 shows the predominant mediolateral cortical thickening (hypertrophy) and the distal displacement of the minimum diaphyseal breadth characteristic of early Homo femora, associated nonetheless with relatively modest cortical thickness within the mid-proximal portion. Synthetic functional imaging of the shaft through the planar representation of its inner structure has revealed distal thickening of the medial cortex, a feature previously unreported in H. erectus. The increase in relative mediolateral bending strength observed in Kresna 11 supports the hypothesis that, rather than simply reflecting differences in patterns of locomotor loading, biomechanical properties of the femoral shaft in archaic Homo are strongly influenced by body shape, i.e., variations in pelvic breadth and femoral neck length. PMID:23036460

Puymerail, Laurent; Ruff, Christopher B; Bondioli, Luca; Widianto, Harry; Trinkaus, Erik; Macchiarelli, Roberto

2012-11-01

20

Molar crown inner structural organization in Javanese Homo erectus.  

PubMed

This contribution investigates the inner organizational pattern (tooth tissue proportions and enamel-dentine junction morphology) of seven Homo erectus permanent molar crowns from the late Lower-early Middle Pleistocene Kabuh Formation of the Sangiran Dome (Central Java, Indonesia). The previous study of their external characteristics confirmed the degree of time-related structural reduction occurred in Javanese H. erectus, and also revealed a combination of nonmetric features which are rare in the Lower and early Middle Pleistocene dental record, but more frequently found in recent humans. In accordance with their outer occlusal morphology, the specimens exhibit a set of derived internal features, such as thick to hyperthick enamel, an incomplete expression of the crest patterns at the enamel-dentine junction (EDJ) level, a sharp EDJ topography. As a whole, these features differ from those expressed in some penecontemporaneous specimens/samples representing African H. erectus/ergaster and H. heidelbergensis, as well as in Neanderthals, but occur in recent human populations. Further research in virtual dental paleoanthropology to be developed at macroregional scale would clarify the polarity and intensity of the intermittent exchanges between continental and insular Southeast Asia around the Lower to Middle Pleistocene boundary, as well as should shed light on the still poorly understood longitudinal evolutionary dynamics across continental Asia. PMID:25209431

Zanolli, Clément

2015-01-01

21

Shell tool use by early members of Homo erectus in Sangiran, central Java, Indonesia: cut mark evidence  

Microsoft Academic Search

Sangiran has been known as a source of fossil Homo erectus but is better known for the absence of archaeological tools. Cut mark analysis of Pleistocene mammalian fossils documents 18 cut marks inflicted by tools of thick clamshell flakes on two bovid bones created during butchery at the Pucangan Formation in Sangiran between 1.6 and 1.5million years ago. These cut

Kildo Choi; Dubel Driwantoro

2007-01-01

22

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

23

Dated co-occurrence of Homo erectus and Gigantopithecus from Tham Khuyen Cave, Vietnam.  

PubMed Central

Tham Khuyen Cave (Lang Son Province, northern Vietnam) is one of the more significant sites to yield fossil vertebrates in east Asia. During the mid-1960s, excavation in a suite of deposits produced important hominoid dental remains of middle Pleistocene age. We undertake more rigorous analyses of these sediments to understand the fluvial dynamics of Pleistocene cave infilling as they determine how skeletal elements accumulate within Tham Khuyen and other east Asian sites. Uranium/thorium series analysis of speleothems brackets the Pleistocene chronology for breaching, infilling, and exhuming the regional paleokarst. Clast analysis indicates sedimentary constituents, including hominoid teeth and cranial fragments accumulated from very short distances and under low fluvial energy. Electron spin resonance analysis of vertebrate tooth enamel and sediments shows that the main fossil-bearing suite (S1-S3) was deposited about 475 thousand years ago. Among the hominoid teeth excavated from S1-S3, some represent Homo erectus and Gigantopithecus blacki. Criteria are defined to differentiate these teeth from more numerous Pongo pygmaeus elements. The dated co-occurrence of Homo erectus and Gigantopithecus blacki at Tham Khuyen helps to establish the long co-existence of these two species throughout east Asia during the Early and Middle Pleistocene. Images Fig. 1 Fig. 2 PMID:8610161

Ciochon, R; Long, V T; Larick, R; González, L; Grün, R; de Vos, J; Yonge, C; Taylor, L; Yoshida, H; Reagan, M

1996-01-01

24

Dated co-occurrence of Homo erectus and Gigantopithecus from Tham Khuyen Cave, Vietnam.  

PubMed

Tham Khuyen Cave (Lang Son Province, northern Vietnam) is one of the more significant sites to yield fossil vertebrates in east Asia. During the mid-1960s, excavation in a suite of deposits produced important hominoid dental remains of middle Pleistocene age. We undertake more rigorous analyses of these sediments to understand the fluvial dynamics of Pleistocene cave infilling as they determine how skeletal elements accumulate within Tham Khuyen and other east Asian sites. Uranium/thorium series analysis of speleothems brackets the Pleistocene chronology for breaching, infilling, and exhuming the regional paleokarst. Clast analysis indicates sedimentary constituents, including hominoid teeth and cranial fragments accumulated from very short distances and under low fluvial energy. Electron spin resonance analysis of vertebrate tooth enamel and sediments shows that the main fossil-bearing suite (S1-S3) was deposited about 475 thousand years ago. Among the hominoid teeth excavated from S1-S3, some represent Homo erectus and Gigantopithecus blacki. Criteria are defined to differentiate these teeth from more numerous Pongo pygmaeus elements. The dated co-occurrence of Homo erectus and Gigantopithecus blacki at Tham Khuyen helps to establish the long co-existence of these two species throughout east Asia during the Early and Middle Pleistocene. PMID:8610161

Ciochon, R; Long, V T; Larick, R; González, L; Grün, R; de Vos, J; Yonge, C; Taylor, L; Yoshida, H; Reagan, M

1996-04-01

25

Dating the Homo erectus bearing travertine from Kocaba? (Denizli, Turkey) at at least 1.1 Ma  

NASA Astrophysics Data System (ADS)

Since its discovery within a travertine quarry, the fragmentary cranium of the only known Turkish Homo erectus, the Kocaba? hominid, has led to conflicting biochronological estimations. First estimated to be ˜500 ka old, the partial skull presents a combination of archaic and evolved features that puts it as an intermediate specimen between the Dmanisi fossils (Homo georgicus) and the Chinese Zhoukoudian skulls (Homo erectus) respectively dated to 1.8 to ˜0.8 Ma. Here we present a multidisciplinary study combining sedimentological, paleontological and paleoanthropological observations together with cosmogenic nuclide concentration and paleomagnetic measurements to provide an absolute chronological framework for the Upper fossiliferous Travertine unit where the Kocaba? hominid and fauna were discovered. The 26Al/10Be burial ages determined on pebbles from conglomeratic levels framing the Upper fossiliferous Travertine unit, which exhibits an inverse polarity, constrains its deposition to before the Cobb Mountain sub-chron, that is between 1.22 and ˜1.5 Ma. The alternative match of the normal polarity recorded above the travertine with the Jaramillo subchron (lower limit 1.07 Ma) may also be marginally compatible with cosmogenic nuclides interpretation, thus the proposed minimum age of 1.1 Ma for the end of massive travertine deposition. The actual age of the fossils is likely to be in the 1.1-1.3 Ma range. This absolute date is in close agreement with the paleoanthropological conclusions based on morphometric comparisons implying that Kocaba? hominid belongs to the Homo erectus s.l. group that includes Chinese and African fossils, and is different from Middle and Upper Pleistocene specimens. Furthermore, this date is confirmed by the large mammal assemblage, typical of the late Villafranchian. Because it attests to the antiquity of human occupation of the Anatolian Peninsula and one of the waves of settlements out of Africa, this work challenges the current knowledge of the Homo erectus dispersal over Eurasia.

Lebatard, Anne-Elisabeth; Alçiçek, M. Cihat; Rochette, Pierre; Khatib, Samir; Vialet, Amélie; Boulbes, Nicolas; Bourlès, Didier L.; Demory, François; Guipert, Gaspard; Mayda, Serdar; Titov, Vadim V.; Vidal, Laurence; de Lumley, Henry

2014-03-01

26

Digital modelling and stereolithographic production of a Homo Erectus skull  

Microsoft Academic Search

The National Museum of Natural History has been carrying out, over the last several years, a study of hominid fossil skulls, which have been discovered in different regions of the world. The aim of the palaeo-anthropological study of these skulls is to reconstruct the genealogic tree of the evolution of man and to understand better, the diversity of the homo

François Pérès; Farid Taha; Marie-Antoinette de Lumley; Emmanuel Cabanis

2004-01-01

27

Discovery of Postcranial Remains of Homo erectus and Associated Artefacts in Bed IV at Olduvai Gorge, Tanzania  

Microsoft Academic Search

The discovery of a left femur shaft and hip bone of Homo erectus in association with an Acheulean industry in Bed IV represents the first direct association at Olduvai of a well defined artefact assemblage with H. erectus.

M. D. Leakey

1971-01-01

28

New dating of the Homo erectus cranium from Lantian (Gongwangling), China.  

PubMed

The Homo erectus cranium from Gongwangling, Lantian County, Shaanxi Province is the oldest fossil hominin specimen from North China. It was found in 1964 in a layer below the Jaramillo subchron and was attributed to loess (L) L15 in the Chinese loess-palaeosol sequence, with an estimated age of ca. 1.15 Ma (millions of years ago). Here, we demonstrate that there is a stratigraphical hiatus in the Gongwangling section immediately below loess 15, and the cranium in fact lies in palaeosol (S) S22 or S23, the age of which is ca. 1.54-1.65 Ma. Closely spaced palaeomagnetic sampling at two sections at Gongwangling and one at Jiacun, 10 km to the north, indicate that the fossil layer at Gongwangling and a similar fossil horizon at Jiacun were deposited shortly before a short period of normal polarity above the Olduvai subchron. This is attributed to the Gilsa Event that has been dated elsewhere to ca. 1.62 Ma. Our investigations thus demonstrate that the Gongwangling cranium is slightly older than ca. 1.62 Ma, probably ca. 1.63 Ma, and significantly older than previously supposed. This re-dating now makes Gongwangling the second oldest site outside Africa (after Dmanisi) with cranial remains, and causes substantial re-adjustment in the early fossil hominin record in Eurasia. PMID:25456822

Zhu, Zhao-Yu; Dennell, Robin; Huang, Wei-Wen; Wu, Yi; Rao, Zhi-Guo; Qiu, Shi-Fan; Xie, Jiu-Bing; Liu, Wu; Fu, Shu-Qing; Han, Jiang-Wei; Zhou, Hou-Yun; Ou Yang, Ting-Ping; Li, Hua-Mei

2015-01-01

29

Way out of Africa: Early Pleistocene paleoenvironments inhabited by Homo erectus in Sangiran, Java  

Microsoft Academic Search

A sequence of paleosols in the Solo Basin, Central Java, Indonesia, documents the local and regional environments present when Homo erectus spread through Southeast Asia during the early Pleistocene. The earliest human immigrants encountered a low-relief lake-margin landscape dominated by moist grasslands with open woodlands in the driest landscape positions. By 1.5Ma, large streams filled the lake and the landscape

E. Arthur Bettis; Adrianne K. Milius; Scott J. Carpenter; Roy Larick; Yahdi Zaim; Yan Rizal; Russell L. Ciochon; Stephanie A. Tassier-Surine; Daniel Murray; Suminto; Sutinko Bronto

2009-01-01

30

Homo erectus and Middle Pleistocene hominins: brain size, skull form, and species recognition.  

PubMed

Hominins that differ from Homo erectus, the Neanderthals, and recent humans are known from Middle Pleistocene localities across the Old World. The taxonomic status of these populations has been clouded by controversy. Perhaps the most critical problem has been an incomplete understanding of variation in skull form. Here, both H. erectus and later mid-Pleistocene hominins are the focus of an investigation aimed at clarifying the relationships among brain volume, basicranial dimensions, neurocranial shape, and certain facial characters. Brain size in H. erectus averages about 950 cm(3), while in a series of Middle Pleistocene crania from Africa and Europe, volume is about 1230 cm(3). If encephalization is the primary mechanism operating in the mid-Pleistocene, then diverse aspects of cranial form cannot all be treated as independent variables. Correlation is utilized to examine the associations among measurements for more than 30 H. erectus crania that are reasonably well preserved. A similar approach is used with the Middle Pleistocene sample. Patterns of covariation are compared in order to assess integration. Next, factor analysis is applied to the H. erectus specimens in an attempt to identify modules, tightly integrated traits that can evolve independently. Studies of the variation within H. erectus are followed by direct comparisons with the Middle Pleistocene population. Discriminant functions facilitate the description of intergroup differences. Traits that vary independently from brain volume include anterior frontal broadening, lateral expansion of the parietal vault, elevation of the lambda-inion chord, and rounding of the sagittal contour of the occipital. This finding helps to resolve the problem of species recognition. Neurocranial proportions as well as characters from the cranial base and face can be incorporated into a differential diagnosis for the mid-Pleistocene sample. Evidence presented here supports arguments for speciation in the Middle Pleistocene. PMID:23850294

Rightmire, G Philip

2013-09-01

31

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

PubMed

Mandibular corpora are well represented in the hominin fossil record, yet few studies have rigorously assessed the utility of mandibular corpus morphology for species recognition, particularly with respect to the linear dimensions that are most commonly available. In this study, we explored the extent to which commonly preserved mandibular corpus morphology can be used to: (i) discriminate among extant hominid taxa and (ii) support species designations among fossil specimens assigned to the genus Homo. In the first part of the study, discriminant analysis was used to test for significant differences in mandibular corpus shape at different taxonomic levels (genus, species and subspecies) among extant hominid taxa (i.e. Homo, Pan, Gorilla, Pongo). In the second part of the study, we examined shape variation among fossil mandibles assigned to Homo (including H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster, late African H. erectus, Asian H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens). A novel randomization procedure designed for small samples (and using group 'distinctness values') was used to determine whether shape variation among the fossils is consistent with conventional taxonomy (or alternatively, whether a priori taxonomic groupings are completely random with respect to mandibular morphology). The randomization of 'distinctness values' was also used on the extant samples to assess the ability of the test to recognize known taxa. The discriminant analysis results demonstrated that, even for a relatively modest set of traditional mandibular corpus measurements, we can detect significant differences among extant hominids at the genus and species levels, and, in some cases, also at the subspecies level. Although the randomization of 'distinctness values' test is more conservative than discriminant analysis (based on comparisons with extant specimens), we were able to detect at least four distinct groups among the fossil specimens (i.e. H. sapiens, H. heidelbergensis, Asian H. erectus and a combined 'African Homo' group consisting of H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster and late African H. erectus). These four groups appear to be distinct at a level similar to, or greater than, that of modern hominid species. In addition, the mandibular corpora of H. neanderthalensis could be distinguished from those of 'African Homo', although not from those of H. sapiens, H. heidelbergensis, or the Asian H. erectus group. The results suggest that the features most commonly preserved on the hominin mandibular corpus have some taxonomic utility, although they are unlikely to be useful in generating a reliable alpha taxonomy for early African members of the genus Homo. PMID:19094183

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

2008-12-01

32

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

PubMed Central

Mandibular corpora are well represented in the hominin fossil record, yet few studies have rigorously assessed the utility of mandibular corpus morphology for species recognition, particularly with respect to the linear dimensions that are most commonly available. In this study, we explored the extent to which commonly preserved mandibular corpus morphology can be used to: (i) discriminate among extant hominid taxa and (ii) support species designations among fossil specimens assigned to the genus Homo. In the first part of the study, discriminant analysis was used to test for significant differences in mandibular corpus shape at different taxonomic levels (genus, species and subspecies) among extant hominid taxa (i.e. Homo, Pan, Gorilla, Pongo). In the second part of the study, we examined shape variation among fossil mandibles assigned to Homo(including H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster, late African H. erectus, Asian H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens). A novel randomization procedure designed for small samples (and using group ‘distinctness values’) was used to determine whether shape variation among the fossils is consistent with conventional taxonomy (or alternatively, whether a priori taxonomic groupings are completely random with respect to mandibular morphology). The randomization of ‘distinctness values’ was also used on the extant samples to assess the ability of the test to recognize known taxa. The discriminant analysis results demonstrated that, even for a relatively modest set of traditional mandibular corpus measurements, we can detect significant differences among extant hominids at the genus and species levels, and, in some cases, also at the subspecies level. Although the randomization of ‘distinctness values’ test is more conservative than discriminant analysis (based on comparisons with extant specimens), we were able to detect at least four distinct groups among the fossil specimens (i.e. H. sapiens, H. heidelbergensis, Asian H. erectus and a combined ‘African Homo’ group consisting of H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster and late African H. erectus). These four groups appear to be distinct at a level similar to, or greater than, that of modern hominid species. In addition, the mandibular corpora of H. neanderthalensis could be distinguished from those of ‘African Homo’, although not from those of H. sapiens, H. heidelbergensis, or the Asian H. erectus group. The results suggest that the features most commonly preserved on the hominin mandibular corpus have some taxonomic utility, although they are unlikely to be useful in generating a reliable alpha taxonomy for early African members of the genus Homo. PMID:19094183

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

2008-01-01

33

Growth processes in teeth distinguish modern humans from Homo erectus and earlier hominins  

Microsoft Academic Search

A modern human-like sequence of dental development, as a proxy for the pace of life history, is regarded as one of the diagnostic hallmarks of our own genus Homo. Brain size, age at first reproduction, lifespan and other life-history traits correlate tightly with dental development. Here we report differences in enamel growth that show the earliest fossils attributed to Homo

Christopher Dean; Meave G. Leakey; Donald Reid; Friedemann Schrenk; Gary T. Schwartz; Christopher Stringer; Alan Walker

2001-01-01

34

LETTER doi:10.1038/nature13962 Homo erectus at Trinil on Java used shells for tool  

E-print Network

LETTER doi:10.1038/nature13962 Homo erectus at Trinil on Java used shells for tool production .Herewereportonafossilfreshwatershellassemblage from the Hauptknochenschicht (`main bone layer') of Trinil (Java, Indonesia), the type localitys from the Pleistocene Hauptknochenschicht at Trinil on Java (ExtendedDataFigs1and2,Supplementary

Cai, Long

35

Cranial morphology of Javanese Homo erectus: New evidence for continuous evolution, specialization, and terminal extinction  

Microsoft Academic Search

Our current knowledge of the evolution of Homo during the early to middle Pleistocene is far from complete. This is not only because of the small number of fossil samples available, but also due to the scarcity of standardized datasets which are reliable in terms of landmark identification, interobserver error, and other distorting factors. This study aims to accurately describe

Yousuke Kaifu; Fachroel Aziz; Etty Indriati; Teuku Jacob; Iwan Kurniawan; Hisao Baba

2008-01-01

36

New reconstruction and morphological description of a Homo erectus cranium: Skull IX (Tjg-1993.05) from Sangiran, Central Java  

Microsoft Academic Search

Skull IX (Tjg-1993.05) was unearthed from the upper stratigraphic zone (Bapang-AG levels) of the hominin-bearing sequence in Sangiran. This remarkably complete cranial specimen of Homo erectus from the early Pleistocene of Java preserves substantial portions of the vault and face. However, the distortion present in the original reconstruction has hampered detailed documentation of its morphological characteristics. We here report a

Yousuke Kaifu; Yahdi Zaim; Hisao Baba; Iwan Kurniawan; Daisuke Kubo; Yan Rizal; Johan Arif; Fachroel Aziz

2011-01-01

37

Cranial Shape in Asian Homo erectus : Geographic, Anagenetic, and Size-Related Variation  

Microsoft Academic Search

\\u000a A strong focus on the morphological ­differences between African and Asian H. erectus has generally overshadowed variation among populations of Asian H. erectus. This study explored variation in Asian H. erectus using 3D geometric morphometric methods, examining the shape of the neurocranium, frontal bone, occipital bone and temporal\\u000a base. Analyses focused on the elucidation of geographic, temporal and size-related patterns

Karen L. Baab

38

Homo erectus in East and Southeast Asia, and the questions of the age of the species and its association with stone artifacts, with special attention to handaxe-like tools  

Microsoft Academic Search

Homo ergaster\\/Homo erectus in Africa and H. erectus in the Old World are securely associated with a toolkit of well-conceived bifacially worked implements of handaxes and cleavers of the Acheulean techno-complex. In India, the abundant handaxe–cleaver assemblages have always been attributed as the work of H. erectus on the basis of comparisons with Africa and the Old World. In 1982,

Gudrun Corvinus

2004-01-01

39

High-resolution record of the Matuyama-Brunhes transition constrains the age of Javanese Homo erectus in the Sangiran dome, Indonesia.  

PubMed

A detailed paleomagnetic study conducted in the Sangiran area, Java, has provided a reliable age constraint on hominid fossil-bearing formations. A reverse-to-normal polarity transition marks a 7-m thick section across the Upper Tuff in the Bapang Formation. The transition has three short reversal episodes and is overlain by a thick normal polarity magnetozone that was fission-track dated to the Brunhes chron. This pattern closely resembles another high-resolution Matuyama-Brunhes (MB) transition record in an Osaka Bay marine core. In the Sangiran sediments, four successive transitional polarity fields lie just below the presumed main MB boundary. Their virtual geomagnetic poles cluster in the western South Pacific, partly overlapping the transitional virtual geomagnetic poles from Hawaiian and Canary Islands' lavas, which have a mean (40)Ar/(39)Ar age of 776 ± 2 ka. Thus, the polarity transition is unambiguously the MB boundary. A revised correlation of tuff layers in the Bapang Formation reveals that the hominid last occurrence and the tektite level in the Sangiran area are nearly coincident, just below the Upper Middle Tuff, which underlies the MB transition. The stratigraphic relationship of the tektite level to the MB transition in the Sangiran area is consistent with deep-sea core data that show that the meteorite impact preceded the MB reversal by about 12 ka. The MB boundary currently defines the uppermost horizon yielding Homo erectus fossils in the Sangiran area. PMID:22106291

Hyodo, Masayuki; Matsu'ura, Shuji; Kamishima, Yuko; Kondo, Megumi; Takeshita, Yoshihiro; Kitaba, Ikuko; Danhara, Tohru; Aziz, Fachroel; Kurniawan, Iwan; Kumai, Hisao

2011-12-01

40

High-resolution record of the Matuyama–Brunhes transition constrains the age of Javanese Homo erectus in the Sangiran dome, Indonesia  

PubMed Central

A detailed paleomagnetic study conducted in the Sangiran area, Java, has provided a reliable age constraint on hominid fossil-bearing formations. A reverse-to-normal polarity transition marks a 7-m thick section across the Upper Tuff in the Bapang Formation. The transition has three short reversal episodes and is overlain by a thick normal polarity magnetozone that was fission-track dated to the Brunhes chron. This pattern closely resembles another high-resolution Matuyama–Brunhes (MB) transition record in an Osaka Bay marine core. In the Sangiran sediments, four successive transitional polarity fields lie just below the presumed main MB boundary. Their virtual geomagnetic poles cluster in the western South Pacific, partly overlapping the transitional virtual geomagnetic poles from Hawaiian and Canary Islands’ lavas, which have a mean 40Ar/39Ar age of 776 ± 2 ka. Thus, the polarity transition is unambiguously the MB boundary. A revised correlation of tuff layers in the Bapang Formation reveals that the hominid last occurrence and the tektite level in the Sangiran area are nearly coincident, just below the Upper Middle Tuff, which underlies the MB transition. The stratigraphic relationship of the tektite level to the MB transition in the Sangiran area is consistent with deep-sea core data that show that the meteorite impact preceded the MB reversal by about 12 ka. The MB boundary currently defines the uppermost horizon yielding Homo erectus fossils in the Sangiran area. PMID:22106291

Hyodo, Masayuki; Matsu'ura, Shuji; Kamishima, Yuko; Kondo, Megumi; Takeshita, Yoshihiro; Kitaba, Ikuko; Danhara, Tohru; Aziz, Fachroel; Kurniawan, Iwan; Kumai, Hisao

2011-01-01

41

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

PubMed Central

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

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

2011-01-01

42

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

PubMed

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

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

2011-01-01

43

Hominid Fossil Record Geology 230: Fossils and Evolution  

E-print Network

of Homo erectus from China #12;Skeleton of Homo erectus, Nariokotome boy from Kenya #12;H. erectus skull of Nariokotome boy #12;The face of Homo erectus #12;Homo erectus from Indonesia, Java Man #12;Homo erectus using. #12;Neandertal night life around the fire. #12;A more modern view of Neandertals with naked skin like

Kammer, Thomas

44

Evolution of the Genus Homo  

NASA Astrophysics Data System (ADS)

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

Tattersall, Ian; Schwartz, Jeffrey H.

2009-05-01

45

Behavioral and Environmental Background to ‘Out-of-Africa I’ and the Arrival of Homo erectus in East Asia  

Microsoft Academic Search

\\u000a Current evidence of hominin fossils and artifacts in China and Indonesia points to the arrival and persistence of the genus\\u000a Homo in East Asia by 1.7 million years ago (Ma). By at least 1.66 Ma, East Asian hominins had spread across a wide range of biotic\\u000a and climatic zones, spanning 7°S–40°N on the basis of well-constrained age data from the

Richard Potts; Robin Teague

46

Landscape development preceding Homo erectus immigration into Central Java, Indonesia: the Sangiran Formation Lower Lahar  

Microsoft Academic Search

The Sangiran Dome is the primary stratigraphic window for the Solo Basin, a coastal feature on the Pliocene–Pleistocene Sunda subcontinent south margin. In the Dome, the Lower Lahar unit (LLU) is a lahar-type debris flow overlying near-shore marine sediments. The event that emplaced the LLU likely originated from sector collapse on a neighboring volcanic edifice. Freshwater mollusc fossils in the

E. Arthur Bettis; Yahdi Zaim; Roy R Larick; Russell L Ciochon; Suminto; Yan Rizal; Mark Reagan; Matthew Heizler

2004-01-01

47

Identification of Zhoukoudian Homo erectus brain asymmetry using 3D laser scanning  

Microsoft Academic Search

Endocasts are important materials used for the study of human brain evolution, and allow examination of the external features\\u000a of brain anatomy from the inside the cranium. Studies examining brain asymmetries in fossil hominids are usually limited to\\u000a scoring of differences in hemisphere protrusion rostrally and caudally, or to comparing the width of the hemispheres. In the\\u000a present study, using

XiuJie Wu; Lei Pan

2011-01-01

48

Improved age control on early Homo fossils from the upper Burgi Member at Koobi Fora, Kenya  

E-print Network

the evolutionary origin, radiation and dispersal of the genus Homo, it is crucial to be able to place substantial fossil record of the genus Homo is first found. Here we combine magnetostratigraphy and strontiumImproved age control on early Homo fossils from the upper Burgi Member at Koobi Fora, Kenya

Utrecht, Universiteit

49

Fossil evidence for the origin of Homo sapiens.  

PubMed

Our species Homo sapiens has never received a satisfactory morphological definition. Deriving partly from Linnaeus's exhortation simply to "know thyself," and partly from the insistence by advocates of the Evolutionary Synthesis in the mid-20th Century that species are constantly transforming ephemera that by definition cannot be pinned down by morphology, this unfortunate situation has led to huge uncertainty over which hominid fossils ought to be included in H. sapiens, and even over which of them should be qualified as "archaic" or as "anatomically modern," a debate that is an oddity in the broader context of paleontology. Here, we propose a suite of features that seems to characterize all H. sapiens alive today, and we review the fossil evidence in light of those features, paying particular attention to the bipartite brow and the "chin" as examples of how, given the continuum from developmentally regulated genes to adult morphology, we might consider features preserved in fossil specimens in a comparative analysis that includes extant taxa. We also suggest that this perspective on the origination of novelty, which has gained a substantial foothold in the general field of evolutionary developmental biology, has an intellectual place in paleoanthropology and hominid systematics, including in defining our species, H. sapiens. Beginning solely with the distinctive living species reveals a startling variety in morphologies among late middle and late Pleistocene hominids, none of which can be plausibly attributed to H. sapiens/H. neanderthalensis admixture. Allowing for a slightly greater envelope of variation than exists today, basic "modern" morphology seems to have appeared significantly earlier in time than the first stirrings of the modern symbolic cognitive system. PMID:21086529

Schwartz, Jeffrey H; Tattersall, Ian

2010-01-01

50

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

PubMed

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

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

2015-03-01

51

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

NASA Astrophysics Data System (ADS)

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

Lee, S. A.

2013-03-01

52

Man the Fat Hunter: The Demise of Homo erectus and the Emergence of a New Hominin Lineage in the Middle Pleistocene (ca. 400 kyr) Levant  

PubMed Central

The worldwide association of H. erectus with elephants is well documented and so is the preference of humans for fat as a source of energy. We show that rather than a matter of preference, H. erectus in the Levant was dependent on both elephants and fat for his survival. The disappearance of elephants from the Levant some 400 kyr ago coincides with the appearance of a new and innovative local cultural complex – the Levantine Acheulo-Yabrudian and, as is evident from teeth recently found in the Acheulo-Yabrudian 400-200 kyr site of Qesem Cave, the replacement of H. erectus by a new hominin. We employ a bio-energetic model to present a hypothesis that the disappearance of the elephants, which created a need to hunt an increased number of smaller and faster animals while maintaining an adequate fat content in the diet, was the evolutionary drive behind the emergence of the lighter, more agile, and cognitively capable hominins. Qesem Cave thus provides a rare opportunity to study the mechanisms that underlie the emergence of our post-erectus ancestors, the fat hunters. PMID:22174868

Ben-Dor, Miki; Gopher, Avi; Hershkovitz, Israel; Barkai, Ran

2011-01-01

53

The first archaic Homo from Taiwan.  

PubMed

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

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

2015-01-01

54

The first archaic Homo from Taiwan  

PubMed Central

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

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

2015-01-01

55

“ Meganthropus ” cranial fossils from Java  

Microsoft Academic Search

There are now twelve significant hominid cranial fossils from the Lower and Middle Pleistocene of Java, all but two being\\u000a from the Sangiran site. Most of this material is well-known in the literature, but three skulls, possibly representing “Meganthropus” are here described in detail for the first time. Most scholars have assigned them all toHomo erectus, while others have suggested

D. E. Tyler

2001-01-01

56

Dental microwear and diets of African early Homo.  

PubMed

Conventional wisdom ties the origin and early evolution of the genus Homo to environmental changes that occurred near the end of the Pliocene. The basic idea is that changing habitats led to new diets emphasizing savanna resources, such as herd mammals or underground storage organs. Fossil teeth provide the most direct evidence available for evaluating this theory. In this paper, we present a comprehensive study of dental microwear in Plio-Pleistocene Homo from Africa. We examined all available cheek teeth from Ethiopia, Kenya, Tanzania, Malawi, and South Africa and found 18 that preserved antemortem microwear. Microwear features were measured and compared for these specimens and a baseline series of five extant primate species (Cebus apella, Gorilla gorilla, Lophocebus albigena, Pan troglodytes, and Papio ursinus) and two protohistoric human foraging groups (Aleut and Arikara) with documented differences in diet and subsistence strategies. Results confirmed that dental microwear reflects diet, such that hard-object specialists tend to have more large microwear pits, whereas tough food eaters usually have more striations and smaller microwear features. Early Homo specimens clustered with baseline groups that do not prefer fracture resistant foods. Still, Homo erectus and individuals from Swartkrans Member 1 had more small pits than Homo habilis and specimens from Sterkfontein Member 5C. These results suggest that none of the early Homo groups specialized on very hard or tough foods, but that H. erectus and Swartkrans Member 1 individuals ate, at least occasionally, more brittle or tough items than other fossil hominins studied. PMID:16226788

Ungar, Peter S; Grine, Frederick E; Teaford, Mark F; El Zaatari, Sireen

2006-01-01

57

Improved age control on early Homo fossils from the upper Burgi Member at Koobi Fora, Kenya.  

PubMed

To address questions regarding the evolutionary origin, radiation and dispersal of the genus Homo, it is crucial to be able to place the occurrence of hominin fossils in a high-resolution chronological framework. The period around 2 Ma (millions of years ago) in eastern Africa is of particular interest as it is at this time that a more substantial fossil record of the genus Homo is first found. Here we combine magnetostratigraphy and strontium (Sr) isotope stratigraphy to improve age control on hominin-bearing upper Burgi (UBU) deposits in Areas 105 and 131 on the Karari Ridge in the eastern Turkana Basin (Kenya). We identify the base of the Olduvai subchron (bC2n) plus a short isolated interval of consistently normal polarity that we interpret to be the Pre-Olduvai event. Combined with precession-forced (~20 kyr [thousands of years]) wet-dry climate cycles resolved by Sr isotope ratios, the magnetostratigraphic data allow us to construct an age model for the UBU deposits. We provide detailed age constraints for 15 hominin fossils from Area 131, showing that key specimens such as cranium KNM-ER 1470, partial face KNM-ER 62000 and mandibles KNM-ER 1482, KNM-ER 1801, and KNM-ER 1802 can be constrained between 1.945 ± 0.004 and 2.058 ± 0.034 Ma, and thus older than previously estimated. The new ages are consistent with a temporal overlap of two species of early Homo that can be distinguished by their facial morphology. Further, our results show that in this time interval, hominins occurred throughout the wet-dry climate cycles, supporting the hypothesis that the lacustrine Turkana Basin was a refugium during regionally dry periods. By establishing the observed first appearance datum of a marine-derived stingray in UBU deposits at 2.058 ± 0.034 Ma, we show that at this time the Turkana Basin was hydrographically connected to the Indian Ocean, facilitating dispersal of fauna between these areas. From a biogeographical perspective, we propose that the Indian Ocean coastal strip should be considered as a possible source area for one or more of the multiple Homo species in the Turkana Basin from over 2 Ma onwards. PMID:24134960

Joordens, Josephine C A; Dupont-Nivet, Guillaume; Feibel, Craig S; Spoor, Fred; Sier, Mark J; van der Lubbe, Jeroen H J L; Nielsen, Trine Kellberg; Knul, Monika V; Davies, Gareth R; Vonhof, Hubert B

2013-12-01

58

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

PubMed

Important changes in the brain have occurred during the course of human evolution. Both absolute and relative size increases can be documented for species of Homo, culminating in the appearance of modern humans. One species that is particularly well-represented by fossil crania is Homo erectus. The mean capacity for 30 individuals is 973 cm(3). Within this group there is substantial variation, but brain size increases slightly in specimens from later time periods. Other Middle Pleistocene crania differ from those of Homo erectus. Characters of the facial skeleton, vault, and cranial base suggest that fossils from sites such as Arago Cave in France, the Sima de los Huesos in Spain, Bodo in Ethiopia, Broken Hill in Zambia, and perhaps Dali in China belong to the taxon Homo heidelbergensis. Ten of these mid-Quaternary hominins have brains averaging 1,206 cm(3) in volume, and many fall beyond the limits of size predicted for Homo erectus of equivalent age. When orbit height is used to construct an index of relative brain size, it is apparent that the (significant) increase in volume documented for the Middle Pleistocene individuals is not simply a consequence of larger body mass. Encephalization quotient values confirm this finding. These changes in absolute and relative brain size can be taken as further corroborative evidence for a speciation event, in which Homo erectus produced a daughter lineage. It is probable that Homo heidelbergensis originated in Africa or western Eurasia and then ranged widely across the Old World. Archaeological traces indicate that these populations differed in their technology and behavior from earlier hominins. PMID:15160365

Rightmire, G Philip

2004-06-01

59

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

NASA Astrophysics Data System (ADS)

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

Lee, Scott

2012-10-01

60

The parietal bone of indonesian homo erectus  

Microsoft Academic Search

A comparative study of Indonesian parietal bones from Sangiran, Sambungmachan 1 and Ngandong has been undertaken. This study\\u000a comprises a morphological and metrical analysis of the individual parietal bones, followed by consideration of the biparietal\\u000a vault. The results are compared with other hominids from earlier and later periods. These hominids were found in China (Sinanthropus\\u000a II, III, X, XI and

D. Grimaud-Hervé

1986-01-01

61

Brief Communication: Shape analysis of the MT 1 proximal articular surface in fossil hominins and shod and unshod Homo.  

PubMed

As a follow-up study to Proctor et al. (Am J Phys Anthropol 135 (2008) 216-224), this study quantifies the first metatarsal proximal articular surface using three-dimensional morphometrics to test for differences in articular surface shape between habitually shod and habitually unshod humans. In addition, differences in shape between Homo, Pan, Gorilla, and Hylobates are compared to the fossil hominin specimens A. L. 333-54, Stw 562, Stw 573 ("Little Foot"), OH 8, SKX 5017, and SK 1813. No difference in surface shape was found between habitually shod and habitually unshod humans. There is a clear quantitative division in articular surface shape between humans and apes that is more pronounced than a previous study by Proctor et al. (Am J Phys Anthropol 135 (2008) 216-224), due to additional landmarks present in this study. The specimen OH 8 is indistinguishable from modern Homo. The fossils A. L. 333-54, Stw 562, and Stw 573 are intermediate in shape between humans and apes. The specimens SKX 5017 and SK 1813 have a more apelike articular surface. When combined with other characteristics, this trait suggests that Paranthropus used a degree of abduction during locomotion that was much less than that in extant apes, but greater than that in Australopithecus, allowing for some small degree of grasping ability. PMID:20925078

Proctor, Daniel J

2010-12-01

62

Human species and mating systems: Neandertal-Homo sapiens reproductive isolation and the archaeological and fossil records.  

PubMed

The present paper examined the assumption of strong reproductive isolation (RI) between Homo neanderthalensis and Homo sapiens, as well as the question of what form it might have taken, using insights from the parallel case of chimpanzee–bonobo hybridization. RI from hybrid sterility or inviability was thought unlikely based on the short separation-to-introgression timeline. The forms of RI that typically develop in primates have relatively short timelines (especially for partial implementation); they generally preclude mating or influence hybrid survival and reproduction in certain contexts, and they have the potential to skew introgression directionality. These RI barriers are also consistent with some interpretations of the archaeological and fossil records, especially when behavioral, cognitive, morphological, and genetic differences between the two human species are taken into consideration. Differences potentially influencing patterns of survival and reproduction include interspecies violence, Neandertal xenophobia, provisioning behavior, and ontogenetic, morphological, and behavioral differences affecting matters such as kin and mate recognition, infanticide, and sexual selection. These factors may have skewed the occurrence of interbreeding or the survival and reproduction of hybrids in a way that might at least partially explain the pattern of introgression. PMID:24344097

Overmann, Karenleigh; Coolidge, Frederick

2013-01-01

63

Basicranial flexion, relative brain size, and facial kyphosis inHomo sapiens and some fossil hominids  

Microsoft Academic Search

Comparative work among nonhominid primates has demon- strated that the basicranium becomes more flexed with increasing brain size relative to basicranial length and as the upper and lower face become more ventrally deflected (Ross and Ravosa (19931 Am. J. Phys. Anthropol. 91:305- 324). In order to determine whether modern humans and fossil hominids follow these trends, the cranial base angle

Callum Ross; Maciej Henneberg

1995-01-01

64

Fossil Skulls from Dmanisi: A Paleodeme Representing Earliest Homo in Eurasia  

Microsoft Academic Search

\\u000a The Plio-Pleistocene site of Dmanisi has yielded much evidence bearing on the morphology and behavior of the earliest hominins\\u000a from western Eurasia. Human remains, animal bones and stone artifacts were deposited at Dmanisi during a brief interval following\\u000a the close of the Olduvai Subchron (1.77 million years ago). The hominin fossils now include an adult braincase (D2280), the\\u000a partial skull

G. Philip Rightmire; David Lordkipanidze

65

Extreme mobility in the Late Pleistocene? Comparing limb biomechanics among fossil Homo, varsity athletes and Holocene foragers.  

PubMed

Descriptions of Pleistocene activity patterns often derive from comparisons of long bone diaphyseal robusticity across contemporaneous fossilized hominins. The purpose of this study is to augment existing understanding of Pleistocene hominin mobility patterns by interpreting fossil variation through comparisons with a) living human athletes with known activity patterns, and b) Holocene foragers where descriptions of group-level activity patterns are available. Relative tibial rigidity (midshaft tibial rigidity (J)/midshaft humeral rigidity (J)) was compared amongst Levantine and European Neandertals, Levantine and Upper Palaeolithic Homo sapiens, Holocene foragers and living human athletes and controls. Cross-country runners exhibit significantly (p<0.05) greater relative tibial rigidity compared with swimmers, and higher values compared with controls. In contrast, swimmers displayed significantly (p<0.05) lower relative tibial rigidity than both runners and controls. While variation exists among all Holocene H. sapiens, highly terrestrially mobile Later Stone Age (LSA) southern Africans and cross-country runners display the highest relative tibial rigidity, while maritime Andaman Islanders and swimmers display the lowest, with controls falling between. All fossil hominins displayed relative tibial rigidity that exceeded, or was similar to, the highly terrestrially mobile Later Stone Age southern Africans and modern human cross-country runners. The more extreme skeletal structure of most Neandertals and Levantine H. sapiens, as well as the odd Upper Palaeolithic individual, appears to reflect adaptation to intense and/or highly repetitive lower limb (relative to upper limb) loading. This loading may have been associated with bipedal travel, and appears to have been more strenuous than that encountered by even university varsity runners, and Holocene foragers with hunting grounds 2000-3000 square miles in size. Skeletal variation among the athletes and foraging groups is consistent with known or inferred activity profiles, which support the position that the Pleistocene remains reflect adaptation to extremely active and mobile lives. PMID:23453436

Shaw, Colin N; Stock, Jay T

2013-04-01

66

Before the Emergence of Homo sapiens: Overview on the Early-to-Middle Pleistocene Fossil Record (with a Proposal about Homo heidelbergensis at the subspecific level).  

PubMed

The origin of H. sapiens has deep roots, which include two crucial nodes: (1) the emergence and diffusion of the last common ancestor of later Homo (in the Early Pleistocene) and (2) the tempo and mode of the appearance of distinct evolutionary lineages (in the Middle Pleistocene). The window between 1,000 and 500 thousand years before present appears of crucial importance, including the generation of a new and more encephalised kind of humanity, referred to by many authors as H. heidelbergensis. This species greatly diversified during the Middle Pleistocene up to the formation of new variants (i.e., incipient species) that, eventually, led to the allopatric speciation of H. neanderthalensis and H. sapiens. The special case furnished by the calvarium found near Ceprano (Italy), dated to 430-385?ka, offers the opportunity to investigate this matter from an original perspective. It is proposed to separate the hypodigm of a single, widespread, and polymorphic human taxon of the Middle Pleistocene into distinct subspecies (i.e., incipient species). The ancestral one should be H. heidelbergensis, including specimens such as Ceprano and the mandible from Mauer. PMID:21716742

Manzi, Giorgio

2011-01-01

67

Before the Emergence of Homo sapiens: Overview on the Early-to-Middle Pleistocene Fossil Record (with a Proposal about Homo heidelbergensis at the subspecific level)  

PubMed Central

The origin of H. sapiens has deep roots, which include two crucial nodes: (1) the emergence and diffusion of the last common ancestor of later Homo (in the Early Pleistocene) and (2) the tempo and mode of the appearance of distinct evolutionary lineages (in the Middle Pleistocene). The window between 1,000 and 500 thousand years before present appears of crucial importance, including the generation of a new and more encephalised kind of humanity, referred to by many authors as H. heidelbergensis. This species greatly diversified during the Middle Pleistocene up to the formation of new variants (i.e., incipient species) that, eventually, led to the allopatric speciation of H. neanderthalensis and H. sapiens. The special case furnished by the calvarium found near Ceprano (Italy), dated to 430–385?ka, offers the opportunity to investigate this matter from an original perspective. It is proposed to separate the hypodigm of a single, widespread, and polymorphic human taxon of the Middle Pleistocene into distinct subspecies (i.e., incipient species). The ancestral one should be H. heidelbergensis, including specimens such as Ceprano and the mandible from Mauer. PMID:21716742

Manzi, Giorgio

2011-01-01

68

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

PubMed

Previous research into tooth crown dimensions and cusp proportions has proved to be a useful way to identify taxonomic differences in Pliocene and Pleistocene fossil hominins. The present study has identified changes in both M(1) crown size and cusp proportions within the genus Homo, with M(1) overall crown size reduction apparently occurring in two main stages. The first stage (a reduction of ca. 17%) is associated with the emergence of Homo ergaster and Homo erectus sensu stricto. The second stage (a reduction of ca. 10%) occurs in Homo sapiens, but the reduced modern human M(1) tooth crown size was only attained in Upper Paleolithic times. The absolute sizes of the individual cusps are highly positively correlated with overall crown size and dental reduction produces a reduction in the absolute size of each of the cusps. Most of the individual cusps scale isometrically with crown size, but the paracone shows a negative allometric relationship, indicating that the reduction in paracone size is less than in the other M(1) cusps. Thus, the phylogenetically oldest cusp in the upper molars also seems to be the most stable cusp (at least in the M(1)). The most striking change in M(1) cusp proportions is a change in the relative size of the areas of the paracone and metacone. The combination of a small relative paracone and a large relative metacone generally characterizes specimens attributed to early Homo, and the presence of this character state in Australopithecus and Paranthropus suggests it may represent the primitive condition for the later part of the hominin clade. In contrast, nearly all later Homo taxa, with the exception of Homo antecessor, show the opposite condition (i.e. a relatively large paracone and a relatively small metacone). This change in the relationship between the relative sizes of the paracone and metacone is related to an isometric reduction of the absolute size of the metacone. This metacone reduction occurs in the context of relative stability in the paracone as crown size decreases. Among later Homo taxa, both Homo heidelbergensis and Homo neanderthalensis show a further reduction of the metacone and an enlargement of the hypocone. Fossil and contemporary H. sapiens samples show a trend toward increasing the relative size of the protocone and decreasing the relative size of the hypocone. In Europe, modern human M(1) cusp proportions are essentially reached during the Upper Paleolithic. Although some variation was documented among the fossil taxa, we suggest that the relative size of the M(1) paracone and metacone areas may be useful for differentiating the earliest members of our genus from subsequent Homo species. PMID:19438761

Quam, Rolf; Bailey, Shara; Wood, Bernard

2009-05-01

69

Homo floresiensis: microcephalic, pygmoid, Australopithecus, or Homo?  

PubMed

The remarkable partial adult skeleton (LB1) excavated from Liang Bua cave on the island of Flores, Indonesia, has been attributed to a new species, Homo floresiensis, based upon a unique mosaic of primitive and derived features compared to any other hominin. The announcement precipitated widespread interest, and attention quickly focused on its possible affinities. LB1 is a small-bodied hominin with an endocranial volume of 380-410 cm3, a stature of 1m, and an approximate geological age of 18,000 years. The describers [Brown, P., Sutikna, T., Morwood, M.J., Soejono, R.P., Jatmiko, Wayhu Saptomo, E., Awe Due, R., 2004. A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia. Nature 431, 1055-1061] originally proposed that H. floresiensis was the end product of a long period of isolation of H. erectus or early Homo on a small island, a process known as insular dwarfism. More recently Morwood, Brown, and colleagues [Morwood, M.J., Brown, P., Jatmiko, Sutikna, T., Wahyu Saptomo, E., Westaway, K.E., Awe Due, R., Roberts, R.G., Maeda, T., Wasisto, S., Djubiantono, T., 2005. Further evidence for small-bodied hominins from the Late Pleistocene of Flores, Indonesia. Nature 437, 1012-1017] reviewed this assessment in light of new material from the site and concluded that H. floresiensis is not likely to be descended from H. erectus, with the genealogy of the species remaining uncertain. Other interpretations, namely that LB1 is a pygmy or afflicted with microcephaly, have also been put forward. We explore the affinities of LB1 using cranial and postcranial metric and non-metric analyses. LB1 is compared to early Homo, two microcephalic humans, a 'pygmoid' excavated from another cave on Flores, H. sapiens (including African pygmies and Andaman Islanders), Australopithecus, and Paranthropus. Based on these comparisons, we conclude that it is unlikely that LB1 is a microcephalic human, and it cannot be attributed to any known species. Its attribution to a new species, Homo floresiensis, is supported. PMID:16919706

Argue, Debbie; Donlon, Denise; Groves, Colin; Wright, Richard

2006-10-01

70

Frontal bone fragment of Homo erectus from Sangiran, Java  

Microsoft Academic Search

In 1994 a hominid frontal bone fragment was found in the river floor of the Brangkal River, the Sangiran area, Central Java.\\u000a The original stratigraphic level is not known at present stage of the research. But it is possible that the bone was derived\\u000a from the Grenzbank zone of the Bapang Formation (Lower\\/Middle Pleistocene). Morphological features of the bone, such

H. Baba; F. Aziz; S. Narasaki; Sudijono; Y. Kaifu; I. Saefudin; E. E. Susanto

2004-01-01

71

Systematic assessment of a maxilla of Homo from Hadar, Ethiopia.  

PubMed

The Hadar site in Ethiopia is a prolific source of hominid fossils attributed to the species Australopithecus afarensis, which spans the period 3.4-3.0 million years (myr) in the Sidi Hakoma, Denen Dora and lower Kada Hadar Members of the Hadar Formation. Since 1992 a major focus of field work conducted at Hadar has centered on sediments younger than 3.0 myr, comprising the bulk of the Kada Hadar Member. Witnessing the rise of the "robust" Australopithecus clade(s), the origin of Homo, and the first record of lithic artifacts, the period between 3.0 and 2.0 myr is strategically vital for paleoanthropology. However, in eastern Africa it is a particularly poorly sampled temporal interval. This paper provides a detailed comparative description of a hominid maxilla with partial dentition found at Hadar in 1994. The specimen, A.L. 666-1, derives from a lithic artifact-bearing horizon high in the Kada Hadar Member, 0.8 m below the BKT-3 tephra, dated by the 40Ar/39Ar method to 2.33 +/- 0.07 myr. Our preliminary investigation of the hominid specimen showed unambiguous affinities with early representatives of the Homo clade (Kimbel et al. [1996] J. Hum. Evol. 31:549-561). Further studies on maxillary and dental morphology lead us to attribute A.L. 666-1 to Homo aff. H. habilis. The new Hadar jaw is the first paleontological evidence for the projection of the H. habilis maxillofacial morphotype well back into the Pliocene. It may represent a male of this species, whose maxillary hypodigm consists chiefly of females. A subsidiary finding of our study is that of the three earliest recorded species of Homo (H. habilis, H. rudolfensis, H. erectus), it is H. habilis that exhibits facial morphology closest to that expected in their last common ancestor. PMID:9209580

Kimbel, W H; Johanson, D C; Rak, Y

1997-06-01

72

Fossils  

NSDL National Science Digital Library

Students discover the science of paleontology and the fossilization process. Why should we study fossils? Use your KWL chart to record information you have learned and anything else you want to know about. First read about the fossils of birds and what we learn from them. Then discover the Fossilization Process. Find out if there are still new dinosaurs to be discovered. Watch paleontologists hunt for ...

tassihj

2009-10-21

73

Dental Evidence for Diets of Early Homo  

Microsoft Academic Search

The evolution of diet in the earliest members of our genus, Homo rudolfensis, H. habilis and H. erectus has received increased attention over the past few years (see Ungar et al., 2006a for review). Many models have been constructed,\\u000a based largely on nutritional studies combined with direct analogy (with living peoples or non-human primates) or on contextual\\u000a evidence, such as

Peter S. Ungar; Robert S. Scott

74

A one-million-year-old Homo cranium from the Danakil (Afar) Depression of Eritrea  

Microsoft Academic Search

One of the most contentious topics in the study of human evolution is that of the time, place and mode of origin of Homo sapiens. The discovery in the Northern Danakil (Afar) Depression, Eritrea, of a well-preserved Homo cranium with a mixture of characters typical of H. erectus and H. sapiens contributes significantly to this debate. The cranium was found

Ernesto Abbate; Andrea Albianelli; Augusto Azzaroli; Marco Benvenuti; Berhane Tesfamariam; Piero Bruni; Nicola Cipriani; Ronald J. Clarke; Giovanni Ficcarelli; Roberto Macchiarelli; Giovanni Napoleone; Mauro Papini; Lorenzo Rook; Mario Sagri; Tewelde Medhin Tecle; Danilo Torre; Igor Villa

1998-01-01

75

Fossils  

NSDL National Science Digital Library

Fossils is an activity for grades 1-2 that enables students to apply their interest in dinosaurs to discovering how fossils tell us about our past. As a result of this activity, the students will be able to: tell a friend or parent who a paleontologist is and what he does; explain what a fossil is; explain how we use fossils to learn about the past; and make a fossil using clay, plaster of paris, and some sort of molding object such as a shell, leaf, bone, etc. A suggested extension of this activity is turning it into an archaeological "dig" by burying objects in plaster of paris and then using dull instruments to dig for the "fossils."

1998-01-01

76

Fossils  

NSDL National Science Digital Library

4th Grade Science Standard 4: Students will understand how fossils are formed, where they may be found in Utah, and how they can be used to make inferences. DISCOVERING FOSSILS!!

81

No Homo  

Microsoft Academic Search

The phrase no homo arose in hip-hop lyrics of the 1990s as a discourse interjection to negate supposed sexual and gender transgressions. Today the phrase has gained currency beyond hip-hop culture and pervades racial and gender continua. As a result, its increasing prevalence in mainstream speech has caused critics to deplore no homo as outright homophobia. This article describes the

Joshua R. Brown

2011-01-01

82

Comment on "A complete skull from Dmanisi, Georgia, and the evolutionary biology of early Homo".  

PubMed

Lordkipanidze et al. (Research Article, 18 October 2013, p. 326) conclude, from gross morphological comparisons and geometric-morphometric analysis of general shape, that the five hominid crania from Dmanisi in Georgia represent a single regional variant of Homo erectus. However, dental, mandibular, and cranial morphologies all suggest taxic diversity and, in particular, validate the previously named H. georgicus. PMID:24763572

Schwartz, Jeffrey H; Tattersall, Ian; Chi, Zhang

2014-04-25

83

The origin of Homo floresiensis and its relation to evolutionary processes under isolation  

Microsoft Academic Search

Since its first description in 2004, Homo floresiensis has been attributed to a species of its own, a descendant of H. erectus or another early hominid, a pathological form of H. sapiens, or a dwarfed H. sapiens related to the Neolithic inhabitants of Flores. In this contribution, we apply a geo- metric morphometric analysis to the skull of H. floresiensis

G. A. LYRAS; M. D. DERMITZAKIS; S. B. VAN DER GEER; J. DE VOS

2009-01-01

84

The late Middle Pleistocene hominin fossil record of eastern Asia: synthesis and review.  

PubMed

Traditionally, Middle Pleistocene hominin fossils that cannot be allocated to Homo erectus sensu lato or modern H. sapiens have been assigned to different specific taxa. For example, in eastern Asia, these hominin fossils have been classified as archaic, early, or premodern H. sapiens. An increasing number of Middle Pleistocene hominin fossils are currently being assigned to H. heidelbergensis. This is particularly the case for the African and European Middle Pleistocene hominin fossil record. There have been suggestions that perhaps the eastern Asian late Middle Pleistocene hominins can also be allocated to the H. heidelbergensis hypodigm. In this article, I review the current state of the late Middle Pleistocene hominin fossil record from eastern Asia and examine the various arguments for assigning these hominins to the different specific taxa. The two primary conclusions drawn from this review are as follows: 1) little evidence currently exists in the eastern Asian Middle Pleistocene hominin fossil record to support their assignment to H. heidelbergensis; and 2) rather than add to the growing list of hominin fossil taxa by using taxonomic names like H. daliensis for northeast Asian fossils and H. mabaensis for Southeast Asian fossils, it is better to err on the side of caution and continue to use the term archaic H. sapiens to represent all of these hominin fossils. What should be evident from this review is the need for an increase in the quality and quantity of the eastern Asian hominin fossil data set. Fortunately, with the increasing number of large-scale multidisciplinary paleoanthropological field and laboratory research projects in eastern Asia, the record is quickly becoming better understood. PMID:21086528

Bae, Christopher J

2010-01-01

85

A comprehensive morphometric analysis of the frontal and zygomatic bone of the Zuttiyeh fossil from Israel.  

PubMed

The Zuttiyeh hominin craniofacial fossil was discovered in Israel in 1925. Radiometric dates and the archaeological context (Acheulo-Yabrudian) bracket the associated cave layers to between 200 and 500 ka (thousands of years ago), making it one of the earliest cranial fossils discovered in the Near East thus far. Its geographic position, at the corridor between Africa and Eurasia, in combination with its probable Middle Pleistocene date make it a crucial specimen for interpreting later human evolution. Since its discovery, qualitative descriptive and traditional morphometric methods have variously suggested affinities to Homo erectus (Zhoukoudian), Homo neanderthalensis (Tabun), and early Homo sapiens (Skhul and Qafzeh). To better determine the taxonomic affinities of the Zuttiyeh fossil, this study uses 3D semilandmark geometric morphometric techniques and multivariate statistical analyses to quantify the frontal and zygomatic region and compare it with other Middle to Late Pleistocene African and Eurasian hominins. Our results show that the frontal and zygomatic morphology of Zuttiyeh is most similar to Shanidar 5, a Near East Neanderthal, Arago 21, a European Middle Pleistocene hominin, and Skhul 5, an early H. sapiens. The shape differences between archaic hominins (i.e., Homo heidelbergensis and H. neanderthalensis) in this anatomical region are very subtle. We conclude that Zuttiyeh exhibits a generalized frontal and zygomatic morphology, possibly indicative of the population that gave rise to modern humans and Neanderthals. However, given that it most likely postdates the split between these two lineages, Zuttiyeh might also be an early representative of the Neanderthal lineage. Neanderthals largely retained this generalized overall morphology, whereas recent modern humans depart from this presumably ancestral morphology. PMID:22176924

Freidline, S E; Gunz, P; Jankovi?, I; Harvati, K; Hublin, J J

2012-02-01

86

The history of the genus Homo  

Microsoft Academic Search

The genusHomo was established by Carolus Linnaeus in 1758. During the course of the past 150 years, the addition of fossil species to the\\u000a genusHomo has resulted in a genus that, according to the taxonomic interpretation, could span as much time as 2.5 Myr, and include\\u000a as many as ten species. This paper reviews the fossil evidence for each of

B. A. Wood

2000-01-01

87

Hominin cognitive evolution: identifying patterns and processes in the fossil and archaeological record  

PubMed Central

As only limited insight into behaviour is available from the archaeological record, much of our understanding of historical changes in human cognition is restricted to identifying changes in brain size and architecture. Using both absolute and residual brain size estimates, we show that hominin brain evolution was likely to be the result of a mix of processes; punctuated changes at approximately 100 kya, 1 Mya and 1.8 Mya are supplemented by gradual within-lineage changes in Homo erectus and Homo sapiens sensu lato. While brain size increase in Homo in Africa is a gradual process, migration of hominins into Eurasia is associated with step changes at approximately 400 kya and approximately 100 kya. We then demonstrate that periods of rapid change in hominin brain size are not temporally associated with changes in environmental unpredictability or with long-term palaeoclimate trends. Thus, we argue that commonly used global sea level or Indian Ocean dust palaeoclimate records provide little evidence for either the variability selection or aridity hypotheses explaining changes in hominin brain size. Brain size change at approximately 100 kya is coincident with demographic change and the appearance of fully modern language. However, gaps remain in our understanding of the external pressures driving encephalization, which will only be filled by novel applications of the fossil, palaeoclimatic and archaeological records. PMID:22734056

Shultz, Susanne; Nelson, Emma; Dunbar, Robin I. M.

2012-01-01

88

Pleistocene Homo sapiens from Middle Awash, Ethiopia  

Microsoft Academic Search

The origin of anatomically modern Homo sapiens and the fate of Neanderthals have been fundamental questions in human evolutionary studies for over a century. A key barrier to the resolution of these questions has been the lack of substantial and accurately dated African hominid fossils from between 100,000 and 300,000 years ago. Here we describe fossilized hominid crania from Herto,

Tim D. White; Berhane Asfaw; David DeGusta; Henry Gilbert; Gary D. Richards; Gen Suwa; F. Clark Howell

2003-01-01

89

Landmark-based shape analysis of the archaic Homo calvarium from Ceprano (Italy).  

PubMed

The Ceprano calvarium represents one of the most important sources of information about both the dynamics of the earliest hominid dispersal toward Europe and the evolution of the genus Homo in the early-to-middle Pleistocene. In this paper, the midsagittal vault profile and the 3D frontal bone morphology of Ceprano are investigated comparatively, using landmark coordinates and Procrustes superimposition. In fact, despite the fact that the skull appears partially distorted by diagenetic pressures (thus precluding a comprehensive landmark-based analysis), some aspects of the overall morphology are suitable for consideration in terms of geometric morphometrics. The midsagittal profile shows an archaic shape, comparable with the H. ergaster/erectus range of variation because of the fronto-parietal flattening, the development of the supraorbital and nuchal structures, and the occurrence of a slightly larger occipital bone. By contrast, the frontal bone displays a derived 3D shape that, mostly because of the widening of the frontal squama, appears comparable with the Afro-European variation of the Middle Pleistocene (i.e., H. heidelbergensis/rhodesiensis). Taking into account the unique morphological pattern displayed by Ceprano, its role as a link between early Homo and the Middle Pleistocene populations of Europe and Africa is not falsified. Thus, when aspects of the Ceprano's morphology are described within the analytical framework provided by geometric morphometrics, the relationships between Ceprano and the subsequent Afro-European fossil record are emphasized, suggesting the occurrence of an ancestral stock of H. heidelbergensis/rhodesiensis that is properly represented by the Italian specimen. PMID:17177181

Bruner, Emiliano; Manzi, Giorgio

2007-03-01

90

From Homo Economicus to Homo Sapiens  

Microsoft Academic Search

In responding to a request for predictions about the future of economics, I predict that Homo Economicus will evolve into Homo Sapiens, or, more simply put, economics will become more related to human behavior. My specific predictions are that Homo Economicus will start to lose IQ, will become a slower learner, will start interacting with other species, and that economists

Richard H. Thaler

2000-01-01

91

Homo cepranensis sp. nov. and the evolution of African-European Middle Pleistocene hominids  

Microsoft Academic Search

The hominid calvarium from Ceprano (Italy) shows peculiar characters, especially in the frontal bone. This specimen differs from the other hominid species (H. ergaster, H. erectus, and H. heidelbergensis). The morphometric and the cladistic analyses show that the Italian fossil is a new hominid species. The typical characters of European H. heidelbergensis are absent in the frontal morphology of Ceprano,

Francesco Mallegni; Emiliano Carnieri; Michelangelo Bisconti; Giandonato Tartarelli; Stefano Ricci; Italo Biddittu; Aldo Segre

2003-01-01

92

Locomotor activity differences between sympatric patas monkeys (Erythrocebus patas) and vervet monkeys (Cercopithecus aethiops): Implications for the evolution of long hindlimb length inHomo  

Microsoft Academic Search

Homo erectus is notable for its taller stature and longer lower limbs relative to earlier hominids, but the selective pressures favoring such long limbs are unclear. Among anthropoid primates, patas monkeys (Erythro- cebus patas) and extant hominids share several extreme characteristics involved with foraging and movement, including the relatively longest lower limb proportions, longest daily travel distances and largest home

Lynne A. Isbell; Jill D. Pruetz; Michelle Lewis; Truman P. Young

1998-01-01

93

Pleistocene Homo sapiens from Middle Awash, Ethiopia.  

PubMed

The origin of anatomically modern Homo sapiens and the fate of Neanderthals have been fundamental questions in human evolutionary studies for over a century. A key barrier to the resolution of these questions has been the lack of substantial and accurately dated African hominid fossils from between 100,000 and 300,000 years ago. Here we describe fossilized hominid crania from Herto, Middle Awash, Ethiopia, that fill this gap and provide crucial evidence on the location, timing and contextual circumstances of the emergence of Homo sapiens. Radioisotopically dated to between 160,000 and 154,000 years ago, these new fossils predate classic Neanderthals and lack their derived features. The Herto hominids are morphologically and chronologically intermediate between archaic African fossils and later anatomically modern Late Pleistocene humans. They therefore represent the probable immediate ancestors of anatomically modern humans. Their anatomy and antiquity constitute strong evidence of modern-human emergence in Africa. PMID:12802332

White, Tim D; Asfaw, Berhane; DeGusta, David; Gilbert, Henry; Richards, Gary D; Suwa, Gen; Howell, F Clark

2003-06-12

94

The Genus Homo : Origin, Speciation and Dispersal  

Microsoft Academic Search

\\u000a The taxonomical interpretation of the fossil record of our own genus Homo is still highly controversial. In spite of obvious major advances concerning the acquisition, analysis and interpretation\\u000a of the fossil specimens there currently remain unbridgeable disagreements concerning the origin, speciation and dispersal\\u000a of our genus. The polarized positions result foremost from different methodological approaches for species recognition (e.g.,\\u000a Tattersall

Winfried Henke; Thorolf Hardt

95

Wild chimpanzee dentition and its implications for assessing life history in immature hominin fossils  

E-print Network

. A revised dental growth chronology for chimpanzees is similar to estimated timing of Homo erectus and therefore has implications for interpreting life history in hominins. The sequence and timing of dental emergence correlate with life history events in catarrhine primates, which include Old World monkeys, apes

96

Variation in enamel thickness within the genus Homo Tanya M. Smith a,b,*, Anthony J. Olejniczak b  

E-print Network

Homo Archaic Homo Neanderthal a b s t r a c t Recent humans and their fossil relatives are classified, Neanderthals show relatively thin enamel in their incisors, canines, premolars, and molars, although incisor

Smith, Tanya M.

97

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

PubMed Central

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

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

2011-01-01

98

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

Microsoft Academic Search

Clarifying the geographic, environmental and behavioural contexts in which the emergence of anatomically modern Homo sapiens occurred has proved difficult, particularly because Africa lacked adequate geochronological, palaeontological and archaeological evidence. The discovery of anatomically modern Homo sapiens fossils at Herto, Ethiopia, changes this. Here we report on stratigraphically associated Late Middle Pleistocene artefacts and fossils from fluvial and lake margin

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

2003-01-01

99

Human migrations map, interactive 2D animationSite: DNA Interactive (www.dnai.org)  

NSDL National Science Digital Library

The red lines show the possible migration pathway of the ancient human Homo erectus (sometimes known as Homo ergaster). There is little controversy about the travels of H. erectus. This possible path was mapped using fossil evidence that spans more than 1.5 million years. Many researchers believe that H. erectus lived until approximately 300,000 years ago. However, H. erectus may have survived in Indonesia until 40,000 years ago.

2008-10-06

100

Antiquity of Homo sapiens in China  

Microsoft Academic Search

TEN years ago a well-preserved skull of an early form of Homo sapiens was unearthed from Pleistocene cave deposits at the Jinniushan site in China. Here we present electron-spin resonance (ESR) and uranium-series dates from five fossil animal teeth collected from the hominid locality. The minimum ESR ages (195-165 kyr) are about 50 kyr younger than the uranium-series dates. Taken

Chen Tiemei; Yang Quan; Wu En

1994-01-01

101

Brain size of Homo floresiensis and its evolutionary implications  

PubMed Central

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

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

2013-01-01

102

Dental microwear and diets of African early Homo  

Microsoft Academic Search

Conventional wisdom ties the origin and early evolution of the genus Homo to environmental changes that occurred near the end of the Pliocene. The basic idea is that changing habitats led to new diets emphasizing savanna resources, such as herd mammals or underground storage organs. Fossil teeth provide the most direct evidence available for evaluating this theory. In this paper,

Peter S. Ungar; Frederick E. Grine; Mark F. Teaford; Sireen El Zaatari

2006-01-01

103

Homo habilis's humanness: Phillip Tobias as a philosopher.  

PubMed

A detailed, interdisciplinary reading of Phillip Tobias's publications on Homo habilis shows how a philosophical notion of "humanness" has structured his interpretation of the fossils attributed to this species. The role of this notion in his research and its backgrounds in philosophy, disciplinary history, and a widespread mid-20th-century climate of opinion are analyzed and discussed. PMID:23272596

Corbey, Raymond

2012-01-01

104

Week of Aug. 5, 2002 Vol. 3, No. 15 A D e p a r t m e n t o f E n e r g y / U n i v e r s i t y o f C a l i f o r n i a L a b o r a t o r y  

E-print Network

, baboons and hyenas; in fact, marks on the fossilized skull indicate that the Homo erectus specimen may have been gnawed on by hyenas or other animals after it died. The latest fossils are about a million

105

Homo Economicus Belief Inhibits Trust  

PubMed Central

As a foundational concept in economics, the homo economicus assumption regards humans as rational and self-interested actors. In contrast, trust requires individuals to believe partners’ benevolence and unselfishness. Thus, the homo economicus belief may inhibit trust. The present three experiments demonstrated that the direct exposure to homo economicus belief can weaken trust. And economic situations like profit calculation can also activate individuals’ homo economicus belief and inhibit their trust. It seems that people’s increasing homo economicus belief may serve as one cause of the worldwide decline of trust. PMID:24146907

Xin, Ziqiang; Liu, Guofang

2013-01-01

106

Locomotor activity differences between sympatric patas monkeys (Erythrocebus patas) and vervet monkeys (Cercopithecus aethiops): implications for the evolution of long hindlimb length in Homo.  

PubMed

Homo erectus is notable for its taller stature and longer lower limbs relative to earlier hominids, but the selective pressures favoring such long limbs are unclear. Among anthropoid primates, patas monkeys (Erythrocebus patas) and extant hominids share several extreme characteristics involved with foraging and movement, including the relatively longest lower limb proportions, longest daily travel distances and largest home ranges for their body or group size, occupancy of some of the driest habitats, and very efficient thermoregulatory systems. We suggest that patas monkeys are an appropriate behavioral model with which to speculate on the selective pressures that might have operated on H. erectus to increase lower limb length. Here, in a comparison of the locomotor activities of patas monkeys and sympatric, closely related vervet monkeys (Cercopithecus aethiops), we provide evidence for the hypothesis that patas use their long stride more to increase foraging efficiency while walking than to run, either from predators or otherwise. PMID:9511914

Isbell, L A; Pruetz, J D; Lewis, M; Young, T P

1998-02-01

107

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

Microsoft Academic Search

Not Available Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints

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

2011-01-01

108

Geometric properties and comparative biomechanics of Homo floresiensis mandibles.  

PubMed

The hypodigm of Homo floresiensis from the cave of Liang Bua on Flores Island in the archipelago of Indonesia includes two mandibles (LB1/2 and LB6/1). The morphology of their symphyses and corpora has been described as sharing similarities with both australopiths and early Homo despite their Late Pleistocene age. Although detailed morphological comparisons of these mandibles with those of modern and fossil hominin taxa have been made, a functional analysis in the context of masticatory biomechanics has yet to be performed. Utilizing data on cortical bone geometry from computed tomography scans, we compare the mechanical attributes of the LB1 and LB6 mandibles with samples of modern Homo, Pan, Pongo, and Gorilla, as well as fossil samples of Paranthropus robustus, Australopithecus africanus and South African early Homo. Structural stiffness measures were derived from the geometric data to provide relative measures of mandibular corpus strength under hypothesized masticatory loading regimes. These mechanical variables were evaluated relative to bone area, mandibular length and estimates of body size to assess their functional affinities and to test the hypothesis that the Liang Bua mandibles can be described as scaled-down variants of either early hominins or modern humans. Relative to modern hominoids, the H. floresiensis material appears to be relatively strong in terms of rigidity in torsion and transverse bending, but is relatively weak under parasagittal bending. Thus, they are 'robust' relative to modern humans (and comparable with australopiths) under some loads but not others. Neither LB1 nor LB6 can be described simply as 'miniaturized' versions of modern human jaws since mandible length is more or less equivalent in Homo sapiens and H. floresiensis. The mechanical attributes of the Liang Bua mandibles are consistent with previous inferences that masticatory loads were reduced relative to australopiths but remained elevated relative to modern Homo. PMID:24560803

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

2014-03-01

109

The distinctiveness and systematic context of Homo neanderthalensis  

Microsoft Academic Search

The “packaging” of the diverse living world is untidy, with the result that there are no absolute criteria for recognizing\\u000a in all contexts the bounded historical entities we call species. However, there is no doubt whatsoever that Homo neanderthalensis is as clear-cut a morphological entity as any in the hominid fossil record: one that is characterized by a whole host

I. Tattersall; J. Schwartz

110

Marquee Fossils  

ERIC Educational Resources Information Center

Professors of an online graduate-level paleontology class developed the concept of marquee fossils--fossils that have one or more unique characteristics that capture the attention and direct observation of students. In the classroom, Marquee fossils integrate the geology, biology, and environmental science involved in the study of fossilized…

Clary, Renee; Wandersee, James

2008-01-01

111

Allometric scaling of infraorbital surface topography in Homo.  

PubMed

Infraorbital morphology is often included in phylogenetic and functional analyses of Homo. The inclusion of distinct infraorbital configurations, such as the "canine fossa" in Homo sapiens or the "inflated" maxilla in Neandertals, is generally based on either descriptive or qualitative assessments of this morphology, or simple linear chord and subtense measurements. However, the complex curvilinear surface of the infraorbital region has proven difficult to quantify through these traditional methods. In this study, we assess infraorbital shape and its potential allometric scaling in fossil Homo (n=18) and recent humans (n=110) with a geometric morphometric method well-suited for quantifying complex surface topographies. Our results indicate that important aspects of infraorbital shape are correlated with overall infraorbital size across Homo. Specifically, individuals with larger infraorbital areas tend to exhibit relatively flatter infraorbital surface topographies, taller and narrower infraorbital areas, sloped inferior orbital rims, anteroinferiorly oriented maxillary body facies, posteroinferiorly oriented maxillary processes of the zygomatic, and non-everted lateral nasal margins. In contrast, individuals with smaller infraorbital regions generally exhibit relatively depressed surface topographies, shorter and wider infraorbital areas, projecting inferior orbital rims, posteroinferiorly oriented maxillary body facies, anteroinferiorly oriented maxillary processes, and everted lateral nasal margins. These contrasts form a continuum and only appear dichotomized at the ends of the infraorbital size spectrum. In light of these results, we question the utility of incorporating traditionally polarized infraorbital morphologies in phylogenetic and functional analyses without due consideration of continuous infraorbital and facial size variation in Homo. We conclude that the essentially flat infraorbital surface topography of Neandertals is not unique and can be explained, in part, as a function of possessing large infraorbital regions, the ancestral condition for Homo. Furthermore, it appears likely that the diminutive infraorbital region of anatomically modern Homo sapiens is a primary derived trait, with related features such as depressed infraorbital surface topography expressed as correlated secondary characters. PMID:19118866

Maddux, Scott D; Franciscus, Robert G

2009-02-01

112

Fossil Fondue  

NSDL National Science Digital Library

To understand how fossils are formed, students model the process of fossilization by making fossils using small toy figures and melted chocolate. They extend their knowledge to the many ways that engineers aid in the study of fossils, including the development of tools and technologies for determining the physical and chemical properties of fossilized organisms, and how those properties tell a story of our changing world.

2014-09-18

113

Fossil primates 1 Fossil primates  

E-print Network

Fossil primates 1 Fossil primates Extinct members of the order of mammals to which humans belong group of living primates. However, the chewing teeth and the locomotor anatomy of these fossil forms). These animals are also known from fossil deposits on Ellesmere Island, in Arctic Canada, which was then covered

Delson, Eric

114

Discovering Fossils: Fossil Tools & Resources  

NSDL National Science Digital Library

Fossil enthusiasts Roy Shephard and Luci Algar combined their professional skills in media and education to develop this informative and entertaining website. Designed to be educational and accessible to children, this site presents a wide variety of information about fossils. The site contains a nice collection of images and diagrams; and includes a fossils guide for beginners, information on preparing fossils, a collection of fossil myths, information on ammonites, and more. The site also contains a Games & Activities section for teachers and students, a glossary of fossil terms, a neat diagram depicting the evolution of life on our planet, and even some free fossil desktop images.

115

Paleoanthropology. Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia.  

PubMed

Our understanding of the origin of the genus Homo has been hampered by a limited fossil record in eastern Africa between 2.0 and 3.0 million years ago (Ma). Here we report the discovery of a partial hominin mandible with teeth from the Ledi-Geraru research area, Afar Regional State, Ethiopia, that establishes the presence of Homo at 2.80 to 2.75 Ma. This specimen combines primitive traits seen in early Australopithecus with derived morphology observed in later Homo, confirming that dentognathic departures from the australopith pattern occurred early in the Homo lineage. The Ledi-Geraru discovery has implications for hypotheses about the timing and place of origin of the genus Homo. PMID:25739410

Villmoare, Brian; Kimbel, William H; Seyoum, Chalachew; Campisano, Christopher J; DiMaggio, Erin N; Rowan, John; Braun, David R; Arrowsmith, J Ramón; Reed, Kaye E

2015-03-20

116

"Fossil" Forecasting.  

ERIC Educational Resources Information Center

Presents a density study in which students calculate the density of limestone substrate to determine if the specimen contains any fossils. Explains how to make fossils and addresses national standards. (YDS)

Brody, Michael J.; deOnis, Ann

2001-01-01

117

Additional evidence for morpho-dimensional tooth crown variation in a New Indonesian H. erectus sample from the Sangiran Dome (Central Java).  

PubMed

This contribution reports fifteen human fossil dental remains found during the last two decades in the Sangiran Dome area, in Central Java, Indonesia. Among this sample, only one of the specimens had already been briefly described, with the other fourteen remaining unreported. Seven of the fifteen isolated teeth were found in a secured stratigraphic context in the late Lower-early Middle Pleistocene Kabuh Formation. The remaining elements were surface finds which, based on coincidental sources of information, were inferred as coming from the Kabuh Formation. Mainly constituted of permanent molars, but also including one upper incisor and one upper premolar, this dental sample brings additional evidence for a marked degree of size variation and time-related structural reduction in Javanese H. erectus. This is notably expressed by a significant decrease of the mesiodistal diameter, frequently associated to the reduction or even loss of the lower molar distal cusp (hypoconulid) and to a more square occlusal outline. In addition to the hypoconulid reduction or loss, this new sample also exhibits a low frequency of the occlusal Y-groove pattern, with a dominance of the X and, to a lesser extent, of the+patterns. This combination is rare in the Lower and early Middle Pleistocene paleoanthropological record, including in the early Javanese dental assemblage from the Sangiran Dome. On the other hand, similar dental features are found in Chinese H. erectus and in H. heidelbergensis. As a whole, this new record confirms the complex nature of the intermittent exchanges that occurred between continental and insular Southeast Asia through the Pleistocene. PMID:23843996

Zanolli, Clément

2013-01-01

118

Additional Evidence for Morpho-Dimensional Tooth Crown Variation in a New Indonesian H. erectus Sample from the Sangiran Dome (Central Java)  

PubMed Central

This contribution reports fifteen human fossil dental remains found during the last two decades in the Sangiran Dome area, in Central Java, Indonesia. Among this sample, only one of the specimens had already been briefly described, with the other fourteen remaining unreported. Seven of the fifteen isolated teeth were found in a secured stratigraphic context in the late Lower-early Middle Pleistocene Kabuh Formation. The remaining elements were surface finds which, based on coincidental sources of information, were inferred as coming from the Kabuh Formation. Mainly constituted of permanent molars, but also including one upper incisor and one upper premolar, this dental sample brings additional evidence for a marked degree of size variation and time-related structural reduction in Javanese H. erectus. This is notably expressed by a significant decrease of the mesiodistal diameter, frequently associated to the reduction or even loss of the lower molar distal cusp (hypoconulid) and to a more square occlusal outline. In addition to the hypoconulid reduction or loss, this new sample also exhibits a low frequency of the occlusal Y-groove pattern, with a dominance of the X and, to a lesser extent, of the+patterns. This combination is rare in the Lower and early Middle Pleistocene paleoanthropological record, including in the early Javanese dental assemblage from the Sangiran Dome. On the other hand, similar dental features are found in Chinese H. erectus and in H. heidelbergensis. As a whole, this new record confirms the complex nature of the intermittent exchanges that occurred between continental and insular Southeast Asia through the Pleistocene. PMID:23843996

Zanolli, Clément

2013-01-01

119

Finding Fossils  

NSDL National Science Digital Library

This OLogy activity serves as a kid-friendly how-to manual about searching for fossils. In Not Just Any Rock Will Do, kids learn that fossils "hide out" in sedimentary rock and see examples of shale and sandstone. Do's and Don'ts for Fossil Hunters gives kids practical tips and a list of fossil-hunting supplies. In Fossils You May Find, there are photos of common invertebrate, vertebrate, and plant fossils to guide kids. Paleontology Clubs and Web Sites lists resources to help kids determine where to hunt for fossils. In Keeping a Field Journal, kids are shown a sample journal entry that points out the types of information they should record.

120

Fossils 1: Fossils and Dinosaurs  

NSDL National Science Digital Library

This lesson will go beyond naming dinosaurs and give students a broad understanding of how we know about the great beasts. This lesson focuses on what we have learned and can learn from fossils. The follow-up lesson, Dinosaurs Fossils - Uncovering the Facts, explores what information can be discerned by comparing fossils to living organisms.

Science Netlinks

2001-10-20

121

Fossil Find  

NSDL National Science Digital Library

In this classroom activity, middle school students simulate a "dinosaur dig." The activity opens with background information for teachers about fossils. Working in groups, students excavate fossil sites created in advance by the teacher, or other group of students, and try to reconstruct a chicken skeleton. The activity closes with a two-page student worksheet that directs students to diagram the fossil site and includes probing questions to help them decode their findings.

122

Fossil Excavation  

NSDL National Science Digital Library

In this activity students excavate their own fossil from a teacher-prepared "rock biscuit". Students chip away the matrix with wooden stirring rods (or sharpened wooden dowels) and glue brushes. In each biscuit is a genuine fossil such as a shark's tooth. The activity is designed to be the culmination of a lesson about fossil collecting, the importance of recording data, and different preparation methods.

123

The Emergence of Homo sapiens.  

ERIC Educational Resources Information Center

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

Rensberger, Boyce

1980-01-01

124

Finding Fossils  

NSDL National Science Digital Library

This activity (located on page 4 of the PDF) is a full inquiry investigation to determine the age of fossils based on where they are discovered. Groups of learners will dig for fossils embedded in a cake of multiple layers, carefully excavating each stratum and eventually preparing a chart from their notes for discussion with the group. The two main lessons from this exercise are that fossils from different layers come from different eras and that multiple interpretations of incomplete fossil evidence are possible. Relates to linked video, DragonflyTV GPS: Baby Dinosaurs.

2012-06-26

125

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

NASA Astrophysics Data System (ADS)

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

Dennell, Robin; Petraglia, Michael D.

2012-07-01

126

Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo.  

PubMed

Some primates, including chimpanzees, throw objects occasionally, but only humans regularly throw projectiles with high speed and accuracy. Darwin noted that the unique throwing abilities of humans, which were made possible when bipedalism emancipated the arms, enabled foragers to hunt effectively using projectiles. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence of when, how and why hominins evolved the ability to generate high-speed throws. Here we use experimental studies of humans throwing projectiles to show that our throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately 2?million years ago in the species Homo erectus. Taking into consideration archaeological evidence suggesting that hunting activity intensified around this time, we conclude that selection for throwing as a means to hunt probably had an important role in the evolution of the genus Homo. PMID:23803849

Roach, Neil T; Venkadesan, Madhusudhan; Rainbow, Michael J; Lieberman, Daniel E

2013-06-27

127

The evolution of humans in Australasia from an environmental perspective  

Microsoft Academic Search

Attempts to understand the evolution within the genus Homo in Australasia have relied on two main theories. The Multiregional scenario suggests that cranial morphology reveals a long-standing continuity between fossil and recent hominids in the region. Out of Africa theorist have favoured the idea that Homo sapiens evolved in Africa, migrated outward, and replaced archaic hominids, such as Homo erectus

Paul Storm

2001-01-01

128

Ediacara Fossils  

ERIC Educational Resources Information Center

Now, a research team from Virginia Tech and Nanjing Institute of Geology and Paleontology has discovered uniquely well-preserved fossil forms from 550-million-year-old rocks of the Ediacaran Period. The research appears in the Proceedings of the National Academy of Sciences. The discovery of these unusually preserved fossils reveals unprecedented…

Science Teacher, 2005

2005-01-01

129

Fossil Fuels.  

ERIC Educational Resources Information Center

This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

Crank, Ron

130

Fossil Fuels  

NSDL National Science Digital Library

How much does the United States depend on fossil fuels? This web page, part of a site on the future of energy, introduces students to fossil fuels as an energy source. Here students read about the uses, benefits, and limitations of fossil fuels. There is also information on how these fuels are distributed geographically and how they affect the U.S. economy through supply and demand. Thought-provoking questions afford students opportunities to reflect on what they've read. Articles about clean coal, the national energy policy, and the formation of fossil fuels, together with a fossil fuels fact sheet, are accessible from a sidebar. In addition, five PBS NewsHour links to energy-related stories are included.

Iowa Public Television. Explore More Project

2004-01-01

131

Fossil humans 1 Fossil humans  

E-print Network

, and close extinct rel- atives) recognizes the family Hylobatidae for the gib- bons and Hominidae for humansFossil humans 1 Fossil humans All prehistoric skeletal remains of humans which are archeologically, anatomically modern humans. In this sense, the term "humans" is used broadly to mean all primates related

Delson, Eric

132

Paleoanthropology. Late Pliocene fossiliferous sedimentary record and the environmental context of early Homo from Afar, Ethiopia.  

PubMed

Sedimentary basins in eastern Africa preserve a record of continental rifting and contain important fossil assemblages for interpreting hominin evolution. However, the record of hominin evolution between 3 and 2.5 million years ago (Ma) is poorly documented in surface outcrops, particularly in Afar, Ethiopia. Here we present the discovery of a 2.84- to 2.58-million-year-old fossil and hominin-bearing sediments in the Ledi-Geraru research area of Afar, Ethiopia, that have produced the earliest record of the genus Homo. Vertebrate fossils record a faunal turnover indicative of more open and probably arid habitats than those reconstructed earlier in this region, which is in broad agreement with hypotheses addressing the role of environmental forcing in hominin evolution at this time. Geological analyses constrain depositional and structural models of Afar and date the LD 350-1 Homo mandible to 2.80 to 2.75 Ma. PMID:25739409

DiMaggio, Erin N; Campisano, Christopher J; Rowan, John; Dupont-Nivet, Guillaume; Deino, Alan L; Bibi, Faysal; Lewis, Margaret E; Souron, Antoine; Garello, Dominique; Werdelin, Lars; Reed, Kaye E; Arrowsmith, J Ramón

2015-03-20

133

Fossil Halls  

NSDL National Science Digital Library

The American Museum of Natural History is home to the world's largest collection of vertebrate fossils, totaling nearly one million specimens. This Web site offers visitors a virtual visit to the Museum's famed Fossil Halls. It features sections on Cladistics, Vertebrate Evolution, Exhibit Specimens, a collection of 19 biographies of important people in paleontology and Virtual Tours of four of the halls. There is also an elementary school teacher guide to the museum exhibit.

134

Size, shape, and asymmetry in fossil hominins: The status of the LB1 cranium based on 3D morphometric analyses  

E-print Network

Size, shape, and asymmetry in fossil hominins: The status of the LB1 cranium based on 3D that LB1 best fits predictions for a small specimen of fossil Homo but not for a small modern human extant African ape species. Compared to other fossil specimens, the degree of asymmetry in LB1

Baab, Karen L.

135

Bird Fossils  

NSDL National Science Digital Library

A fossil of a small, feathered animal, Longisquama insignis, that lived approximately 220 million years ago (Ma) in what is now Central Asia, was re-discovered recently in the dusty drawers of a Moscow museum collection. This discovery has rocked the paleontological world because the fossil exhibits feather impressions, making it possibly the world's oldest known bird. Archaeopteryx, thought until now to be the oldest true bird, is from a limestone deposit in Germany dated at approximately 145 Ma. This new fossil discovery fires the debate over whether birds are descended from dinosaurs, or branched off from an earlier group of reptiles. This week's In The News takes a look at scientists' latest understanding of the reptile-bird evolutionary transition, and the surrounding controversies.

136

The status of Homo heidelbergensis (Schoetensack 1908).  

PubMed

The species Homo heidelbergensis is central to many discussions about recent human evolution. For some workers, it was the last common ancestor for the subsequent species Homo sapiens and Homo neanderthalensis; others regard it as only a European form, giving rise to the Neanderthals. Following the impact of recent genomic studies indicating hybridization between modern humans and both Neanderthals and "Denisovans", the status of these as separate taxa is now under discussion. Accordingly, clarifying the status of Homo heidelbergensis is fundamental to the debate about modern human origins. PMID:22718477

Stringer, Chris

2012-05-01

137

Dermatitis and systemic mycosis in lined seahorses Hippocampus erectus associated with a marine-adapted Fusarium solani species complex pathogen  

Technology Transfer Automated Retrieval System (TEKTRAN)

During a 4 month epizootic, 100% of 152 lined seahorses Hippocampus erectus in three separate groups died while in quarantine following shipment to a public aquarium. Twelve animals with skin depigmentation and ulceration were received by the Aquatic Pathology Service, University of Georgia, College...

138

Fossil Identification  

NSDL National Science Digital Library

This activity asks students to identify examples of types of fossils amongst the exhibits at the Museum of the Earth at the Paleontological Research Institution in Ithaca, New York. Students will build on their understanding of the history of life, paleontology, taphonomy, ichnology, and paleoecologyâespecially reefs.

Connie Soja, Colgate University, csoja@colgate.edu

139

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

PubMed

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

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

2008-10-01

140

Fossil Fuels  

NSDL National Science Digital Library

The Department of Energy Web site Fossil Fuels is billed as an energy education site mainly for older kids, but can be enjoyed by adult kids as well. The site gives an introduction to energy, and then a more detailed look at the acquisition and uses of coal, oil, and gas. The good descriptions, illustrations, and animations, along with the frequent questions page and glossary of related terms, combine to give a clear and enlightening overview of the subject.

141

Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo  

PubMed Central

Although some primates, including chimpanzees, throw objects occasionally1,2, only humans regularly throw projectiles with high speed and great accuracy. Darwin noted that humans’ unique throwing abilities, made possible when bipedalism emancipated the arms, enabled foragers to effectively hunt using projectiles3. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence on when, how, and why hominins evolved the ability to generate high-speed throws4-8. Here, we show using experimental studies of throwers that human throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately two million years ago in the species Homo erectus. Given archaeological evidence that suggests hunting activity intensified around this time9, we conclude that selection for throwing in order to hunt likely played an important role in the evolution of the human genus. PMID:23803849

Roach, Neil T.; Venkadesan, Madhusudhan; Rainbow, Michael J.; Lieberman, Daniel E.

2013-01-01

142

Genetic and Fossil Evidence for the Origin of Modern Humans  

Microsoft Academic Search

The origin of living Homo sapiens has once again been the subject of much debate. Genetic data on present human population relationships and data from the Pleistocene fossil hominid record are used to compare two contrasting models for the origin of modern humans. Both genetics and paleontology support a recent African origin for modern humans rather than a long period

C. B. Stringer; P. Andrews

1988-01-01

143

Describing Fossils  

NSDL National Science Digital Library

Students are given a description of a fossil brachiopod, from the literature, along with a one-page handout describing the basic morphology of brachiopods. Students work independently to make a scale drawing of the fossil described (brachial valve, pedicle valve, anterior view, lateral view). They have access to textbooks (Moore, Laliker & Fisher; Clarkson), the Treatise volume, and the internet to get information on morphological terms. This takes about an hour, after which I display all of the diagrams on the wall along with the photographs from the paper from which the description was extracted. We discuss some of the differences and where problems arose in interpreting the description. I emphasize the importance of an accurate drawing or photograph to accompany a description. Students are then given a different brachiopod specimen and asked to produce a written description (pedicle-valve, brachial valve, anterior view, lateral view) of their fossil similar to the one that they readâi.e. using all of the appropriate terms. They are told that other students will be trying to match their description to their specimen. I collect all of the descriptions, edit them (remove portions that use incorrect terminology or inappropriate), and produce a handout of all of the descriptions. At the next class, students are given the descriptions and asked to match descriptions to specimens. They do this independently outside of class. The specimens are made available in the lab room for several days. I add a couple of 'extra' specimens (without description) so that it is not a process of elimination.

Judy Massare

144

Crown size and cusp proportions in Homo antecessor upper first molars. A comment on Quam et al. 2009  

PubMed Central

A recent evaluation of upper first molar (M1) crown size and cusp proportions in the genus Homo (Quam et al. 2009) describes Homo antecessor as maintaining a primitive pattern of cusp proportions, similar to that identified in australopithecines and the earliest members of the genus Homo. These results contrast with those of Gómez-Robles et al. (2007), who described the crown shape in these molars as derived and similar to Neanderthals and European Homo heidelbergensis. The reassessment of these measurements following the same methodology described by Quam et al. (2009) in all the M1s that are currently part of the hypodigm of H. antecessor demonstrates that the fossils from TD6 not only have the same cusp proportions identified in later Homo species, but also a strongly reduced metacone and a large hypocone shared with Middle and Upper Pleistocene members of the Neanderthal lineage. The evolutionary significance of these features should be evaluated in light of the results provided by recently discovered dental, cranial, mandibular, and postcranial H. antecessor fossils. PMID:21208207

Gómez-Robles, Aida; de Castro, José María Bermúdez; Martinón-Torres, María; Prado-Simón, Leyre

2011-01-01

145

Crown size and cusp proportions in Homo antecessor upper first molars. A comment on Quam et al. 2009.  

PubMed

A recent evaluation of upper first molar (M¹) crown size and cusp proportions in the genus Homo (Quam et al. 2009) describes Homo antecessor as maintaining a primitive pattern of cusp proportions, similar to that identified in australopithecines and the earliest members of the genus Homo. These results contrast with those of Gómez-Robles et al. (2007), who described the crown shape in these molars as derived and similar to Neanderthals and European Homo heidelbergensis. The reassessment of these measurements following the same methodology described by Quam et al. (2009) in all the M(1) s that are currently part of the hypodigm of H. antecessor demonstrates that the fossils from TD6 not only have the same cusp proportions identified in later Homo species, but also a strongly reduced metacone and a large hypocone shared with Middle and Upper Pleistocene members of the Neanderthal lineage. The evolutionary significance of these features should be evaluated in light of the results provided by recently discovered dental, cranial, mandibular, and postcranial H. antecessor fossils. PMID:21208207

Gómez-Robles, Aida; de Castro, José María Bermúdez; Martinón-Torres, María; Prado-Simón, Leyre

2011-02-01

146

The evolutionary history of the hominin hand since the last common ancestor of Pan and Homo  

PubMed Central

Molecular evidence indicates that the last common ancestor of the genus Pan and the hominin clade existed between 8 and 4 million years ago (Ma). The current fossil record indicates the Pan-Homo last common ancestor existed at least 5 Ma and most likely between 6 and 7 Ma. Together, the molecular and fossil evidence has important consequences for interpreting the evolutionary history of the hand within the tribe Hominini (hominins). Firstly, parsimony supports the hypothesis that the hand of the last common ancestor most likely resembled that of an extant great ape overall (Pan, Gorilla, and Pongo), and that of an African ape in particular. Second, it provides a context for interpreting the derived changes to the hand that have evolved in various hominins. For example, the Australopithecus afarensis hand is likely derived in comparison with that of the Pan–Homo last common ancestor in having shorter fingers relative to thumb length and more proximo-distally oriented joints between its capitate, second metacarpal, and trapezium. This evidence suggests that these derived features evolved prior to the intensification of stone tool-related hominin behaviors beginning around 2.5 Ma. However, a majority of primitive features most likely present in the Pan-Homo last common ancestor are retained in the hands of Australopithecus, Paranthropus/early Homo, and Homo floresiensis. This evidence suggests that further derived changes to the hands of other hominins such as modern humans and Neandertals did not evolve until after 2.5 Ma and possibly even later than 1.5 Ma, which is currently the earliest evidence of Acheulian technology. The derived hands of modern humans and Neandertals may indicate a morphological commitment to tool-related manipulative behaviors beyond that observed in other hominins, including those (e.g. H. floresiensis) which may be descended from earlier tool-making species. PMID:18380869

Tocheri, Matthew W; Orr, Caley M; Jacofsky, Marc C; Marzke, Mary W

2008-01-01

147

Technical note: virtual reconstruction of KNM-ER 1813 Homo habilis cranium.  

PubMed

A very limiting factor for paleoanthropological studies is the poor state of preservation of the human fossil record, where fragmentation and deformation are considered normal. Although anatomical information can still be gathered from a distorted fossil, such specimens must typically be excluded from advanced morphological and morphometric analyses, thus reducing the fossil sample size and, ultimately, our knowledge of human evolution. In this contribution we provide the first digital reconstruction of the KNM-ER 1813 Homo habilis cranium. Based on state of-the-art three-dimensional digital modeling and geometric morphometric (GM) methods, the facial portion was aligned to the neurocranium, the overall distortion was removed, and the missing regions were restored. The reconstructed KNM-ER 1813 allows for an adjustment of the anthropometric measurements gathered on the original fossil. It is suitable for further quantitative studies, such as GM analyses focused on skull morphology or for finite element analysis to explore the mechanics of early Homo feeding behavior and diet. PMID:24318950

Benazzi, Stefano; Gruppioni, Giorgio; Strait, David S; Hublin, Jean-Jacques

2014-01-01

148

Genetic, physiologic and ecogeographic factors contributing to variation in Homo sapiens: Homo floresiensis reconsidered  

Microsoft Academic Search

A new species, Homo floresiensis, was recently named for Pleistocene hominid remains on Flores, Indonesia. Significant controversy has arisen regarding this species. To address controversial issues and refocus investigations, I examine the affinities of these remains with Homo sapiens. Clarification of problematic issues is sought through an integration of genetic and physiological data on brain ontogeny and evolution. Clarification of

GARY D. RICHARDS

2006-01-01

149

Are the oldest 'fossils', fossils  

NASA Technical Reports Server (NTRS)

A comparative statistical study has been carried out on populations of modern algae, Precambrian algal microfossils, the 'organized elements' of the Orgueil carbonaceous meteorite, and the oldest microfossil-like objects now known (spheroidal bodies from the Fig Tree and Onverwacht Groups of the Swaziland Supergroup, South Africa). The distribution patterns exhibited by the more than 3000 m.y.-old Swaziland microstructures bear considerable resemblance to those of the abiotic 'organized elements' but differ rather markedly from those exhibited by younger, assuredly biogenic, populations. Based on these comparisons, it is concluded that the Swaziland spheroids could be, at least in part, of nonbiologic origin; these oldest known fossil-like microstructures should not be regarded as constituting firm evidence of Archean life.

Schopf, J. W.

1976-01-01

150

Will My Fossil Float?  

ERIC Educational Resources Information Center

Explains how young students can be introduced to fossils. Suggests books to read and science activities including "Fossils to Eat" where students make fossils from peanut butter, honey, and powdered milk. (PR)

Riesser, Sharon; Airey, Linda

1993-01-01

151

What Is a Fossil?  

NSDL National Science Digital Library

In this classroom activity, young students explore the differences between bone and trace fossils. The activity opens with background information for teachers about fossils. After describing what a fossil is in their own words, students learn that a fossil is "any evidence of life that is at least 10,000 years old." They then explore the differences between trace and bone fossils by examining pictures. The activity concludes with a student worksheet that challenges them to identify trace and bone fossils.

152

Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany  

PubMed Central

The Mauer mandible, holotype of Homo heidelbergensis, was found in 1907 in fluvial sands deposited by the Neckar River 10 km southeast of Heidelberg, Germany. The fossil is an important key to understanding early human occupation of Europe north of the Alps. Given the associated mammal fauna and the geological context, the find layer has been placed in the early Middle Pleistocene, but confirmatory chronometric evidence has hitherto been missing. Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 ± 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa. We address the paleoanthropological significance of the Mauer jaw in light of this dating evidence. PMID:21041630

Wagner, Günther A.; Krbetschek, Matthias; Degering, Detlev; Bahain, Jean-Jacques; Shao, Qingfeng; Falguères, Christophe; Voinchet, Pierre; Dolo, Jean-Michel; Garcia, Tristan; Rightmire, G. Philip

2010-01-01

153

Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany.  

PubMed

The Mauer mandible, holotype of Homo heidelbergensis, was found in 1907 in fluvial sands deposited by the Neckar River 10 km southeast of Heidelberg, Germany. The fossil is an important key to understanding early human occupation of Europe north of the Alps. Given the associated mammal fauna and the geological context, the find layer has been placed in the early Middle Pleistocene, but confirmatory chronometric evidence has hitherto been missing. Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 ± 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa. We address the paleoanthropological significance of the Mauer jaw in light of this dating evidence. PMID:21041630

Wagner, Günther A; Krbetschek, Matthias; Degering, Detlev; Bahain, Jean-Jacques; Shao, Qingfeng; Falguères, Christophe; Voinchet, Pierre; Dolo, Jean-Michel; Garcia, Tristan; Rightmire, G Philip

2010-11-16

154

New taphonomical approaches: The Javanese Pleistocene open-air sites (Sangiran, central Java)  

Microsoft Academic Search

Since the 1960s, the National Indonesian Center for Archaeological Research, in collaboration with the Gajah Mada University, has been organizing field excavations on open-air sites in the Sangiran dome, one of the most famous places of palaeoanthropological discoveries in Southeast Asia. That project led to the discovery of Homo erectus fossils, and the collection of numerous mammal fossils in localities

Anne Bouteaux; Anne-Marie Moigne

2010-01-01

155

Fossils, Rocks, and Time  

NSDL National Science Digital Library

This on-line book, published by the United States Geological Survey (USGS), discusses the use of fossils in determining the age of rocks. The publication covers how to place events in correct temporal order, a description of the geologic time scale, the use of fossils to indicate rock ages, the law of fossil succession, index fossils, and radioactive dating.

Lucy E. Edwards

1997-06-26

156

Deductions from Fossil Preservtion  

NSDL National Science Digital Library

Students will view fossils, sometimes with supporting illustrations, and answer questions about them via deductive reasoning. The exercise is highly interactive, with the instructor providing hints and helpful questions. The questions concern ways in which fossil preservation reveals information about things like what kind of organism the fossil represents, how that organism lived, and how the fossil came into being.

Steven Stanley

157

A review of early Homo in southern Africa focusing on cranial, mandibular and dental remains, with the description of a new species (Homo gautengensis sp. nov.).  

PubMed

The southern African sample of early Homo is playing an increasingly important role in understanding the origins, diversity and adaptations of the human genus. Yet, the affinities and classification of these remains continue to be in a state of flux. The southern African sample derives from five karstic palaeocave localities and represents more than one-third of the total African sample for this group; sampling an even wider range of anatomical regions than the eastern African collection. Morphological and phenetic comparisons of southern African specimens covering dental, mandibular and cranial remains demonstrate this sample to contain a species distinct from known early Homo taxa. The new species Homo gautengensis sp. nov. is described herein: type specimen Stw 53; Paratypes SE 255, SE 1508, Stw 19b/33, Stw 75-79, Stw 80, Stw 84, Stw 151, SK 15, SK 27, SK 45, SK 847, SKX 257/258, SKX 267/268, SKX 339, SKX 610, SKW 3114 and DNH 70. H. gautengensis is identified from fossils recovered at three palaeocave localities with current best ages spanning approximately 2.0 to 1.26-0.82 million years BP. Thus, H. gautengensis is probably the earliest recognised species in the human genus and its longevity is apparently well in excess of H. habilis. PMID:20466364

Curnoe, D

2010-06-01

158

Genetics and the making of Homo sapiens  

Microsoft Academic Search

Understanding the genetic basis of the physical and behavioural traits that distinguish humans from other primates presents one of the great new challenges in biology. Of the millions of base-pair differences between humans and chimpanzees, which particular changes contributed to the evolution of human features after the separation of the Pan and Homo lineages 5–7 million years ago? How can

Sean B. Carroll

2003-01-01

159

Description, new reconstruction, comparative anatomy, and classification of the Sterkfontein Stw 53 cranium, with discussions about the taxonomy of other southern African early Homo remains  

Microsoft Academic Search

Specimen Stw 53 was recovered in 1976 from Member 5 of the Sterkfontein Formation. Since its incomplete initial description and comparison, the partial cranium has figured prominently in discussions about the systematics of early Homo. Despite publication of a preliminary reconstruction in 1985, Stw 53 has yet to be compared comprehensively to other Plio-Pleistocene fossils or assessed systematically. In this

Darren Curnoe; Phillip V. Tobias

2006-01-01

160

Mandible and Taxonomy of the Earliest European Homo  

Microsoft Academic Search

Although variability of the mandible makes it problematic for taxonomy, the holotypes of three of the oldest European species,\\u000a Home georgicus, H. antecessor, H. heidelbergensis, are mandibles. Moreover, the distinctive validity of these three species cannot be established from these particular mandibles.\\u000a The holotype of H. georgicus is pathological and similar to H. erectus in some important features, while others

P. F. Fabbri

2006-01-01

161

Influences of limb proportions and body size on locomotor kinematics in terrestrial primates and fossil hominins.  

PubMed

During locomotion, mammalian limb postures are influenced by many factors including the animal's limb length and body mass. Polk (2002) compared the gait of similar-sized cercopithecine monkeys that differed limb proportions and found that longer-limbed monkeys usually adopt more extended joint postures than shorter-limbed monkeys in order to moderate their joint moments. Studies of primates as well as non-primate mammals that vary in body mass have demonstrated that larger animals use more extended limb postures than smaller animals. Such extended postures in larger animals increase the extensor muscle mechanical advantage and allow postures to be maintained with relatively less muscular effort (Polk, 2002; Biewener 1989). The results of these previous studies are used here to address two anthropological questions. The first concerns the postural effects of body mass and limb proportion differences between australopithecines and members of the genus Homo. That is, H. erectus and later hominins all have larger body mass and longer legs than australopithecines, and these anatomical differences suggest that Homo probably used more extended postures and probably required relatively less muscular force to resist gravity than the smaller and shorter-limbed australopithecines. The second question investigates how animals with similar size but different limb proportions differ in locomotor performance. The effects of limb proportions on gait are relevant to inferring postural and locomotor differences between Neanderthals and modern Homo sapiens which differ in their crural indices and relative limb length. This study demonstrates that primates with relatively long limbs achieve higher walking speeds while using lower stride frequencies and lower angular excursions than shorter-limbed monkeys, and these kinematic differences may allow longer-limbed taxa to locomote more efficiently than shorter-limbed species of similar mass. Such differences may also have characterized the gait of Homo sapiens in comparison to Neanderthals, but more experimental data on humans that vary in limb proportions are necessary in order to evaluate this question more thoroughly. PMID:15454335

Polk, J D

2004-10-01

162

Transitional Tetrapod Fossil  

NSDL National Science Digital Library

In this video segment from NOVA: Judgment Day: Intelligent Design on Trial, learn about the discovery of a well-preserved transitional fossil and how such transitional fossils support the theory of evolution.

WGBH Educational Foundation

2007-11-01

163

Fun with Fossils  

NSDL National Science Digital Library

Fossils provide a valuable record of the plant and animal life and environmental conditions from millions, even billions of years ago. In this lesson, students create their own fossils, and then use multimedia resources to learn how real fossils form and what scientists can learn from them. They should understand that fossils provide evidence of plants and animals that lived long ago, as well as the environmental conditions at that time. Instructions, a materials list, and links to multimedia resources are provided.

2005-01-01

164

Picture Matching Fossils  

NSDL National Science Digital Library

Teaching the students how to picture match fossils and to use the Treatise to find more information. Students are given a wide range of fossils to look at and appropriate material to match their fossil to an image which gives the genus and species name. With that information, the students turn to the Treatise of Invertebrate Paleontology to find upper level taxonomic names.

Elizabeth Rhenberg

165

Follow a Fossil  

NSDL National Science Digital Library

The Follow a Fossil Web site is presented by the Denver Museum of Nature and Science. It documents the prospecting, evacuation, preparation, curation, research, and exhibiting of vertebrate, invertebrate, and plant fossils. The site is simple and effective, giving a good introduction to the process of finding and using fossils for learning about the past.

166

Is It a Fossil?  

NSDL National Science Digital Library

This formative assessment item is used to uncover students' ideas about fossils before a lesson has begun. Students will determine whether examples are fossils, and what sort of inferences can be made about prior environments because of fossils. This probe is aligned with the National Science Education Standards. Resources are provided along with instructional suggestions.

Jessica Fries-Gaither

167

Face-to-Fossil  

NSDL National Science Digital Library

This Web article is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here they meet Deena Soris, who interviews the fossil of a Protoceratops. The more-than-20 questions answered by this dinosaur fossil cover topics such as what were you like when you were alive and how did you become a fossil.

168

A description of the geological context, discrete traits, and linear morphometrics of the Middle Pleistocene hominin from Dali, Shaanxi Province, China.  

PubMed

In 1978, a nearly complete hominin fossil cranium was recovered from loess deposits at the site of Dali in Shaanxi Province, northwestern China. It was subsequently briefly described in both English and Chinese publications. Here we present a comprehensive univariate and nonmetric description of the specimen and provide comparisons with key Middle Pleistocene Homo erectus and non-erectus hominins from Eurasia and Africa. In both respects we find affinities with Chinese H. erectus as well as African and European Middle Pleistocene hominins typically referred to as Homo heidelbergensis. Specifically, the Dali specimen possesses a low cranial height, relatively short and arched parietal bones, an angled occipital bone, and a nonprominent articular tubercle relative to the preglenoid surface all of which distinguish it from Afro/European Middle Pleistocene Homo and align it with Asian H. erectus. At the same time, it displays a more derived morphology of the supraorbital torus and supratoral sulcus and a thinner tympanic plate than H. erectus, a relatively long upper (lambda-inion) occipital plane with a clear separation of inion and opisthocranion, and an absolute and relative increase in brain size, all of which align it with African and European Middle Pleistocene Homo. Finally, traits such as the form of the frontal keel and the relatively short, broad midface align Dali specifically with other Chinese specimens from the Middle Pleistocene and Late Pleistocene, including H. erectus, and differentiate these from the Afro/European specimens of this time period. PMID:23283667

Wu, Xinzhi; Athreya, Sheela

2013-01-01

169

A new hominid fossil skull (L.H. 18) from the Ngaloba Beds, Laetoli, northern Tanzania  

Microsoft Academic Search

In 1976, a fossil hominid skull was recovered from the Ngaloba Beds at Laetoli, Northern Tanzania; its morphology is discussed here. The discovery of this skull is of great interest and importance because of its very substantial presumed antiquity and its largely anatomically modern morphology. The discovery has considerable implications for the antiquity and origin of modern Homo sapiens, a

M. H. Day; M. D. Leakey; C. Magori

1980-01-01

170

Fossils of Kentucky  

NSDL National Science Digital Library

Information on Kentucky fossils is organized by type, age, and region. General fossil facts are given, and there are out-of-print technical reports available at this site. A fossil identification key helps users identify unknown fossils by shape or by descriptive terms. A Geologic and Paleontologic Cookbook offers directions for creating edible models that illustrate prehistoric and other Earth Science concepts (such as trilobite cookies and layer-cake geology). There are links to more K-12 activities and other fossil websites.

171

Genome Digging: Insight into the Mitochondrial Genome of Homo  

PubMed Central

Background A fraction of the Neanderthal mitochondrial genome sequence has a similarity with a 5,839-bp nuclear DNA sequence of mitochondrial origin (numt) on the human chromosome 1. This fact has never been interpreted. Although this phenomenon may be attributed to contamination and mosaic assembly of Neanderthal mtDNA from short sequencing reads, we explain the mysterious similarity by integration of this numt (mtAncestor-1) into the nuclear genome of the common ancestor of Neanderthals and modern humans not long before their reproductive split. Principal Findings Exploiting bioinformatics, we uncovered an additional numt (mtAncestor-2) with a high similarity to the Neanderthal mtDNA and indicated that both numts represent almost identical replicas of the mtDNA sequences ancestral to the mitochondrial genomes of Neanderthals and modern humans. In the proteins, encoded by mtDNA, the majority of amino acids distinguishing chimpanzees from humans and Neanderthals were acquired by the ancestral hominins. The overall rate of nonsynonymous evolution in Neanderthal mitochondrial protein-coding genes is not higher than in other lineages. The model incorporating the ancestral hominin mtDNA sequences estimates the average divergence age of the mtDNAs of Neanderthals and modern humans to be 450,000–485,000 years. The mtAncestor-1 and mtAncestor-2 sequences were incorporated into the nuclear genome approximately 620,000 years and 2,885,000 years ago, respectively. Conclusions This study provides the first insight into the evolution of the mitochondrial DNA in hominins ancestral to Neanderthals and humans. We hypothesize that mtAncestor-1 and mtAncestor-2 are likely to be molecular fossils of the mtDNAs of Homo heidelbergensis and a stem Homo lineage. The dN/dS dynamics suggests that the effective population size of extinct hominins was low. However, the hominin lineage ancestral to humans, Neanderthals and H. heidelbergensis, had a larger effective population size and possessed genetic diversity comparable with those of chimpanzee and gorilla. PMID:21151557

Ovchinnikov, Igor V.; Kholina, Olga I.

2010-01-01

172

Fossilized bioelectric wire - the trace fossil Trichichnus  

NASA Astrophysics Data System (ADS)

The trace fossil Trichichnus is proposed as an indicator of fossil bioelectric bacterial activity at the interface oxic - anoxic zone of marine sediments. This fulfils the idea that such processes, commonly found in the modern realm, should be also present in the geological past. Trichichnus is an exceptional trace fossil due to its very thin diameter (mostly less than 1 mm) and common pyritic filling. It is ubiquitous in some fine-grained sediments, where it has been interpreted as a burrow formed deeper than any other trace fossils, below the redox boundary. Trichichnus formerly referred to as deeply burrowed invertebrates, has been found as remnant of a fossilized intrasediment bacterial mat that is pyritized. As visualized in 3-D by means of X-ray computed microtomography scanner, Trichichnus forms dense filamentous fabric, which reflects that produced by modern large, mat-forming, sulphide-oxidizing bacteria, belonging mostly to Trichichnus-related taxa, which are able to house a complex bacterial consortium. Several stages of Trichichnus formation, including filamentous, bacterial mat and its pyritization, are proposed to explain an electron exchange between oxic and suboxic/anoxic layers in the sediment. Therefore, Trichichnus can be considered a fossilized "electric wire".

K?dzierski, M.; Uchman, A.; Sawlowicz, Z.; Briguglio, A.

2014-12-01

173

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

PubMed

Mammalian lipoxygenases (LOXs) have been implicated in cell differentiation and in the biosynthesis of pro- and anti-inflammatory lipid mediators. The initial draft sequence of the Homo neanderthalensis genome (coverage of 1.3-fold) suggested defective leukotriene signaling in this archaic human subspecies since expression of essential proteins appeared to be corrupted. Meanwhile high quality genomic sequence data became available for two extinct human subspecies (H. neanderthalensis, Homo denisovan) and completion of the human 1000 genome project provided a comprehensive database characterizing the genetic variability of the human genome. For this study we extracted the nucleotide sequences of selected eicosanoid relevant genes (ALOX5, ALOX15, ALOX12, ALOX15B, ALOX12B, ALOXE3, COX1, COX2, LTA4H, LTC4S, ALOX5AP, CYSLTR1, CYSLTR2, BLTR1, BLTR2) from the corresponding databases. Comparison of the deduced amino acid sequences in connection with site-directed mutagenesis studies and structural modeling suggested that the major enzymes and receptors of leukotriene signaling as well as the two cyclooxygenase isoforms were fully functional in these two extinct human subspecies. PMID:25447821

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

2015-01-01

174

Fossil Mapping of Utah  

NSDL National Science Digital Library

Fossils are evidence of living organisms from the past and are usually preserved in sedimentary rocks. A fossil may be an impression left in sediments, the preserved remains of an organism, or a trace mark showing that an organism once existed. Fossils are usually made from the hard parts of an organism because soft parts decay quickly. Fossils provide clues to Earth's history. They provide evidence that can be used to make inferences about past environments. Fossils can be compared to one another, to living organisms, and to organisms that lived long ago. Students will understand how fossils are formed, where they may be found in Utah, and how they can be used to make inferences. Research locations where fossils are found in Utah and construct a simple fossil map. 4th Grade Utah Core Curriculum, Science Benchmark, Standard 4, Objective 1, UEN TASK Congratulations. You have all become Paleontologists. You study fossils and it is your job to map the fossils of Utah for the State. Students will be divided into 4 groups. Each group will be given a Utah County Map. Each group will focus on one category ...

Ramsey

2009-11-18

175

Fossil Energy Website  

NSDL National Science Digital Library

This site serves as a gathering point for US Department of Energy (USDOE) materials related to fossil energy. Well-organized and easily navigated, the Fossil Energy Website hosts a wealth of resources, including fossil energy news, related USDOE budget information, an events calendar, in-depth explorations of selected issues, speeches and testimony, technical reports, statistics, and an overview of fossil energy-related global activities, among others. Additional resources include regulatory information, a news headlines ticker, a free email update service, related links, and professional notices.

176

Plant Fossil Record  

NSDL National Science Digital Library

The International Organization of Palaeobotany (IOP) manages the Plant Fossil Record (PFR) database. The recently released version of the database, PFR2.2, offers descriptive details of most plant fossil genera and modern genera with fossil species. Based on "the scientific literature ... or museum collections," the database is organized into five sections: Genera (references for plant fossil genera published mostly before 1985), Descriptions (containing descriptive details of "the type specimens of more than 10,000 extinct plant genera"), Taxonomy (an "informal system of vascular plant classification" based on published schemes), Occurrences (distribution information and references), and Palaeo Maps.

177

Descriptions of the lower limb skeleton of Homo floresiensis.  

PubMed

Bones of the lower extremity have been recovered for up to nine different individuals of Homo floresiensis - LB1, LB4, LB6, LB8, LB9, LB10, LB11, LB13, and LB14. LB1 is represented by a bony pelvis (damaged but now repaired), femora, tibiae, fibulae, patellae, and numerous foot bones. LB4/2 is an immature right tibia lacking epiphyses. LB6 includes a fragmentary metatarsal and two pedal phalanges. LB8 is a nearly complete right tibia (shorter than that of LB1). LB9 is a fragment of a hominin femoral diaphysis. LB10 is a proximal hallucal phalanx. LB11 includes pelvic fragments and a fragmentary metatarsal. LB13 is a patellar fragment, and LB14 is a fragment of an acetabulum. All skeletal remains recovered from Liang Bua were extremely fragile, and some were badly damaged when they were removed temporarily from Jakarta. At present, virtually all fossil materials have been returned, stabilized, and hardened. These skeletal remains are described and illustrated photographically. The lower limb skeleton exhibits a uniquely mosaic pattern, with many primitive-like morphologies; we have been unable to find this combination of ancient and derived (more human-like) features in either healthy or pathological modern humans, regardless of body size. Bilateral asymmetries are slight in the postcranium, and muscle markings are clearly delineated on all bones. The long bones are robust, and the thickness of their cortices is well within the ranges seen in healthy modern humans. LB1 is most probably a female based on the shape of her greater sciatic notch, and the marked degree of lateral iliac flaring recalls that seen in australopithecines such as "Lucy" (AL 288-1). The metatarsus has a human-like robusticity formula, but the proximal pedal phalanges are relatively long and robust (and slightly curved). The hallux is fully adducted, but we suspect that a medial longitudinal arch was absent. PMID:19062072

Jungers, W L; Larson, S G; Harcourt-Smith, W; Morwood, M J; Sutikna, T; Due Awe, Rokhus; Djubiantono, T

2009-11-01

178

Dental microwear texture analysis and diet in the Dmanisi hominins Herman Pontzera,*, Jessica R. Scottb  

E-print Network

Dental microwear texture analysis and diet in the Dmanisi hominins Herman Pontzera,*, Jessica R: Homo erectus Evolution Microwear Diet Dmanisi a b s t r a c t Reconstructions of foraging behavior and diet are central to our understanding of fossil hominin ecology and evolution. Current hypotheses

Pontzer, Herman

179

Fossil Dig Site  

NSDL National Science Digital Library

In this activity (located on page 5 of PDF), learners work in groups to create dig sites for display. Learners arrange dry, uncooked pasta "bones" to resemble dinosaur fossils on a foam tray of wet soil. Use this activity to introduce learners to dinosaur anatomy, dig sites, fossils, and paleontology in general.

Chicago Children's Museum

2011-01-01

180

"It's Alive!" Fossil Activity  

NSDL National Science Digital Library

The first lab activity for the course is called "PaleontologyâPast, Present, and Future". In addition to discussing several documents related to present and future research directions in the field, students review a brief timeline of the historical development of paleontology as a science. Then they get their first opportunity to work directly with fossils. Students are presented with a set of fossil specimens in boxes (with no identifying labels). Each student selects one fossil of their own. They are asked to make and record very close, detailed observations of the specimen, and to sketch the fossil. Then they are told to "think like it's 1600." Someone has brought this object, taken out of the local rocks, for the student to investigate. The student must write a "proof" that this fossil was obviously once alive, and is not just an interesting mineral or rock formation. They can use their observations, compare the specimen to other objects with which they're familiar, resort to pure logic, or apply any other avenue of argumentation they think will help make their case. Note: In the next lab, on fossil preservation and taphonomy, the students revisit their fossil specimen, and determine its mode of preservation. Indeed, the student's "pet fossil" could be used throughout the course to illustrate various components of the course content.

Peg Yacobucci

181

Trace Fossil Image Database  

NSDL National Science Digital Library

This database from Emory University consists of images and basic information concerning trace fossils photographed by Anthony Martin. Included in this information is the formation, age, and locality of the specimen if known. Many of the images were originally photographed while in the field, and each type of trace fossil has numerous examples to browse through.

Anthony Martin

182

Dinosaur Footprints & Fossils  

NSDL National Science Digital Library

In this activity, early learners simulate fossil prints in play dough or clay. Using plastic dinosaur feet to make footprints on their “mud” (much as dinosaurs walked around their habitat) and harvest items (leaves, corn, twigs, acorns) to make impressions, learners simulate fossil prints. This resource includes open-ended discussion questions to encourage reflection.

2012-12-27

183

Make a Model Fossil  

NSDL National Science Digital Library

This activity is a combination outdoor/indoor lab where students will collect natural materials from the environment and use them to create both a mold and cast model of a fossil. Students will learn how a fossil is formed and why scientists use models to help them understand how things work and develop.

184

Bacteria: Fossil Record  

NSDL National Science Digital Library

This description of the fossil record of bacteria focuses on one particular group of bacteria, the cyanobacteria or blue-green algae, which have left a fossil record that extends far back into the Precambrian. The oldest cyanobacteria-like fossils known are nearly 3.5 billion years old and are among the oldest fossils currently known. Cyanobacteria are larger than most bacteria and may secrete a thick cell wall. More importantly, cyanobacteria may form large layered structures, called stromatolites (if more or less dome-shaped) or oncolites (if round). The site also refers to pseudomorphs of pyrite and siderite, and a group of bacteria known as endolithic. Two links are available for more information. One provides information on the discovery of possible remains of bacteria-like organisms on a meteorite from Mars and the other has a research report on fossilized filamentous bacteria and other microbes, found in Cretaceous amber.

185

Fossil fuels -- future fuels  

SciTech Connect

Fossil fuels -- coal, oil, and natural gas -- built America`s historic economic strength. Today, coal supplies more than 55% of the electricity, oil more than 97% of the transportation needs, and natural gas 24% of the primary energy used in the US. Even taking into account increased use of renewable fuels and vastly improved powerplant efficiencies, 90% of national energy needs will still be met by fossil fuels in 2020. If advanced technologies that boost efficiency and environmental performance can be successfully developed and deployed, the US can continue to depend upon its rich resources of fossil fuels.

NONE

1998-03-01

186

Fossil Identification Project  

NSDL National Science Digital Library

Students attend a class fieldtrip where over five locations across Tennessee representing three different geological time periods (Ordovician, Devonian, and Cretaceous) are visited. The students are required to collect 20 different taxa (5 of which must be unique to each student) and then using the knowledge they have gained in labs identify their taxa to species level. They must make a powerpoint presentation summarizing the paleocological and paleoclimatological information gained about each locality through the collection of the fossil taxa. The activity helps familiarize students with the geology of Tennessee and field collection of fossils in addition to lab identification of fossils.

Melissa Lobegeier

187

Brief communication: two human fossil deciduous molars from the Sangiran dome (Java, Indonesia): outer and inner morphology.  

PubMed

Currently, the human deciduous dental record from the Pleistocene deposits of the Sangiran Dome, Java, consists of only eight specimens. Here we report two deciduous crowns collected near the village of Pucung. While their precise geo-chronological context remains unknown, a provenance from the Early-Middle Pleistocene Kabuh Formation, or from the Early Pleistocene "Grenzbank Zone," is very likely. These isolated specimens consist of an upper first molar (PCG.1) and a lower second molar (PCG.2). Taxonomic discrimination of the Indonesian tooth record is difficult because of the convergence in crown size and appearance between Pongo and Homo. Accordingly, as PCG.2 still bears a concretion masking most of its features, we coupled the outer analysis of the two specimens with an investigation of their inner morphology. In addition to external characteristics, virtual imaging and quantitative assessment of inner morphology and tissue proportions support an attribution to the taxon Homo, and we preliminary allocate both specimens toH. erectus. PMID:22281866

Zanolli, Clément; Bondioli, Luca; Mancini, Lucia; Mazurier, Arnaud; Widianto, Harry; Macchiarelli, Roberto

2012-03-01

188

Palaeopathological and variant conditions of the Homo heidelbergensis type specimen (Mauer, Germany).  

PubMed

Although early Homo specimens are now known from a number of African, Asian and European Middle Pleistocene sites, the taxon Homo heidelbergensis was initially introduced for the Mauer jaw recovered in 1907. Fossil hominids from the earlier Middle Pleistocene of Europe are very rare and the Mauer mandible is generally accepted as one of the most ancient, with an age of approximately 700 kyr. A new preparation of the mandible was conducted in 1996 and gave rise to the detailed palaeopathological examination which is presented here. Based on comparative analyses, the extreme breadth of the mandibular ramus and its flat intercondylar incision, in conjunction with the flattening and broadening of the coronoid process tip, results either from an idiosyncratic pattern of the course and insertion of the temporalis muscle on the coronoid process or from the temporalis possessing an accessory head. The incidence of periodontal pocketing, together with a vertical reduction of the alveolar margin to approximately 3.00 mm, and a slight protuberance formed in vicinity of the right M(2)can safely be interpreted as pathognomonic indications of periodontal disease. The short distance between the enamel-dentine junction of the teeth and the horizontal alveolar margins could either be an inherited variant or may result from incipient osteoporosis. In addition, an arthrotic condition with slight osteophytic peripheral exostoses and an arthrolit (i.e. an articular calculus or "joint mouse") on the left condylus articularisand a depression in the medial part of the left mandibular condyle extending into the inferior part of the ramus are present. These features are indicative of a trauma-induced osteochondrosis dissecans. The diagnosis therefore suggests that the observed depression results from a well-healed fracture. This traumatic event illustrates the demanding living conditions endured by humans during the European Middle Pleistocene. The variations and pathological conditions observed in Mauer do not question the mandible's role as type specimen for the taxon Homo heidelbergensis. PMID:12727464

Czarnetzki, A; Jakob, T; Pusch, C M

2003-04-01

189

Minerals and Fossils  

NSDL National Science Digital Library

This site is dedicated to rock and mineral collecting. It contains information for worldwide mineral and fossil collectors with articles, mineral photos, videos, a search engine and free classified ads.

mineraltown.com

190

Fossilized Dinosaur Bones  

NSDL National Science Digital Library

This slide show presents images of dinosaur bones and shows paleotologists at work excavating and preserving these fossils, the best evidence remaining of these long-lost creatures. A background essay and discussion questons are included.

191

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

PubMed

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

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

2006-06-01

192

Evidence of Evolution I. Fossils and the fossil record  

E-print Network

radioactive elements · Generally applied to igneous & metamorphic rocks, so what about fossils & sedimentary in the rocks deposited in those Eras. #12;#12;Why is the fossil record incomplete? · fossilization - "lucky in the rock! Accurate method for determining the age of fossils and rocks - Measures the decay of certain

Dever, Jennifer A.

193

Fossil Systematic Description Project  

NSDL National Science Digital Library

Students describe an unknown vertebrate fossil (or fossils, if multiple specimens are necessary for identification). This exercise is the culmination of their lab studies in the morphology of the vertebrate skeleton and requires them to integrate their ability to describe the morphology with research into the literature on their assigned animal. Students also become familiar with presentation of research through writing a formal scientific paper in the style of a particular journal.

Samantha Hopkins

194

Dinosaur Trace Fossils  

NSDL National Science Digital Library

Anthony J. Martin, Senior Lecturer at Emory University, provides this interesting Website on dinosaur trace fossils -- namely tracks, trails, burrows, borings, gnawings, eggs, nests, gizzard stones, and dung of dinosaurs. The site offers a brief overview followed by illustrated descriptions of particular trace fossil types: Tracks and Trackways, Eggs and Nests, Tooth Marks, Gastroliths, and Coprolites. A series of links points users to further information, and a bibliography on Vertebrate Ichnology provides additional readings (through 1997).

Martin, Anthony J.

195

Fossil Age Estimation Model  

NSDL National Science Digital Library

In this activity (page 1 of the PDF), learners will model how paleontologists estimate the age of fossil discoveries by extracting “fossil” playing cards from newspapers stacked in chronological order. Learners identify the “age” of the card based on the “evidence” (printed date) in the surrounding pages. They then create a data table and graph and analyze their findings. Use this activity to introduce learners to paleontology and geology. Relates to the linked video, DragonflyTV GPS: Dinosaurs.

Twin Cities Public Television, Inc.

2006-01-01

196

Fossil energy program  

NASA Astrophysics Data System (ADS)

The progress made during the period from July 1 through September 30 for the Oak Ridge National Laboratory research and development projects in support of the increased utilization of coal and other fossil fuels as sources of clean energy is reported. The following topics are discussed: coal conversion development, chemical research and development, materials technology, fossil energy materials program, liquefaction projects, component development, process analysis, environmental control technology, atmospheric fluidized bed combustion, underground coal gasification, coal preparation and waste utilization.

McNeese, L. E.

1981-12-01

197

The Great Fossil Find  

NSDL National Science Digital Library

On an imaginary fossil hunt, learners "find" (remove from envelope) paper "fossils" of some unknown creature, only a few at a time. Each time, they attempt to reconstruct the creature, and each time their interpretation tends to change as new pieces are "found." Use this as an introduction to the nature of science inquiry -- scientists don't always have all the information, scientists must form interpretations of the information, scientists must work together to come to consensus about interpretations.

Steve Rendak

1999-01-01

198

Absolute and relative endocranial size in Neandertals and later Pleistocene Homo.  

PubMed

Eurasian Neandertals encompass the entire observed range of recent and fossil Homo sapiens in absolute, but not relative endocranial volume, and Neandertals attest an average EQ significantly lower than their Upper Pleistocene successors. While the cognitive, social, and evolutionary implications of this phenomenon have been emphasised, the statistical basis of a mean inference of EQ in the Neandertal hypodigm has not been appropriately demonstrated. A demonstrable male bias in the available postcranial, not cranial, series has skewed perceptions of Neandertal brain-to-body size scaling towards a rejection of the null hypothesis. A simple resolution to this problem is a concise assessment of paired associated covariates against a suitable recent human comparator series. Permutations of Fisher's z and Student's t statistics are valid metrics in tests of significance in single datum hypotheses. Bootstrapped single observation tests determined significance in body size, absolute and relative endocranial volume in Pleistocene archaic, early modern, and late Pleistocene H. sapiens. With respect to absolute ECV, all current Middle-Upper Pleistocene crania fall within the substantial recent Homo range. Nevertheless, simple indices derived from raw and modified data in normal and logarithmic space reveal that Western European Neandertal males approach the lower extremes of our observed size range in relative ECV, yet none exceed statistical significance. Results confirm that relative ECV/brain size in Neandertals was not significantly depressed relative to recent and fossil H. sapiens and this is consistent with a substantial body of data from living humans dismissing any simple correspondence of relative brain size with intelligence and, by extension, evolutionary success. PMID:24954798

Gallagher, Andrew

2014-10-01

199

Fossil Simulation in the Classroom  

ERIC Educational Resources Information Center

Describes classroom science demonstrations and experiments that simulate the process of fossil formation. Lists materials, procedures and suggestions for successful activities. Includes ten student activities (coral fossils, leaf fossils, leaf scars, carbonization, etc.). Describes a fossil game in which students work in pairs. (CS)

Hoehn, Robert G.

1977-01-01

200

004118:a0001 Fossil Record  

E-print Network

004118:a0001 Fossil Record Michael J Benton, University of Bristol, Bristol, UK Fossils life. 004118:s0001 Introduction 004118:p0001 Fossils are the remains of plants and animals that once lived. The common image of a fossil is an ancient shell or bone that has been turned to rock

Benton, Michael

201

Functional protein divergence in the evolution of Homo sapiens  

E-print Network

Open Access2008Lopez-Bigaset al.V lume 9, Issue 2, Article R33Research Functional protein divergence in the evolution of Homo sapiens Nuria Lopez-Bigas*, Subhajyoti De† and Sarah A Teichmann† Addresses: *Research Unit on Biomedical Informatics... process In the alternative functional classification scheme consid- ered, the KOGs database [29], there are orthologous groups of proteins from seven eukaryotic genomes: three animals (the nematode C. elegans, the fruit fly Drosophila melanogaster and Homo...

Lopez-Bigas, Nuria; De, Subhajyoti; Teichmann, Sarah A

2008-02-15

202

Characterizing the evolutionary path(s) to early Homo.  

PubMed

Numerous studies suggest that the transition from Australopithecus to Homo was characterized by evolutionary innovation, resulting in the emergence and coexistence of a diversity of forms. However, the evolutionary processes necessary to drive such a transition have not been examined. Here, we apply statistical tests developed from quantitative evolutionary theory to assess whether morphological differences among late australopith and early Homo species in Africa have been shaped by natural selection. Where selection is demonstrated, we identify aspects of morphology that were most likely under selective pressure, and determine the nature (type, rate) of that selection. Results demonstrate that selection must be invoked to explain an Au. africanus-Au. sediba-Homo transition, while transitions from late australopiths to various early Homo species that exclude Au. sediba can be achieved through drift alone. Rate tests indicate that selection is largely directional, acting to rapidly differentiate these taxa. Reconstructions of patterns of directional selection needed to drive the Au. africanus-Au. sediba-Homo transition suggest that selection would have affected all regions of the skull. These results may indicate that an evolutionary path to Homo without Au. sediba is the simpler path and/or provide evidence that this pathway involved more reliance on cultural adaptations to cope with environmental change. PMID:25470780

Schroeder, Lauren; Roseman, Charles C; Cheverud, James M; Ackermann, Rebecca R

2014-01-01

203

Fossil turbulence revisited  

E-print Network

A theory of fossil turbulence presented in the 11th Liege Colloquium on Marine turbulence is "revisited" in the 29th Liege Colloquium "Marine Turbulence Revisited". The Gibson (1980) theory applied universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as it is constrained and fossilized by buoyancy forces. Towed oceanic microstructure measurements of Schedvin (1979) confirmed the predicted universal constants. Universal constants, spectra, hydrodynamic phase diagrams (HPDs) and other predictions of the theory have been reconfirmed by a wide variety of field and laboratory observations. Fossil turbulence theory has many applications; for example, in marine biology, laboratory and field measurements suggest phytoplankton species with different swimming abilities adjust their growth strategies differently by pattern recognition of several days of turbulence-fossil-turbulence dissipation and persistence times above threshold values, signaling a developing surface layer sea change. In cosmology, self-gravitational structure masses are interpreted as fossils of primordial hydrodynamic states.

Carl H. Gibson

1999-04-27

204

The Sima de los Huesos (Burgos, northern Spain): palaeoenvironment and habitats of Homo heidelbergensis during the Middle Pleistocene  

NASA Astrophysics Data System (ADS)

Interpreting how environmental dynamics respond to global climate change and how this has affected human evolution and dispersal is an on-going topic of debate. During the early Middle Pleistocene (˜0.6-0.4 Ma), as compared to earlier, environmental conditions were relatively more stable, with longer climatic cycles alternating between open and forested landscapes. During this interval, humans spread successfully providing an important number of fossil sites where fossils or tools are reported. The Atapuerca-Sima de los Huesos (Burgos, northern Spain) site (Atapuerca-SH) is one of the earliest localities with hominin evidence in the European Middle Pleistocene, with the most important accumulation of Homo heidelbergensis so far. We have analyzed the abundant faunal record from Sima de los Huesos, which is mainly comprised of carnivores, in order to approach an interpretation of the palaeoenvironmental circumstances where these hominids inhabited within the Sierra. Other sites from Sierra de Atapuerca referred to the same Faunal Unit (FU 6), are roughly contemporaneous, and include important ungulates, which are here analyzed with Atapuerca-SH. Additional information provided by isotopic analysis helps elucidate the ancient ecology of taxa present in Sima de los Huesos allowing for an accurate portrayal of the setting in which humans lived. The timing of the spread of Homo heidelbergensis is dominated by a relative climatic and environmental stability and points to a landscape dominated by savannah-like open woodland.

García, Nuria; Arsuaga, Juan Luis

2011-06-01

205

Dinoflagellata: Fossil Record  

NSDL National Science Digital Library

Information on this page pertains to dinoflagellates, the fossil record of which may extend into the Precambrian. Spherical organic-walled microfossils known as acritarchs, some of which may be dinoflagellate hystrichospheres, first appear in rocks about 1.8 billion years old. Exactly what the acritarchs were is not known with certainty; they probably included a number of clades of eukaryotic algae, and are thus a form taxon, including all those spore-like fossils which have not been conclusively assigned to another group.

206

Fossil Fuels: Capstone  

NSDL National Science Digital Library

This lesson summarizes our dependency upon fossil fuels, pointing out that there are very few aspects of our daily life that are not impacted by their use. The discussion centers around whether these fuels could be replaced and makes the point that there is a significant percentage of them which is used to manufacture products and is not simply burned for energy. The lesson includes an activity in which students use an online calculator to estimate how much of each fossil fuel they are responsible for consuming each year.

John Pratte

207

What is a Fossil?  

NSDL National Science Digital Library

In this activity about dinosaurs, learners explore how and why fossils form. First, learners are introduced to dinosaur fossils by reading the book "Bones, Bones, Dinosaur Bones" by Byron Barton. Then, learners make impressions in clay using a seashell, pennies, dinosaur teeth and other items. Next, learners make dinosaur tracks in the clay as they "walk" plastic models across the soft clay. Learners also use sponges pre-cut in the shape of dinosaur feet to make more tracks. This activity is featured on page 29 of the "Dinosphere" unit of study for K-2 learners.

2014-04-14

208

Climatic Influences on the Evolution of Early Homo?  

Microsoft Academic Search

The nature of the human fossil record is less than ideal for the generation of precise correlations between environmental variables and patterns of evolution in specific lineages. Nonetheless, a critical look at what can and cannot be said from individual fossil morphology and the correlation of specific environmental proxies with specific hominin fossils may lead to a greater understanding of

Susan C. Antón

2007-01-01

209

Population Genomics Reveals Seahorses (Hippocampus erectus) of the Western Mid-Atlantic Coast to Be Residents Rather than Vagrants  

PubMed Central

Understanding population structure and areas of demographic persistence and transients is critical for effective species management. However, direct observational evidence to address the geographic scale and delineation of ephemeral or persistent populations for many marine fishes is limited. The Lined seahorse (Hippocampus erectus) can be commonly found in three western Atlantic zoogeographic provinces, though inhabitants of the temperate northern Virginia Province are often considered tropical vagrants that only arrive during warm seasons from the southern provinces and perish as temperatures decline. Although genetics can locate regions of historical population persistence and isolation, previous evidence of Virginia Province persistence is only provisional due to limited genetic sampling (i.e., mitochondrial DNA and five nuclear loci). To test alternative hypotheses of historical persistence versus the ephemerality of a northern Virginia Province population we used a RADseq generated dataset consisting of 11,708 single nucleotide polymorphisms (SNP) sampled from individuals collected from the eastern Gulf of Mexico to Long Island, NY. Concordant results from genomic analyses all infer three genetically divergent subpopulations, and strongly support Virginia Province inhabitants as a genetically diverged and a historically persistent ancestral gene pool. These results suggest that individuals that emerge in coastal areas during the warm season can be considered “local” and supports offshore migration during the colder months. This research demonstrates how a large number of genes sampled across a geographical range can capture the diversity of coalescent histories (across loci) while inferring population history. Moreover, these results clearly demonstrate the utility of population genomic data to infer peripheral subpopulation persistence in difficult-to-observe species. PMID:25629166

Boehm, J. T.; Waldman, John; Robinson, John D.; Hickerson, Michael J.

2015-01-01

210

Population Genomics Reveals Seahorses (Hippocampus erectus) of the Western Mid-Atlantic Coast to Be Residents Rather than Vagrants.  

PubMed

Understanding population structure and areas of demographic persistence and transients is critical for effective species management. However, direct observational evidence to address the geographic scale and delineation of ephemeral or persistent populations for many marine fishes is limited. The Lined seahorse (Hippocampus erectus) can be commonly found in three western Atlantic zoogeographic provinces, though inhabitants of the temperate northern Virginia Province are often considered tropical vagrants that only arrive during warm seasons from the southern provinces and perish as temperatures decline. Although genetics can locate regions of historical population persistence and isolation, previous evidence of Virginia Province persistence is only provisional due to limited genetic sampling (i.e., mitochondrial DNA and five nuclear loci). To test alternative hypotheses of historical persistence versus the ephemerality of a northern Virginia Province population we used a RADseq generated dataset consisting of 11,708 single nucleotide polymorphisms (SNP) sampled from individuals collected from the eastern Gulf of Mexico to Long Island, NY. Concordant results from genomic analyses all infer three genetically divergent subpopulations, and strongly support Virginia Province inhabitants as a genetically diverged and a historically persistent ancestral gene pool. These results suggest that individuals that emerge in coastal areas during the warm season can be considered "local" and supports offshore migration during the colder months. This research demonstrates how a large number of genes sampled across a geographical range can capture the diversity of coalescent histories (across loci) while inferring population history. Moreover, these results clearly demonstrate the utility of population genomic data to infer peripheral subpopulation persistence in difficult-to-observe species. PMID:25629166

Boehm, J T; Waldman, John; Robinson, John D; Hickerson, Michael J

2015-01-01

211

Early Pleistocene 40Ar\\/39Ar ages for Bapang Formation hominins, Central Jawa, Indonesia  

Microsoft Academic Search

The Sangiran dome is the primary stratigraphic window for the Plio-Pleistocene deposits of the Solo basin of Central Jawa. The dome has yielded nearly 80 Homo erectus fossils, around 50 of which have known findspots. With a hornblende 40 Ar\\/ 39 Ar plateau age of 1.66 ± 0.04 mega-annum (Ma) reportedly associated with two fossils [Swisher, C.C., III, Curtis, G.

Roy Larick; Russell L. Ciochon; Yahdi Zaim; Suminto Sudijono; Yan Rizal; Fachroel Aziz; Mark Reagan; Matthew Heizler

2001-01-01

212

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

PubMed

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

Brown, Peter

2012-02-01

213

Fossil Halls: Cladistics  

NSDL National Science Digital Library

Part of a larger virtual tour of the Museum's famed Fossil Halls, this Web site has an overview explaining the cladistic method of scientific analysis as well as how to read cladograms. It answers the following questions: What is the best way to reconstruct evolutionary history? What is a cladogram? What is an advanced feature? Why use cladistics?

214

Rethinking Fossil Fuels  

NSDL National Science Digital Library

Climate change and fossil fuel use are connected. It would serve the world well to: begin a moratorium on coal-fired power plants; explore and use renewable energy; insist on immediate action from world governments; and penalize industries putting excess CO2 into the atmosphere.

James Hansen (NASA Goddard Institute for Space Studies; )

2008-09-09

215

Advanced fossil energy utilization  

SciTech Connect

This special issue of Fuel is a selection of papers presented at the symposium ‘Advanced Fossil Energy Utilization’ co-sponsored by the Fuels and Petrochemicals Division and Research and New Technology Committee in the 2009 American Institute of Chemical Engineers (AIChE) Spring National Meeting Tampa, FL, on April 26–30, 2009.

Shekhawat, D.; Berry, D.; Spivey, J.; Pennline, H.; Granite, E.

2010-01-01

216

Therapod Fossil Hunt Dispatch  

NSDL National Science Digital Library

This online article reports on the finding of a dromaeosaur fossil, the best specimen to date to show that feathers existed long before modern birds and flight. The research was a collaboration between the American Museum of Natural History and the Geological Museum of China.

217

Fossils and Minerals  

NSDL National Science Digital Library

This site from the Black Hills Institute features information about different types of fossils, minerals, meteorites, and geology in general. Each topic has a brief description, with links to a more detailed explanation. Various samples and books are abailable for purchase on the site.

Inc. Black Hills Institute of Geological Research

218

Fossilization of Acidophilic Microorganisms  

Microsoft Academic Search

This study examines fossil microorganisms found in iron-rich deposits in an extreme acidic environment, the Tinto River in SW Spain. Both electron microscopy (SEM and TEM) and non-destructive in situ microanalytical techniques (EDS, EMP and XPS) were used to determine the role of permineralization and encrustation in preserving microorganisms forming biofilms in the sediments. Unicellular algae were preserved by silica

Virginia Souza-Egipsy; Angeles Aguilera; Eva Mateo-Martí; José Angel Martín-Gago; Ricardo Amils

2010-01-01

219

Gas-phase Dissociation of homo-DNA Oligonucleotides  

NASA Astrophysics Data System (ADS)

Synthetic modified oligonucleotides are of interest for diagnostic and therapeutic applications, as their biological stability, pairing selectivity, and binding strength can be considerably increased by the incorporation of unnatural structural elements. Homo-DNA is an oligonucleotide homologue based on dideoxy-hexopyranosyl sugar moieties, which follows the Watson-Crick A-T and G-C base pairing system, but does not hybridize with complementary natural DNA and RNA. Homo-DNA has found application as a bioorthogonal element in templated chemistry applications. The gas-phase dissociation of homo-DNA has been investigated by ESI-MS/MS and MALDI-MS/MS, and mechanistic aspects of its gas-phase dissociation are discussed. Experiments revealed a charge state dependent preference for the loss of nucleobases, which are released either as neutrals or as anions. In contrast to DNA, nucleobase loss from homo-DNA was found to be decoupled from backbone cleavage, thus resulting in stable products. This renders an additional stage of ion activation necessary in order to generate sequence-defining fragment ions. Upon MS3 of the primary base-loss ion, homo-DNA was found to exhibit unspecific backbone dissociation resulting in a balanced distribution of all fragment ion series.

Stucki, Silvan R.; Désiron, Camille; Nyakas, Adrien; Marti, Simon; Leumann, Christian J.; Schürch, Stefan

2013-12-01

220

Dual-laser homo-FRET on the cell surface.  

PubMed

Inhomogeneous broadening and red-edge effects have been detected on a highly mobile system of fluorescently conjugated mAbs targeted to cell surface receptors. By exploiting site-selective spectroscopy and the characteristic loss of homo-FRET on increasing excitation and decreasing emission wavelengths, contributions of physical rotation and homo-FRET to the depolarization of fluorescence anisotropy have been separated. Absolute homo-FRET efficiency has been determined by ratioing two anisotropies: a homo-FRET-sensitive one, which is excited at the absorption main band and detected at the long wavelength region of emission, and a homo-FRET-insensitive one, which is excited at the long wavelength region of absorption and detected at the short wavelength region of emission. Because the anisotropies are simultaneously detected in a unified detection scheme of a dual T-format arrangement, the method is applicable for the real-time tracking of dynamical changes of physical rotations and proximities. The utility of the method is demonstrated in the context of the MHCII molecule and the heavy and light chains of the MHCI molecule, a system of three receptors with well-characterized close mutual proximities. Although the method is presented for a flow cytometer, it can also be realized in a fluorescence microscope capable for dual-laser excitation and dual-anisotropy detection. PMID:25668611

Bene, László; Ungvári, Tamás; Fedor, Roland; Nagy, István; Damjanovich, László

2015-05-01

221

Is Homo heidelbergensis a distinct species? New insight on the Mauer mandible.  

PubMed

The discovery of new fossils in Africa, Asia, and Europe, and the recognition of a greater diversity in the middle Pleistocene fossil record, has led to a reconsideration of the species Homo heidelbergensis. This nomen, formulated by Schoetensack in 1908 to describe the Mauer jaw (Germany), was almost forgotten during most of the past century. Numerous fossils have been attributed to it but no consensus has arisen concerning their classification. The holotype anatomical traits are still poorly understood, and numerous fossils with no mandibular remains have been placed in the taxon. Some researchers propose H. heidelbergensis as an Afro-European taxon that is ancestral to both modern humans and Neandertals whereas others think it is a strictly European species that is part of the Neandertal lineage. We focus on the validity of H. heidelbergensis, using the traditional basis of species recognition: anatomical description. We provide a comparative morphological analysis using 47 anatomical traits of 36 Pleistocene fossils from Africa, Asia, and Europe and 35 extant human mandibles. We re-examine the mandibular features of Mauer and discuss the specimen's inclusion in H. heidelbergensis, as well as alternative evolutionary theories. To lend objectivity to specimen grouping, we use multiple correspondence analysis associated with hierarchical classification that creates clusters corresponding to phenetic similarities between jaws. Our phenetic and comparative morphological analyses support the validity of H. heidelbergensis as a taxon. A set of morphological features can be statistically identified for the definition of the species. Some traits can be used to delimit H. heidelbergensis in an evolutionary framework (e.g., foramina mentale posteriorly positioned, horizontal retromolar surface). Those traits are also present on African (e.g., Tighenif) and European (e.g., Sima de los Huesos) specimens that show a close relationship with the Mauer mandible. Therefore, the definition of H. heidelbergensis is more precise and mainly supports the theory of an Afro-European taxon, which is the last common ancestor of H. neanderthalensis and H. sapiens. However, the results of this study fail to entirely discount the hypothesis that considers H. heidelbergensis as a chronospecies leading to the Neandertals. PMID:19249816

Mounier, Aurélien; Marchal, François; Condemi, Silvana

2009-03-01

222

W. TECUMSEH FITCH School of Psychology, University of St Andrews  

E-print Network

engaged in. Did Australopithecines sing? Did Homo erectus drum? Did Neanderthals dance? These questions, 1995) are Aurignacian and associated with modern Homo sapiens (the Neanderthal "flutes" cited remain

Fitch, Tecumseh

223

The largest fossil rodent  

PubMed Central

The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000?kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2?Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities. PMID:18198140

Rinderknecht, Andrés; Blanco, R. Ernesto

2008-01-01

224

Fossil Halls: Timelines  

NSDL National Science Digital Library

Part of a larger virtual tour of the Museum's famed Fossil Halls, this Web site allows students to travel back in time to several prehistoric points in the history of Earth. At each, they'll find a fleshed-out portrait of the period's creatures and their environment. The eight periods students will visit, some of which include more than one point-in-time snapshot, are Pleistocene, Miocene, Oligocene, Eocene, Cretaceous, Jurassic, Permian and Devonian Periods.

225

The Unknown Fossil Report  

NSDL National Science Digital Library

This project challenges the students ingenuity, creativity, and resourcefulness! They each receive a fossil of unknown identity (general geographic locality may be given, e.g., I-55 south of St. Louis, MO). The specimen is described in as much detail as possible. Their report should include taxonomic classification (as complete as they can), age, paleoecology, Earth history, and other interpretations they can infer. Identification may require library work, Internet search, etc.

Max Reams

226

Restoring Fossil Creek  

NSDL National Science Digital Library

As part of an ongoing environmental project and partnership with a local university, high school students monitor changes to Fossil Creek in Arizona. Components of the project include fish behavior studies, responses to fishing, water chemistry measurements, aquatic invertebrate studies, photographic recording, riparian habitat transects, and small mammal trapping transects. The data collected will ultimately provide an invaluable annual record for students, working scientists, and the wider community as changes are monitored over time.

Carri J. LeRoy

2004-07-01

227

Bibliography of Fossil Vertebrates  

NSDL National Science Digital Library

The Society of Vertebrate Paleontology (SVP), one of most reputable American paleontological societies, sponsors this online edition of its Bibliography of Fossil Vertebrates. The database, which currently covers the years 1509-1958 and 1981-1993 with approximately 112,000 references, is searchable by author, subject, taxon, language, editor, and journal book or volume title. A help page with query instructions for the somewhat finicky search engine is provided.

1997-01-01

228

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

PubMed Central

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

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

2011-01-01

229

The Astonishing Micropygmies  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. The stunning discovery of a Late Pleistocene hominin skeleton, on the Indonesian island of Flores has thrown the anthropological world into a frenzy. The primitive and derived features of the skeleton, but most curiously its tiny stature suggest a new species of diminutive Homo erectus called H. floresiensis. In a provocative Perspective, Jared Diamond provides a scintillating synthesis of the evidence for a new H. erectus species and debates the reasons why the fossil remains of this pygmy hominin have only now been discovered.

Jared Diamond (University of California at Los Angeles; Geography Department)

2004-12-17

230

New partial skeleton of Homo habilis from Olduvai Gorge, Tanzania  

Microsoft Academic Search

A new partial skeleton of an adult hominid from lower Bed I (about 1.8 Myr ago), Olduvai Gorge, is described. This specimen's craniodental anatomy indicates attribution to Homo habilis, but its postcranial anatomy, including small body size and relatively long arms, is strikingly similar to that of some early Australopithecus individuals.

Donald C. Johanson; Fidelis T. Masao; Gerald G. Eck; Tim D. White; Robert C. Walter; William H. Kimbel; Berhane Asfaw; Paul Manega; Prosper Ndessokia; Gen Suwa

1987-01-01

231

HOMO SACER AND CLINICAL TESTING IN THE DEVELOPING WORLD  

Microsoft Academic Search

Author Micaela Klein explores FDA drug trials in Kano Nigeria, and demonstrates how these trials can be understood through Gior- gio Agamben's concept of the homo sacer. Through examining the methods and guidelines of Pfizer's trials of its drug, Trovan, Klein finds that the lack of informed consent on the part of the test patients shows that some developing states

MICAELA KLEIN

232

Thermal decomposition of homo- and copolymers of isobutylene  

Microsoft Academic Search

The thermal properties of polyisobutylene and isobutylene-isoprene copolymers were studied. Thermal curves were interpreted with regard to supplementary data. It was found that the degradation of both homo- and copolymers proceeds to a much higher extent in air than in argon. It follows from the results that peroxide formation plays a significant role in the degradation of this group of

L. Šlusarski; G. Janowska

1980-01-01

233

Unsolved Problems in Comparing Brain Sizes in Homo Sapiens  

Microsoft Academic Search

When brain size is compared across taxonomic levels, there is a clear relation between body parameters and brain size. It is generally stated that the correlation between brain size and body parameters becomes very small at the species level (Aboitiz, 1996), but this is not the case for Homo sapiens where there is a strong correlation between brain size and

M. Peters; L. Jäncke; J. F. Staiger; G. Schlaug; Y. Huang; H. Steinmetzi

1998-01-01

234

Enantioselective Intramolecular Aldehyde Alkylation with Simple Olefins: Direct Access to Homo-Ene Products  

E-print Network

Enantioselective Intramolecular Aldehyde Alkylation with Simple Olefins: Direct Access to Homo. Conceptually, this novel mechanism allows direct access to "homo-ene"- type products. Carbocyclic transformations, including direct enantioselective - allylic alkylation,7 -enolation,8 -vinylation,9 -chlorination

MacMillan, David W. C.

235

Cycles in fossil diversity  

SciTech Connect

It is well-known that the diversity of life appears to fluctuate during the course the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 Ma). Using Sepkoski's compendium of the first and last stratigraphic appearances of 36380 marine genera, we report a strong 62 {+-} 3 Myr cycle, which is particularly strong in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance, we also consider contributing environmental factors and possible causes.

Rohde, Robert A.; Muller, Richard A.

2004-10-20

236

A Fossil Thermometer  

NSDL National Science Digital Library

In this activity, students calculate temperatures during a time in the geologic record when rapid warming occurred using a well known method called 'leaf-margin analysis.' Students determine the percentage of the species that have leaves with smooth edges, as opposed to toothed, or jagged, edges. Facsimiles of fossil leaves from two collection sites are examined, categorized, and the data is plugged into an equation to provide an estimate of paleotemperature for two sites in the Bighorn Basin. It also introduces students to a Smithsonian scientist who worked on the excavation sites and did the analysis.

Smithsonian Institution

237

Fossilized Dinosaur Teeth Adaptations  

NSDL National Science Digital Library

In this activity, learners use models of fossilized dinosaur teeth to understand how dinosaur teeth were used. Learners specifically research Tyrannosaurus rex and Triceratops horridus dinosaurs and determine that Triceratops teeth work the way pliers and scissors operate, and T. rex teeth are like sharp knives. Learners match and sort dinosaurs by the type and use of their teeth. This activity is featured on pp.14-18 (part of a lesson that begins on p.7) of the "Dinosphere" unit of study for grades 3-5.

Rick Crosslin

2004-01-01

238

Fossil Mammal Research Group  

NSDL National Science Digital Library

This website presents the Fossil Mammal Research Group whose "members are palaeontologists and archaeologists as well as palaeoenvironmental specialists in the School of Biological & Earth Sciences, Liverpool John Moores University, UK." Subjects of study by the Research group include mammalian fauna development over the past 30 million years, Plio-Pleistocene and Holocene climate change, and more. The website links to subpages for a list of Publications from 1998-2004, Major Projects going on around the world, Conferences, and relevant links. The site also provides a page presenting group members along with their research interests and email addresses.

239

New insights into mid-late Pleistocene fossil hominin paranasal sinus morphology.  

PubMed

Mid-late Pleistocene fossil hominins such as Homo neanderthalensis and H. heidelbergensis are often described as having extensively pneumatized crania compared with modern humans. However, the significance of pneumatization in recognizing patterns of phyletic diversification and/or functional specialization has remained controversial. Here, we test the null hypothesis that the paranasal sinuses of fossil and extant humans and great apes can be understood as biological spandrels, i.e., their morphology reflects evolutionary, developmental, and functional constraints imposed onto the surrounding bones. Morphological description of well-preserved mid-late Pleistocene hominin specimens are contrasted with our comparative sample of modern humans and great apes. Results from a geometric morphometric analysis of the correlation between paranasal sinus and cranial dimensions show that the spandrel hypothesis cannot be refuted. However, visualizing specific features of the paranasal sinus system with methods of biomedical imaging and computer graphics reveals new aspects of patterns of growth and development of fossil hominins. PMID:18951483

Zollikofer, Christoph P E; Ponce De León, Marcia S; Schmitz, Ralf W; Stringer, Christopher B

2008-11-01

240

New hominid fossils from Member 1 of the Swartkrans formation, South Africa.  

PubMed

Member 1 of the Swartkrans Formation is comprised of two sedimentary infills, the Lower Bank (LB) and the Hanging Remnant (HR). Together, the LB and HR preserve fossils of early Homo and Paranthropus robustus, Earlier Stone Age lithic artifacts, purported bone digging tools and butchered animal bones. Collectively, this evidence was the first to establish the co-existence of two early Pleistocene hominid species and also led to inferences of plant root harvesting and meat-eating by one or both of those species. P. robustus is the more abundant of the two hominids at Swartrkrans, represented in Member 1 by hundreds of fossils that derive from at least 99 individuals. Thus, Swartkrans Member 1 stands as the world's single largest repository of that extinct species. Here we add to the Member 1 sample of hominid fossils with descriptions of 14 newly discovered specimens. PMID:22440747

Pickering, Travis Rayne; Heaton, Jason L; Clarke, Ronald J; Sutton, Morris B; Brain, C K; Kuman, Kathleen

2012-05-01

241

Unearthing Important Fossils  

NSDL National Science Digital Library

Over the past several weeks, a flurry of dinosaur and other fossil discoveries have reached the mainstream news. From the two 530-million-year-old fish-like creatures that could be the earliest known vertebrates found in China, to the bones of two dinosaurs in Madagascar that may be the oldest dinosaurs ever found, to the "60-ton giraffe-like creature" (3) found in Oklahoma (called Sauroposeidon proteles, or "thunder lizard"), paleontologists are immersed in discovery. The significance of the first discovery is triggering excitement among paleontologists, worldwide. In particular, the discovery of the two "fish-like" fossils in China (to be published in this week's journal Nature) indicates that fish (i.e., vertebrates) evolved much earlier than previously thought and that "the rates of evolution in the oceans during the Cambrian period must have been exceptionally fast" (1). This week's In The News discusses some of the recently unveiled discoveries and provides background information and resources on vertebrate paleontology.

Payne, Laura X.

242

Fossil Microorganisms in Archaean  

NASA Technical Reports Server (NTRS)

Ancient Archean and Proterozoic rocks are the model objects for investigation of rocks comprising astromaterials. The first of Archean fossil microorganisms from Baltic shield have been reported at the last SPIE Conference in 2005. Since this confeence biomorphic structures have been revealed in Archean rocks of Karelia. It was determined that there are 3 types of such bion structures: 1. structures found in situ, in other words microorganisms even-aged with rock matrix, that is real Archean fossils biomorphic structures, that is to say forms inhabited early formed rocks, and 3. younger than Archean-Protherozoic minerali microorganisms, that is later contamination. We made attempt to differentiate these 3 types of findings and tried to understand of burial of microorganisms. The structures belongs (from our point of view) to the first type, or real Archean, forms were under examination. Practical investigation of ancient microorganisms from Green-Stone-Belt of Northern Karelia turns to be very perspective. It shows that even in such ancient time as Archean ancient diverse world existed. Moreover probably such relatively highly organized cyanobacteria and perhaps eukaryotic formes existed in Archean world.

Astafleva, Marina; Hoover, Richard; Rozanov, Alexei; Vrevskiy, A.

2006-01-01

243

Fossils 2: Uncovering the Facts  

NSDL National Science Digital Library

This lesson is the second in a two-part series on fossils. It explores the information that can be discerned by comparing fossils to living organisms. Students explore fossils and are responsible for using what they have learned to do their own extrapolating. Students conduct an interview with the remains of a Protoceratops. In preparation for the interview, they brainstorm the questions for which they would like answers and then narrow their questions to those that can really be answered by studying the Protoceratops fossils.

244

Learning from the Fossil Record  

NSDL National Science Digital Library

Another interesting and helpful resource from the University of California Berkeley Museum of Paleontology is the Learning from the Fossil Record Web site. Educators will find a list of over twenty fossil related classroom activities presented by different authors with titles such as Building a Topographic Model, Determining the Age Of Rocks and Fossils, Fossilization and Adaptation, the Dinosaur Body Structure, Microfossils, and other interesting subjects. The detailed descriptions include everything needed to complete the individual exercises including background information, procedures, and downloads. The unique collection should be a helpful addition to any junior high or high school science curriculum.

245

Genotype-specific responses of Bromus erectus to elevated CO{sub 2} at different levels of biodiversity and endophyte infection - a field experiment  

SciTech Connect

In 1994 we initiated a long-term field experiment in a calcareous grassland to study the effects of elevated CO{sub 2} on individuals, populations, and communities. Clonal replicates of 54 genotypes of the dominant grass Bromus erectus were grown in communities planted at three levels of biodiversity (5-, 12-, 31-species plots) and exposed to ambient and elevated CO{sub 2}. The same genotypes were also individually grown in tubes within the field plots. Some genotypes were infected by the endophytic fungus Epichloee typhina. Elevated CO{sub 2} had no significant effects on plant growth, however, there was large variation among genotypes in all measured characters. A significant CO{sub 2}-by-genotype interaction was found for leaf length in the competition-free tubes. Infection by the endophyte led to the abortion of all inflorescences but increased vegetative growth, especially under competitive conditions.

Steinger, T.; Groppe, K.; Schmid, B. [Univ. of Basel (Switzerland)]|[Univ. of Zurich (Switzerland)

1995-06-01

246

Fossils, feet and the evolution of human bipedal locomotion  

PubMed Central

We review the evolution of human bipedal locomotion with a particular emphasis on the evolution of the foot. We begin in the early twentieth century and focus particularly on hypotheses of an ape-like ancestor for humans and human bipedal locomotion put forward by a succession of Gregory, Keith, Morton and Schultz. We give consideration to Morton's (1935) synthesis of foot evolution, in which he argues that the foot of the common ancestor of modern humans and the African apes would be intermediate between the foot of Pan and Hylobates whereas the foot of a hypothetical early hominin would be intermediate between that of a gorilla and a modern human. From this base rooted in comparative anatomy of living primates we trace changing ideas about the evolution of human bipedalism as increasing amounts of postcranial fossil material were discovered. Attention is given to the work of John Napier and John Robinson who were pioneers in the interpretation of Plio-Pleistocene hominin skeletons in the 1960s. This is the period when the wealth of evidence from the southern African australopithecine sites was beginning to be appreciated and Olduvai Gorge was revealing its first evidence for Homo habilis. In more recent years, the discovery of the Laetoli footprint trail, the AL 288-1 (A. afarensis) skeleton, the wealth of postcranial material from Koobi Fora, the Nariokotome Homo ergaster skeleton, Little Foot (Stw 573) from Sterkfontein in South Africa, and more recently tantalizing material assigned to the new and very early taxa Orrorin tugenensis, Ardipithecus ramidus and Sahelanthropus tchadensis has fuelled debate and speculation. The varying interpretations based on this material, together with changing theoretical insights and analytical approaches, is discussed and assessed in the context of new three-dimensional morphometric analyses of australopithecine and Homo foot bones, suggesting that there may have been greater diversity in human bipedalism in the earlier phases of our evolutionary history than previously suspected. PMID:15198703

Harcourt-Smith, W E H; Aiello, L C

2004-01-01

247

Evidence of Evolution I. Fossils and the fossil record  

E-print Network

to igneous & metamorphic rocks, so what about fossils & sedimentary rocks? · "bracketing" · And organic in some regions than others Eras defined by major changes in the types of fossils found in the rocks://www.pbs.org/wgbh/evolution/library/03/3/l_033_01.html Radiometric dating ­ the clock in the rock! Accurate method for determining

Dever, Jennifer A.

248

Fossil turbulence and fossil turbulence waves can be dangerous  

E-print Network

Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than any other forces that tend to damp the eddies out. By this definition, turbulence always cascades from small scales where vorticity is created to larger scales where turbulence fossilizes. Fossil turbulence is any perturbation in a hydrophysical field produced by turbulence that persists after the fluid is no longer turbulent at the scale of the perturbation. Fossil turbulence patterns and fossil turbulence waves preserve and propagate energy and information about previous turbulence. Ignorance of fossil turbulence properties can be dangerous. Examples include the Osama bin Laden helicopter crash and the Air France 447 Airbus crash, both unfairly blamed on the pilots. Observations support the proposed definitions, and suggest even direct numerical simulations of turbulence require caution.

Carl H Gibson

2012-11-25

249

Mandibular condyle traits in Neanderthals and other Homo: a comparative, correlative, and ontogenetic study.  

PubMed

The relationship between the mandibular condyle and the crest of the mandibular notch (CMN) has historically entered into discussions of Neanderthal characteristics and was recently suggested to be autapomorphic in Neanderthals. The Neanderthal CMN has been described as intersecting the condyle in the middle, while the modern human CMN runs to the condyle's lateral end. A large lateral condylar tubercle (LCT) has also been observed in Neanderthals and thought to be related to medial (or less lateral) CMN position. In addition, the presence of a less lateral CMN early in ontogeny, as seen in the Amud 7 infant, has been argued to demonstrate great evolutionary divergence in Neanderthals. Using a scoring system for each trait, this study first examines the expression of CMN position and LCT size in 102 adult modern humans and in samples of Neanderthals and other fossil Homo. Then, CMN position is scored in 208 subadult modern humans to elucidate the ontogeny of this trait. Results show that CMN position is not autapomorphic in Neanderthals, but Neanderthals have significantly more CMNs in the least-lateral score category than does the modern human sample. Large LCTs are found to be strongly predictive of less lateral CMN position, although less lateral CMN position may exist in the absence of a large LCT. The complex ontogenetic pattern of CMN expression observed indicates that features of subadult and adult condylar morphology cannot be constructively compared without first considering subadult morphology on its own functional and developmental terms. PMID:12237935

Jabbour, Rebecca S; Richards, Gary D; Anderson, John Y

2002-10-01

250

Descriptions of the lower limb skeleton of Homo floresiensis  

Microsoft Academic Search

Bones of the lower extremity have been recovered for up to nine different individuals of Homo floresiensis – LB1, LB4, LB6, LB8, LB9, LB10, LB11, LB13, and LB14. LB1 is represented by a bony pelvis (damaged but now repaired), femora, tibiae, fibulae, patellae, and numerous foot bones. LB4\\/2 is an immature right tibia lacking epiphyses. LB6 includes a fragmentary metatarsal

W. L. Jungers; S. G. Larson; W. Harcourt-Smith; M. J. Morwood; T. Sutikna; Rokhus Due Awe; T. Djubiantono

2009-01-01

251

Segregation of type I collagen homo- and heterotrimers in fibrils  

PubMed Central

Normal type I collagen is a heterotrimer of two ?1(I) and one ?2(I) chains, but various genetic and environmental factors result in synthesis of homotrimers which consist of three ?1(I) chains. The homotrimers completely replace the heterotrimers only in rare recessive disorders. In the general population, they may comprise just a small fraction of type I collagen. Nevertheless, they may play a significant role in pathology, e.g., synthesis of 10-15% homotrimers due to a polymorphism in the ?1(I) gene may contribute to osteoporosis. Homotrimer triple helices have different stability and less efficient fibrillogenesis than heterotrimers. Their fibrils have different mechanical properties. However, very little is known about their molecular interactions and fibrillogenesis in mixtures with normal heterotrimers. Here we studied the kinetics and thermodynamics of fibril formation in such mixtures by combining traditional approaches with 3D confocal imaging of fibrils, in which homo- and heterotrimers were labeled by different fluorescent colors. Following a temperature jump from 4 to 32 °C, in a mixture we first observed rapid formation of homotrimer aggregates. The aggregates promoted nucleation of homotrimer fibrils which served as seeds for mixed and heterotrimer fibrils. The separation of colors in confocal images indicated segregation of homo- and heterotrimers at a subfibrillar level throughout the process. The fibril color patterns continued to change slowly after the fibrillogenesis appeared to be complete, due to dissociation and reassociation of the pepsin-treated homo- and heterotrimers, but this remixing did not significantly reduce the segregation even after several days. Independent homo- and heterotrimer solubility measurements in mixtures confirmed that the subfibrillar segregation was an equilibrium property of intermolecular interactions and not just a kinetic phenomenon. We argue that the subfibrillar segregation may exacerbate effects of a small fraction of ?1(I) homotrimers on formation, properties, and remodeling of collagen fibers. PMID:18721810

Han, Sejin; McBride, Daniel J.; Losert, Wolfgang; Leikin, Sergey

2010-01-01

252

Fossil-Based Hydrogen Production  

E-print Network

Fossil-Based Hydrogen Production Distributed Natural Gas WithCarbonSequestration Biomass Hydro Wind Solar Coal Nuclear Natural Gas Oil Arlene AndersonArlene Anderson #12;Barriers Fossil-Based Hydrogen Production · Capital Costs · O&M · Separation Technology · Control and Safety · Feedstock and Water Issues

253

Biodiversity of the Fossil Record  

E-print Network

Biodiversity of the Fossil Record Geology 331, Paleontology #12;Linnean Classification: Example of Life #12;Cyanobacteria? 3.5 BY old, Australia #12;Stromatolite, 3.5 BY old, Australia #12;Modern stromatolites produced by cyanobacteria, Sharks Bay, Australia Cambrian, NY #12;Fossil bacteria 2BY old from

Kammer, Thomas

254

Life of a Vertebrate Fossil  

NSDL National Science Digital Library

Unless you have a very large research grant, it can be difficult to find fossil bones. Fortunately, this very fine online learning module from the Smithsonian's Natural History Museum can help both young and old to learn about locating fossil bones, among other things. Through this multimedia feature created by the History Museum's department of paleobiology, visitors will learn what paleontologists do in each stage in the life of a vertebrate fossil. With the assistance of short video clips, interactive diagrams, and photographs, visitors will learn about how fossils are prepared for examination and how scientists unravel the stories of these paleontological finds. Finally, visitors will also learn how fossils are stored and preserved.

255

Organic molecules as chemical fossils - The molecular fossil record  

NASA Technical Reports Server (NTRS)

The study of biochemical clues to the early earth and the origin of life is discussed. The methods used in such investigation are described, including the extraction, fractionation, and analysis of geolipids and the analysis of kerogen. The occurrence of molecular fossils in the geological record is examined, discussing proposed precursor-product relationships and the molecular assessment of deep sea sediments, ancient sediments, and crude petroleums. Alterations in the molecular record due to diagenesis and catagenesis are considered, and the use of microbial lipids as molecular fossils is discussed. The results of searches for molecular fossils in Precambrian sediments are assessed.

Eglinton, G.

1983-01-01

256

Ediacaran Fossils: Metazoan Origins in the  

E-print Network

Ediacaran Fossils: Metazoan Origins in the Proterozoic Geology 331, Paleontology #12;#12;The in sandstone. How were they preserved? #12;A fossil sea pen from the Ediacaran of Australia. Ediacaran fossils

Kammer, Thomas

257

Fossils as Information  

NASA Astrophysics Data System (ADS)

This book discusses procedures for handling information derived from the fossil record, and the application of this information to solving problems in geological succession and earth history. The main purpose of the book is to analyze shortcomings of the existing procedures, and to propose in their place a new set of data-handling arrangements of much greater simplicity and efficiency. The author argues that the procedures in current use are cumbersome and inefficient, and that, partly as a consequence of these information-handling methods, palaeontology has failed to make advances commensurate with technological improvements. In this book he proposes a fundamentally new system which could make possible the integrated use of every detail of geological information taken from the rocks. This would achieve better resolution in sequence correlation, in paleoecologic interpretation and in logging the course of evolution. Compatibility of style with existing records has been maintained to avoid any danger of loss of valuable data, and to simplify the process of re-evaluating old records. The book will be of interest to all paleontologists, particularly those dealing with microfossils, and is intended to stimulate discussion and criticism of both the analysis and the proposal.

Hughes, Norman Francis

1989-11-01

258

Fossil fuel furnace reactor  

DOEpatents

A fossil fuel furnace reactor is provided for simulating a continuous processing plant with a batch reactor. An internal reaction vessel contains a batch of shale oil, with the vessel having a relatively thin wall thickness for a heat transfer rate effective to simulate a process temperature history in the selected continuous processing plant. A heater jacket is disposed about the reactor vessel and defines a number of independent controllable temperature zones axially spaced along the reaction vessel. Each temperature zone can be energized to simulate a time-temperature history of process material through the continuous plant. A pressure vessel contains both the heater jacket and the reaction vessel at an operating pressure functionally selected to simulate the continuous processing plant. The process yield from the oil shale may be used as feedback information to software simulating operation of the continuous plant to provide operating parameters, i.e., temperature profiles, ambient atmosphere, operating pressure, material feed rates, etc., for simulation in the batch reactor.

Parkinson, William J. (Los Alamos, NM)

1987-01-01

259

Submarine hydrothermal fossils confirmed  

NASA Astrophysics Data System (ADS)

Researchers from Princeton University (D. Crerrar et al, Econ. Geol., May 1982) have documented, in considerable detail, evidence for the formation of some of the 800 or more manganiferous chert deposits occurring in the central belt of the Fransiscan formation in northwestern California. They confirm the surprisingly old conclusion o f Tiaferro and Hudson (Cal. Div. Mines Bull., 125, 217-276, 1943) that the Fransiscan chert deposits probably represent the fossil remains of submarine hydrothermal vents.The deposits resemble recently discovered hydrothermal mounds near the Galapagos rift, the Gulf of Aden, and the Mid-Atlantic Ridge. As the Princeton investigators point out, there are important implications of the existence of deep hydrothermal circulation systems at oceanic spreading centers throughout geologic time. They note that the calculated annual flow of hydrothermal fluids in such processes is about 1017 g, which implies that the entire volume of the oceans could circulate completely every 10 million years. With such circulation, the hydrothermal processes along midocean ridges could control the composition of seawater and strongly influence the geochemical flux of elements in the marine environment.

Bell, Peter M.

260

FOSSIL2 energy policy model documentation: FOSSIL2 documentation  

SciTech Connect

This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large, as is appropriate for a system dynamics simulation model. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. Volumes II and III of this report list the equations that comprise the FOSSIL2 model, along with variable definitions and a cross-reference list of the model variables. Volume III lists the model equations and a one line definition for equations, in a short, readable format.

None

1980-10-01

261

Did Early Man reach Java during the Late Pliocene?  

Microsoft Academic Search

Homo erectus (Pithecanthropus) reached Java from the Asian continent and became one of the oldest islanders in the world. This article deals with the palaeomagnetic and40Ar\\/39Ar dating of the “lower lahar”, a layer located at the base of the fossil-bearing series of the Sangiran dome. Combined40Ar\\/39Ar and palaeomagnetic data show that the deposition of the lower lahar, marking the emergence

François Sémah; Hassane Saleki; Christophe Falguères; Gilbert Féraud; Tony Djubiantono

2000-01-01

262

Paleomagnetic dates of hominid remains from Yuanmou, China, and other Asian sites  

Microsoft Academic Search

Two hominid upper central incisors found in the Yuanmou Basin in southwest China in 1965 have affinities with Homo erectus fossils from Zhoukoudian, but exhibit primitive features. The Yuanmou hominid remains are alleged to be coeval with or older than African specimens dated at about 1·8m.y.a. Recent age refinements of geomagnetic short reversal events and excursions permit assigning the Yuanmou

Masayuki Hyodo; Hideo Nakaya; Atsushi Urabe; Haruo Saegusa; Xue Shunrong; Yin Jiyun; Ji Xuepin

2002-01-01

263

Metric and geometric morphometric analysis of new hominin fossils from Maba (Guangdong, China).  

PubMed

We present an analysis of a set of previously unreported hominin fossils from Maba (Guangdong, China), a cave site that is best known for the presence of a partial hominin cranium currently assigned as mid-Pleistocene Homo and that has been traditionally dated to around the Middle-Late Pleistocene transition. A more recent set of Uranium series dates indicate that the Maba travertine may date to >237 ka (thousands of years ago), as opposed to the original U-series date, which placed Maba at 135-129 ka. The fossils under study include five upper first and second molars and a partial left mandible with a socketed m3, all recovered from different parts of the site than the cranium or the dated sediments. The results of our metric and 2D geometric morphometric ('GM') study suggest that the upper first molars are likely from modern humans, suggesting a more recent origin. The upper second molars align more closely with modern humans, though the minimum spanning tree from the 2D GM analysis also connects Maba to Homo neanderthalensis. The patterning in the M2s is not as clear as with the M1s. The m3 and partial mandible are morphometrically intermediate between Holocene modern humans and older Homo sapiens. However, a minimum spanning tree indicates that both the partial mandible and m3 align most closely with Holocene modern humans, and they also may be substantially younger than the cranium. Because questions exist regarding the context and the relationship of the dated travertine with the hominin fossils, we suggest caution is warranted in interpreting the Maba specimens. PMID:25104621

Xiao, Dongfang; Bae, Christopher J; Shen, Guanjun; Delson, Eric; Jin, Jennie J H; Webb, Nicole M; Qiu, Licheng

2014-09-01

264

Dating Fossil Pollen: A Simulation.  

ERIC Educational Resources Information Center

Describes a hands-on simulation in which students determine the age of "fossil" pollen samples based on the pollen types present when examined microscopically. Provides instructions for the preparation of pollen slides. (MDH)

Sheridan, Philip

1992-01-01

265

The legacy of fossil fuels.  

PubMed

Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30?Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production. PMID:21290608

Armaroli, Nicola; Balzani, Vincenzo

2011-03-01

266

Getting Into the Fossil Record  

NSDL National Science Digital Library

This computer activity provides a basic understanding of what a fossil is and the factors involved in becoming part of the fossil record. It is organized as an informational tour in two sections: one for middle school and one for high school. Students move at a self-selected pace by progressing and answering questions. A teacher's guide contains all necessary instructions as well as lesson plans, handouts, and assessment tools.

Jennifer Johnson

267

Do co-occurring plant species adapt to one another? The response of Bromus erectus to the presence of different Thymus vulgaris chemotypes.  

PubMed

Local modification of the soil environment by individual plants may affect the performance and composition of associated plant species. The aromatic plant Thymus vulgaris has the potential to modify the soil through leaching of water-soluble compounds from leaves and litter decomposition. In southern France, six different thyme chemotypes can be distinguished based on the dominant monoterpene in the essential oil, which is either phenolic or non-phenolic in structure. We examine how soils from within and away from thyme patches in sites dominated by either phenolic or non-phenolic chemotypes affect germination, growth and reproduction of the associated grass species Bromus erectus. To do so, we collected seeds of B. erectus from three phenolic and three non-phenolic sites. Seeds and seedlings were grown on soils from these sites in a reciprocal transplant type experiment in the glasshouse. Brome of non-phenolic origin performed significantly better on its home soil than on soil from a different non-phenolic or a phenolic site. This response to local chemotypes was only observed on soil collected directly underneath thyme plants and not on soil in the same site (<5 m away) but where no thyme plants were present. This is preliminary evidence that brome plants show an adaptive response to soil modifications mediated by the local thyme chemotypes. Reproductive effort was consistently higher in brome of phenolic origin than in brome of non-phenolic origin (on both thyme- and grass-soil), indicating that life-history variation may be related to environmental factors which also contribute to the spatial differentiation of thyme chemotypes. Moreover, we found that brome growing on thyme-soil in general was heavier than when growing on grass-soil, regardless of the origin of the brome plants. This is concordant with thyme-soil containing higher amounts of organic matter and nitrogen than grass-soil. Our results indicate that patterns of genetic differentiation and local adaptation may modify competitive interactions and possible facilitation effects in natural communities. PMID:15309611

Ehlers, Bodil K; Thompson, John

2004-11-01

268

Craniofacial morphology of Homo floresiensis: Description, taxonomic affinities, and evolutionary implication  

Microsoft Academic Search

This paper describes in detail the external morphology of LB1\\/1, the nearly complete and only known cranium of Homo floresiensis. Comparisons were made with a large sample of early groups of the genus Homo to assess primitive, derived, and unique craniofacial traits of LB1 and discuss its evolution. Principal cranial shape differences between H. floresiensis and Homo sapiens are also explored

Yousuke Kaifu; Hisao Baba; Thomas Sutikna; Michael J. Morwood; Daisuke Kubo; E. Wahyu Saptomo; Jatmiko; Rokhus Due Awe; Tony Djubiantono

2011-01-01

269

Travels with the Fossil Hunters  

NASA Astrophysics Data System (ADS)

Whether dodging bullets in West Africa, or rabid dogs in Pakistan, surviving yak-butter tea in Tibet, or eating raw fish in China, the life of a globe-trotting fossil hunter is often hazardous and always filled with surprises. Travels with the Fossil Hunters lets readers share the wonder, joys of discovery, and excitement of these intrepid scientists. Packed with more than 100 beautiful, full-color photographs, the volume takes readers on twelve expeditions to remote parts of the world in search of diverse fossil remains, from those of dinosaurs to human ancestors. Each expedition by paleontologists from London's Natural History Museum reveals the problems and challenges of working in extreme conditions, from the deserts of the Sahara and Yemen to the frozen wastes of Antarctica, from the mountains of India to the forests of Latvia. Along the way they also describe the paleontology and geology of the countries they visit and the scientific reasons for their expeditions. With a foreword from Sir David Attenborough and an introduction from Richard Fortey, this fascinating book will appeal to amateur and professional fossil hunters alike and to readers interested in accounts of exotic locales. Peter Whybrow is a research scientist at the Natural History Museum, London. His research interests include Arabian Miocene vertebrates, paleoclimates, paleogeography, and biotic diversity. He is senior editor with A. Hill of Fossil Vertebrates of Arabia (Yale University Press, New Haven, 1999).

Whybrow, Peter J.

2000-04-01

270

Atavisms in homo sapiens: a Bolkian heterodoxy revisited.  

PubMed

An atavism is the "..reappearance of a lost character (morphology or behaviour) typical of remote ancestors and not seen in the parents or recent ancestors of the organisms displaying the atavistic character" (Hall, 1984). In humans, hypertrichosis (extensive body hair), the presence of a tail and supernumerary nipples are often quoted as examples (Hall, 1995). However, Louis Bolk (1866-1930) explained these phenomena in another way. He considered human morphology as an unspecialized expression of the mammalian developmental pattern. The latter also encompasses potentialities for unilateral or propulsive development pathways (specializations) that usually remain latent in humans, but can become expressed in other species. According to Bolk, the appearance of so-called atavisms in human results from the occasional expression of these latencies in Homo sapiens; they do not recapitulate ancestral conditions. PMID:8693850

Verhulst, J

1996-03-01

271

Mauer - the type site of Homo heidelbergensis: palaeoenvironment and age  

NASA Astrophysics Data System (ADS)

The mandible of Homo heidelbergensis was found 1907 in the sand pit Grafenrain at Mauer in coarse fluvial sands 24 m below the surface, deposited in a former course of the Neckar River. These 'Mauer sands' are overlain by a series of glacial-climate loess deposits with intercalated interglacial palaeosols, which can be correlated with Quaternary climate history, thus indicating an early Middle Pleistocene age for H. heidelbergensis. The 'Mauer sands' are famous for their rather rich mammal fauna, which clearly indicates interglacial climate conditions. The faunal evidence - in particular the micromammals - place the 'Mauer sands' into MIS 15 or MIS 13 although most stratigraphic arguments favour correlation to MIS 15 and therefore to an age of ca 600 ka.

Wagner, Günther A.; Maul, Lutz Christian; Löscher, Manfred; Schreiber, H. Dieter

2011-06-01

272

Homo Heuristicus: Less-is-More Effects in Adaptive Cognition  

PubMed Central

Heuristics are efficient cognitive processes that ignore information. In contrast to the widely held view that less processing reduces accuracy, the study of heuristics shows that less information, computation, and time can in fact improve accuracy. We discuss some of the major progress made so far, focusing on the discovery of less-is-more effects and the study of the ecological rationality of heuristics which examines in which environments a given strategy succeeds or fails, and why. Homo heuristicus has a biased mind and ignores part of the available information, yet a biased mind can handle uncertainty more efficiently and robustly than an unbiased mind relying on more resource-intensive and general-purpose processing strategies. PMID:23613644

Brighton, Henry; Gigerenzer, Gerd

2012-01-01

273

Fossils: Observing, Making and Learning  

NSDL National Science Digital Library

In this activity, learners explore how casts of fossilized bones are created and used to learn about dinosaurs. Learners make observations, draw diagrams and share their findings. Learners also make clay molds to create plaster copies of real fossils. Then, learners consider how animals' and dinosaurs' body parts were used for protection, hunting, eating, etc. This activity is featured on pp.11-13 (part of a lesson that begins on p.7) of the "Dinosphere" unit of study for grades 3-5.

Rick Crosslin

2004-01-01

274

Tour of Park Geology: Fossils  

NSDL National Science Digital Library

This National Park Service Geology site provides links to tours of individual National Parks, Monuments, and Recreation Areas that contain fossils. Where appropriate, for each park, links are provided to park geology, maps, photographs, geologic research, related links, visitor information, multimedia resources, and teacher features (resources for teaching geology with National Park examples). The list includes places such as the Grand Canyon, Dinosaur National Monument, Yellowstone, and Death Valley, along with less well-known areas such as the John Day Fossil Beds National Monument in Oregon.

275

STRUCTURES INTERNES CLAVICULAIRES CHEZ PAN, GORILLA ET HOMO. MTHODE D'ANALYSE ET RSULTATS PRLIMINAIRES  

E-print Network

STRUCTURES INTERNES CLAVICULAIRES CHEZ PAN, GORILLA ET HOMO. MÉTHODE D'ANALYSE ET RÉSULTATS PRÉLIMINAIRES INTERNAL STRUCTURES OF THE CLAVICLE IN PAN, GORILLA AND HOMO. METHOD OF ANALYSIS AND PRELIMINARY density bone structure superior to that of gorillas and humans. For a quarter of chimpanzees

Paris-Sud XI, Université de

276

The economic agent as rule maker and rule user: Homo Sapiens Oeconomicus  

Microsoft Academic Search

The paper discusses the micro foundations of evolutionary economics, introducing a unified concept of the economic agent as a rule maker and rule user. Based on recent findings of the neuronal, cognitive and behavioral sciences, Homo Sapiens Oeconomicus emerges as an alternative to Homo Oeconomicus. A taxonomy of rules distinguishing between cognitive, behavioral and blueprint rules and a set of

Kurt Dopfer

2004-01-01

277

FOSSIL2 energy policy model documentation: FOSSIL2 documentation  

SciTech Connect

This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large, as is appropriate for a system dynamics simulation model. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. Volumes II and III of this report list the equations that comprise the FOSSIL2 model, along with variable definitions and a cross-reference list of the model variables. Volume II provides the model equations with each of their variables defined, while Volume III lists the equations, and a one line definition for equations, in a shorter, more readable format.

None

1980-10-01

278

Brain shape in human microcephalics and Homo floresiensis  

PubMed Central

Because the cranial capacity of LB1 (Homo floresiensis) is only 417 cm3, some workers propose that it represents a microcephalic Homo sapiens rather than a new species. This hypothesis is difficult to assess, however, without a clear understanding of how brain shape of microcephalics compares with that of normal humans. We compare three-dimensional computed tomographic reconstructions of the internal braincases (virtual endocasts that reproduce details of external brain morphology, including cranial capacities and shape) from a sample of 9 microcephalic humans and 10 normal humans. Discriminant and canonical analyses are used to identify two variables that classify normal and microcephalic humans with 100% success. The classification functions classify the virtual endocast from LB1 with normal humans rather than microcephalics. On the other hand, our classification functions classify a pathological H. sapiens specimen that, like LB1, represents an ?3-foot-tall adult female and an adult Basuto microcephalic woman that is alleged to have an endocast similar to LB1's with the microcephalic humans. Although microcephaly is genetically and clinically variable, virtual endocasts from our highly heterogeneous sample share similarities in protruding and proportionately large cerebella and relatively narrow, flattened orbital surfaces compared with normal humans. These findings have relevance for hypotheses regarding the genetic substrates of hominin brain evolution and may have medical diagnostic value. Despite LB1's having brain shape features that sort it with normal humans rather than microcephalics, other shape features and its small brain size are consistent with its assignment to a separate species. PMID:17277082

Falk, Dean; Hildebolt, Charles; Smith, Kirk; Morwood, M. J.; Sutikna, Thomas; Jatmiko; Saptomo, E. Wayhu; Imhof, Herwig; Seidler, Horst; Prior, Fred

2007-01-01

279

Are the small human-like fossils found on Flores human endemic cretins?  

PubMed Central

Fossils from Liang Bua (LB) on Flores, Indonesia, including a nearly complete skeleton (LB1) dated to 18?kyr BP, were assigned to a new species, Homo floresiensis. We hypothesize that these individuals are myxoedematous endemic (ME) cretins, part of an inland population of (mostly unaffected) Homo sapiens. ME cretins are born without a functioning thyroid; their congenital hypothyroidism leads to severe dwarfism and reduced brain size, but less severe mental retardation and motor disability than neurological endemic cretins. We show that the fossils display many signs of congenital hypothyroidism, including enlarged pituitary fossa, and that distinctive primitive features of LB1 such as the double rooted lower premolar and the primitive wrist morphology are consistent with the hypothesis. We find that the null hypothesis (that LB1 is not a cretin) is rejected by the pituitary fossa size of LB1, and by multivariate analyses of cranial measures. We show that critical environmental factors were potentially present on Flores, how remains of cretins but not of unaffected individuals could be preserved in caves, and that extant oral traditions may provide a record of cretinism. PMID:18319214

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

2008-01-01

280

Geology Fieldnotes: Fossil Butte National Monument, Wyoming  

NSDL National Science Digital Library

Fossil Butte National Monument preserves a 50-million year old bed of Eocene limestone that contains one of the richest fossil deposits in the world. Site features include park geology information, photographs of fossils, related links, visitor information, multimedia resources, and resources for teaching geology with National Park examples. The park geology section discusses the Monument's geologic history and fossil beds, focusing on the conditions that created the fossil-rich region and on the history of fossil collection in the area. A map of the Monument is also included.

281

Numerical description of selected endo- and ectocranial dimensions in Homo sapiens and the three Homo heidelbergensis: Kabwe, Atapuerca and Petralona.  

PubMed

Investigation of hominid cranial morphology is of particular importance for those dealing with questions concerning both ontogenetic and phylogenetic aspects in the genus Homo. The present study provides a numerical description of several regions of extant human crania and, in addition, mid-Pleistocene crania, given in distances and angles. This study is seen as a basic preparatory work that is most useful for further investigation on cranial development in hominids. The sample used consisted of 60 recent adult human crania as well as stereolithographic models of three H. heidelbergensis crania: Kabwe, Atapuerca and Petralona. 12 ecto- and 20 endocranial landmarks were selected and 3D-coordinates taken on each cranium using a 3D Polhemus 3Space FASTRAK tracking system. From the resulting data set, 21 ectocranial and 17 endocranial distances were calculated, in addition to 41 angles of the ectocranium and 21 angles of the endocranium; the measurements are presented in tables, serving as a reference database. PMID:12529956

Bernhard, M; Schäfer, K; Seidler, H

2002-12-01

282

Fossil Identification and Classification Lab  

NSDL National Science Digital Library

Students pick, sort, box, and identify fossils (mostly mollusks but also bryozoa, arthropods, cnidaria, and annelids) from richly fossiliferous, clastic marine sediment, compile a faunal list,compare the fauna with modern taxa, and make evaluate a paleogeographic model for the taxa found.

Ralph Willoughby

283

FOSSIL: A Robust Relational Learner  

Microsoft Academic Search

. The research reported in this paper describes Fossil, an ILPsystem that uses a search heuristic based on statistical correlation. Thisalgorithm implements a new method for learning useful concepts in thepresence of noise. In contrast to Foil's stopping criterion, which allowstheories to grow in complexity as the size of the training sets increases,we propose a new stopping criterion that is

Johannes Ffirnkranz

1994-01-01

284

Biomechanics in fossil plant biology  

Microsoft Academic Search

The use of biomechanics for the analysis of the form—function relationship in palaeobotany is reviewed. Four fields of application of biomechanics are discussed and illustrated, i.e. the functional analysis of plants and plant organs (examples: lianas, leaf margin types), reconstruction of fossil plants (growth habit, tree height), functional analysis of ontogeny (lianas, trees), and evolutionary pathways (evolution of early land

Volker Mosbrugger; Anita Roth

1996-01-01

285

Rule Fossilization: A Tentative Model  

ERIC Educational Resources Information Center

A cybernetic model of factors involved in the fossilization of grammatical and lexical forms in learner grammars is offered. A distinction is made between affective and cognitive dimensions of a multidimensional channel of human communication; and the effect of expected and unexpected feedback on these two dimensions is discussed. (Author/POP)

Vigil, Neddy A.; Oller, John W.

1976-01-01

286

Biodiversity of the Fossil Record  

E-print Network

Biodiversity of the Fossil Record Geology 331, Paleontology #12;Linnean Classification: Example;www.evogeneao.com/tree.html The Tree of Life #12;Cyanobacteria? 3.5 BY old, Australia #12;Stromatolite, 3.5 BY old, Australia #12;Modern stromatolites produced by cyanobacteria, Sharks Bay, Australia

Kammer, Thomas

287

Synthetic soup ground trace fossils  

NSDL National Science Digital Library

This is a lab exercise where students make synthetic trace fossils (using fishing lures) that was presented as a scientific study: BIOGENIC SEDIMENTARY STRUCTURES PRODUCED BY WORMS IN SOUPY, SOFT MUDS: OBSERVATIONS FROM THE CHATTANOOGA SHALE (UPPER DEVONIAN) AND EXPERIMENTS, by VADEC LOBZA AND JURGEN SCHIEBER, JOURNAL OF SEDIMENTARY RESEARCH, VOL. 69, NO. 5, SEPTEMBER, 1999, P. 1041â1049

Clint Cowan

288

Theory of fossil magnetic field  

NASA Astrophysics Data System (ADS)

Theory of fossil magnetic field is based on the observations, analytical estimations and numerical simulations of magnetic flux evolution during star formation in the magnetized cores of molecular clouds. Basic goals, main features of the theory and manifestations of MHD effects in young stellar objects are discussed.

Dudorov, Alexander E.; Khaibrakhmanov, Sergey A.

2015-02-01

289

Hagerman Fossil Beds National Monument  

NSDL National Science Digital Library

This National Park Service website offers descriptions of: the animal fossils found at this park, including the extinct Hagerman horse; the geology of the park which is mostly floodplain sediments of primarily silty clays; and the geological, hydrological, and hydrostratigraphical aspects of a landslide model. There are photos of park landslides, prehistoric projectile points, and the historical Oregon Trail.

290

Fossil Forests and Silicified Trunks  

Microsoft Academic Search

IN NATURE, vol. xix. p. 257, the discovery of fossil forests in the spring region of the Yellowstone River is referred to. I have visited the United States National Park, and its geysers, and observed exactly how silicified trunks in situ originate. All geologists suppose that this must have happened beneath water, and consequently Mr. Holmes supposes a constant alternation

Otto Kuntze

1879-01-01

291

Fossil/modern mole phylogeny  

NSDL National Science Digital Library

This study is introduced at the beginning of class, and runs throughout the quarter. Students are first given a paper describing a morphological phylogeny of modern moles. The first few weeks' labs teach the students basic phylogenetic methods and the aspects of skeletal morphology needed to understand the character descriptions. Students in groups of 2 or 3 are assigned a set of characters from a particular region of the skeleton (i.e. humerus, lower teeth, skull, etc.). Those groups are responsible for learning to distinguish those characters on a representative group of modern specimens (for which the character codings are already available in the paper they have) and then coding those characters for a number of fossil taxa. The fossils are either described in papers posted on the course website or are represented by specimens held in the instructor's research lab. Students are responsible for finding time to come in and work with the specimens. The next to last lab of the quarter is concerned with analyzing data within each group, for the class as a whole, for fossil taxa alone, and for fossil and modern taxa. Students then write up the results of their analyses for their term project due at the end of the quarter.

292

Fossil Energy: Drivers and Challenges.  

NASA Astrophysics Data System (ADS)

Concerns about rapid economic growth, energy security, and global climate change have created a new landscape for fossil energy exploration, production, and utilization. Since 85% of primary energy supply comes from fossil fuels, and 85% of greenhouse gas emissions come from fossil fuel consumption, new and difficult technical and political challenges confront commercial, governmental, and public stakeholders. As such, concerns over climate change are explicitly weighed against security of international and domestic energy supplies, with economic premiums paid for either or both. Efficiency improvements, fuel conservation, and deployment of nuclear and renewable supplies will help both concerns, but are unlikely to offset growth in the coming decades. As such, new technologies and undertakings must both provide high quality fossil energy with minimal environmental impacts. The largest and most difficult of these undertakings is carbon management, wherein CO2 emissions are sequestered indefinitely at substantial incremental cost. Geological formations provide both high confidence and high capacity for CO2 storage, but present scientific and technical challenges. Oil and gas supply can be partially sustained and replaced through exploitation of unconventional fossil fuels such as tar-sands, methane hydrates, coal-to-liquids, and oil shales. These fuels provide enormous reserves that can be exploited at current costs, but generally require substantial energy to process. In most cases, the energy return on investment (EROI) is dropping, and unconventional fuels are generally more carbon intensive than conventional, presenting additional carbon management challenges. Ultimately, a large and sustained science and technology program akin to the Apollo project will be needed to address these concerns. Unfortunately, real funding in energy research has dropped dramatically (75%) in the past three decades, and novel designs in fission and fusion are not likely to provide any substantial offset in the next 30 years when they are most needed internationally.

Friedmann, Julio

2007-04-01

293

Dynamic and Steady-State Responses of Inorganic Nitrogen Pools and NH3 Exchange in Leaves of Lolium perenne and Bromus erectus to Changes in Root Nitrogen Supply1  

PubMed Central

Short- and long-term responses of inorganic N pools and plant-atmosphere NH3 exchange to changes in external N supply were investigated in 11-week-old plants of two grass species, Lolium perenne and Bromus erectus, characteristic of N-rich and N-poor grassland ecosystems, respectively. A switch of root N source from NO3? to NH4+ caused within 3 h a 3- to 6-fold increase in leaf apoplastic NH4+ concentration and a simultaneous decrease in apoplastic pH of about 0.4 pH units in both species. The concentration of total extractable leaf tissue NH4+ also increased two to three times within 3 h after the switch. Removal of exogenous NH4+ caused the apoplastic NH4+ concentration to decline back to the original level within 24 h, whereas the leaf tissue NH4+concentration decreased more slowly and did not reach the original level in 48 h. After growing for 5 weeks with a steady-state supply of NO3? or NH4+, L. perenne were in all cases larger, contained more N, and utilized the absorbed N more efficiently for growth than B. erectus, whereas the two species behaved oppositely with respect to tissue concentrations of NO3?, NH4+, and total N. Ammonia compensation points were higher for B. erectus than for L. perenne and were in both species higher for NH4+- than for NO3?-grown plants. Steady-state levels of apoplastic NH4+, tissue NH4+, and NH3 emission were significantly correlated. It is concluded that leaf apoplastic NH4+ is a highly dynamic pool, closely reflecting changes in the external N supply. This rapid response may constitute a signaling system coordinating leaf N metabolism with the actual N uptake by the roots and the external N availability. PMID:11842177

Mattsson, Marie; Schjoerring, Jan K.

2002-01-01

294

Schewel and Schipper 1 FOSSIL FREIGHT: HOW MUCH FOSSIL FUEL DOES IT TAKE TO MOVE FOSSIL1  

E-print Network

Schewel and Schipper 1 FOSSIL FREIGHT: HOW MUCH FOSSIL FUEL DOES IT TAKE TO MOVE FOSSIL1 FUEL?2 Laura Schewel 1 and Lee Schipper 2 3 (1) UC Berkeley, Energy and Resources Group4 (2) UC Berkeley author: LAURA.SCHEWEL@BERKELEY.EDU7 8 Word Count: 45339 Figures:1010 Tables: 411 12 Laura Schewel (laura.schewel

Kammen, Daniel M.

295

Identifying Fossils: Exploring the Mississippi River Bluffs  

NSDL National Science Digital Library

This activity is a geology lab where students learn about fossils found in sedimentary rocks and show their understanding by writing a literary nonfiction paper from the perspective of one of those fossils.

296

JiTT - Ethics of Fossil Collecting  

NSDL National Science Digital Library

1) What do you think it means for a fossil resource to be "abused"? 2) What's the issue with fossil hunting on federal land (such as National Parks)? Explain what your interpretation of the conflict ...

Laura Guertin

297

Evolving Form and Function: Fossils and Development  

E-print Network

Evolving Form and Function: Fossils and Development Proceedings of a symposium honoring Adolf: Fossils and Development Proceedings of a symposium honoring Adolf Seilacher for his contributions of Natural History, Yale University. All rights reserved. Frontispiece: Photograph of Dr. Adolf Seilacher

Patel, Nipam H.

298

Hunting Invertebrate Fossils in the Classroom  

NSDL National Science Digital Library

This activity is designed to provide a general knowledge about paleontology and its intimate relationship to sedimentary geology. It will introduce the student to fossils with an emphasis on the invertebrate phyla. As a result of this activity students will acquire a general knowledge of fossils and paleontology, be able to identify the major invertebrate groups commonly found in the fossil record, and learn how fossils tell us about the history of the earth.

Jon Garbisch

299

Fossilization and Adaptation Activities in Paleontology  

NSDL National Science Digital Library

This activity introduces students to the concepts of time, past life, and fossils. After completing these exercises students will be able to evaluate the importance of fossils to our knowledge of past life, identify conditions necessary for fossilization, construct a possible scenario for formation of fossils, understand how organisms are adapted to their environments, and understand the relationships of modern and ancient communities with their environments.

Brent Breithaupt

300

New fossil hominids from Laetolil, Tanzania  

Microsoft Academic Search

New fossil hominid specimens from the Laetolil fossil locality in Tanzania are described. The material includes mandibles and teeth derived from reliably-dated deposits of Pliocene age. Preliminary descriptions, measure- ments and illustrations are presented This paper furnishes a preliminary de- scription of hominid remains recovered from the Laetolil fossil locality in Tanzania. The specimens were found during 1974 and 1975

Tim D. White

1977-01-01

301

Fossils in Antarctica: British Antarctic Survey  

NSDL National Science Digital Library

Although marching penguins add to Antarctica's allure, The British Antarctic Survey (BAS) has found fossil evidence that dinosaurs, marsupials, and forests inhabited the area long before penguins charmed the world with their trademark waddle. Since 1940, when the fossil collection of the BAS was started, it has grown to 40,000 specimens. The "Fossils" section of the BAS website can be found on the left side of the homepage in the "About Antarctica" area, and is divided into two explanatory sections: "Fossils from the Antarctic" and "Fossil Locations in Antarctica". There are also links in each section, near the top right hand corner of the page, to "Type and Figured Fossil Collection" and "Fossils Picture Gallery". In the "Fossils from the Antarctic" section, the types of fossils found are explained and include: molluscs, arthropods, echinoderms and plants. The "Fossil Locations in Antarctica" section has a map of the three islands where a large amount of fossils have been found, along with descriptions of each island and what general types of fossils have been found on them.

302

Cretaceous Fossils: Plants Quick Identification Gallery  

NSDL National Science Digital Library

This site forms a component of the CretaceousFossils.com page providing detailed information and high resolution photos of Cretaceous plants. The site supplies a practical, visual resource designed to facilitate identification of plant fossils from the Cretaceous Period. Educators and students alike may find this site and its links useful for viewing, identifying and downloading photos of exceptionally preserved fossil plant specimens.

Minor Keith

303

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

E-print Network

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial

Scherer, Norbert F.

304

Using extant morphological variation to understand fossil  

E-print Network

Using extant morphological variation to understand fossil relationships: a cautionary tale Rebecca of insights that are pertinent to how we evaluate relationships among our fossil human ancestors. Here I summarize four such insights. I then use a fossil hominid example to illustrate how our understanding

Ackermann, Rebecca Rogers

305

Looking at Fossils in New Ways  

ERIC Educational Resources Information Center

Existing fossils could be studied from a different prospective with the use of new methods of analysis for gathering more information. The new techniques of studying fossils binds the new and the old techniques and information and provides another way to look at fossils.

Flannery, Maura C.

2005-01-01

306

Constraining fossil calibrations for molecular clocks  

E-print Network

Constraining fossil calibrations for molecular clocks Sir, In a recent paper, Mu¨ller and Reisz(1) proposed how fossil calibrations should be selected for application in molecular clock studies. The topic molecules. Nonetheless, we believe that these authors have erred both in their proposal of fossil

Kumar, Sudhir

307

A surprise inside a T. Rex fossil  

NSDL National Science Digital Library

When scientists looked inside the leg bone of a recently discovered Tyrannosaurus rex fossil, they found something they weren't expecting. Typically, only the hard parts of an animal, like the bones, are preserved as fossils. This T. rex fossil, however, contained some beautifully preserved soft tissue inside the bone, where the marrow once was.

American Association for the Advancement of Science (AAAS; )

2005-03-24

308

004144:a0001 Fossil Record: Quality  

E-print Network

004144:a0001 Fossil Record: Quality Michael J Benton, University of Bristol, Bristol, UK There are divergent opinions about the quality of the fossil record and its ability to give a useful representation phylogenies, suggests that the fossils do tell the story relatively well. 004144:s0001 Introduction 004144:p

Benton, Michael

309

Cycads: Fossil evidence of late paleozoic origin  

USGS Publications Warehouse

Plant fossils from Lower Permian strata of the southwestern United States have been interpreted as cycadalean megasporophylls. They are evidently descended from spermopterid elements of the Pennsylvanian Taeniopteris complex; thus the known fossil history of the cycads is extended from the Late Triassic into the late Paleozoic. Possible implications of the Permian fossils toward evolution of the angiosperm carpel are considered.

Mamay, S.H.

1969-01-01

310

Fossil: A Robust Relational Learner Johannes Furnkranz  

E-print Network

Fossil: A Robust Relational Learner Johannes F¨urnkranz juffi@ai.univie.ac.at Austrian Research in this paper describes Fossil, an ILP system that uses a search heuristic based on statistical correlation, Fossil's stopping criterion depends on a search heuristic that estimates the utility of literals

Fürnkranz, Johannes

311

The conservation and use of fossil vertebrate sites: British fossil reptile sites  

E-print Network

The conservation and use of fossil vertebrate sites: British fossil reptile sites Michael J. Benton and William A. Wimbledon BENTON. M. J. & W. A. WIMBLEDON. 19R5. The conservation and use of fossil vertebrate sites: British fossil reptile sites. Proc. Geol. Ass., 96 (I). 1-0. Over a thousand sites in Britain

Benton, Michael

312

Fossil groups of galaxies: Are they groups? Are they fossils?  

NASA Astrophysics Data System (ADS)

Fossil groups present a puzzle to current theories of structure formation. Despite the low number of bright galaxies, their high velocity dispersions and high TX indicate cluster-like potential wells. Measured concentration parameters seem very high indicating early formation epochs in contradiction with the observed lack of large and well defined cooling cores. There are very few fossil groups with good quality X-ray data and their idiosyncrasies may enhance these apparent contradictions. The standard explanation for their formation suggests that bright galaxies within half the virial radii of these systems were wiped out by cannibalism forming the central galaxy. Since dry mergers, typically invoked to explain the formation of the central galaxies, are not expected to change the IGM energetics significantly, thus not preventing the formation of cooling cores, we investigate the scenario where recent gaseous (wet) mergers formed the central galaxy injecting energy and changing the chemistry of the IGM in fossil groups. We show a test for this scenario using fossil groups with enough X-ray flux in the Chandra X-ray Observatory archive by looking at individual metal abundance ratio distributions near the core. Secondary SN II powered winds would tend to erase the dominance of SN IA ejecta in the core of these systems and would help to erase previously existing cold cores. Strong SN II-powered galactic winds resulting from galaxy merging would be trapped by their deep potential wells reducing the central enhancement of SN Ia/SN II iron mass fraction ratio. The results indicate that there is a decrement in the ratio of SN Ia to SN II iron mass fraction in the central regions of the systems analyzed, varying from 99±1% in the outer regions to 85±2% within the cooling radius (Figure 1) and would inject enough energy into the IGM preventing central gas cooling. The results are consistent with a scenario of later formation epoch for fossil groups, as they are defined, when compared to galaxy clusters and normal groups.

Dupke, Renato de Alencar; Miller, Eric; de Oliveira, Claudia Mendes; Sodre, Laerte; Rykoff, Eli; de Oliveira, Raimundo Lopes; Proctor, Rob

2010-11-01

313

Clustering Fossils in Solid Inflation  

E-print Network

In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tensor perturbation induces observable clustering fossils in the form of quardupole anisotropy in large scale structure power spectrum. In this work we revisit the bispectrum analysis for the scalar-scalar-scalar and tensor-scalar-scalar for the general parameter space of solid. We consider the parameter space of the model in which the level of non-Gaussianity generated is consistent with Planck constraints. Specializing to this allowed range of model parameter, we calculate the quadrupole anisotropy induced from the long tensor perturbations on the power spectrum of scalar perturbations. We argue that imprints of clustering fossil from primordial gravitational waves on large scale structures can be detected from the future galaxy surveys.

Mohammad Akhshik

2014-09-10

314

FOSSIL SPRINGS ROADLESS AREA, ARIZONA.  

USGS Publications Warehouse

Based on field studies, the Fossil Springs Roadless Area in central Arizona is concluded to have little promise for the occurrence of mineral or energy resources. Rocks in the Supai Formation (Pennsylvanian-Permian) near the central part of the roadless area contain widespread but spotty copper mineralization and trace amounts of uranium. Analyses obtained during the study define geochemical anomalies in two portions of the area that remain unexplained. The suites of anomalous metals suggest the possibility of hydrothermal veins and the presence of ultramafic rocks; neither were found in the field. Although there is little promise for the occurrence of mineral resources in the Fossil Springs Roadless Area, studies to identify the source of the geochemical anomalies could have valuable implications for regional studies and mineral exploration in the surrounding area.

Beard, L.S.; Ellis, C.E.

1984-01-01

315

Inferential reasoning by exclusion in children (Homo sapiens).  

PubMed

The cups task is the most widely adopted forced-choice paradigm for comparative studies of inferential reasoning by exclusion. In this task, subjects are presented with two cups, one of which has been surreptitiously baited. When the empty cup is shaken or its interior shown, it is possible to infer by exclusion that the alternative cup contains the reward. The present study extends the existing body of comparative work to include human children (Homo sapiens). Like chimpanzees (Pan troglodytes) that were tested with the same equipment and near-identical procedures, children aged three to five made apparent inferences using both visual and auditory information, although the youngest children showed the least-developed ability in the auditory modality. However, unlike chimpanzees, children of all ages used causally irrelevant information in a control test designed to examine the possibility that their apparent auditory inferences were the product of contingency learning (the duplicate cups test). Nevertheless, the children's ability to reason by exclusion was corroborated by their performance on a novel verbal disjunctive syllogism test, and we found preliminary evidence consistent with the suggestion that children used their causal-logical understanding to reason by exclusion in the cups task, but subsequently treated the duplicate cups information as symbolic or communicative, rather than causal. Implications for future comparative research are discussed. PMID:21728410

Hill, Andrew; Collier-Baker, Emma; Suddendorf, Thomas

2012-08-01

316

Fossil contourites: a critical review  

NASA Astrophysics Data System (ADS)

Despite three decades of study, there is still great controversy over the recognition and interpretation of fossil contourites exposed in ancient series on land. In order to best examine this problem, we briefly review the evidence from modern systems, including the many examples of Cenozoic contourites that have been recovered from DSDP/ODP drilling on major drifts in the present-day oceans. The range of contourite facies described from both deep-water (>2000 m) and mid-water (300-2000 m) drifts are mostly fine-grained, bioturbated and homogeneous, often with a distinct bedding cyclicity, and with some coarser-grained sandy contourites developed under higher-energy bottom currents. There are also a number of current-controlled sediment bodies that have formed in outer shelf/upper slope settings (50-300 m) under the influence of counter currents, underflows and major surface currents. These are not considered contourites sensu stricto, but may be mistaken as such in ancient examples. The most commonly described fossil contourites in the literature have been interpreted by the authors concerned as bottom-current reworked turbidites. However, a critical review suggests that these are the facies most subject to misinterpretation and many of the sediments claimed as fossil contourites are almost certainly fine-grained turbidites, whereas others were more likely formed under outer shelf/upper slope current systems. There remain very few ancient examples that are more closely comparable to modern contourites; these include the Cretaceous Talme Yafe Formation in Israel, the Ordovician Jiuxi Drift in China, and parts of the Paleogene Lefkara Formation, Cyprus and the Neogene Misaki Formation in Japan. We present a set of possible criteria for the recognition of fossil contourites and bottom-current reworked turbidites.

Stow, Dorrik A. V.; Faugères, Jean-Claude; Viana, Adriano; Gonthier, Eliane

1998-01-01

317

Fossil Collection and Museum Curation  

NSDL National Science Digital Library

Before we go into the field, students are exposed to field collection techniques and appropriate information to collect at the outcrop. This assignment is good for field trips because students each collect 1 or few samples, but spend time on the outcrop measuring a section and collecting associated lithologic and other fossil data if available (locality information, exposure, over and underlying sedimentology, details of host rock, sedimentary structures, assocaited fossils, diversity and abundance, taphonomic condition of fossils, etc). The field locality can be anywhere where there are resaonably well preserved fossils (and should give students an appreciation of museum quality specimens). This allows this exercise to be flexible as field trip localities change. All of the information that they collect in the field will be included in their field notebook that is handed in at the end of the field trip for evaluation. In the lab-I used class time-students are asked to make a detailed sketch of their sample that they can take to the library with them, and a discussion is held as to where to look for information to identify specimens with. Students are given a week (variable depending on the availability of resources, for example if monographs need to be aquired through inter-library loan) to idenitfy their specimen and then asked to catalog them for the museum. They fill out a SUNY Oswego Paleontology Museum card, which they have seen all semester for their sample and are given the option to donate it to the collection or keep it.

Diana Boyer

318

Extinction and the fossil record  

NASA Technical Reports Server (NTRS)

The author examines evidence of mass extinctions in the fossil record and searches for reasons for such large extinctions. Five major mass extinctions eliminated at least 40 percent of animal genera in the oceans and from 65 to 95 percent of ocean species. Questions include the occurrence of gradual or catastrophic extinctions, causes, environment, the capacity of a perturbation to cause extinctions each time it happens, and the possibility and identification of complex events leading to a mass extinction.

Sepkoski, J. J. Jr; Sepkoski JJ, ,. J. r. (Principal Investigator)

1994-01-01

319

Dinosaurs: Ancient Fossils, New Discoveries  

NSDL National Science Digital Library

This Web site, created to complement the Museum's Dinosaurs: Ancient Fossils, New Discoveries exhibit, offers a virtual visit to the Museum, complete with text, photos, video clips, audio interviews, and more and includes much of the information which was in the original exhibit which is now closed. The site includes information on the bio-mechanics of dinosaurs and the reasons behind some of their strange appearances.

320

Turbulence and diffusion: fossil turbulence  

E-print Network

Fossil turbulence processes are central to turbulence, turbulent mixing, and turbulent diffusion in the ocean and atmosphere, in astrophysics and cosmology, and in most other natural flows. George Gamov suggested in 1954 that galaxies might be fossils of primordial turbulence produced by the Big Bang. John Woods showed that breaking internal waves on horizontal dye sheets in the interior of the stratified ocean form highly persistent remnants of these turbulent events, which he called fossil turbulence. The dark mixing paradox of the ocean refers to undetected mixing that must exist somewhere to explain why oceanic scalar fields like temperature and salinity are so well mixed, just as the dark matter paradox of galaxies refers to undetected matter that must exist to explain why rotating galaxies don't fly apart by centrifugal forces. Both paradoxes result from sampling techniques that fail to account for the extreme intermittency of random variables involved in self-similar, nonlinear, cascades over a wide range of scales; turbulent vorticity for dark mixing, and accreting small-planetary-mass MACHO number density for dark matter.

Carl H. Gibson

2003-03-31

321

Craniofacial diversity in early Homo and the affinities of the Sterkfontein Valley  

Microsoft Academic Search

The Sterkfontein Valley specimens SK 847 (Swartkrans Member 1) and Stw 53 (Sterkfontein Member 5) provide important evidence\\u000a of earlyHomo in southern Africa. However, specific identity has been disputed, with that of SK 847 especially contentious. Opinions differ\\u000a markedly as to whether the specimens are conspecific or not, whether they should be referred to East African earlyHomo species, or whether

A. Bilsborough

2002-01-01

322

The First Humans: A Summary Perspective on the Origin and Early Evolution of the Genus Homo  

Microsoft Academic Search

Origin, adaptation and diversity are eternal themes in human evolution. These issues are equally timeless with respect to\\u000a our own lineage. Human paleontologists continue to grapple with questions surrounding the origin and early evolution of our\\u000a own genus. How do we identify the earliest members the genus Homo? How many species of Homo were there in the Pliocene and Pleistocene,

Frederick E. Grine; John G. Fleagle

323

Initiation of the microgene polymerization reaction with non-repetitive homo-duplexes  

Microsoft Academic Search

Microgene Polymerization Reaction (MPR) is used as an experimental system to artificially simulate evolution of short, non-repetitive homo-duplex DNA into multiply-repetitive products that can code for functional proteins. Blunt-end ligation by DNA polymerase is crucial in expansion of homo-duplexes (HDs) into head-to-tail multiple repeats in MPR. The propagation mechanism is known, but formation of the initial doublet (ID) by juxtaposing

Mark Itsko; Arieh Zaritsky; Avinoam Rabinovitch; Eitan Ben-Dov

2008-01-01

324

A New Kind of Economy is Born - Social Decision-Makers Beat the "Homo Economicus"  

E-print Network

The Internet and Social Media change our way of decision-making. We are no longer the independent decision makers we used to be. Instead, we have become networked minds, social decision-makers, more than ever before. This has several fundamental implications. First of all, our economic theories must change, and second, our economic institutions must be adapted to support the social decision-maker, the "homo socialis", rather than tailored to the perfect egoist, known as "homo economicus".

Helbing, Dirk

2013-01-01

325

Patterns of craniofacial integration in extant Homo, Pan, and Gorilla.  

PubMed

Brain size increased greatly during Pleistocene human evolution, while overall facial and dentognathic size decreased markedly. This mosaic pattern is due to either selective forces that acted uniquely on each functional unit in a modularized, developmentally uncoupled craniofacial complex, or alternatively, selection that acted primarily on one unit, with the other responding passively as part of a coevolved set of ontogenetically and evolutionarily integrated structures. Using conditional independence modeling on homologous linear measurements of the height, breadth, and depth of the cranium in Pan (n = 95), Gorilla (n = 102), and recent Homo (n = 120), we reject the null hypothesis of equal levels of overall cranial integration. While all three groups share the pattern of greater neurocranial integration with distinct separation between the face and neurocranium (modularization), family differences do exist. The apes are more integrated in their entire crania, but display a particularly strong pattern of integration within the facial complex related to prognathism. Modern humans display virtually no facial integration, a pattern which is likely related to their markedly decreased facial projection. Modern humans also differ from their great ape counterparts in being more integrated within the breadth dimension of the cranial vault, likely tied to the increase in brain size and eventual globularity seen in human evolution. That the modern human integration pattern differs from the ancestral African great ape pattern along the inverse neurocranial-facial trend seen in human evolution indicates that this shift in the pattern of integration is evolutionarily significant, and may help to clarify aspects of the current debate over defining modern humans. PMID:16552733

Polanski, Joshua M; Franciscus, Robert G

2006-09-01

326

Design of homo-organic acid producing strains using multi-objective optimization.  

PubMed

Production of homo-organic acids without byproducts is an important challenge in bioprocess engineering to minimize operation cost for separation processes. In this study, we used multi-objective optimization to design Escherichia coli strains with the goals of maximally producing target organic acids, while maintaining sufficiently high growth rate and minimizing the secretion of undesired byproducts. Homo-productions of acetic, lactic and succinic acids were targeted as examples. Engineered E. coli strains capable of producing homo-acetic and homo-lactic acids could be developed by taking this systems approach for the minimal identification of gene knockout targets. Also, failure to predict effective gene knockout targets for the homo-succinic acid production suggests that the multi-objective optimization is useful in assessing the suitability of a microorganism as a host strain for the production of a homo-organic acid. The systems metabolic engineering-based approach reported here should be applicable to the production of other industrially important organic acids. PMID:25542849

Kim, Tae Yong; Park, Jong Myoung; Kim, Hyun Uk; Cho, Kwang Myung; Lee, Sang Yup

2015-03-01

327

Oldest Fossil Basidiomycete Clamp Connections  

E-print Network

of the family Polyporaceae (Hibbett et al. 1994), and suggested that the fossil was a saprotroph. The biological nature of the relationship between Botryopteris antiqua and the Visean clamp-bearing hyphae is difficult to determine because of the incompleteness... of both the host plant and fungus. The fungus could have been biotrophic or saprotrophic. If the conical callosities found in several of the cortical cells (Fig. 1m,n) formed in response to invading clamp-bearing hyphae, then this host response would favor...

Krings, Michael; Dotzler, Nora; Galtier, Jean; Taylor, Thomas N.

2011-01-01

328

Evolution and the Fossil Record  

NSDL National Science Digital Library

This publication of the American Geological Institute is a non-technical introduction to evolution and aims to help the general public gain a better understanding of one of the fundamental underlying concepts of modern science. Concepts covered include geologic time, change through time, Darwin's theory of evolution, evolution as a mechanism for change, the nature of species, the nature of theory, paleontology, and determination of age. Four case studies highlight examples of evolution from the fossil record to provide a perspective for understanding the evolution of life on Earth.

Dale Springer

2007-12-12

329

Teaching Paleontology: Fascinating Fossils (title provided or enhanced by cataloger)  

NSDL National Science Digital Library

This National Park Service (NPS) educational website contains a presentation for upper-elementary students about fossils and how they form. Detailed photos and illustrations discuss fossil types such as petrification or permineralization, carbon fossils, trace fossils, casts and molds, pseudofossils and index fossils. This slide show indicates how these different fossil types form and are preserved, and in which National Park areas they are found. The parks mentioned included John Day Fossil Beds, Petrified Forest, Agate Fossil Beds, Florissant Fossil Beds, and Hagerman Fossil Beds.

Florissant Fossil Beds National Monument

1999-12-17

330

Fossil energy biotechnology: A research needs assessment  

NASA Astrophysics Data System (ADS)

The Office of Program Analysis of the U.S. Department of Energy commissioned this study to evaluate and prioritize research needs in fossil energy biotechnology. The objectives were to identify research initiatives in biotechnology that offer timely and strategic options for the more efficient and effective uses of the Nation's fossil resource base, particularly the early identification of new and novel applications of biotechnology for the use or conversion of domestic fossil fuels. Fossil energy biotechnology consists of a number of diverse and distinct technologies, all related by the common denominator -- biocatalysis. The expert panel organized 14 technical subjects into three interrelated biotechnology programs: (1) upgrading the fuel value of fossil fuels; (2) bioconversion of fossil feedstocks and refined products to added value chemicals; and (3) the development of environmental management strategies to minimize and mitigate the release of toxic and hazardous petrochemical wastes.

1993-11-01

331

Fossil energy program. Summary document  

SciTech Connect

This program summary document presents a comprehensive overview of the research, development, and demonstration (RD and D) activities that will be performed in FY 1981 by the Assistant Secretary for Fossil Energy (ASFE), US Department of Energy (DOE). The ASFE technology programs for the fossil resources of coal, petroleum (including oil shale) and gas have been established with the goal of making substantive contributions to the nation's future supply and efficienty use of energy. On April 29, 1977, the Administration submitted to Congress the National Energy Plan (NEP) and accompanying legislative proposals designed to establish a coherent energy policy structure for the United States. Congress passed the National Energy Act (NEA) on October 15, 1978, which allows implementation of the vital parts of the NEP. The NEP was supplemented by additional energy policy statements culminating in the President's address on July 15, 1979, presenting a program to further reduce dependence on imported petroleum. The passage of the NEA-related energy programs represent specific steps by the Administration and Congress to reorganize, redirect, and clarify the role of the Federal Government in the formulation and execution of national energy policy and programs. The energy technology RD and D prog4rams carried out by ASFE are an important part of the Federal Government's effort to provide the combination and amounts of energy resources needed to ensure national security and continued economic growth.

None

1980-05-01

332

Trace fossil assemblages in selected shelf sandstones  

E-print Network

IN DELTA AND DELTA MARGIN FACIES Introduction Coyote Creek Lone Pine Field Summary TRACE F'OSSILS IN SELECTED SHELF FACIES Introduction Sacatosa Recluse Field Dos Arroyos Field House Creek Field Dlmitos Ranch Kurten Field East Binger Field..., Alpine Parker 2, Recluse Field, Wyoming (D-0) Trace fossils present and log responses of the San Miguel Sandstone, Endeavor-Steeger Halsell 1-112, Sacatosa area, Texas. The size of the bars denotes the relative abundance of the trace fossils repre...

Locke, Kathleen Ann

1983-01-01

333

Layered Fossil Parfait: Deeper is Older  

NSDL National Science Digital Library

In this activity, learners explore dinosaur fossils by making an edible treat. First, learners read "Dinosaur Bones" by Aliki to examine how fossils are formed. Then, the educator sifts through the class garbage to demonstrate that the deeper something is buried the older it may be. Next, learners make a layered dinosaur fossil model using candy and other treats. This activity is featured on page 30 of the "Dinosphere" unit of study for K-2 learners.

Rick Crosslin

2004-01-01

334

Quantification de révolution morphologique du crâne des Hominidés et hétérochronies  

NASA Astrophysics Data System (ADS)

Comparisons of adult skulls of various species of great apes, fossil hominids and modern humans in the sagittal, Francfort and ortho-sagittal planes reveal a series of three separate organisation plans: 'Great Ape', 'Australopithecine' and 'Homo', the latter including primitive men ( Homo ergaster-erectus-neandertalensis) and modern humans ( Homo sapiens). Morphological changes between these plans are quantified for the first time here by vector fields. This study confirms the existence of cranio-facial contraction, which occurs as a series of leaps. The juvenile morphology of the great ape skull is broadly preserved in adult Homo sapiens, suggesting that numerous heterochronies have occurred in mosaic during ontogeny (hypermorphosis, hypomorphosis, post-displacements).

Chaline, Jean; David, Bruno; Magniez-Jannin, Françoise; Malassé, Anne Dambricourt; Marchand, Didier; Courant, Frédéric; Millet, Jean-Jacques

1998-02-01

335

Fossilization Processes in Thermal Springs  

NASA Technical Reports Server (NTRS)

To create a comparative framework for the study of ancient examples, we have been carrying out parallel studies of the microbial biosedimentology, taphonomy and geochemistry of modem and sub-Recent thermal spring deposits. One goal of the research is the development of integrated litho- and taphofacies models for siliceous and travertline sinters. Thermal springs are regarded as important environments for the origin and early evolution of life on Earth, and we seek to utilize information from the fossil record to reconstruct the evolution of high temperature ecosystems. Microbial contributions to the fabric of thermal spring sinters occur when population growth rates keep pace with, or exceed rates of inorganic precipitation, allowing for the development of continuous biofilms or mats. In siliceous thermal springs, microorganisms are typically entombed while viable. Modes of preservation reflect the balance between rates of organic matter degradation, silica precipitation and secondary infilling. Subaerial sinters are initially quite porous and permeable and at temperatures higher than about 20 C, organic materials are usually degraded prior to secondary infilling of sinter frameworks. Thus, organically-preserved microfossils are rare and fossil information consists of characteristic biofabrics formed by the encrustation and underplating of microbial mat surfaces. This probably accounts for the typically low total organic carbon values observed in thermal spring deposits. In mid-temperature, (approx. 35 - 59 C) ponds and outflows, the surface morphology of tufted Phormidium mats is preserved through mat underplating by thin siliceous: crusts. Microbial taxes lead to clumping of ceils and/or preferred filament orientations that together define higher order composite fabrics in thermal spring stromatolites (e.g. network, coniform, and palisade). At lower temperatures (less than 35 C), Calothrix mats cover shallow terracette pools forming flat carpets or pustular surfaces that produce palisade and "shrub" fabrics, respectively. At finer scales, composite fabrics are seen to consist distinctive associations of microstructures formed by the encrustation of individual cells and filaments. Composite fabrics survive the diagenetic transitions from primary opaline silica to quartz and are known from subaerial thermal spring deposits as old as Lower Carboniferous. However, fossil microorganisms tend to be rare in older deposits, and are usually preserved only where cells or sheaths have been stained by iron oxides. In subaqueous mineralizing springs at lower temperatures, early infilling leads to a more rapid and complete reduction in porosity and permeability. This process, along with the slower rates of microbial degradation at lower temperatures, creates a more favorable situation for organic matter preservation. Application of this taphonomic model to the Rhynie Chert, previously interpreted as subaerial, suggest it was probably deposited in a subaqueous spring setting at lower temperatures.

Farmer, Jack D.; Cady, Sherry; Desmarais, David J.; Chang, Sherwood (Technical Monitor)

1995-01-01

336

Proposing Explanations for Fossil Footprints  

NSDL National Science Digital Library

This activity will allow students to observe and interpret fossil footprint evidence. From the evidence, they are asked to construct defensible hypotheses or explanations for events that took place in the geological past. Students will be asked to propose explanations and make predictions based on evidence, recognize and analyze alternative explanations and predictions, understand that scientific explanations are subject to change as new evidence becomes available, and understand that scientific explanations must meet certain criteria. Students learn that scientific explanations must be consistent with experimental and observational evidence, should also be logical, respect the rules of evidence, be open to criticism, report methods and procedures, and make knowledge public. The site contains all of the information and instructions needed to complete the activity.

337

Fossil diatoms and neogene paleolimnology  

USGS Publications Warehouse

Diatoms have played an important role in the development of Neogene continental biostratigraphy and paleolimnology since the mid-19th Century. The history of progress in Quaternary diatom biostratigraphy has developed as a result of improved coring techniques that enable sampling sediments beneath existing lakes coupled with improved chronological control (including radiometric dating and varve enumeration), improved statistical treatment of fossil diatom assemblages (from qualitative description to influx calculations of diatom numbers or volumes), and improved ecological information about analogous living diatom associations. The last factor, diatom ecology, is the most critical in many ways, but progresses slowly. Fortunately, statistical comparison of modern diatom assemblages and insightful studies of the nutrient requirements of some common freshwater species are enabling diatom paleolimnologists to make more detailed interpretations of the Quaternary record than had been possible earlier, and progress in the field of diatom biology and ecology will continue to refine paleolimnological studies. The greater age and geologic setting of Tertiary diatomaceous deposits has prompted their study in the contexts of geologic history, biochronology and evolution. The distribution of diatoms of marine affinities in continental deposits has given geologists insights about tectonism and sea-level change, and the distribution of distinctive (extinct?) diatoms has found utilization both in making stratigraphic correlations between outcrops of diatomaceous deposits and in various types of biochronological studies that involve dating deposits in different areas. A continental diatom biochronologic scheme will rely upon evolution, such as the appearance of new genera within a family, in combination with regional environmental changes that are responsible for the wide distribution of distinctive diatom species. The increased use of the scanning electron microscope for the detailed descriptions of fossil diatoms will provide the basis for making more accurate correlations and identifications, and the micromorphological detail for speculations about evolutionary relationships. ?? 1988.

Platt, Bradbury J.

1988-01-01

338

The Fossil Record Noel A. Heim and Dana H. Geary  

E-print Network

II.9 The Fossil Record Noel A. Heim and Dana H. Geary OUTLINE 1. Fossilization and taphonomy 2. The nature of the fossil record 3. Marine diversity in the Phanerozoic 4. The value of the fossil record The fossil record documents the history of life over the course of the past 3.5 billion years, demonstrates

Heim, Noel A.

339

Forty Years Later: Updating the Fossilization Hypothesis  

ERIC Educational Resources Information Center

A founding concept in second language acquisition (SLA) research, fossilization has been fundamental to understanding second language (L2) development. The Fossilization Hypothesis, introduced in Selinker's seminal text (1972), has thus been one of the most influential theories, guiding a significant bulk of SLA research for four decades; 2012…

Han, ZhaoHong

2013-01-01

340

Creature Features - Showcase of Living Fossils  

NSDL National Science Digital Library

This activity is a side project that students work on through the organismal portion of a course in paleobiology/paleontology. Students present on the lifestyle, habitat, and behavior of "living fossil" groups. The activity ties the fossil record to the modern living world and allows students to engage with ideas of evolutionary stasis, taphonomy, and functional morphology.

David Sunderlin

341

56 SCIENCE SCOPE Fossil sharks: Learning  

E-print Network

56 SCIENCE SCOPE Fossil sharks: Learning from and about the past by Catalina Pimiento and Rose M. Recent studies on preferences in museums have revealed that children are fasci- nated by fossil sharks--the remains of sharks that inhabited the oceans of the past (MacFadden 2006). This has created new

Bermingham, Eldredge

342

The original colours of fossil beetles  

PubMed Central

Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group. PMID:21957131

McNamara, Maria E.; Briggs, Derek E. G.; Orr, Patrick J.; Noh, Heeso; Cao, Hui

2012-01-01

343

Do alternative energy sources displace fossil fuels?  

NASA Astrophysics Data System (ADS)

A fundamental, generally implicit, assumption of the Intergovernmental Panel on Climate Change reports and many energy analysts is that each unit of energy supplied by non-fossil-fuel sources takes the place of a unit of energy supplied by fossil-fuel sources. However, owing to the complexity of economic systems and human behaviour, it is often the case that changes aimed at reducing one type of resource consumption, either through improvements in efficiency of use or by developing substitutes, do not lead to the intended outcome when net effects are considered. Here, I show that the average pattern across most nations of the world over the past fifty years is one where each unit of total national energy use from non-fossil-fuel sources displaced less than one-quarter of a unit of fossil-fuel energy use and, focusing specifically on electricity, each unit of electricity generated by non-fossil-fuel sources displaced less than one-tenth of a unit of fossil-fuel-generated electricity. These results challenge conventional thinking in that they indicate that suppressing the use of fossil fuel will require changes other than simply technical ones such as expanding non-fossil-fuel energy production.

York, Richard

2012-06-01

344

The First Fossil Record of Caecilian Amphibians  

Microsoft Academic Search

THREE groups of amphibians are living today-frogs, salamanders and caecilians. The fossil record of frogs and salamanders is relatively poor1,2, but representatives of most groups have been discovered. For the caecilians, however, no authentic fossils have been recognized, until now. We describe here a single diagnostic vertebra from the Palaeocene of Brazil.

Richard Estes; MARVALEE H. WAKE

1972-01-01

345

HEMATITE AND CALCITE COATINGS ON FOSSIL VERTEBRATES  

Microsoft Academic Search

Hematite coatings are common on vertebrate fossils from Paleocene\\/Eocene paleosol deposits in the Bighorn Basin, Wyoming. In general, hematite coatings are found only on fossils and are limited to soils exhibiting hydromorphic features and moderate maturity. Pet- rographic and isotopic evidence suggests that hematite and micritic calcite formed at nearly the same time in a pedogenic environment, whereas sparry calcite

HUIMING BAO; PAUL L. KOCH; ROBERT P. HEPPLE

346

Atomic force microscopy of Precambrian microscopic fossils  

PubMed Central

Atomic force microscopy (AFM) is a technique used routinely in material science to image substances at a submicron (including nm) scale. We apply this technique to analysis of the fine structure of organic-walled Precambrian fossils, microscopic sphaeromorph acritarchs (cysts of planktonic unicellular protists) permineralized in ?650-million-year-old cherts of the Chichkan Formation of southern Kazakhstan. AFM images, backed by laser-Raman spectroscopic analysis of individual specimens, demonstrate that the walls of these petrified fossils are composed of stacked arrays of ?200-nm-sized angular platelets of polycyclic aromatic kerogen. Together, AFM and laser-Raman spectroscopy provide means by which to elucidate the submicron-scale structure of individual microscopic fossils, investigate the geochemical maturation of ancient organic matter, and, potentially, distinguish true fossils from pseudofossils and probe the mechanisms of fossil preservation by silica permineralization. PMID:12089337

Kempe, André; Schopf, J. William; Altermann, Wladyslaw; Kudryavtsev, Anatoliy B.; Heckl, Wolfgang M.

2002-01-01

347

John Day Fossil Beds National Monument  

NSDL National Science Digital Library

This National Park Service website offers an education section which includes: programs for visiting school groups involving the geological and evolutionary processes of the park, working with fossil casts, and other fossil activities; a list of classroom materials to send for (some have cost) including a horse fossil study kit, a general fossil kit, a teacher packet, and a videotape on the paleontology work at the park and evolution of the horse; and a list of teacher workshops in Oregon. There are species lists for vertebrate and plant fossils, diagrams of the major geologic formations and illustrations of different paleobiomes, species lists for existing flora and fauna, and a fire management plan. Regional and park history is covered as well as the history of the Chinookan, Sahaptian, Shoshonean, and Salishan Indians of Eastern Oregon. There is also information for planning a visit to the park.

348

Grain-size and grain-shape analyses using digital imaging technology: Application to the fluvial formation of the Ngandong paleoanthropological site in Central Java, Indonesia  

NASA Astrophysics Data System (ADS)

This study implements grain-size and grain-shape analyses to better understand the fluvial processes responsible for forming the Ngandong paleoanthropological site along the Solo River in Central Java. The site was first discovered and excavated by the Dutch Geological Survey in the early 1930's, during which fourteen Homo erectus fossils and thousands of other macrofaunal remains were uncovered. The Homo erectus fossils discovered at Ngandong are particularly interesting to paleoanthropologists because the morphology of the excavated crania suggests they are from a recently-living variety of the species. The primary scientific focus for many years has been to determine the absolute age of the Ngandong fossils, while the question of exactly how the Ngandong site itself formed has been frequently overlooked. In this study I use Retsch CAMSIZER digital imaging technology to conduct grain-size and grain-shape analyses of sediments from the terrace stratigraphy at the Ngandong site to understand if there are significant differences between sedimentary layers in grain-size and/or grain-shape, and what these differences mean in terms of local paleoflow dynamics over time. Preliminary analyses indicate there are four distinct sedimentary layers present at Ngandong with regard to size sorting, with the fossil-bearing layers proving to be the most poorly-sorted and most similar to debris-flow deposits. These results support hypotheses by geoarchaeologists that the fossil-bearing layers present at Ngandong were deposited during special flow events rather than under normal stream flow conditions.

Sipola, Maija

2013-04-01

349

Nicotinamidase/pyrazinamidase of Mycobacterium tuberculosis forms homo-dimers stabilized by disulfide bonds.  

PubMed

Recombinant wild-pyrazinamidase from H37Rv Mycobacterium tuberculosis was analyzed by gel electrophoresis under differential reducing conditions to evaluate its quaternary structure. PZAse was fractionated by size exclusion chromatography under non-reducing conditions. PZAse activity was measured and mass spectrometry analysis was performed to determine the identity of proteins by de novo sequencing and to determine the presence of disulfide bonds. This study confirmed that M. tuberculosis wild type PZAse was able to form homo-dimers in vitro. Homo-dimers showed a slightly lower specific PZAse activity compared to monomeric PZAse. PZAse dimers were dissociated into monomers in response to reducing conditions. Mass spectrometry analysis confirmed the existence of disulfide bonds (C72-C138 and C138-C138) stabilizing the quaternary structure of the PZAse homo-dimer. PMID:25199451

Rueda, Daniel; Sheen, Patricia; Gilman, Robert H; Bueno, Carlos; Santos, Marco; Pando-Robles, Victoria; Batista, Cesar V; Zimic, Mirko

2014-12-01

350

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

PubMed

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

Schwartz, J H; Tattersall, I

1996-10-01

351

Global and local processing in adult humans (Homo sapiens), 5-year-old children (Homo sapiens), and adult cotton-top tamarins (Saguinus oedipus).  

PubMed

This study compared adults (Homo sapiens), young children (Homo sapiens), and adult tamarins (Saguinus oedipus) while they discriminated global and local properties of stimuli. Subjects were trained to discriminate a circle made of circle elements from a square made of square elements and were tested with circles made of squares and squares made of circles. Adult humans showed a global bias in testing that was unaffected by the density of the elements in the stimuli. Children showed a global bias with dense displays but discriminated by both local and global properties with sparse displays. Adult tamarins' biases matched those of the children. The striking similarity between the perceptual processing of adult monkeys and humans diagnosed with autism and the difference between this and normatively developing human perception is discussed. PMID:17115853

Neiworth, Julie J; Gleichman, Amy J; Olinick, Anne S; Lamp, Kristen E

2006-11-01

352

Systematics of some enigmatic "fossils"  

NSDL National Science Digital Library

Students are given sets of different shaped fasteners (staples, paper clips, tacks, etc.) and work with the instructor through a guided exercise in which they construct a character matrix and cladogram depicting the phylogeny of the "organisms". Students are then divided into small groups; each group receives a set of various shapes/colors of pasta. (The sets are all the same.) Each group must decide how many species are present in their sample (considering the potential for ontogenetic and sexual variation within species), choose and define characters for a cladistic analysis, and construct a character matrix. The instructor runs the matrices through cladistic analysis software, and the following week the students receive the results from analysis of each group's data. The class then discusses the effects of species definition, character choice, etc. on phylogenetic hypotheses. The activity allows students to directly confront issues of identifying and distinguishing morphological species. Conflicting results obtained by different groups analyzing the same data set drive home the complicated nature of character choice and definition in construction of a character matrix for cladistic analysis, and underscore the fact that individual cladograms represent phylogenetic hypotheses subject to modification by further analysis. (This last point becomes necessary background as students encounter different/competing hypotheses of phylogenetic relationships during study of fossil invertebrates.)

Allison Tumarkin-Deratzian

353

Clean Fossil Energy Conversion Processes  

NASA Astrophysics Data System (ADS)

Absolute and per-capita energy consumption is bound to increase globally, leading to a projected increase in energy requirements of 50% by 2020. The primary source for providing a majority of the energy will continue to be fossil fuels. However, an array of enabling technologies needs to be proven for the realization of a zero emission power, fuel or chemical plants in the near future. Opportunities to develop new processes, driven by the regulatory requirements for the reduction or elimination of gaseous and particulate pollutant abound. This presentation describes the chemistry, reaction mechanisms, reactor design, system engineering, economics, and regulations that surround the utilization of clean coal energy. The presentation will cover the salient features of the fundamental and process aspects of the clean coal technologies in practice as well as in development. These technologies include those for the cleaning of SO2, H2S, NOx, and heavy metals, and separation of CO2 from the flue gas or the syngas. Further, new combustion and gasification processes based on the chemical looping concepts will be illustrated in the context of the looping particle design, process heat integration, energy conversion efficiency, and economics.

Fan, L.-S.

2007-03-01

354

An Indoor Fossil/Archeological Dig  

NSDL National Science Digital Library

In this activity, students will participate in a simulated fossil hunt or archeological excavation. Working in groups, they will excavate fossils or artifacts buried in a container and tag, number and label, and record the position and details of each object encountered. They will make site sketches as each layer is removed. When all the objects have been found, and all the information obtained, the group can compose a field report on the dig site that makes some inferences about the conditions that existed at the time the fossil/artifact was buried. A student worksheet is provided.

2011-06-24

355

Running head: EXPLAINING ANTISOCIAL PUNISHMENT Homo homini lupus? Explaining antisocial punishment  

E-print Network

Running head: EXPLAINING ANTISOCIAL PUNISHMENT 1 Homo homini lupus? Explaining antisocial punishment Karolina Sylwester1 Benedikt Herrmann2 Joanna J. Bryson1 1 University of Bath Department Commission #12;EXPLAINING ANTISOCIAL PUNISHMENT 2 ABSTRACT1 Punishing group members who parasitize their own

Bryson, Joanna J.

356

© InternationalJournal.org Selected Genetic Destination: The Rise of Homo sapiens genomicus  

E-print Network

Abstract: Selected genetic destination is a species’, such as Homo sapiens, possessing control of the genetic evolution of a species (other species and their own species) with the use of genetic engineering techniques (Grandy 2010b). Since the completion of the human genome project in 2003 scientists and philosophers have speculated on the possibility of not only curing numerous diseases, but also the possibility to be able to enhance humans with genetic engineering (Grandy 2006c). Serious philosophical and religious debate has arisen in response to the possibility of the non-medical use of gene therapy. There is much gray area that needs to be defined when discussing what medical gene therapy and genetic enhancements are. I have proposed that the use of genetic enhancement will give rise to a new species Homo sapiens genomicus (Grandy 2010b). In this paper I will discuss the differences between passive human enhancement and aggressive human enhancement, the different possible subspecies (especially Homo sapiens genomicus) that may evolve in the future, the possibility of genetically engineering species better suited to survive in space, and reasons to support the use of genetic engineering to improve humankind. In conclusion, I will discuss where the Homo sapiens sapiens subspecies stands in the grand scheme of things.

John K. Grandy

357

Homo- and heterofermentative lactobacilli differently affect sugarcane-based fuel ethanol fermentation  

Technology Transfer Automated Retrieval System (TEKTRAN)

The antagonism between by yeast and lactobacilli is largely dependent on the initial population of each organism. While homo-fermentative lactobacillus present higher inhibitory effect upon yeast when in equal cell number, in industrial fuel ethanol conditions where high yeast cell densities prevail...

358

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

ERIC Educational Resources Information Center

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

Poti, Patrizia; Hayashi, Misato; Matsuzawa, Tetsuro

2009-01-01

359

Adaptive sex ratio variation in pre-industrial human (Homo sapiens) populations?  

E-print Network

Adaptive sex ratio variation in pre-industrial human (Homo sapiens) populations? Virpi Lummaa-20014 Turku, Finland Sex allocation theory predicts that in a population with a biased operational sex ratio (OSR), parents will increase their ¢tness by adjusting the sex ratio of their progeny towards

Lummaa, Virpi

360

ON THE CONCEPT OF (HOMO)MORPHISM : A KEY NOTION IN THE LEARNING OF ABSTRACT ALGEBRA  

E-print Network

ON THE CONCEPT OF (HOMO)MORPHISM : A KEY NOTION IN THE LEARNING OF ABSTRACT ALGEBRA Thomas Algebra more accessible. I. INTRODUCTION In our context, Abstract Algebra means the discipline devoted to the study of algebraic structures, according to the new paradigm established after the publication of van

Paris-Sud XI, Université de

361

FAUSTIAN FIGURES: MODERNITY AND MALE (HOMO)SEXUALITIES IN SPANISH COMMERCIAL LITERATURE, 1900-1936  

Microsoft Academic Search

I contend in this study that commercial novels and theater from early twentiethcentury Spain often present male (homo)sexual characters as a point of constellation for anxieties regarding modernization in Madrid and Barcelona. In works by Jacinto Benavente, Josep Maria de Sagarra, El Caballero Audaz (José María Carretero), Antonio de Hoyos y Vinent, Carmen de Burgos, Álvaro Retana, Eduardo Zamacois, and

Jeffrey Zamostny

2012-01-01

362

Greater Emphasis on Female Attractiveness in Homo sapiens: A Revised Solution to an Old Evolutionary Riddle  

Microsoft Academic Search

Substantial evidence from psychology and cross-cultural anthropology supports a general rule of greater emphasis on female physical attractiveness in Homo sapiens. As sensed by Darwin (1871) and clarified by Trivers (1972), generally higher female parental investment is a key determinant of a common pattern of sexual selection in which male animals are more competitive, more eager sexually and more conspicuous

Jonathan Gottschall

363

Comparative skeletal features betweenHomo floresiensis and patients with primary growth hormone insensitivity (Laron syndrome)  

Microsoft Academic Search

Comparison between the skeletal remains of Homo floresiensis and the auxological and roentgeno- logical findings in a large Israeli cohort of patients with Laron Syndrome (LS, primary or classical GH insensitiv- ity or resistance) revealed striking morphological simi- larities, including extremely small stature and reduced cranial volume. LS is an autosomal recessive disease caused by a molecular defect of the

Israel Hershkovitz; Liora Kornreich; Zvi Laron

2007-01-01

364

RESTRAINING THE GENUINE HOMO ECONOMICUS: WHY THE ECONOMY CANNOT BE DIVORCED FROM ITS GOVERNANCEn  

Microsoft Academic Search

The Homo economicus of traditional economics is far from being completely self-interested, rational, or as individualistic as he is purported to be; he will haggle to death over price but will not take what he wants by force. Implicitly, he is assumed to behave ruthlessly within a well-defined bubble of sainthood. Based on a simple model, I first examine what

STERGIOS SKAPERDAS

2003-01-01

365

The relationship between synonymous codon usage and protein structure in Escherichia coli and Homo sapiens  

Microsoft Academic Search

The role of silent position in the codon on the protein structure is an interesting and yet unclear problem. In this paper, 563 Homo sapiens genes and 417 Escherichia coli genes coding for proteins with four different folding types have been analyzed using variance analysis, a multivariate analysis method newly used in codon usage analysis, to find the correlation between

Wanjun Gu; Tong Zhou; Jianmin Ma; Xiao Sun; Zuhong Lu

2004-01-01

366

Spitzer Digs Up Galactic Fossil  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Figure 1

[figure removed for brevity, see original site] Figure 2

This false-color image taken by NASA's Spitzer Space Telescope shows a globular cluster previously hidden in the dusty plane of our Milky Way galaxy. Globular clusters are compact bundles of old stars that date back to the birth of our galaxy, 13 or so billion years ago. Astronomers use these galactic 'fossils' as tools for studying the age and formation of the Milky Way.

Most clusters orbit around the center of the galaxy well above its dust-enshrouded disc, or plane, while making brief, repeated passes through the plane that each last about a million years. Spitzer, with infrared eyes that can see into the dusty galactic plane, first spotted the newfound cluster during its current pass. A visible-light image (inset of Figure 1) shows only a dark patch of sky.

The red streak behind the core of the cluster is a dust cloud, which may indicate the cluster's interaction with the Milky Way. Alternatively, this cloud may lie coincidentally along Spitzer's line of sight.

Follow-up observations with the University of Wyoming Infrared Observatory helped set the distance of the new cluster at about 9,000 light-years from Earth - closer than most clusters - and set the mass at the equivalent of 300,000 Suns. The cluster's apparent size, as viewed from Earth, is comparable to a grain of rice held at arm's length. It is located in the constellation Aquila.

Astronomers believe that this cluster may be one of the last in our galaxy to be uncovered.

This image composite was taken on April 21, 2004, by Spitzer's infrared array camera. It is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

Galactic Fossil Found Behind Curtain of Dust In Figure 2, the image mosaic shows the same patch of sky in various wavelengths of light. While the visible-light image (left) shows a dark sky speckled with stars, infrared images (middle and right), reveal a never-before-seen bundle of stars, called a globular cluster. The left panel is from the California Institute of Technology's Digitized Sky Survey; the middle panel includes images from the NASA-funded Two Micron All-Sky Survey and the University of Wyoming Infrared Observatory (circle inset); and the right panel is from NASA's Spitzer Space Telescope.

The Two Micron All-Sky Survey false-color image was obtained using near-infrared wavelengths ranging from 1.3 to 2.2 microns. The University of Wyoming Observatory false-color image was captured on July 31, 2004, at wavelengths ranging from 1.2 to 2.2 microns. The Spitzer false-color image composite was taken on April 21, 2004, by its infrared array camera. It is composed of images obtained at four mid-infrared wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

2004-01-01

367

Physiological and life history strategies of a fossil large mammal in a resource-limited environment  

PubMed Central

Because of their physiological and life history characteristics, mammals exploit adaptive zones unavailable to ectothermic reptiles. Yet, they perform best in energy-rich environments because their high and constant growth rates and their sustained levels of resting metabolism require continuous resource supply. In resource-limited ecosystems such as islands, therefore, reptiles frequently displace mammals because their slow and flexible growth rates and low metabolic rates permit them to operate effectively with low energy flow. An apparent contradiction of this general principle is the long-term persistence of certain fossil large mammals on energy-poor Mediterranean islands. The purpose of the present study is to uncover the developmental and physiological strategies that allowed fossil large mammals to cope with the low levels of resource supply that characterize insular ecosystems. Long-bone histology of Myotragus, a Plio-Pleistocene bovid from the Balearic Islands, reveals lamellar-zonal tissue throughout the cortex, a trait exclusive to ectothermic reptiles. The bone microstructure indicates that Myotragus grew unlike any other mammal but similar to crocodiles at slow and flexible rates, ceased growth periodically, and attained somatic maturity extremely late by ?12 years. This developmental pattern denotes that Myotragus, much like extant reptiles, synchronized its metabolic requirements with fluctuating resource levels. Our results suggest that developmental and physiological plasticity was crucial to the survival of this and, perhaps, other large mammals on resource-limited Mediterranean Islands, yet it eventually led to their extinction through a major predator, Homo sapiens. PMID:19918076

Köhler, Meike; Moyà-Solà, Salvador

2009-01-01

368

Virtual assessment of the endocranial morphology of the early modern European fossil calvaria from cioclovina, romania.  

PubMed

Endocasts provide evidence on size and shape characteristics, blood supply trajectories, and neurological features of the brain, allowing comparative analyses of fossil hominins crucial to our understanding of human brain evolution. Here, we assess the morphological features of the virtual endocast of the Cioclovina Upper Paleolithic calvarium, one of the earliest reliably dated European modern human fossils. Our study was conducted on a computed tomography (CT) scan of the original specimen. The endocranial profile was approximated via a semiautomatic segmentation of the CT data. Virtual reconstructions of the endocast were used for assessing the morphological features of the endocranium and for the estimation of the endocranial volume. Cioclovina exhibits a clockwise torque with a small anterior extension of the left frontal lobe over the right one and a protrusion of the right occipital lobe over the left, most likely due to the superior sagittal sinus coursing over the occipital pole. There is an obvious right predominance of the posterior drainage system. Interestingly, the area of the frontal sinus is occupied by dense bony tissue with small air cells corresponding probably to a natural bony loss in the diploë and to vascular spaces. An estimated endocranial volume of 1498.53 cc was calculated. The convolutional details of the third inferior frontal gyrus (Broca's caps) are indistinguishable from those found in modern Homo sapiens, and the left occipital lobe appears wider than the right, a possible correlate of right-handedness. Our metric analysis of endocranial measurements also aligns Cioclovina with modern humans. PMID:21634023

Kranioti, Elena F; Holloway, Ralph; Senck, Sascha; Ciprut, Tudor; Grigorescu, Dan; Harvati, Katerina

2011-07-01

369

Capturing and Storing Fossil-Fuel Carbon  

NASA Astrophysics Data System (ADS)

Can the global energy system continue to be dominated by fossil fuels throughout the 21st century without leading to an unacceptable rise in the concentration of atmospheric CO2? Yes, if a substantial fraction of the carbon in the fossil fuels can be captured and stored elsewhere than in the atmosphere. Of critical importance are: 1) the commercialization of a non-carbon fuel, presumably hydrogen, that is produced from fossil fuels in large-scale facilities in conjunction with CO2 capture, and 2) the storage of CO2 in geological formations, especially deep saline aquifers. Modeling and analysis has not yet identified any showstoppers. Hydrogen production from fossil fuels at refineries and ammonia plants is already fully commercial, as is injection of CO2 into oil reservoirs. Under development are hydrogen vehicles powered by internal combustion engines and by fuel cells. Carbon capture and storage appears to have the potential to play a major role in global environmental management.

Keith, David

2002-03-01

370

Evolution of the biosphere and fossil fuels  

SciTech Connect

The effect of fundamental events in biological evolution on the scale of fossil-fuel accumulation from the historical aspect is considered. Four main stages in the establishment of the ancient biospheres are recognized: pro-, proto-, neoto-, and acmeobiospheres. The hypothesis is based on especially favorable conditions for the formation of oil and fossil fuels during late Archean and early Proterozoic time. Their composition did not vary appreciably. During the Phanerozoic Eon, when the development of a mature biosphere reached its apogee, the explosion-like increase in complexity of the organic world changed the relationships of a number of fossil fuels and their evolutionary history in a radical way. This led to manifold differentiation within each type of fossil fuel.

Lopatin, N.V.

1980-10-01

371

Hybrid solar-fossil fuel power generation  

E-print Network

In this thesis, a literature review of hybrid solar-fossil fuel power generation is first given with an emphasis on system integration and evaluation. Hybrid systems are defined as those which use solar energy and fuel ...

Sheu, Elysia J. (Elysia Ja-Zeng)

2012-01-01

372

Fossil energy program. Progress report, July 1980  

SciTech Connect

This report - the seventy-second of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology, component development and process evaluation, technical support to major liquefaction projects, process and program analysis, fossil energy environmental analysis, coal preparation and waste utilization, coal preparation plant automation, atmospheric fluidized bed coal combustor for cogeneration, technical support to the TVA fluidized bed combustion demonstration plant program, fossil energy applications assessments, performance assurance system support for fossil energy projects, international assessment of atmospheric fluidized bed combustion technology, and PFBC systems analysis.

McNeese, L. E.

1980-10-01

373

Fossil Hominids: The Evidence for Human Evolution  

NSDL National Science Digital Library

An "overview of the study of human evolution, and of the currently accepted fossil evidence" is used to inform arguments for creationists and evolutionists. The main portion of the site contains information about the hominid species (with a timeline), a list of the most important hominid fossils (including Lucy), guest articles, a bibliography, and illustrations. Other sections of the site provide a blog, paleoanthropology news, links, and creationist arguments.

Foley, Jim

374

Adventures in Paleontology: 36 Classroom Fossil Activities  

NSDL National Science Digital Library

Millions of years after vanishing from the Earth, dinosaurs still have the power to stir students' curiosity. Deepen that interest with Adventures in Paleontology, a series of lively hands-on activities especially for middle schoolers. This beautifully illustrated full color book features 36 activities that open students up to a variety of foundational sciences, including biology, geology, chemistry, physics, and astronomy. For example: ? "How Do Fossils Form?" discusses how organisms become fossils and illustrates the concept with activities that simulate fossil-making processes. ? "What Can You Learn From Fossils?" explores what fossils teach about ancient organisms. ? "Mass Extinction and Meteor Collisions With Earth" discusses recently discovered links between meteor and asteroid impacts on Earth and the demise of animals like dinosaurs. Other chapters cover how to tell the age of the Earth; how dinosaurs evolved; and diversity, classification, and taxonomy. The final chapters offer humanistic perspectives on fossils in literature and art. As an attention-grabbing complement to the text, vivid full color illustrations show not just skeletons and animal tracks but also what dinosaurs probably looked like in their natural settings. Handy line drawings guide students through each step of the activities.

Irwin Slesnick

2006-01-01

375

Fossil group origins. IV. Characterization of the sample and observational properties of fossil systems  

NASA Astrophysics Data System (ADS)

Context. Virialized halos grow by the accretion of smaller ones in the cold dark matter scenario. The rate of accretion depends on the different properties of the host halo. Those halos for which this accretion rate was very fast and efficient resulted in systems dominated by a central galaxy surrounded by smaller galaxies that were at least two magnitudes fainter. These galaxy systems are called fossil systems, and they can be the fossil relics of ancient galaxy structures. Aims: We started an extensive observational program to characterize a sample of 34 fossil group candidates spanning a broad range of physical properties. Methods: Deep r-band images were obtained with the 2.5-m Isaac Newton Telescope and Nordic Optic Telescope. Optical spectroscopic observations were performed at the 3.5-m Telescopio Nazionale Galileo for ~1200 galaxies. This new dataset was completed with Sloan Digital Sky Survey Data Release 7 archival data to obtain robust cluster membership and global properties of each fossil group candidate. For each system, we recomputed the magnitude gaps between the two brightest galaxies (?m12) and the first and fourth ranked galaxies (?m14) within 0.5 R200. We consider fossil systems to be those with ?m12 ? 2 mag or ?m14 ? 2.5 mag within the errors. Results: We find that 15 candidates turned out to be fossil systems. Their observational properties agree with those of non-fossil systems. Both follow the same correlations, but the fossil systems are always extreme cases. In particular, they host the brightest central galaxies, and the fraction of total galaxy light enclosed in the brightest group galaxy is larger in fossil than in non-fossil systems. Finally, we confirm the existence of genuine fossil clusters. Conclusions: Combining our results with others in the literature, we favor the merging scenario in which fossil systems formed from mergers of L? galaxies. The large magnitude gap is a consequence of the extreme merger ratio within fossil systems and therefore it is an evolutionary effect. Moreover, we suggest that at least one fossil group candidate in our sample could represent a transitional fossil stage. This system could have been a fossil in the past, but not now owing to the recent accretion of another group of galaxies.

Zarattini, S.; Barrena, R.; Girardi, M.; Castro-Rodriguez, N.; Boschin, W.; Aguerri, J. A. L.; Méndez-Abreu, J.; Sánchez-Janssen, R.; Catalán-Torrecilla, C.; Corsini, E. M.; del Burgo, C.; D'Onghia, E.; Herrera-Ruiz, N.; Iglesias-Páramo, J.; Jimenez Bailon, E.; Lozada Muoz, M.; Napolitano, N.; Vilchez, J. M.

2014-05-01

376

The properties of fossil groups of galaxies  

NASA Astrophysics Data System (ADS)

Numerical simulations as well as optical and X-ray observations over the last few years have shown that poor groups of galaxies can evolve to what is called a fossil group. Dynamical friction as the driving process leads to the coalescence of individual galaxies in ordinary poor groups leaving behind nothing more than a central, massive elliptical galaxy supposed to contain the merger history of the whole group. Due to merging timescales for less-massive galaxies and gas cooling timescales of the X-ray intragroup medium exceeding a Hubble time, a surrounding faint-galaxy population having survived this galactic cannibalism as well as an extended X-ray halo similar to that found in ordinary groups, is expected. Recent studies suggest that fossil groups are very abundant and could be the progenitors of brightest cluster galaxies (BCGs) in the centers of rich galaxy clusters. However, only a few objects are known to the literature. This article aims to summarize the results of observational fossil group research over the last few years and presents ongoing work by the authors. Complementary to previous research, the SDSS and RASS surveys have been cross-correlated to identify new fossil structures yielding 34 newly detected fossil group candidates. Observations with ISIS at the 4.2 m William Herschel Telescope on La Palma have been carried out to study the stellar populations of the central ellipticals of 6 fossil groups. In addition multi-object spectroscopy with VLTs VIMOS has been performed to study the shape of the OLF of one fossil system.

Eigenthaler, P.; Zeilinger, W. W.

2009-12-01

377

Yukon gold mine yields ancient horse fossil 700,000yearold fossil discovered in Yukon permafrost yields genome world record.  

E-print Network

Yukon gold mine yields ancient horse fossil 700,000yearold fossil discovered in Yukon permafrost an unusually large horse fossil in the Yukon permafrost, he knew it was important. Now, in a new study published in the journal Nature, this fossil is rewriting the story of equine evolution as the ancient

Machel, Hans

378

A Fossil Hunt Tells the Age of Sediments  

NSDL National Science Digital Library

In this activity, students will identify an assemblage of fossils, determine their age, evaluate the fossil population, and make some inferences about the ancient environment in which they existed. The discovery aspect of this exercise is that all of the fossils the students will find existed together in only one time period. The environment of these fossils, a fresh water lake, is ascertained from using the fossil guidebook. A student worksheet and discussion questions are provided.

2005-10-06

379

Molecular structure, vibrational spectroscopic, first-order hyperpolarizability and HOMO, LUMO studies of 2-aminobenzimidazole.  

PubMed

In the present work, we reported a combined experimental and theoretical study on molecular structure, vibrational spectra and HOMO-LUMO analysis of 2-aminobenzimidazole (2-ABD). The FTIR (400-4000 cm(-1)) and FT-Raman spectra (50-3500 cm(-1)) of 2-ABD were recorded. The molecular geometry, harmonic vibrational wavenumbers and bonding features of 2-ABD in the ground-state have been calculated by using the density functional B3LYP method with 6-311++G(d,p) and 6-31G(d) as basis sets. The energy and oscillator strength were calculated by time-dependent density functional theory (TD-DFT) result complements with the experimental findings. The calculated HOMO and LUMO energies showed that charge transfer occurs within the molecule. Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound which showed good agreement with the observed spectra. PMID:21981941

Sudha, S; Karabacak, M; Kurt, M; Cinar, M; Sundaraganesan, N

2011-12-15

380

Recent synchronous radiation of a living fossil.  

PubMed

Modern survivors of previously more diverse lineages are regarded as living fossils, particularly when characterized by morphological stasis. Cycads are often cited as a classic example, reaching their greatest diversity during the Jurassic-Cretaceous (199.6 to 65.5 million years ago) then dwindling to their present diversity of ~300 species as flowering plants rose to dominance. Using fossil-calibrated molecular phylogenies, we show that cycads underwent a near synchronous global rediversification beginning in the late Miocene, followed by a slowdown toward the Recent. Although the cycad lineage is ancient, our timetrees indicate that living cycad species are not much older than ~12 million years. These data reject the hypothesized role of dinosaurs in generating extant diversity and the designation of today's cycad species as living fossils. PMID:22021670

Nagalingum, N S; Marshall, C R; Quental, T B; Rai, H S; Little, D P; Mathews, S

2011-11-11

381

Valdosta State University's Virtual Museum of Fossils  

NSDL National Science Digital Library

Valdosta State University's Virtual Museum of Fossils offers information on animals since the Precambrian era. The website offers two navigation options. In the Find an Animal section, users can view fossils by clicking on different areas of the geologic timescales for Prokaryotes, Eukaryotes, Invertebrates, and Vertebrates. In the Choose a Time section, students can learn about the major characteristics of each era. For each period, this link also offers a map of the world, the characteristics of the landscape at the time, and pictures of fossils of the animals that lived during the period. While the Take a Tour link is still under construction, the abundance of information covering the geologic past makes the site worth the visit.

382

John Day Fossil Beds National Monument  

NSDL National Science Digital Library

Millions of years ago, central Oregon was a hotbed of volcanic activity. Curious geologists and others can learn about the John Day Fossil Beds National Monument on this most excellent Flash-enabled online tour. After "flying" in overhead to the site, visitors can learn about the 40 million year history of the site that would later become the John Day Fossil Beds. The next area of the site is titled "The Present Unlocks the Past" and it includes an exploration of the evolution of the horse in prehistoric Oregon, along with offering access into the daily life of a working paleontologist. In the interactive feature "Whose skull is whose?", visitors will get the change to compare the skulls of ancient animals with those of their modern analogs. After that, visitors can get a better sense of the current state of affairs in the fossil beds by looking over a thirteen-image slideshow of this gorgeous section of Oregon.

383

Synthesis and biological evaluation of C-13' substituted 7'-homo-anhydrovinblastine derivatives.  

PubMed

Recent publications highlighted that vinca derivatives either functionalized on C-12' or enlarged on cycle C' could be more cytotoxic than vinblastine or vinorelbine, both used in anti-cancer therapy. By combining these two results, nine new 7'-homo-anhydrovinblastine derivatives functionalized on C-13' were elaborated. The synthesis of key intermediates, their one-step transformation into final products in mild conditions and their biological activities are presented. PMID:25804719

Gherbovet, Olga; La Spisa, Fabio; Thoret, Sylviane; Alvarez, Maria Concepcion Garcia; Levaique, Hélène; Bignon, Jérôme; Roussi, Fanny

2015-04-15

384

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

PubMed

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

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

2010-01-01

385

Young Children's (Homo sapiens) Understanding of Knowledge Formation in Themselves and Others  

Microsoft Academic Search

Three- and 4-year-old children (Homo sapiens) were tested for comprehension of knowledge formation. In Experiment 1, 34 subjects watched as a surprise was hidden under 1 of 4 obscured cups. The experimenter then pointed to the cup. All children searched under the correct cup, but no 3-year-olds (in contrast to most 4-year-olds) could explain how they knew where to look.

Daniel J. Povinelli; Sandra deBlois

1992-01-01

386

Pygmoid Australomelanesian Homo sapiens skeletal remains from Liang Bua, Flores: Population affinities and pathological abnormalities  

Microsoft Academic Search

Liang Bua 1 (LB1) exhibits marked craniofacial and postcranial asymmetries and other indicators of abnormal growth and development. Anomalies aside, 140 cranial features place LB1 within modern human ranges of variation, resembling Australomelanesian populations. Mandibular and dental features of LB1 and LB6\\/1 either show no substantial deviation from modern Homo sapiens or share features (receding chins and rotated premolars) with

T. Jacob; E. Indriati; R. P. Soejono; K. Hsü; D. W. Frayer; R. B. Eckhardt; A. J. Kuperavage; A. Thorne; M. Henneberg

2006-01-01

387

Functional capabilities of modern and fossil hominid hands: three-dimensional analysis of trapezia.  

PubMed

Three-dimensional (3D) trapezium models from Homo sapiens, Gorilla gorilla, Pan troglodytes, Australopithecus afarensis (A.L.333-80), and Homo habilis (O.H.7-NNQ) were acquired through laser digitizing. Least-square planes were generated for each articular surface, and the angles between the planes were compared. Each extant species displays an overall pattern that distinguishes it from the others. The observed angles in G. gorilla and P. troglodytes are more similar to one other than either is to H. sapiens. Our results, obtained from using new 3D modeling and analytical tools, raise interesting questions about the functional capabilities of the fossil trapezia. Multivariate statistical analyses indicate that A.L.333-80 is morphologically more similar to that of modern humans, whereas the O.H.7 trapezium is more similar to that of the gorilla. Significant differences between A.L.333-80 and the extant species occur, but some similarities to humans suggest the ability to form the distinctively human forceful pad-to-side and three-jaw chuck grips. Some key morphological differences from humans highlighted and quantified by our research suggest limitations in the functional capabilities of the O.H.7 trapezium, particularly in those that facilitate pronation at the base of the second metacarpal. If the O.H.7 trapezium represents part of the hand responsible for manufacturing and using the stone tools found at Olduvai, our results suggest that the hand manipulated the stones in a way for which we have no modern analog. Alternative considerations are that the O.H.7 trapezium is not representative of other trapezia from its species (i.e., N=1), or that it represents another primate or hominid species. PMID:12949830

Tocheri, M W; Marzke, M W; Liu, D; Bae, M; Jones, G P; Williams, R C; Razdan, A

2003-10-01

388

On the trail of the genus Homo between archaic and derived morphologies.  

PubMed

The topic of this review is the evolution of the genus Homo, focusing on evolutionary transitions that occurred during the Early and Middle Pleistocene. Two crucial issues are addressed in particular: 1) the emergence in the Early Pleistocene of the archaic variant of Homo that might represent the last common ancestor before the emergence of at least two (more probably three) geographically distinct trajectories; and (2) the evolution of these derived lineages, ultimately leading to the allopatric speciations of the most encephalised species of Homo: H. neanderthalensis and H. sapiens. In this framework, the time window between 1.0 million years ago (Ma) and 500 thousand years ago (ka) is of crucial importance, since it is probable that a new kind of humanity emerged in this period and then spread across a wide area encompassing Africa and Eurasia. These humans are represented by a number of specimens that are included within the single, polymorphic, and widespread species H. heidelbergensis. It is suggested that, in the course of the Middle Pleistocene, this species diversified in a number of incipient species -or subspecies- geographically and phenotypically distinct from one another. The case-study furnished by the calvarium found near Ceprano, in Italy, is of great interest in this regard, since it displays the least derived morphology seen among the hypodigm of H. heidelbergensis, and may represent better than other specimens the ancestral morphotype (i.e., the stem subspecies) of this taxon. PMID:23274748

Manzi, Giorgio

2012-01-01

389

Fossils: An Ancient Sea in Indiana  

NSDL National Science Digital Library

Paleontologists have been remarkably successful in determining what earlier life forms looked like, as well as how they probably behaved when alive. This interactive feature illustrates a slab of rock containing fossils of several types of creatures that once inhabited the Borden Sea, over 300 million years ago in what is now central Indiana. Clicking on highlighted fossils accesses animations of what they may have looked like in life, along with a brief description of the organism. Reconstructions such as these have given scientists insight into evolutionary processes and trends. A background essay and discussion questions are included.

390

Insect diversity in the fossil record  

NASA Technical Reports Server (NTRS)

Insects possess a surprisingly extensive fossil record. Compilation of the geochronologic ranges of insect families demonstrates that their diversity exceeds that of preserved vertebrate tetrapods through 91 percent of their evolutionary history. The great diversity of insects was achieved not by high origination rates but rather by low extinction rates comparable to the low rates of slowly evolving marine invertebrate groups. The great radiation of modern insects began 245 million years ago and was not accelerated by the expansion of angiosperms during the Cretaceous period. The basic trophic machinery of insects was in place nearly 100 million years before angiosperms appeared in the fossil record.

Labandeira, C. C.; Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)

1993-01-01

391

How Do Scientists Find Dinosaur Fossils?  

NSDL National Science Digital Library

This lesson plan is about the process by which paleontologists locate, excavate, and study dinosaurs. Students will write journal entries pretending they are on a dinosaur dig. They will also make fact sheets about this recently discovered Jobaria dinosaur; place Jobaria into a timeline to indicate the periods in which it lived; visit a website to learn about the steps involved in finding and excavating dinosaur fossils, then list these steps and explain their importance; describe what the bones in an interactive Jobaria skeleton indicate about this dinosaur; and view pictures of a trip teenagers took to look for dinosaur fossils.

392

Brachiopod exercise for FossilPlot  

NSDL National Science Digital Library

Students are taught how to use FossilPlot software in the lab prior to this exercise. Students work individual to work through the short exercise, handing in a copy of the diversity graphs for the brachiopod orders (which will be tested in the following midterm) and a completed worksheet. The exercise reinforces the main functions of FossilPlot and addresses basic concepts on diversity and biostratigraphy. Once the assignments are collected and graded, we discuss the outcomes of the exercise in class.

Leif Tapanila

393

Fossils, Genes and The Origin of Organs  

SciTech Connect

A toolkit of experimental and comparative biology can be applied to understand the great transformations in the history of life. Expeditionary paleontology can be used to target key nodes of the tree of life for which new fossils can provide insights into major morphological transformations. These fossils often have intermediate conditions that allow extant creatures to be compared in new ways. The tools of developmental genetics can then be used to explore these new comparisons to understand the genetic basis for macroevolutionary change. These different approaches can be used to predict new discoveries and this is only possible because of the empirical content of the tree of life.

Shubin, Neil (University of Chicago) [University of Chicago

2011-04-20

394

Microbial Fossils Detected in Desert Varnish  

NASA Technical Reports Server (NTRS)

Mars Global Surveyor Thermal Emission Spectrometer data indicate regions with significant levels of hematite (_Fe2O3). Fe-oxides, like hematite, can form as aqueous mineral precipitates and as such may preserve microscopic fossils or other biosignatures. Several potential terrestrial analogues to martian hematite like hydrothermal vents have preserved microfossils. Microbial fossilization in Fe-oxides is often a function of biomineralization. For example, goethite (FeO2H) encrustation of fungal mycelia from the mid-Tertiary preserved fungal morphologies such that their genera could be determined.

Flood, B. E.; Allen, C.; Longazo, T.

2003-01-01

395

Fossil generation restructuring in the Ukraine  

SciTech Connect

This paper describes the Ukrainian electrical system as it was in 1991, defines the need for restructuring, outlines the restructuring process, identifies a number of major obstacles that are hindering the implementation of the fossil generation, restructuring process, and points out major problems in the coal procurement system. It describes the visits to several Ukrainian power plants, defines restructuring success to date, makes suggestions for improved restructuring progress, highlights lessons learned, and enlightens the audience on the opportunities of investing in the Ukrainian power generation industry. The primary focus is on the Fossil Generator Advisor task, which was carried out under the direction of Hagler Bailly Consulting, Inc. (Hagler Bailly).

Galambas, J.W. [Hagler Bailly Consulting, Inc., Boulder, CO (United States)

1996-12-31

396

Homo sapiens (Cro-magnon and modern human), Chris StringerSite: DNA Interactive (www.dnai.org)  

NSDL National Science Digital Library

Interviewee: Chris Stringer DNAi Location:Applications>Human origins>our family tree>Modern humans: a late arrival Human origins expert Chris Stringer talks about the arrival of Homo sapiens and our possible ancestors.

2008-10-06

397

Polychaete chaetae: Function, fossils, and phylogeny  

Microsoft Academic Search

Synopsis In this article we review the phylogenetic distribution of major chaetal types within the Polychaeta, discuss what has been demonstrated about chaetal function in modern worms, and examine what is known about the evolution of chaete through the fossil record. We conclude with specific cautions about how chaetae are treated in phylogenetic analyses and make suggestions about how they

Rachel A. Merz; Sarah A. Woodin

2006-01-01

398

Colloidal and polymeric nature of fossil amber  

Microsoft Academic Search

Fossilized ambers from several geographical origins, copal from the Kauri pine tree of New Zealand and modern white spruce tree resin have been analyzed by the following analytical techniques: dynamic light scattering, optical and scanning electron microscopy, gel permeation chromatography, IR spectroscopy, rheology and viscometry. The results dispute the prevailing view that amber is largely an insoluble, continuously crosslinked, integral

Douglas Gold; Benjamin Hazen; Wilmer G. Miller

1999-01-01

399

Solid modeling of fossil small mammal teeth  

NASA Astrophysics Data System (ADS)

This paper presents an approach to create solid models of fossil small mammal teeth using a combination of microcomputed tomography, object based image analysis and voxel modeling. Small mammal teeth, because of their durability, are widely found in Cenozioc sediments the world over and play a key role in stratigraphy as well as in researching the rapid evolution and the paleogeographic spreading of small mammals. Recent advances in microcomputed tomography make this non-destructive analysis method an ideal data source for high-resolution 3D models of fossil small animal teeth. To derive internally consistent solid models of such fossils from micro-CT imagery, we propose a combination of 3D object based image analysis and solid modeling. Incorporating paleontological expert knowledge in the image processing cycle, object based image analysis yields topologically consistent image stacks classified by the main tooth components—enamel, dentine and pulp. Forwarding these data to a voxel modeling system, they can be quantitatively analyzed in an unprecedented manner: going beyond the possibilities of the state-of-art surface models, solid models are capable of unambiguously portraying the entire object volume—teeth can be peeled by material properties, subvolumes can be extracted and automatically analyzed by Boolean operations. The proposed method, which can be flexibly extended to handle a range of paleontological and geological micro-objects, is demonstrated with two typical fossil small mammal teeth.

Marschallinger, Robert; Hofmann, Peter; Daxner-Höck, Gudrun; Ketcham, Richard A.

2011-09-01

400

Introduction Fossil age constraints for continental sedimentary  

E-print Network

) for sedimentary rocks exposed primarily on Hitra and small islands south of Smøla; Early to Mid Devonian agesIntroduction Fossil age constraints for continental sedimentary deposits are invariably more; Osmundsen & Andersen 2001), precise dating of the Devonian sedimentary basins has been particularly

Andersen, Torgeir Bjørge

401

Mass Extinctions in the Marine Fossil Record  

Microsoft Academic Search

A new compilation of fossil data on invertebrate and vertebrate families indicates that four mass extinctions in the marine realm are statistically distinct from background extinction levels. These four occurred late in the Ordovician, Permian, Triassic, and Cretaceous periods. A fifth extinction event in the Devonian stands out from the background but is not statistically significant in these data. Background

David M. Raup; J. John Sepkoski

1982-01-01

402

Fossilized Gravitational Wave Relic and Primordial Clocks  

E-print Network

If long wavelength primordial tensor modes are coupled to short wavelength scalar modes, the scalar curvature two-point function will have an off-diagonal component. This `fossil' remnant is a signature of a mode coupling that cannot be achieved in single clock inflation. Any constraint on its presence allows a cross check of the relationship between the dynamical generation of the fluctuations and the evolution of the inflationary background. We use the example of non-Bunch Davies initial states for the tensor and scalar modes to demonstrate that physically reasonable fossils, consistent with current data, can be observable in the near future. We illustrate how the fossil off-diagonal power spectrum is a complementary probe to the squeezed limit bispectra of the scalar and tensor sectors individually. We also quantify the relation between the observable signal and the squeezed limit bispectrum for a general scalar-scalar-fossil coupling, and note the effect of superhorizon tensor modes on the anisotropy in scalar modes.

Suddhasattwa Brahma; Elliot Nelson; Sarah Shandera

2014-05-01

403

Fossil Cores In The Kepler Data  

NASA Astrophysics Data System (ADS)

Most gas giant exoplanets with orbital periods < few days are unstable against tidal decay and may be tidally disrupted before their host stars leave the main sequence. These gas giants probably contain rocky/icy cores, and so their cores will be stranded near their progenitor's Roche limit (few hours orbital period). These fossil cores will evade the Kepler mission's transit search because it is focused on periods > 0.5 days, but finding these fossil cores would provide unprecedented insights into planetary interiors and formation ? e.g., they would be a smoking gun favoring formation of gas giants via core accretion. We propose to search for and characterize fossil cores in the Kepler dataset. We will vet candidates using the Kepler photometry and auxiliary data, collect ground-based spectra of the host stars and radial-velocity (RV) and adaptive optics (AO) data to corroborate candidates. We will also constrain stellar tidal dissipation efficiencies (parameterized by Q) by determining our survey's completeness, elucidating dynamical origins and evolution of exoplanets even if we find no fossil cores. Our preliminary search has already found several dozen candidates, so the proposed survey has a high likelihood of success.

Jackson, Brian

404

Amino acid racemization dating of fossil bones  

Microsoft Academic Search

The development of amino acid racemization as a dating technique holds considerable promise for resolving questions of human evolution and culture histories. The advantages of this method are: fossil bone can be directly dated; only gram quantities are needed for analysis; and the range extends beyond that of radiocarbon. Amino acid racemization rates are dependent upon both time and temperature.

Jeffrey L. Bada; Patricia Masters Helfman

1975-01-01

405

Realistic ocean energy alternatives to fossil fuels  

Microsoft Academic Search

The US Commission on Ocean Policy endorsed the Administrations complete dependence on fossil fuels as the primary energy source for the nation. Two very significant alternatives were rejected or neglected. The first alternative was sea based semi submerged nuclear power plant ships deployed in a line paralleling the coastline of the United States. The US has developed and deployed hundreds

John Piña Craven

2005-01-01

406

Fossil Energy Materials Program conference proceedings  

SciTech Connect

The US Department of Energy Office of Fossil Energy has recognized the need for materials research and development to assure the adequacy of materials of construction for advanced fossil energy systems. The principal responsibility for identifying needed materials research and for establishing a program to address these needs resides within the Office of Technical Coordination. That office has established the Advanced Research and Technology Development (AR and TD) Fossil Energy Materials Program to fulfill that responsibility. In addition to the AR and TD Materials Program, which is designed to address in a generic way the materials needs of fossil energy systems, specific materials support activities are also sponsored by the various line organizations such as the Office of Coal Gasification. A conference was held at Oak Ridge, Tennessee on May 19-21, 1987, to present and discuss the results of program activities during the past year. The conference program was organized in accordance with the research thrust areas we have established. These research thrust areas include structural ceramics (particularly fiber-reinforced ceramic composites), corrosion and erosion, and alloy development and mechanical properties. Eighty-six people attended the conference. Papers have been entered individually into EDB and ERA. (LTN)

Judkins, R.R. (comp.)

1987-08-01

407

Science Sampler: Fossil patterns in time  

NSDL National Science Digital Library

This lesson works well as an introduction to Earth history, when students are asked to consider time periods of millions and billions of years. It would be a most helpful experience when introducing fossils, as part of an overview of the diversity of life

Larry Flammer

2011-02-01

408

The Fascinating Story of Fossil Fuels  

ERIC Educational Resources Information Center

How this energy source was created, its meaning to mankind, our drastically reduced supply, and why we cannot wait for nature to make more are considered. Today fossil fuels supply 96 percent of the energy used but we must find alternate energy options if we are to combat the energy crisis. (BL)

Asimov, Isaac

1973-01-01

409

Mycorrhization of fossil and living plants  

Microsoft Academic Search

The widespread mycorrhization together with the fossil record indicate that plants and fungi have evolved in mycorrhizal relationship since the colonization of land by early plants. In living plants most mycorrhizal symbioses are mutualistic associations in which fungus and plant exchange metabolites and nutrients required for their growth and survival. They concern either the gametophyte and\\/or the sporophyte of most

Christine Strullu-Derrien; Désiré-Georges Strullu

2007-01-01

410

Are hydrothermal vent animals living fossils?  

Microsoft Academic Search

Since their discovery in 1977, hydrothermal vent communities have provided many surprises about life in the deep sea and in extreme environments. It has been suggested that vent communities contain many living fossils and that deep-sea chemosynthetic environments, such as vents and hydrocarbon seeps, are buffered from extinction events that affect the photic zone. This hypothesis is based on the

Crispin T. S. Little; Robert C. Vrijenhoek

2003-01-01

411

Insect Diversity in the Fossil Record  

Microsoft Academic Search

Insects possess a surprisingly extensive fossil record. Compilation of the geochronologic ranges of insect families demonstrates that their diversity exceeds that of preserved vertebrate tetrapods through 91 percent of their evolutionary history. The great diversity of insects was achieved not by high origination rates but rather by low extinction rates comparable to the low rates of slowly evolving marine invertebrate

Conrad C. Labandeira; J. John Sepkoski Jr.

1993-01-01

412

The Proterozoic Fossil Record of Heterotrophic Eukaryotes  

E-print Network

not by heterotrophs but by algae. Most of the fossils that can be assigned to a modern clade are algal (red), is interpreted as an alga (Han and Runnegar, 1992; Schneider et al., 2002). The presence of red algae in rocks diversity, in fact, autotrophy, which characterizes the algae and land plants, appears to be a derived

Porter, Susannah

413

A cranium for the earliest Europeans: phylogenetic position of the hominid from Ceprano, Italy.  

PubMed

The human fossil evidence unequivocally pertaining to the first inhabitants of Europe at present includes the sample from Atapuerca-TD6 (Spain) and the incomplete adult calvaria discovered near Ceprano, in Southern Latium (Italy). On the basis of regional correlations and a series of absolute dates, the age of the Ceprano hominid is estimated to range between 800 and 900 kilo-annum (ka). In addition, the association with archaic (Mode 1) Paleolithic findings from the same area is suggested. After the completed reconstruction of the calvaria, we present here a new study dealing with the general and more detailed aspects of the morphology displayed by Ceprano, in comparison to fossil samples ranging between Early and Middle Pleistocene. According to our results, cranial features indicate that Ceprano represents a unique morphological bridge between the clade Homo ergaster/erectus and later Middle Pleistocene specimens commonly referred to Homo heidelbergensis (and/or to Homo rhodesiensis), particularly those belonging to the African fossil record that ultimately relates to the origin of modern humans. In conclusion, given its geographical, chronological, and phylogenetic position, an attribution to the species Homo antecessor is considered, although the sample from Atapuerca-TD6 is not directly comparable to Ceprano. Alternatively, a new species-ancestral to later European and African hominines-should be named to accommodate such a unique fossil specimen. PMID:11504953

Manzi, G; Mallegni, F; Ascenzi, A

2001-08-14

414

Probable Carbonate Fossilization Processes Within Dead Sea Microbial Remains  

NASA Technical Reports Server (NTRS)

Microbial fossilization processes in the Dead Sea is primarily associated with the calcium cation. The putative fossilized microbes do not represent the reported living microbial population. Additional information is contained in the original extended abstract.

Morris, P. A.; Wentworth, S. J.; Thomas-Keprta, K. L.; Allen, C. C.; McKay, D. S.

2001-01-01

415

Fossil Woodwardia virginica Foliage From the Middle Miocene Yakima Canyon  

NSDL National Science Digital Library

Fossil Woodwardia virginica foliage from the middle Miocene Yakima Canyon flora of central Washington State, USA. Vegetative and fertile features of this fossil are remarkably similar to those of the modern ""Virginia chain fern"" of the Atlantic coastal region, USA.

Kathleen B. Pigg (Arizona State University; Department of Plant Biology ADR; POSTAL)

2004-03-09

416

Ediacaran Fossils: Last 50 m.y. of the Proterozoic  

E-print Network

Ediacaran Fossils: Last 50 m.y. of the Proterozoic Geology 331, Paleontology #12;#12;The Doushantuo;Modern sea pens, relatives of corals #12;A fossil sea pen from the Ediacaran of Australia #12;Mawsonites

Kammer, Thomas

417

Geology Fieldnotes: Florissant Fossil Beds National Monument, Colorado  

NSDL National Science Digital Library

Florissant Fossil Beds National Monument preserves huge petrified redwood trees and incredibly detailed fossils of ancient insects and plants. Features include park geology information, photographs of fossils, related links, visitor information, multimedia resources, and resources for teaching geology with National Park examples. The park geology section discusses the park's geologic history and the plants and insects found in the fossil beds. A map of the Monument is also included.

418

Emergy Depletion and Offset of Fossil Energy Assets in China  

Microsoft Academic Search

Coal, petroleum and natural gas are the three main sources of fossil energy. This paper classified fossil energy sources as eco-assets. Using ecological economics, it was calculated that the cumulative emergy wastage of fossil energy sources in China from 1953 to 2006 was 7.08 times 1025sej. This paper considered agricultural residue to be a substitute for fossil energy sources. The

Chen Ya-lin; Han Yong-wei; Gao Ji-xi; Tian Mei-rong

2009-01-01

419

Recent Human Evolution in East Asia and Australasia  

Microsoft Academic Search

In both East Asia and Australasia arguments for evolutionary continuity between middle-late Pleistocene hominid populations and modern Homo sapiens are of long standing. In both regions, however, problems of chronological distribution, dating and preservation of hominid skeletal materials provide an effective barrier to extending regional sequences back to `archaic' Homo sapiens or Homo erectus. The earliest securely dated modern Homo

Peter Brown

1992-01-01

420

The living fossil of human judgment.  

PubMed

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

Schwarz, Michael

2014-06-01

421

Carbon Capture by Fossil Fuel Power Plants: An Economic Analysis  

E-print Network

Carbon Capture by Fossil Fuel Power Plants: An Economic Analysis ¨Ozge I¸slegen Graduate School excellent research assistance. #12;Carbon Capture by Fossil Fuel Power Plants: An Economic Analysis Abstract: For fossil fuel power plants to be built in the future, carbon capture and storage (CCS) technologies offer

Silver, Whendee

422

New form of information from T. rex and Mastodon fossils  

NSDL National Science Digital Library

After discovering a giant T. rex leg bone fossil in Montana, back in 2003, a team of scientists had a problem: It wouldn't fit in their helicopter. When they broke the fossil open in order to fit the pieces inside, this led to a shocking discovery. Some of the dinosaur's soft tissues such as blood vessels were still present inside the fossil.

American Association for the Advancement of Science (AAAS; )

2007-04-12

423

Fossil Energy Program semiannual progress report, April 1988September 1988  

Microsoft Academic Search

This report covers progress made during the period April 1 through September 30, 1988, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by DOE Office of Fossil Energy, DOE Office of Basic Energy Sciences, and the Tennessee Valley Authority. Included are programs in: materials research,

1989-01-01

424

First Fossil Lamprey: A Record from the Pennsylvanian of Illinois  

Microsoft Academic Search

A fossil record of lampreys has previously been unknown. A new genus demonstrates the presence of this group in the Pennsylvanian. The body outline, parts of the head skeleton, rasping tongue mechanism, gill basket, and other internal organs are preserved. The fossils are very similar in structure to modern forms. The absence of hagfish characters in the fossil supports the

David Bardack; Rainer Zangerl

1968-01-01

425

Opportunism and competition in the non-fossil fuel obligation  

E-print Network

Opportunism and competition in the non-fossil fuel obligation Paolo Agnolucci July 2005 Tyndall are the responsibility of the author(s) alone and not the Tyndall Centre. #12;Summary The Non-Fossil Fuel Order (NFFO Electricity; Renewable Policy, Non-Fossil Fuel Obligation; Moral Hazard; Post-contractual Opportunism #12

Watson, Andrew

426

FOSSIL ANTHROPOIDS OF THE r y ALEMCAMBRIDGE INDIA  

E-print Network

; . ~ 1@'· t p t1tCO FOSSIL ANTHROPOIDS OF THE r y ALEMCAMBRIDGE INDIA EXPEDITION Q,F 1935 ? ~ -~~r J FOSSIL ANTHROPOIDS OF THE YALE-CAMBRIDGE INDIA EXPEDITION OF 1935 WILLIAM K. GREGORY MILO .. . .... . .. ... . . . . .. . .. . .... ...... . ..... . .. . ... .. . .. . .. ...... . ,, ·· following 27 1 #12;( FOSSIL ANTHROPOIDS OF THE YALE-CAMBRIDGE INDIA EXPEDITION OF 1935 INTRODUCTION The Yale

Boyer, Edmond

427

Fossil Folklore from India: The Siwalik Hills and the Mahâbhârata  

Microsoft Academic Search

All over the world, from antiquity to the present, people have often explained fossil discoveries as proof of the historical truth of legends and myths, or used them as a basis for a new legend. Most often, large vertebrate fossils have been explained as bones and teeth of giant humans, dragons and monsters, saints and heroes. Smaller invertebrate fossils were

Alexandra van der Geer; Michael Dermitzakis; John de Vos

2008-01-01

428

Reducing Fossil Carbon Emissions and Building Environmental Awareness at  

E-print Network

Reducing Fossil Carbon Emissions and Building Environmental Awareness at Dartmouth College Summary selected the mission: "To reduce Dartmouth College's fossil carbon emissions." We believe this mission's responsibility to educate others about how it is reducing its fossil carbon emissions and encourage them to do

429

Fossil Groups in the Sloan Digital Sky Survey  

E-print Network

A search for fossil groups in the Sloan Digital Sky Survey was performed using virtual observatory tools. A cross-match of the positions of all SDSS Luminous Red Galaxies (with r fossil groups. Considering this sample, the estimated space density of fossil systems is $n =(1.0 \\pm 0.6) \\times 10^{-6}$ $h_{50}^3$ Mpc$^{-3}$.

Walter A. Santos; Claudia Mendes de Oliveira; Laerte Sodré Jr

2007-08-14

430

Fossil Papio Cranium From !Ncumtsa (Koanaka) Hills, Western Ngamiland, Botswana  

E-print Network

Fossil Papio Cranium From !Ncumtsa (Koanaka) Hills, Western Ngamiland, Botswana Blythe A. Williams cercopithecoid; baboon; Kalahari; Pleistocene ABSTRACT Three fossils, a cranium of Papio, a cer- copithecid crania of Papio are extremely rare in the fossil record outside of South Africa and because

431

RESEARCH PAPER The first fossil record of Polyrhachis (Hymenoptera: Formicidae  

E-print Network

RESEARCH PAPER The first fossil record of Polyrhachis (Hymenoptera: Formicidae: Formicinae) from taxon represents the first occurrence of the genus in the fossil record. The origin and rise of one Á Polyrhachis Á New species Á Miocene Á Fossil ant Kurzfassung Aus dem Obermioza¨n von Kreta (Grie

Villemant, Claire

432

SURVEY OF SOCIAL INSECTS IN THE FOSSIL RECORD*  

E-print Network

SURVEY OF SOCIAL INSECTS IN THE FOSSIL RECORD* BY LAURIE BURNHAM Museum of Comparative Zoology the fossil record for clues not only on the antiquity of sociality, but also on the nature of these early recognized by Emerson (1955) have a fossil record extending at least as far back as the Tertiary. In 1967

Villemant, Claire

433

Molecular Determinants of Arenavirus Z Protein Homo-Oligomerization and L Polymerase Binding?  

PubMed Central

The arenavirus Z is a zinc-binding RING protein that has been implicated in multiple functions during the viral life cycle. These roles of Z involve interactions with viral and cellular proteins that remain incompletely understood. In this regard, Z inhibits viral RNA transcription and replication through direct interaction with the viral L polymerase. Here, we defined the L-binding domain of Tacaribe virus (TCRV) Z protein and the structural requirements mediating Z homo-oligomerization. By using site-directed mutagenesis, coimmunoprecipitation, and functional assays, we showed that residues R37, N39, W44, L50, and Y57, located around the zinc coordination site I, play a critical role in the Z-L interaction. We also found that Z protein from either TCRV or the pathogenic Junin virus (JUNV) self-associates into oligomeric forms in mammalian cells. Importantly, mutation of the myristoylation site, the strictly conserved residue G at position 2, severely impaired the ability of both TCRV Z and JUNV Z to self-interact as well as their capacity to accumulate at the plasma membrane, strongly suggesting that Z homo-oligomerization is associated with its myristoylation and cell membrane targeting. In contrast, disruption of the RING structure or substitution of W44 or N39, which are critical for L protein recognition, did not affect Z self-binding. Overall, the data presented here indicate that homo-oligomerization is not a requirement for Z-L interaction or Z-mediated polymerase activity inhibition. PMID:21957305

Loureiro, Maria Eugenia; Wilda, Maximiliano; Levingston Macleod, Jesica M.; D'Antuono, Alejandra; Foscaldi, Sabrina; Buslje, Cristina Marino; Lopez, Nora

2011-01-01

434

Palaeomagnetic analysis of the Sterkfontein palaeocave deposits: implications for the age of the hominin fossils and stone tool industries.  

PubMed

Palaeomagnetic analysis was conducted on speleothems from Members 1-5 at Sterkfontein Cave, South Africa. Palaeomagnetic analysis of siltstone and speleothem from the bulk of Member 4 indicate a reversed magnetic polarity that dates the deposits and its Australopithecus africanus fossils to between 2.58 and ~2.16 Ma. Further confirmation of this age comes in the form of two short normal polarity events correlated to the Rèunion (~2.16 Ma) and Huckleberry Ridge (~2.05 Ma) events in speleothem capping the bulk of Member 4 and coeval with deposition of the final phase of Member 4, including A. africanus fossil Sts 5. At ~2.16-2.05 Ma, Sts 5 is the youngest representative of A. africanus yet discovered. Palaeomagnetic analysis of the Silberberg Grotto deposits identifies a single short geomagnetic field event in flowstone overlying the StW 573 Australopithecus fossil, which is suggested to represent the Rèunion event at ~2.16 Ma. This further supports the uranium lead age estimates of 2.3-2.2 Ma for the StW 573 fossil. Based on a reversed polarity for the deposits below the skeleton it cannot be older than 2.58 Ma. If StW 573 is considered to be a second species of Australopithecus then this indicates that two species of Australopithecus are present at Sterkfontein between 2.6 and 2.0 Ma. All of the Member 5 deposits date to less than 1.8 Ma based on a comparison of palaeomagnetic, faunal, and electron spin resonance age estimates. The StW 53 fossil bearing infill (M5A) is intermediate in age between Member 4 and the rest of Member 5 (B-C) at around 1.78-1.49 Ma. The rest of Member 5 (B-C) containing Oldowan and Acheulian stone tools and Homo and Paranthropus fossils was deposited gradually between 1.40 and 1.07 Ma, much younger than previously suggested. PMID:21392817

Herries, Andy I R; Shaw, John

2011-05-01

435

Molecular structure, First-order hyperpolarizability and HOMO-LUMO studies of L- Histidinium Dinitrate  

NASA Astrophysics Data System (ADS)

The geometric parameters and hyperpolarizabilities of a nonlinear optical material L- Histidinium Dinitrate (LHDN) was investigated by density functional theory and presented. The compound crystallizes in the noncentro symmetric space group P212121 of orthorhombic system. The first order hyperpolarizability (?) of this molecular system is calculated using B3LYP/6-31G (d,p) method on the finite-field approach. The calculation results also show that the LHDN molecule might have microscopic nonlinear optical behavior with non zero values. The Optical absorption spectrum and second harmonic generation were investigated. The calculated HOMO and LUMO energies showed that charge transfer occurs within the molecule.

Arulmozhi, S.; Madhavan, J.

2015-02-01

436

Catalysis and chemodivergence in the interrupted, formal homo-Nazarov cyclization using allylsilanes.  

PubMed

A chemodivergent, Lewis acid catalyzed allylsilane interrupted formal homo-Nazarov cyclization is disclosed. With catalytic amounts of SnCl4 and in the presence of allyltrimethylsilane, a formal Hosomi-Sakurai-type allylation of the oxyallyl cation intermediate is observed. A variety of functionalized donor-acceptor cyclopropanes and allylsilanes were shown to be amenable to the reaction transformation and the allyl products were formed in up to 92% yield. Under dilute reaction conditions with stoichiometric SnCl4 and at reduced temperatures, an unusual formal [3 + 2]-cycloaddition between the allylsilane and the oxyallyl cation occurred to give hexahydrobenzofuran products in up to 69% yield. PMID:25495709

Shenje, Raynold; Williams, Corey W; Francois, Katherine M; France, Stefan

2014-12-19

437

Fossil Biodiversity: Red Noise Plus Signal  

E-print Network

We have examined the Fourier power spectrum as well as the Hurst exponent of extinction, origination, and total biodiversity in the marine fossil record, using a recently improved geologic timescale. We find all of them strongly inconsistent with past claims of self-similarity as well as inconsistent with random walk behavior. Instead, they are dominated by low-frequency power, with approximate f^-2 power over one decade in frequency. The spectrum turns over at about 10^5 y, lending plausibility to connections with galactic dynamics. Even in the background of this low-frequency dominance, a previously noted 62 My biodiversity cycle stands out with better than 99% confidence above the noise level, accounting for about 35% of the total variance in the fossil biodiversity record.

Melott, A L; Melott, Adrian L.; Lieberman, Bruce S.

2006-01-01

438

Diatoms: a fossil fuel of the future.  

PubMed

Long-term global climate change, caused by burning petroleum and other fossil fuels, has motivated an urgent need to develop renewable, carbon-neutral, economically viable alternatives to displace petroleum using existing infrastructure. Algal feedstocks are promising candidate replacements as a 'drop-in' fuel. Here, we focus on a specific algal taxon, diatoms, to become the fossil fuel of the future. We summarize past attempts to obtain suitable diatom strains, propose future directions for their genetic manipulation, and offer biotechnological pathways to improve yield. We calculate that the yields obtained by using diatoms as a production platform are theoretically sufficient to satisfy the total oil consumption of the US, using between 3 and 5% of its land area. PMID:24529448

Levitan, Orly; Dinamarca, Jorge; Hochman, Gal; Falkowski, Paul G

2014-03-01

439

Fossil energy waste management. Technology status report  

SciTech Connect

This report describes the current status and recent accomplishments of the Fossil Energy Waste Management (FE WM) projects sponsored by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The primary goal of the Waste Management Program is to identify and develop optimal strategies to manage solid by-products from advanced coal technologies for the purpose of ensuring the competitiveness of advanced coal technologies as a future energy source. The projects in the Fossil Energy Waste Management Program are divided into three types of activities: Waste Characterization, Disposal Technologies, and Utilization Technologies. This technology status report includes a discussion on barriers to increased use of coal by-products. Also, the major technical and nontechnical challenges currently being addressed by the FE WM program are discussed. A bibliography of 96 citations and a list of project contacts is included if the reader is interested in obtaining additional information about the FE WM program.

Bossart, S.J.; Newman, D.A.

1995-02-01

440

Fossil Biodiversity: Red Noise Plus Signal  

E-print Network

We have examined the Fourier power spectrum as well as the Hurst exponent of extinction, origination, and total biodiversity in the marine fossil record, using a recently improved geologic timescale. We find all of them strongly inconsistent with past claims of self-similarity as well as inconsistent with random walk behavior. Instead, they are dominated by low-frequency power, with approximate f^-2 power over one decade in frequency. The spectrum turns over at about 10^8 y, lending plausibility to connections with galactic dynamics. Even in the background of this low-frequency dominance, a previously noted 62 My biodiversity cycle stands out with better than 99% confidence above the noise level, accounting for about 35% of the total variance in the fossil biodiversity record.

Adrian L. Melott; Bruce S. Lieberman

2006-06-14

441

Structural coloration in a fossil feather  

PubMed Central

Investigation of feathers from the famous Middle Eocene Messel Oil Shale near Darmstadt, Germany shows that they are preserved as arrays of fossilized melanosomes, the surrounding beta-keratin having degraded. The majority of feathers are preserved as aligned rod-shaped eumelanosomes. In some, however, the barbules of the open pennaceous, distal portion of the feather vane are preserved as a continuous external layer of closely packed melanosomes enclosing loosely aligned melanosomes. This arrangement is similar to the single thin-film nanostructure that generates an iridescent, structurally coloured sheen on the surface of black feathers in many lineages of living birds. This is, to our knowledge, the first evidence of preservation of a colour-producing nanostructure in a fossil feather and confirms the potential for determining colour differences in ancient birds and other dinosaurs. PMID:19710052

Vinther, Jakob; Briggs, Derek E. G.; Clarke, Julia; Mayr, Gerald; Prum, Richard O.

2010-01-01

442

Structural coloration in a fossil feather.  

PubMed

Investigation of feathers from the famous Middle Eocene Messel Oil Shale near Darmstadt, Germany shows that they are preserved as arrays of fossilized melanosomes, the surrounding beta-keratin having degraded. The majority of feathers are preserved as aligned rod-shaped eumelanosomes. In some, however, the barbules of the open pennaceous, distal portion of the feather vane are preserved as a continuous external layer of closely packed melanosomes enclosing loosely aligned melanosomes. This arrangement is similar to the single thin-film nanostructure that generates an iridescent, structurally coloured sheen on the surface of black feathers in many lineages of living birds. This is, to our knowledge, the first evidence of preservation of a colour-producing nanostructure in a fossil feather and confirms the potential for determining colour differences in ancient birds and other dinosaurs. PMID:19710052

Vinther, Jakob; Briggs, Derek E G; Clarke, Julia; Mayr, Gerald; Prum, Richard O

2010-02-23

443

Determining Age of Rocks and Fossils  

NSDL National Science Digital Library

This activity will help students to have a better understanding of the basic principles used to determine the age of rocks and fossils. It consists of several parts: to have students determine relative age of a geologically complex area, to familiarize students with the concept of half-life in radioactive decay, to have students see that individual runs of statistical processes are less predictable than the average of many runs, and to demonstrate how the rate of radioactive decay and the buildup of the resulting decay product is used in radiometric dating of rocks. Students learn to use the principles of determining relative age to show how ages of rocks and fossils can be narrowed even if they cannot be dated radiometrically.

Frank McKinney

444

FOSSIL RIDGE WILDERNESS STUDY AREA, COLORADO.  

USGS Publications Warehouse

The Fossil Ridge Wilderness Study Area, approximately 20 mi northeast of Gunnison in central Colorado, was studied and its mineral-resource potential assessed. Portions of the study area have substantiated resource potential for gold, silver, copper, lead, zinc, molybdenum, uranium, thorium, rare-earth elements, and high-calcium limestone. Much of the area has a probable resource potential for the preceeding commodities as well as for tin. Various other elements are found in anomalous concentrations within the study area, but there is likelihood for their occurrence in amounts sufficient to constitute resources. Exploration, especially for molybdenum, gold, and uranium, has been active in the past and is expected to continue in the future. No potential for fossil fuel resources was identified in this study.

DeWitt, Ed; Kluender, Steven E.

1984-01-01

445

Cranial vault shape in fossil hominids: Fourier descriptors in norma lateralis.  

PubMed

Two major views of human evolution have elicited considerable controversy. These are: [1] the "out of Africa" hypothesis and [2] the "multiregional" hypothesis. This paper is an attempt to try to reconcile these two scenarios using hominid cranial vault data. Elliptical Fourier functions (EFFs) were used to describe, in visual and numerical terms, the shape of the human cranial vault in norma lateralis. Using jpeg images, contours of the cranial vault of a large sample of hominid specimens were pre-processed in Photoshop CS and rotated in 2D space (positional-orientation) so that a line drawn from nasion to porion was horizontal. The cranial vault image was then digitized with 72 closely-spaced points and submitted to a specially written routine that computed EFFs normalized by scaling (size-standardization). This ensured that the representation was invariant with respect to starting point, size and orientation. Statistically significant differences were found between the H. sapiens sample and both the H. erectus and H. neanderthalensis samples. In contrast, there were no statistically significant differences between the H. erectus and H. neanderthalensis groups, leading to three conclusions: [1] the similarity in cranial vault shape between H. erectus and H. neanderthalensis suggests a single gradually evolving lineage; [2] The taxon H. heidelbergensis can be embedded into the H. erectus?H. neanderthalensis line; and [3] H. sapiens seems to be a separate evolutionary development and is considered here either as a separate species or as a possible example of an allopatric semispecies (Grant, 1977). The results here suggest that human evolution over the last 2 Ma may turn out to be neither totally multiregional or simply out of Africa but rather represents a considerably more complicated picture. PMID:20801442

Lestrel, P E; Ohtsuki, F; Wolfe, C A

2010-10-01

446

Oral Presentation of a Fossil Group  

NSDL National Science Digital Library

Each student chooses a different fossil group that interests him/her and prepares a 10 minute PowerPoint presentation about that group, lavishly illustrated and richly illuminated with fascinating facts! This can be as large a group as a phylum or as small as a species. Powerpoint handouts are given out during the oral presentation. Students must have a concluding slide citing references. The discussion must go beyond what is presented by the professor in lecture.

Max Reams

447

Fossil hominids from the Laetolil Beds  

Microsoft Academic Search

Remains of 13 early hominids have been found in the Laetolil Beds in northern Tanzania, 30 miles south of Olduvai Gorge. Potassium-argon dating of the fossiliferous deposits gives an upper limit averaging 3.59 Myr and a lower limit of 3.77 Myr. An extensive mammalian fauna is associated. The fossils occur in the upper 30 m of ash-fall and aeolian tuffs

M. D. Leakey; R. L. Hay; G. H. Curtis; R. E. Drake; M. K. Jackes

1976-01-01

448

Guidelines on fossil boiler field welding  

Microsoft Academic Search

Welding is a key maintenance activity in the repair and replacement of critical boiler pressure-part components. Unless trained welders use qualified procedures and documented practices, significant delays to outages may result from defective weld repairs, and future weld-related failures may cause costly outages. To address these issues, a comprehensive guideline on field-welding practices for fossil-fired boilers has been developed. It

1993-01-01

449

Adaptation, plant evolution, and the fossil record  

NASA Technical Reports Server (NTRS)

The importance of adaptation in determining patterns of evolution has become an important focus of debate in evolutionary biology. As it pertains to paleobotany, the issue is whether or not adaptive evolution mediated by natural selection is sufficient to explain the stratigraphic distributions of taxa and character states observed in the plant fossil record. One means of addressing this question is the functional evaluation of stratigraphic series of plant organs set in the context of paleoenvironmental change and temporal patterns of floral composition within environments. For certain organ systems, quantitative estimates of biophysical performance can be made on the basis of structures preserved in the fossil record. Performance estimates for plants separated in time or space can be compared directly. Implicit in different hypotheses of the forces that shape the evolutionary record (e.g. adaptation, mass extinction, rapid environmental change, chance) are predictions about stratigraphic and paleoenvironmental trends in the efficacy of functional performance. Existing data suggest that following the evolution of a significant structural innovation, adaptation for improved functional performance can be a major determinant of evolutionary changes in plants; however, there are structural and development limits to functional improvement, and once these are reached, the structure in question may no longer figure strongly in selection until and unless a new innovation evolves. The Silurian-Devonian paleobotanical record is consistent with the hypothesis that the succession of lowland floodplain dominants preserved in the fossil record of this interval was determined principally by the repeated evolution of new taxa that rose to ecological importance because of competitive advantages conferred by improved biophysical performance. This does not seem to be equally true for Carboniferous-Jurassic dominants of swamp and lowland floodplain environments. In these cases, environmental disruption appears to have been a major factor in shaping the fossil record. This does not mean that continuing adaptation was not important during this interval, but it may indicate that adaptive evolution was strongest in environments other than those best represented in the paleobotanical record.

Knoll, A. H.; Niklas, K. J.

1987-01-01

450

Identifying Fossil Bacteria in Martian Materials  

NASA Technical Reports Server (NTRS)

Within the next decade, robotic missions are going to Mars with the search for evidence for extant and extinct life as at least one of the mission objectives. Moreover, the first Martian samples will be returned to Earth in 2008. It is therefore imperative that we can be certain that we can identify life in Martian rocks. In this paper we will not be discussing extant life but will concentrate on fossil life.

Westall, F.; McKay, D. S.; Gibson, E. K., Jr.

1999-01-01

451

Fossil pollen records of extant angiosperms  

Microsoft Academic Search

The fossil record for angiosperm pollen types which are comparable to recent taxa is evaluated, following a similar survey\\u000a published in 1970. Special attention is paid to the dating of the sediments. Evidence for 139 families is considered to be\\u000a reliable, for others the records are cited as provisional, pending the accumulation of more evidence. Some published records\\u000a are shown

Jan Muller

1981-01-01

452

Fossil dust shells around luminous supergiants  

NASA Technical Reports Server (NTRS)

The observed frequency with which infrared excesses appear in F, G, and K supergiants of luminosity class Ia supports the idea that these excesses arise in a 'fossil' circumstellar dust shell that was formed during a prior M-super-giant phase of evolution. The required leftward evolution of the star on the H-R diagram would then imply that the Ledoux, rather than the Schwarzschild, criterion for convective mixing is the correct criterion to use in stellar evolution calculations.

Stothers, R.

1975-01-01

453

Early Pleistocene 40Ar/39Ar ages for Bapang Formation hominins, Central Jawa, Indonesia  

PubMed Central

The Sangiran dome is the primary stratigraphic window for the Plio-Pleistocene deposits of the Solo basin of Central Jawa. The dome has yielded nearly 80 Homo erectus fossils, around 50 of which have known findspots. With a hornblende 40Ar/39Ar plateau age of 1.66 ± 0.04 mega-annum (Ma) reportedly associated with two fossils [Swisher, C.C., III, Curtis, G. H., Jacob, T., Getty, A. G., Suprijo, A. & Widiasmoro (1994) Science 263, 1118–1121), the dome offers evidence that early Homo dispersed to East Asia during the earliest Pleistocene. Unfortunately, the hornblende pumice was sampled at Jokotingkir Hill, a central locality with complex lithostratigraphic deformation and dubious specimen provenance. To address the antiquity of Sangiran H. erectus more systematically, we investigate the sedimentary framework and hornblende 40Ar/39Ar age for volcanic deposits in the southeast quadrant of the dome. In this sector, Bapang (Kabuh) sediments have their largest exposure, least deformation, and most complete tephrostratigraphy. At five locations, we identify a sequence of sedimentary cycles in which H. erectus fossils are associated with epiclastic pumice. From sampled pumice, eight hornblende separates produced 40Ar/39Ar plateau ages ranging from 1.51 ± 0.08 Ma at the Bapang/Sangiran Formation contact, to 1.02 ± 0.06 Ma, at a point above the hominin-bearing sequence. The chronological sequence of 40Ar/39Ar ages follows stratigraphic order across the southeast quadrant. An intermediate level yielding four nearly complete crania has an age of about 1.25 Ma. PMID:11309488

Larick, Roy; Ciochon, Russell L.; Zaim, Yahdi; Sudijono; Suminto; Rizal, Yan; Aziz, Fachroel; Reagan, Mark; Heizler, Matthew

2001-01-01

454

Spatial Bias in the Marine Fossil Record  

PubMed Central

Inference of past and present global biodiversity requires enough global data to distinguish biological pattern from sampling artifact. Pertinently, many studies have exposed correlated relationships between richness and sampling in the fossil record, and methods to circumvent these biases have been proposed. Yet, these studies often ignore paleobiogeography, which is undeniably a critical component of ancient global diversity. Alarmingly, our global analysis of 481,613 marine fossils spread throughout the Phanerozoic reveals that where localities are and how intensively they have been sampled almost completely determines empirical spatial patterns of richness, suggesting no separation of biological pattern from sampling pattern. To overcome this, we analyze diversity using occurrence records drawn from two discrete paleolatitudinal bands which cover the bulk of the fossil data. After correcting the data for sampling bias, we find that these two bands have similar patterns of richness despite markedly different spatial coverage. Our findings suggest that i) long-term diversity trends result from large-scale tectonic evolution of the planet, ii) short-term diversity trends are region-specific, and iii) paleodiversity studies must constrain their analyses to well-sampled regions to uncover patterns not driven by sampling. PMID:24204570

Vilhena, Daril A.; Smith, Andrew B.

2013-01-01

455

Tool making, hand morphology and fossil hominins  

PubMed Central

Was stone tool making a factor in the evolution of human hand morphology? Is it possible to find evidence in fossil hominin hands for this capability? These questions are being addressed with increasingly sophisticated studies that are testing two hypotheses; (i) that humans have unique patterns of grip and hand movement capabilities compatible with effective stone tool making and use of the tools and, if this is the case, (ii) that there exist unique patterns of morphology in human hands that are consistent with these capabilities. Comparative analyses of human stone tool behaviours and chimpanzee feeding behaviours have revealed a distinctive set of forceful pinch grips by humans that are effective in the control of stones by one hand during manufacture and use of the tools. Comparative dissections, kinematic analyses and biomechanical studies indicate that humans do have a unique pattern of muscle architecture and joint surface form and functions consistent with the derived capabilities. A major remaining challenge is to identify skeletal features that reflect the full morphological pattern, and therefore may serve as clues to fossil hominin manipulative capabilities. Hominin fossils are evaluated for evidence of patterns of derived human grip and stress-accommodation features. PMID:24101624

Marzke, Mary W.

2013-01-01

456

Models for simulating the fossil record  

NASA Astrophysics Data System (ADS)

Computer modeling of the distribution of fossils within depositional sequences provides a means for generating hypotheses and increasing understanding of the fossil record. The simulation presented here joins the basin-scale stratigraphic modeling program STRATA, a random-branching model of species origination and extinction, and a model relating the probability of species occurrence to sedimentary facies. Model results indicate that facies sensitivity of species has the strongest control on range offset, i.e., the time between last appearance in a stratigraphic column and the time of extinction within a basin or the time between first appearance in a column and time of origination in a basin. Model results also predict the distribution of zones of increased range offset within depositional sequences. In the results presented here, increased range offset occurs within the transgressive systems tract of the deep basin, in far updip settings, and near the shelf break of the late highstand to early lowstand. The model also demonstrates how incompleteness of the fossil record is partitioned among sampling bias, facies bias, and unconformity bias. In this simulation, sampling bias and facies bias are roughly equal in magnitude and constant across the basin, but unconformity bias increasingly dominates over these two in updip positions.

Holland, Steven M.; Patzkowsky, Mark E.

1999-06-01

457

Fossil avian eggshell preserves ancient DNA  

PubMed Central

Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has approximately 125 times lower bacterial load than bone, making it a highly suitable substrate for high-throughput sequencing approaches. Importantly, the preservation of DNA in Pleistocene eggshell from Australia and Holocene deposits from Madagascar indicates that eggshell is an excellent substrate for the long-term preservation of DNA in warmer climates. The successful recovery of DNA from this substrate has implications in a number of scientific disciplines; most notably archaeology and palaeontology, where genotypes and/or DNA-based species identifications can add significantly to our understanding of diets, environments, past biodiversity and evolutionary processes. PMID:20219731

Oskam, Charlotte L.; Haile, James; McLay, Emma; Rigby, Paul; Allentoft, Morten E.; Olsen, Maia E.; Bengtsson, Camilla; Miller, Gifford H.; Schwenninger, Jean-Luc; Jacomb, Chris; Walter, Richard; Baynes, Alexander; Dortch, Joe; Parker-Pearson, Michael; Gilbert, M. Thomas P.; Holdaway, Richard N.; Willerslev, Eske; Bunce, Michael

2010-01-01

458

Tool making, hand morphology and fossil hominins.  

PubMed

Was stone tool making a factor in the evolution of human hand morphology? Is it possible to find evidence in fossil hominin hands for this capability? These questions are being addressed with increasingly sophisticated studies that are testing two hypotheses; (i) that humans have unique patterns of grip and hand movement capabilities compatible with effective stone tool making and use of the tools and, if this is the case, (ii) that there exist unique patterns of morphology in human hands that are consistent with these capabilities. Comparative analyses of human stone tool behaviours and chimpanzee feeding behaviours have revealed a distinctive set of forceful pinch grips by humans that are effective in the control of stones by one hand during manufacture and use of the tools. Comparative dissections, kinematic analyses and biomechanical studies indicate that humans do have a unique pattern of muscle architecture and joint surface form and functions consistent with the derived capabilities. A major remaining challenge is to identify skeletal features that reflect the full morphological pattern, and therefore may serve as clues to fossil hominin manipulative capabilities. Hominin fossils are evaluated for evidence of patterns of derived human grip and stress-accommodation features. PMID:24101624

Marzke, Mary W

2013-11-19

459

The Undead: Fossil Galaxy Alive Again  

NASA Astrophysics Data System (ADS)

This project investigates the formation and evolution of fossil galaxies, specifically the history of active galactic nucleus (AGN) activity as it relates to galaxy mergers. We used low-frequency radio data from the J-VLA radio telescope's new P-band receivers [300-350MHz] to observe fossil galaxy J171811.93+563956.1 (referenced as FG30) at a red-shift of z=0.114. This galaxy was selected for its strong X-ray emission from the surrounding IGM, because it is indicative of an AGN. After cleaning and calibrating the data using CASA, images were generated to map the intensity of radio emission, revealing that FG30 is nearly a point source and lacks any prominent AGN jets. Analysis of the SDSS optical spectrum of FG30 revealed strong evidence of shocks. We believe that past AGN activity heated the intergalactic medium (IGM) to produce the strong X-ray emission, though the jets have been dormant for long enough that the IGM filled in the regions previously cleared by jets. The density of new material is now causing strong shocks when hit by newly restarted jets. This implies the start of a new epoch of AGN activity for FG30, which was most likely caused by a recent galaxy merger. This observation demonstrates that not all fossil groups have been quiescent, as the dominant theories suggested.*This work was supported by the National Science Foundation's REU program through NSF Award AST-1004881.

Berglund, Kallan; Wilcots, Eric M.

2015-01-01

460

Traversing the mountaintop: world fossil fuel production to 2050  

PubMed Central

During the past century, fossil fuels—petroleum liquids, natural gas and coal—were the dominant source of world energy production. From 1950 to 2005, fossil fuels provided 85–93% of all energy production. All fossil fuels grew substantially during this period, their combined growth exceeding the increase in world population. This growth, however, was irregular, providing for rapidly growing per capita production from 1950 to 1980, stable per capita production from 1980 to 2000 and rising per capita production again after 2000. During the past half century, growth in fossil fuel production was essentially limited by energy demand. During the next half century, fossil fuel production will be limited primarily by the amount and characteristics of remaining fossil fuel resources. Three possible scenarios—low, medium and high—are developed for the production of each of the fossil fuels to 2050. These scenarios differ primarily by the amount of ultimate resources estimated for each fossil fuel. Total fossil fuel production will continue to grow, but only slowly for the next 15–30 years. The subsequent peak plateau will last for 10–15 years. These production peaks are robust; none of the fossil fuels, even with highly optimistic resource estimates, is projected to keep growing beyond 2050. World fossil fuel production per capita will thus begin an irreversible decline between 2020 and 2030. PMID:19770156

Nehring, Richard

2009-01-01

461

Traversing the mountaintop: world fossil fuel production to 2050.  

PubMed

During the past century, fossil fuels--petroleum liquids, natural gas and coal--were the dominant source of world energy production. From 1950 to 2005, fossil fuels provided 85-93% of all energy production. All fossil fuels grew substantially during this period, their combined growth exceeding the increase in world population. This growth, however, was irregular, providing for rapidly growing per capita production from 1950 to 1980, stable per capita production from 1980 to 2000 and rising per capita production again after 2000. During the past half century, growth in fossil fuel production was essentially limited by energy demand. During the next half century, fossil fuel production will be limited primarily by the amount and characteristics of remaining fossil fuel resources. Three possible scenarios--low, medium and high--are developed for the production of each of the fossil fuels to 2050. These scenarios differ primarily by the amount of ultimate resources estimated for each fossil fuel. Total fossil fuel production will continue to grow, but only slowly for the next 15-30 years. The subsequent peak plateau will last for 10-15 years. These production peaks are robust; none of the fossil fuels, even with highly optimistic resource estimates, is projected to keep growing beyond 2050. World fossil fuel production per capita will thus begin an irreversible decline between 2020 and 2030. PMID:19770156

Nehring, Richard

2009-10-27

462

Emissions Scenarios and Fossil-fuel Peaking  

NASA Astrophysics Data System (ADS)

Intergovernmental Panel on Climate Change (IPCC) emissions scenarios are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. Built into the assumptions for these scenarios are estimates for ultimately recoverable resources of various fossil fuels. There is a growing chorus of critics who believe that the true extent of recoverable fossil resources is much smaller than the amounts taken as a baseline for the IPCC scenarios. In a climate optimist camp are those who contend that "peak oil" will lead to a switch to renewable energy sources, while others point out that high prices for oil caused by supply limitations could very well lead to a transition to liquid fuels that actually increase total carbon emissions. We examine a third scenario in which high energy prices, which are correlated with increasing infrastructure, exploration and development costs, conspire to limit the potential for making a switch to coal or natural gas for liquid fuels. In addition, the same increasing costs limit the potential for expansion of tar sand and shale oil recovery. In our qualitative model of the energy system, backed by data from short- and medium-term trends, we have a useful way to gain a sense of potential carbon emission bounds. A bound for 21st century emissions is investigated based on two assumptions: first, that extractable fossil-fuel resources follow the trends assumed by "peak oil" adherents, and second, that little is done in the way of climate mitigation policies. If resources, and perhaps more importantly, extraction rates, of fossil fuels are limited compared to assumptions in the emissions scenarios, a situation can arise in which emissions are supply-driven. However, we show that even in this "peak fossil-fuel" limit, carbon emissions are high enough to surpass 550 ppm or 2°C climate protection guardrails. Some indicators are presented that the scenario presented here should not be disregarded, and comparisons are made to the outputs of emission scenarios used for the IPCC reports.

Brecha, R.

2008-12-01

463

Evaluation of hybrid solar/fossil Rankine-cooling concept  

NASA Astrophysics Data System (ADS)

The hybrid solar/fossil Rankine cycle is analyzed thermodynamically to determine fuel use and efficiency. The hybrid system is briefly compared with solar organic Rankine systems with a fossil fuel auxiliary mode, and with geothermal resources. The economic evaluation compares the present value of the superheater fuel cost over the system lifetime with the first cost reduction obtained by substituting a hybrid solar/fossil Rankine engine. The economics analysis indicates that even if the hybrid solar/fossil Rankine cooling system were developed to the point of being a commercial product with an economic advantage over an otherwise equivalent solar organic Rankine cooling system, it would gradually lose that advantage with rising fuel costs and decreasing collector costs. From the standpoint of national fossil fuel conservation, the hybrid concept would be preferable only in applications where the operating duration in the solar/fossil mode would be substantially greater than in the fossil fuel only auxiliary mode.

Curran, H. M.

1980-11-01

464

Fossil Energy Program semiannual progress report, October 1990--March 1991  

SciTech Connect

This report covers progress made during the period October 1, 1990, through March 31, 1991, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, the DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Office of Basic Energy Sciences, the DOE Fossil Energy Office of Petroleum Reserves, the DOE Fossil Energy Naval Petroleum and Oil Shale Reserves, and the US Agency for International Development. The Fossil, Energy Program organization chart is shown in the appendix. Topics include: alloys, ceramics and composite research and development; corrosion and erosion research; environmental analysis and information systems; coal conversion development; mild gasification product characterization; coal combustion research; strategic petroleum reserve planning and modeling; and coal structure and chemistry.

Judkins, R.R.

1992-07-01

465

Midsagittal cranial shape variation in the genus Homo by geometric morphometrics.  

PubMed

Midsagittal profiles of crania referred to different taxa of the genus Homo have been analyzed by geometric morphometric techniques. Comparisons between single specimens using the thin-plate-spline function suggest a generalized reduction of the lower face, associated with antero-posterior development of the braincase occurring (possibly in parallel evolution) along distinct human lineages. Furthermore, Neandertals display a projection of the midface, and modern humans show a derived globularity of the vault associated with midsagittal parietal bulging. Principal Component Analysis demonstrates a bimodal pattern of variation, which describes an "archaic" pole (rather heterogeneous in terms of taxonomy) clearly distinguishable from the modern one. The first two principal components - that explain together 80% of the total variance in shape - involve respectively fronto-parietal expansion and midfacial prognathism. These results contribute to identify different structural patterns in human evolution, supporting discontinuity rather than continuity of cranial shape among different taxa of the genus Homo, especially when considering the differences between Neandertals and early modern humans. PMID:15636068

Bruner, Emiliano; Saracino, Barbara; Ricci, Francesca; Tafuri, Maryanne; Passarello, Pietro; Manzi, Giorgio

2004-06-01

466

Relationship between cusp size and occlusal wear pattern in Neanderthal and Homo sapiens first maxillary molars.  

PubMed

Tooth wear studies in mammals have highlighted the relationship between wear facets (attritional areas produced during occlusion by the contact between opposing teeth) and physical properties of the ingested food. However, little is known about the influence of tooth morphology on the formation of occlusal wear facets. We analyzed the occlusal wear patterns of first maxillary molars (M(1) s) in Neanderthals, early Homo sapiens, and contemporary modern humans. We applied a virtual method to analyze wear facets on the crown surface of three-dimensional digital models. Absolute and relative wear facet areas are compared with cusp area and cusp height. Although the development of wear facets partially follows the cusp pattern, the results obtained from the between-group comparisons do not reflect the cusp size differences characterizing these groups. In particular, the wear facets developed along the slopes of the most discriminate cusp between Neanderthals and Homo sapiens (hypocone) do not display any significant difference. Moreover, no correlations have been found between cusp size and wear facet areas (with the exception of the modern sample) and between cusp height and wear facet areas. Our results suggest that cusp size is only weakly related to the formation of the occlusal wear facets. Other factors, such as, diet, food processing, environmental abrasiveness, and nondietary habits are probably more important for the development and enlargement of wear facets, corroborating the hypotheses suggested from previous dental wear studies. PMID:21337711

Fiorenza, Luca; Benazzi, Stefano; Viola, Bence; Kullmer, Ottmar; Schrenk, Friedemann

2011-03-01

467

Aggregation propensity of Aib homo-peptides of different length: an insight from molecular dynamics simulations.  

PubMed

Interactions between peptides are relevant from a biomedical point of view, in particular for the role played by their aggregates in different important pathologies, and also because peptide aggregates represent promising scaffolds for innovative materials. In the present article, the aggregation properties of the homo-peptides formed by ?-aminoisobutyric acid (U) residues are discussed. The peptides investigated have chain lengths between six and 15 residues and comprise benzyl and naphthyl groups at the N- and C-termini, respectively. Spectroscopic experiments and molecular dynamics simulations show that the shortest homo-peptide, constituted by six U, does not exhibit any tendency to aggregate under the conditions examined. On the other hand, the homologous peptide with 15 U forms very stable and compact aggregates in 70/30(v/v) methanol/water solution. Atomic force microscopy images indicate that these aggregates promote formation of long fibrils once they are deposited on a mica surface. The aggregation phenomenon is mainly due to hydrophobic interactions occurring between very stable helical structures, and the aromatic groups in the peptides seem to play a minor role. PMID:24845474

Bocchinfuso, Gianfranco; Conflitti, Paolo; Raniolo, Stefano; Caruso, Mario; Mazzuca, Claudia; Gatto, Emanuela; Placidi, Ernesto; Formaggio, Fernando; Toniolo, Claudio; Venanzi, Mariano; Palleschi, Antonio

2014-07-01

468

Hawaii energy strategy project 2: Fossil energy review. Task 1: World and regional fossil energy dynamics  

SciTech Connect

This report in the Hawaii Energy Strategy Project examines world and regional fossil energy dynamics. The topics of the report include fossil energy characteristics, the world oil industry including reserves, production, consumption, exporters, importers, refining, products and their uses, history and trends in the global oil market and the Asia-Pacific market; world gas industry including reserves, production, consumption, exporters, importers, processing, gas-based products, international gas market and the emerging Asia-Pacific gas market; the world coal industry including reserves, classification and quality, utilization, transportation, pricing, world coal market, Asia-Pacific coal outlook, trends in Europe and the Americas; and environmental trends affecting fossil fuels. 132 figs., 46 tabs.

Breazeale, K. [ed.; Isaak, D.T.; Yamaguchi, N.; Fridley, D.; Johnson, C.; Long, S.

1993-12-01

469

Diet in Early Homo : A Review of the Evidence and a New Model of Adaptive Versatility  

Microsoft Academic Search

Several recent studies have stressed the role of dietary change in the origin and early evolution of our genus in Africa. Resulting models have been based on nutrition research and analogy to living peoples and nonhuman primates or on archeological and paleoenvironmen- tal evidence. Here we evaluate these models in the context of the hominin fossil record. Inference of diet

Peter S. Ungar; Frederick E. Grine; Mark F. Teaford

2006-01-01

470

Reconstructing the ups and downs of primate brain evolution: implications for adaptive hypotheses and Homo floresiensis  

Microsoft Academic Search

BACKGROUND: Brain size is a key adaptive trait. It is often assumed that increasing brain size was a general evolutionary trend in primates, yet recent fossil discoveries have documented brain size decreases in some lineages, raising the question of how general a trend there was for brains to increase in mass over evolutionary time. We present the first systematic phylogenetic

Stephen H Montgomery; Isabella Capellini; Robert A Barton; Nicholas I Mundy

2010-01-01

471

Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 4: Energy from fossil fuels  

NASA Technical Reports Server (NTRS)

The conversion of fossil-fired power plants now burning oil or gas to burn coal is discussed along with the relaxation of air quality standards and the development of coal gasification processes to insure a continued supply of gas from coal. The location of oil fields, refining areas, natural gas fields, and pipelines in the U.S. is shown. The technologies of modern fossil-fired boilers and gas turbines are defined along with the new technologies of fluid-bed boilers and MHD generators.

Williams, J. R.

1974-01-01

472

Abstracts: Eighth Annual Conference on Fossil Energy Materials. Fossil Energy Program  

SciTech Connect

Abstracts are presented for about 40 papers. The Fossil Energy Advanced Research and Technology Development Materials program is an integrated materials research activity of the fossil energy coal program, whose objective is to conduct R and D for all advanced coal conversion and utilization technologies. The program is aimed at understanding materials behavior in coal system environments and the development of new materials for improving plant operations and reliability. A generic approach is used for addressing multiple coal technologies; for example, the hot-gas particulate filter development is applicable to pressurized fluidized bed combustion, integrated coal gasification combined-cycle, coal combustion, and indirectly fired combined-cycle systems.

Not Available

1994-07-01

473

Helical screw sense of homo-oligopeptides of C?-methylated ?-amino acids as determined with vibrational circular dichroism  

Microsoft Academic Search

Vibrational circular dichroism spectra for three homo-oligopeptides, p-BrBz-[D-(?Me)Phe]4,5-OtBu and p-BrBz-(D-Iva)5-OtBu, are presented and interpreted to show that the C?-methylated ?-amino acids (?Me)Phe and Iva of the same optical configuration favor helical conformations of the opposite screw sense. The D-(?Me)Phe tetra- and pentapeptides are folded in a right-handed 310-helix, which is consistent with previous findings regarding homo-oligomers of C?-methylated amino acids

Gorm Yoder; Timothy A Keiderling; Fernando Formaggio; Marco Crisma; Claudio Toniolo; Johan Kamphuis

1995-01-01

474

Si, SiC homo junctions and n-SiC/p-Si hetero junction: MM-wave performance characteristics  

NASA Astrophysics Data System (ADS)

A recent report on realization/studies of Si-SiC hetero junction has given impetus to explore them for generation of rf power in double drift impact ionization avalanche transit time (IMPATT) mode. MM-wave properties of this hetero junction are compared with corresponding Si and SiC homo .junction. Interesting feature of ionization free n-SiC zone localizes the avalanche zone to less than 10% of depletion zone resulting in diode efficiency around 27% (against only 10-15% for both homo junctions Si and SiC) and three fold high rf negative resistance, which can be therefore termed as promising high rf power source.

Pati, S. P.; Tripathy, P. R.; Choudhury, S. K.; Mukharjee, M.; Purohit, P.

2012-10-01

475

The Quaternary fossil-pollen record and global change  

SciTech Connect

Fossil pollen provide one of the most valuable records of vegetation and climate change during the recent geological past. Advantages of the fossil-pollen record are that deposits containing fossil pollen are widespread, especially in areas having natural lakes, that fossil pollen occurs in continuous stratigraphic sequences spanning millennia, and that fossil pollen occurs in quantitative assemblages permitting a multivariate approach for reconstructing past vegetation and climates. Because of stratigraphic continuity, fossil pollen records climate cycles on a wide range of scales, from annual to the 100 ka Milankovitch cycles. Receiving particular emphasis recently are decadal to century scale changes, possible from the sediments of varved lakes, and late Pleistocene events on a 5--10 ka scale possibly correlating with the Heinrich events in the North Atlantic marine record or the Dansgaard-Oeschger events in the Greenland ice-core record. Researchers have long reconstructed vegetation and climate by qualitative interpretation of the fossil-pollen record. Recently quantitative interpretation has developed with the aid of large fossil-pollen databases and sophisticated numerical models. In addition, fossil pollen are important climate proxy data for validating General Circulation Models, which are used for predicting the possible magnitude future climate change. Fossil-pollen data also contribute to an understanding of ecological issues associated with global climate change, including questions of how and how rapidly ecosystems might respond to abrupt climate change.

Grimm, E.C. (Illinois State Museum, Springfield, IL (United States). Research and Collections Center)

1993-03-01

476

Fossil fuel conversion--measurement and modeling  

SciTech Connect

The main objective of this program is to understand the chemical and physical mechanisms in coal conversion processes and incorporate this knowledge in computer-aided reactor engineering technology for the purposes of development, evaluation, design, scale-up, simulation, control and feedstock evaluation in advanced coal conversion devices. To accomplish this objective, this program will: (1) provide critical data on the physical and chemical processes in fossil fuel gasifiers and combustors; (2) further develop a set of comprehensive codes; and (3) apply these codes to model various types of combustors and gasifiers (fixed-bed, transport reactor, and fluidized-bed for coal and gas turbines for natural gas).

Solomon, P.R.; Smoot, L.D.; Serio, M.A.; Hamblen, D.G.; Brewster, B.S.; Radulovic, P.T.

1994-10-01

477

Future requirements for fossil power plants  

NASA Astrophysics Data System (ADS)

The fast increasing installation of technologies to convert renewable energy into power influences the operation of conventional power plants. New requirements on the technology, on the operation and on the economic have to be considered for already running and future power plants. Currently, first experiences with such a production and market situation are available. Technologies are discussed to store power and to reduce CO2 emissions. New compensation models are necessary to enable economic operation of fossil power plants in base load. This article gives a short review about available technologies and future challenges.

Gaderer, M.; Spliethoff, H.

2013-06-01

478

Forests in a fossil-fuel world  

SciTech Connect

Humanity's use of the fossilized remains of ancient forests now threatens the health and productivity of the modern-day descendants of these trees. Air pollution and acid rain are attacking forests around the world, threatening ecological disaster unless action is taken. Weakened by the stress of air pollutants, acidic and impoverished soils, or toxic metals, trees lose their resistance to natural events such as drought, insect attacks, and frost. Although the mechanisms of this damage are not understood, a growing body of circumstantial evidence is unfolding in North America and in the forests of West Germany. International cooperation and government recognition that prices must include the cost of pollution damage are essential.

Postel, S.

1984-08-01

479

Earth's early fossil record: Why not look for similar fossils on Mars?  

NASA Technical Reports Server (NTRS)

The oldest evidence of life on Earth is discussed with attention being given to the structure and formation of stromatolites and microfossils. Fossilization