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A procedure is outlined for distinguishing among competing hypotheses for fossil morphology and then used to evaluate current views on the meaning of Neandertal skeletal morphology. Three explanations have dominated debates about the meaning of Neandertal cranial features: climatic adaptation, anterior dental loading, and genetic drift. Neither climatic(More)
Cranial morphology is widely used to reconstruct evolutionary relationships, but its reliability in reflecting phylogeny and population history has been questioned. Some cranial regions, particularly the face and neurocranium, are believed to be influenced by the environment and prone to convergence. Others, such as the temporal bone, are thought to reflect(More)
Previous studies have differed in expectations about whether long limbs should increase or decrease the energetic cost of locomotion. It has recently been shown that relatively longer lower limbs (relative to body mass) reduce the energetic cost of human walking. Here we report on whether a relationship exists between limb length and cost of human running.(More)
Recent research has shown that genetic drift may have produced many cranial differences between Neandertals and modern humans. If this is the case, then it should be possible to estimate population genetic parameters from Neandertal and modern human cranial measurements in a manner analogous to how estimates are made from DNA sequences. Building on previous(More)
Numerous studies have discussed the influence of thermoregulation on hominin body shape concluding, in accordance with Allen's rule, that the presence of relatively short limbs on both extant as well as extinct hominin populations offers an advantage for survival in cold climates by reducing the limb's surface area to volume ratio. Moreover, it has been(More)
The Froude number has been widely used in anthropology to adjust for size differences when comparing gait parameters or other nonmorphological locomotor variables (such as optimal walking speed or speed at gait transitions) among humans, nonhuman primates, and fossil hominins. However, the dynamic similarity hypothesis, which is the theoretical basis for(More)
A human partial maxillary dentition and a fragmentary cranium were recovered from Obi-Rakhmat Grotto in northeastern Uzbekistan in 2003. Initial descriptions of this single juvenile (OR-1) from a Middle Paleolithic archaeological context have emphasized its mosaic morphological pattern; the dentition appears archaic, while certain morphological aspects of(More)
Scenarios for modern human origins are often predicated on the assumption that modern humans arose 200,000e100,000 years ago in Africa. This assumption implies that something 'special' happened at this point in time in Africa, such as the speciation that produced Homo sapiens, a severe bottleneck in human population size, or a combination of the two. The(More)
Neandertal femora are distinct from contemporaneous near-modern human femora. Traditionally, these contrasts in femoral shape have been explained as the result of the elevated activity levels and limited cultural abilities of Neandertals. More recently, however, researchers have realized that many of these femoral differences may be explained by the(More)
Increasing aridity and drought severity forecast for many land areas could reduce the land carbon (C) sink. However, with limited long-term direct measures, it is difficult to distinguish direct drying effects from counter effects of CO2 enrichment and nitrogen (N) deposition. Here, we document a >50% decline in production of a native C3 grassland over four(More)