Saturday, May 7, 2011

Did europeans get their facial form from Neanderthals?

 



Many noted paleoanthropological researchers currently argue that modern Europeans may share close biological relationships with archaic Neanderthal man


Evidence comes from craniofacial measurements used to compare hominid species. This research shows that nuances relating to the cranial outlines of European Neanderthals are identical to the nuances observed in modern Europeans




Morphological differences between these two populations are said to exist primarily with respect to facial form 




One theory purposes that such facial morphological differences may have come as the result of a reduction in tooth size that took place over a period of thousands of years






For example, the Krapina Neanderthals at the end of the last interglacial differed from Homo erectus only in having larger front teeth, while “Classic” Neanderthals of Western Europe had teeth that are 15% smaller than those of the earlier Krapina Neanderthals and only 5% larger than early Upper Paleolithic Neanderthals. It is these incremental reductions in tooth size, along with their resulting changes in craniofacial form which are believed, “by some”, to reflect an (in situ) evolution of modern European facial form from an ancestral Neanderthal one




While this theory represents a rather extreme position, other more widely accepted theories argue simply that early Europeans may have interbred with Neanderthals at rates great enough that Neanderthal features can still be observed in modern, particularly ‘northwestern European’ populations, today .




While the morphological aspects of the earliest modern humans in Europe (more than 33,000 B.P.) indicate that they do in fact possess an anatomical pattern largely inline with the morphology of the earliest (Middle Paleolithic) African modern humans; they also exhibit features that are distinctively Neanderthal 




For example, numerous craniofacial, dental, and postcranial traits in European early humans are unlikely to have come from middle Paleolithic modern humans, and have been argued to be Neanderthal in origin . If associated admixture between Europeans were rare or non existent, one would expect only to find a few of these non early modern human traits in a few European early modern humans; however, this is not the case 






In short, European populations may reflect both their predominant African early modern human ancestry and a substantial degree of admixture between those early modern humans and the indigenous European Neanderthals


According to Trinkaus (2007), given the tens of thousands of years since then and the limitations inherent in ancient DNA, this process is largely invisible in the molecular mtDNA record. However, it is still highly apparent in the paleontological record . Others still, believe that Europeans may have simply evolved from an ancestral Neanderthal form, in situ


Ovchinnikov, I. V., A. Götherström, G. P. Romanova, V. M. Kharttonov, K. Lidén, and W. Goodwin (2000). Molecular analysis of Neanderthal DNA from the northern Caucasus. Nature, 404:490-
Trinkaus T. (2007). European early modern humans and the fate of the Neandertals. PNAS _ May 1, 2007vol. 104 no. 18 7367–7372



EVOLUTION OR INTERBREEDING?













2 comments:

  1. I've got Asperger's syndrome, which many authorities think is caused by a Neanderthal throwback gene. Since AS only affects people of European heritage like myself, this would tend to agree with the hypothesis.

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  2. awsome post respect from brother louis in the uk

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