Sunday, October 18, 2015

An Early Date for Prehistoric China-men

From Dienekes' Blog: Modern humans in China ~80,000 years ago (?)
Another (?)-worthy paper has just appeared in Nature in the heels of the African ancient genome paper. Time will tell how these worldview-altering discoveries will change the story of Mankind, and a degree of skepticism is warranted. In the view I've held for a few years, modern humans expanded to Arabia before 100 thousand years ago, started leaving it 70 thousand years ago as the ecological situation worsened due to desertification and broke through the "Neandertal barrier" between 70-50 thousand years ago when they developed the skills and technology to overcome them.

The new paper claims that modern humans were in China 80 thousand years ago and came to Europe much later because Neandertal represented a barrier to successful entry to Europe. This begs the question of how they reached China without encountering Neandertals, as Neandertals were also in West Asia where -presumably- they passed through to get to China. A coastal route to south China would explain away this problem, but the coastal migration is usually envisioned much later, at around 60 thousand years ago. On top of that, how did Chinese end up having equal (or more) levels of Neandertals admixture if modern humans first went to China and later moved west and successfully outcompeted the Neandertals. How were they able to do so eventually? (There is no evidence that the kind of advantages associated with behavioral modernity first emerged in East Asia). It's possible that there were 80 thousand year-old modern humans in China (just as there were 100 thousand year-old modern humans in Israel), but that the later East Asians are not descended from them.
A moderately interesting wrinkle in the story of human evolution and expansion out of Africa. I'm not really accustomed to thinking of Neandertal as a barrier to modern human expansion. By all accounts I've seen, they were not particularly abundant even at the height of their era, and they folded pretty fast in the face of us "moderns". They were lucky to have some fraction of the genome survive by a certain amount of interbreeding (and perhaps even more to the point, the successful integration of the neandertal-modern hybrids into the moderns societies.

Wombat-socho has "Rule 5 Sunday: Pre-Halloween Pinups" up at The Other McCain.

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