Tuesday, September 4, 2018

Neanderthals R Us...this season, at least




"Decoding Neanderthals" is a fascinating documentary about the latest research on Neanderthals. It seems the consensus on these problematic creatures changes every other decade or so, in an almost pendulum-like fashion. When I was a kid, Neanderthals were considered a subspecies of Homo sapiens. There was even a French animated comic which depicted Neanderthals as identical to "real" humans. Then the pendulum swung in the other direction, and suddenly the Neanderthals became a separate species of slightly dull evolutionary cousins who didn't quite make it through. They were absolutely not our ancestors, and their DNA wasn't like ours, either.

Now, the pendulum has swung in the other direction again! Are we to believe "Decoding Neanderthals", these paleo-brutes (who are said to have the mother of all image problems) were closely related to our own species, so closely that they could interbreed with us and produce fertile offspring. I admit I was stunned. I must have missed this piece of sensational science news somewhere in between Justin Bieber's and Britney Spears' latest exploits...

The documentary further claims that Neanderthals were more intelligent than previously imagined, and had a symbolic culture. They could produce glue through an artificial, "industrial" process (rather than just gather natural glue from, say, trees). Neanderthals also used red paint on their bodies, might have used feathers for decoration, and buried their dead. Genetic research shows that these supposedly primitive hominins had the same gene for language skills as modern humans. I wonder how long before the old speculations about a "cave bear cult" is dusted off and reused?

But, as mentioned, the most sensational new piece of evidence is that Neanderthals interbred with Homo sapiens. Researchers have found that Africans have almost no Neanderthal DNA, Asians have somewhat more and Europeans have the most. In Europe, there is a concentration of Neanderthal DNA in Tuscany (an area of Italy). It seems our species interbred with Neanderthals after leaving Africa and migrating to Asia. The number of Neanderthal genes in European DNA is about 3%. It should be noted that this doesn't disprove the African origins of Homo sapiens. Rather, it shows that Neanderthals must have *been* Homo sapiens, presumably an early and specially adapted subspecies. This is not sufficiently emphasized in the documentary.

That being said, it seems Homo sapiens neanderthalensis has been rehabilitated as part of the extended human family, and successfully solved its image problems.
At least until the pendulum swings back again...

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