Jun 12, 2012

The Humans Who Went Extinct

There has been a lot of new information from the Paleoanthropological world of late regarding our much maligned cousins, the Neanderthals.  I have a soft spot in my heart for these guys and gals instilled by my physical anthropology undergrad past examining their generous occipital bun, small chin, large nasal opening and famous, short, sloping forehead represented in the skull casts that I used to handle.  And recently I read a fairly decent little book on our cousins entitled, The Humans Who Went Extinct: Why Neanderthals Died Out and We Survived.  The author, Clive Finlayson, is the Director of the Gibraltar Museum and adjunct professor for the University of Toronto.  Finlayson is situated in the perfect geographic region to discuss the extinction of the Neanderthals,  the caves dotting Gibraltar are the last place on Earth where the Neanderthal's lived; pushed to very edge of Europe before dying out 25,000 years ago. But pushed by what?  The recently arrived fully modern Homo sapiens?  Or a changing climate?  And why would an incredibly successful species that had been denizens of Europe for 600,000 years just fade away.
In the book the author deftly recreates the forested world in which the Neanderthals lived.  And this is where Finlayson's strength as an ecologist shows through.  He believes that the Neanderthal were a species that thrived in forested areas as ambush hunters.  This goes against the conventional picture of a singularly, cold adapted species with long body and short appendages living on the wind ravaged steppe just in sight of an encroaching glacier.  It was the open steppes, replacing the the increasingly mosaic forests, that did them in and not some Ragnarok final showdown with Homo sapiens.  This theory of Findlayson's has been validated by recent evidence published in the journal Molecular Biology and Evolution suggesting that the Neanderthal population had  a catastrophic crash 40,000 years ago probably due to climate change and slowly flickered out over the next 15,000 years holed up in isolated refuges like the one found in Gibraltar.  Another belief that Finlayson expounds upon was that Neanderthal culture and intelligence was much more complex than tradition held, based on modified shells that could have been used for decoration.  This has also been validated by the discovery of seal paintings Nerja cave in Malaga, Spain dating back to 43,000 years ago.  This is 13,000 years before Homo sapiens arrived in the same region.
Depiction of seals in Nerja Cave, Malaga Spain
What the author gets wrong in the book is his educated guess that Homo sapiens and Neanderthals did not interbreed, or if they did it was isolated and had no impact on the modern human genome.  Almost immediately after the book was published the analysis of the Neanderthal's  and the newly discovered close cousin of the Neanderthal the Denisovan's, DNA findings were released.  This rocked the paleoanthropological world (and my Anthro-armchair world)  with data that proved that modern Europeans and Asians shared 2.5 percent of their DNA with Neanderthals and that modern people from Oceania shared up to 5 percent of their DNA with the Denisovans! (The only Denisovan bone ever found was the pinky of a young girl in a cave in Siberia, crazy eh?).
Possible Neanderthal modified shells
But this is a great book for the curious soul who wants to know more about the increasingly clear picture of human origins. But the title is now incorrect because the Neanderthals never went extinct, but still exist in most of humanity's genetic makeup.

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