Sun May 1, 2011

The Neanderthal in Us All

Things of the past have KUNC commentator Dr. Marc Ringel thinking about the things in his life that lie ahead.

I can’t tell you how many times I set out to read “The Hobbit” but gave up before finishing.  Once I even got through two-thirds of the book before I came to the same inevitable conclusion that I didn’t really give a rip about these hairy little creatures.

I had a similar response to Jean Auel’s Earth Children novels about the Neanderthals.  I read a significant portion of Clan of the Cave Bear, the first fat book of a series that has now extended to six.  For me the only difference between Tolkein’s and Auel’s characters was that in the latter case, they were hairy big creatures that I didn’t give a rip about.

Recently researchers have been reconsidering the hypothesis that reigned at the time Ms. Auel began writing her well-researched tomes.  It was assumed previously that Cro-Magnons were simply too smart and culturally sophisticated for Neanderthals.

Neanderthals, whose brain cases are actually larger than those of modern humans, left behind an arsenal of tools and sophisticated artwork that rival the early Cro-Magnons.  And the older specie was inventive enough to have survived about 200,000 years of rapidly fluctuating climate conditions, marked by glaciers that advanced and retreated over their homelands in Europe.

But the archeological record is clear.  There are no Neanderthal remains younger than 28,000 years old, which is about when Cro-Magnons started leaving ample evidence of their habitation of the territory once held by their bigger, heavy-browed neighbors on the evolutionary tree.

What then, if it wasn’t physical, intellectual or cultural inferiority, could have led to the rapid extinction of the Neanderthal specie?  A recent conjecture is that it was a virus that did in the ancestors of the Clan of the Cave Bear.

Neanderthals, like all human and pre-human species, originated in Africa.   Over the course of 200 millennia of European residence, the Neanderthals’ immune system learned to live with the bacteria, viruses and parasites with which it shared the continent.

Then along came the Cro-Magnons, a new wave of African immigrants.  These newcomers brought with them their tools, their culture and their microscopic fellow travelers.  It’s hypothesized that at least one of the Cro-Magnon bugs, which was completely foreign to the Neanderthal immune system, proved fatal to the whole specie.

To find a modern example of this phenomenon we need look no further than the devastating effect that smallpox and other European diseases had on Native American populations when they first encountered white folks.  Infections claimed many, many more native lives than did European soldiers and their guns.

Why then did Cro-Magnon bugs wipe out Neanderthals and not vice versa?  Because in tropical Africa, where the Cro-Magnons originated, there are plenty of primates whose genome is similar enough to humans’ to pose a low hurdle to a bug that wants to jump species.

Most new human infectious diseases appear to come from other animals.  In recent times HIV, the virus that causes AIDS, probably got its start in Africa in non-human primates.

The reasoning goes that over the course of millennia in Africa, Cro-Magnons learned to live with a host of infective agents that they shared with primates.  One or more of these bugs that hitched a ride with Cro-Magnons who emigrated from Africa proved fatal to Neanderthals.

As I contemplate these ancient ancestors and the approaching marriage of our son this summer I find myself thankful that the wedding party will consist solely of homo sapiens, which greatly simplifies decisions about what sorts of clothes will best flatter everybody.  And I really do give a rip about these particular medium-size, not-so-hairy hominids who I hope before long will produce more of our own species…not Neanderthals, not Cro-Magnons, and especially not Hobbits.

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