Race to the finish:
It used to be so simple. There was a program I saw once that showed an enthusiastic young man aided by a docile crowd showing how we all came out of Africa and then spread north, east and west until the last ripple of pre-historic folk settled Tierra del Fuego. All divisions amongst people were purely cosmetic. Some sixty thousand years ago we were essentially all sitting around the same campfire, one big extended family. So of course since it was television I believed it and that ended it.
Some racial theorists have suggested that people have occurred in “races.” I don’t buy the category, but there it is. I was simply uneasy about the concept until I realized something. “Race” pretty much means skin color. There were white Europeans (who look rather red to me). There were red American Indians (who look rather tan to me). There were yellow Asians (who don’t look yellow at all to me unless they have hepatitis, which apparently is quite common among them). And there were black Africans (who appear to me to range from tan to dark to so dark they look bluish; it’s something to do with the way melanin – the usual brown skin pigment – scatters light. Blue eyes are blue because of the same melanin that makes brown eyes brown.). All right. That’s four colors. The ancient Greeks recognized four humors, which were supposed to make us what we are. I think they referred to hair color. There was yellow bile, which made people irascible and must have referred to the yellow haired and pugnacious Teutonic folk to the north. There was black bile, which made people depressed and helpless, which probably referred to the Persians with whom the Greeks had wars. There was blood, which probably referred to the Greeks themselves; their statues contain traces of red paint in the hair. Blood makes you cheerful and active. And there was white phlegm, which would be old people, and since they tended to own the jelly beans white was good in a quiet sort of way. So race was just a combination of inaccurate physiology and politics.
The first modern humans were thought to date back maybe a hundred thousand years. That has now gone to a couple hundred thousand. The question was what became of the Neanderthal people who preceded us. They went back to, oh I don’t know, maybe 600 thousand years ago. They did quite well until modern people showed up and then the Neanderthals vanished. Kind of makes you suspicious, I should think.
There used to be debates about whether Neanderthals contributed anything to the modern human genome. So far as I could follow it the no-contribution folks were wining until they managed to decipher the Neanderthal gnome. It turns out that some 2% of the genetic material in humans in most of the world is actually Neanderthal. The exception is Africa, where apparently there never were Neanderthals. Well 2% isn’t much, is it? It’s just a curiosity, a relic of ancient times.
The Neanderthal stronghold extended from the Mid East through Europe and western Asia and they were last seen in Europe. That struck me as odd. There are a couple or three things that are distinctively European: long head, robust build and red hair. They also treat women rather well compared with the rest of the world. I thought this all might mean that Europeans carried more Neanderthal genes than others did, but this proves not to be true. Outside Africa that 2% seems like a constant everywhere outside Africa. So to avoid believing in a coincidence I came up with the idea that Neanderthals also treated women well. For that reason people liked them. A human-Neanderthal hybrid who looked and acted like a Neanderthal, even if not because of any more Neanderthal genes, had a social advantage. In other words selection recreated the Neanderthal appearance in the presence of Neanderthals without using Neanderthal genes.
Then a clammy thought came over me. We share something like 95% of our genetic material with chimpanzees. So of the 5% of us that is distinctively human – keep me honest on this – 40% is Neanderthal. That’s so close to 50% that it would be hard to make a case that it could not be 50%. If that line of reasoning is sound, then everyone outside Africa is as much Neanderthal as “modern.” Hmm.
Somebody found a piece of a finger bone in a cave in Russia. That was enough so you could say, “Yep, it’s human all right.” It was contemporary with Neanderthals and modern humans but genetic analysis showed that it was neither Neanderthal nor modern. That line appears to persist in significant proportion in much of Asia. I dealt with this news by ignoring it. Those people were called the Denisovans. Denisovan-Neanderthal-modern people spread all the way to Australia, where the Aborigines have 6% Denisovan genetic material. That news does call into question my 40% calculation. You’ll have to let somebody else figure this out.
And now they say (sorry there are no references on any of this, but you can check it out in Wikipedia) that there is still something missing. There was at least one other group that contributed to the modern human genome.
So there are now at least four different surviving human lines, only one of which comes from Africa.
Blast! I thought it made sense. And I don’t see how it goes together at all. I would expect that the racial theorists will get back into the game sooner or later. I’m not looking forward to that.
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