Sunday, August 18, 2013

Ergaster's Childern

(Picture from here.)

When I first moved up here to Massachusetts I did what I always do, I went to the science museum. There was an exhibit of the cave paintings. The docent talked about them and said (as close as I remember): "Who were these wonderful artists? It certainly wasn't these folks. They just weren't capable." With that he brandished a Neanderthal skull.

That ticked me off. First, because the cave paintings were made long after the Neanderthals had died out. So, while it's true they didn't do the work, since they were already dead it was a meaningless point. Second, it was a snide way at taking a whack at Neanderthals as brutes-- an odd sort of racism. Translated: "They weren't us so they couldn't have done this."

It's not an accident that my first published story, "A Capella", is about a Neanderthal cave artist.

Nothing sparks discussion like the Neanderthals. Were they brutes? Were they not so brutes? Clearly, we succeeded when they failed. How did we do that? Or, translated, in what way were we preternaturally superior to them? After all: we're here. They're not. We must be better.

There have been lots of hypotheses on the Neanderthal demise-- most of which involve some sort of compare/contrast relationship with competing humans. They had bigger brains than ours so that had to be addressed-- and it has, a few times. One study suggests that their brain organization is substantially different than ours. Neanderthals have a larger visual system than that of modern humans and that reduced the available space for cognitive systems. Another one implicated bunnies in their demise-- or, rather, their inability to catch them. Modern humans will eat anything: bunnies, squirrels, birds, each other. The Bunny Hypothesis suggests that Neanderthals did not have the capacity to be this flexible.

As time has gone on the differences in capability between Neanderthals and modern humans has diminished.

Do Neanderthals have complex tools? Check. There's one tool-- a lissoir-- was invented by Neanderthals before the tool was used by modern humans. In fact, there's a distinct possibility that humans learned about the tool from Neanderthals. Did Neanderthals have art and culture? Check, check, check and check. Neanderthals buried their dead with ornamentation, wore jewelry and make up. Did Neanderthals eat things other than big mammals? (I.e., the Bunny Hypothesis.) Check. Neanderthals ate fish and birds, processed wood and hides and ate their vegetables. They may also have understood that some plants had medicinal values. (See here.) Now that's pretty sophisticated.

It's not clear that they ate or didn't eat bunnies. It's also not so clear from what I've read how much small game there was to eat or when modern humans learned to catch it. Paleo-Indians subsisted largely on now extinct mega-fauna: giant beaver, ox, mammoths, etc. Not much different from Neanderthals.

A good deal of new information has been showing up since the Neanderthal genome was fully sequenced. Interbreeding between Neanderthals and modern humans has become pretty definitive now-- to the point a hybrid may have been found. (See here.)

A problem with understanding Neanderthals comes from mis-connecting our own tribe with Neanderthals. For one reason or another, Neanderthals have become defined by their opposition to human beings. There are differences between Neanderthals and modern humans. Possibly the ocular system as mentioned above. The olfactory neurological system in modern humans is 12% greater in size than in Neanderthals. (Which, of course, could not reflect any cognitive deficit comparing modern humans to Neanderthals. Right? Right?)

To me, the most interesting news that is coming out regarding Neanderthals is that they may have largely died out long before they met humans. There was little or no competition between the two groups, though there was enough encounters for interbreeding.

New radio carbon dating techniques (see here) make the time overlap between modern humans and Neanderthals problematic. This is interestingly corroborated with some DNA evidence (see here and here) suggesting that Neanderthal populations may have crashed prior to modern humans came to Europe. In fact, it may have been the sheer dumb luck of timing that a population of modern humans didn't buy the farm right alongside Neanderthals.

There's this concept of refugia in ecology. A refugia is a place of relative calmness when everything else is crashing down-- usually because of either local or global climate change. When the femets hit the windmill a hundred thousand years ago during the Last Glacial Maximum, modern humans hadn't moved north. Their refugia were safer than those of Neanderthals so much farther north. (See here and here.)

Neither group could protect the future. Things were going downhill-- I suspect both groups knew it. They both went where it looked like things could remain if not okay, at least survivable. But the range of choices between the two groups was different. Neanderthals got nailed. Modern humans fared better. When modern humans finally did get to Eurasia the remaining Neanderthal and Denisovan groups were tiny.

As they say, it's better to be lucky than smart.

Which brings us to the question of how did humans really evolve? Annalee Newitz suggests its a crooked, branching road that brought us to now, filled with little groups (such as the hobbits) that didn't quite make it to modern times.

There may even be a new addition to our ranks, the Red Deer People of southwest China. The find there dates to between 14,500 to 11,500 years ago and the skeletons show an intriguing mix of modern and primitive human qualities. Too soon to tell anything about them. But they did clearly overlap humans in time. Were they a relic population of humans? Were they a different sub-species, as were Denisovans or Neanderthals? Were they a completely different species such as Homo floresiensis? We don't know yet.

I wonder sometimes if our continuing defining of other species, even those related to ourselves, only in opposition to what we consider human is a relic of our essential loneliness.

Homo ergaster is the founding species of us all, the more sophisticated descendant of Homo habilis. From habilis came the rest of us, ergaster's children, of which only we, of mixed heritage, remain.

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