Just to give people a quick update on what is going on in paleoanthropolgy at the moment. It has been a while since I told you anything. I am not any expert, but I do follow this more than most folks do. I did a series on the out-of-Africa 50,000 BCE consensus over a decade ago, and that is still strong. However, important complications have come up. Despite the evidence that language should have made a fairly quick leap to our current level just before some someones left Ethiopia at that time, after a long buildup foundation-laying of facial expression, tone, simple language and abstraction, it still isn't definitely true. Fairly advanced communication may have come in earlier.
Homo sapiens have been found out of Africa well before 50,000 BCE, and as there were other hominids close enough to us to breed with us long before that, some pieces of our ancestry are not in that group that left Africa at the traditionally-understood time. There were sapiens in West Asia in 140,000B CE and there is even a skull piece found in Greece that looks like 200,000 BCE. The Neanderthals and Denisovans extend back into that time frame and even deeper, and they were not in Africa. The Homo sapiens found in the Levant from 65,000BCE and before may have actually gone back into Africa and contributed some genetic material after have left long before, and maybe, maybe, the Neanderthals may have made their way back through the Mediterranean area and into Africa. The picture is getting more complicated.
It is important to keep in mind that whatever homo sapiens we find, in or out of Africa may not be the ancestors of any current humans. We picture the tree as leading to us in some way, a teleological approach to evolution that is an act of faith on our part, not a requirement of the process. Most hominid lines just died out, leaving nothing behind but some tools and bones, no descendants. How our ancestors outcompeted them is unknown. The Neanderthals may have been hanging by a thread anyway, and any slight advantage in our line may have been enough. Luck is also a possible explanation, Yet the Denisovans were diverse - three different strains and counting at present - and were spread over a variety of environments. Luck seems an insufficient explanation. Our thoughts go quickly to the things we think are special about ourselves - language, abstract thought, ability to cooperate, or our keen fashion sense - but disease resistance or improved digestions are just as possible. We don't know. We're here and they're not.
I may get inspired to give you some actual updated research with footnotes and recommended reading over the next month or so, as I have spent more time than usual on this recently. For now, it's just the partly-understood outline.
3 comments:
At some point you have to wonder if the genetic data points are all that solid.
When they match up with linguistic or cultural artifact changes, you can feel that they're pretty good.
But when all you have is a few finger bones and a fragment of a skull you have to worry that maybe you don't have a good handle on the dating, or even the number of varieties of hominid.
In a different field, I strongly suspect that "cosmic inflation" is a bit of magic to fill in a hole that doesn't really exist, and only seems to be there because we don't understand something else properly.
I for one will look forward to it. The story of our of Africa has changed so much since I was in school that I struggle to stay on top of it and I find it fascinating.
I eagerly await that post!
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