This is a companion discussion topic for the original entry at https://biologos.org/blogs/archive/the-evolutionary-significance-of-the-daoxian-teeth-discovery
Jim Kidder (@Jimpithecus) is available to respond to thoughtful, on-topic comments and questions about this article.
Thanks for the interesting post!
I wonder if there might be some minor corrections needed in this part:
“If the early date for Daoxian (80 kya) is correct, then there was a time
of overlap between them and populations represented by the very archaic
looking Mapa cranium, which has very large brow ridges, a large face and
a long head. Did they interbreed with them? Did they shun them? Did
they meet them at all? The sharp differences between the moderns and
their archaic cousins suggest one of the last two possibilities. If, on
the other hand, the late date is correct, then there was a time period
of about 40 thousand years in which we do not know what kinds of
interactions may have taken place.”
Perhaps you meant to use early and late oppositely to what’s written above.
Specifically, 80kya is more recent - a relatively late date - compared to 120kya.
Also, by “one of the last two possibilties” I gather you mean no interbreeding. If so, perhaps it would be clearer to write “Did they not meet them at all?” rather than “Did they meet them at all?” so the reader knows that both of the referenced possibilities (not meeting, or meeting but shunning) do not lead to interbreeding.
You are, perhaps correct. I think I meant late in the sense of later in time. Good catch.
I wonder if this could be a mistake. Even AAS Science magazine says “But some question whether the dates are accurate.” ( http://news.sciencemag.org/evolution/2015/10/first-modern-humans-china ). I have noticed that occasionally scientists will come out with some new exciting claim which is an outlier that is pretty much ignored over time. There certainly is a lot of evidence which is for one successful migration at 50 to 70 kya. However, it is interesting that the Israel sites could have been a stepping stone for a earlier, probably ultimately unsuccessful, migration. And perhaps this is wild speculation, what if behaviorally modernity started around Skhul/Qafzeh (where some of the first evidences show up) and some of those homo s. sapiens went back to Africa (where it may have more fully developed) and some of them went on to China?
The whole “behavioral modernity” is tricky because the population represented by the Skhul/Qafzeh material were, apparently using what in Europe would be described as “Middle Palaeolithic” tools. There is some supposition that the tool ratios were not the same as in the Neandertal sites but that is all. Further, the North East African material from Herto and Omo were using some roughly equivalent tools called “Middle Stone Age” (MSA). In the Levant, you don’t have modern tools until you get the Manot Cave material, at 50 kya. There was a technological transition there that lagged behind the biophysical one.
There is, among palaeoanthropologists, always the temptation to “push” things back as far as possible. “Gee, it sure would be nice if we really did have modern humans at 80-100 kya in China.” So goes the thinking. The cave layers are pretty well defined but there is always some question. There is a modern cranium floating around from the site of Liujiang that was touted as being the earliest modern in China but had rotten dates associated with it. It is now pretty much agreed that it is no older than 10-15 kya.
Interesting. Russ Ciochan thinks that the teeth are not that old but does not really say why. Even if the stalagmite comes from a different trench than the teeth, if it can be dated and its spatial relationship to the teeth can be quantified, which it seems to have been, then the dates should be fairly secure. 234U/230Th works pretty well for this time period.
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