April 07, 2007

Tianyuan Cave

I'm surprised that the news from Tianyuan Cave didn't create more of a stir:

According to the "Out of Africa" theory, modern humans (Homo sapiens) evolved in East Africa and then spread out across the globe about 70,000 years ago, replacing earlier, or archaic, human populations, such as the Neanderthals, with very little, if any, interbreeding.

The Tianyuan remains display diagnostic features of modern H. sapiens. But co-author Erik Trinkaus and his colleagues argue, controversially, that the bones also display features characteristic of earlier human species, such as relatively large front teeth.

The most likely explanation, they argue, is interbreeding between early modern humans emerging from Africa and the archaic populations they encountered in Europe and Asia.

"The pattern we see across the Old World is basically a modern human in terms of its newly emerged characteristics, but also a minority of traits that are absent or lost in the earliest modern humans in East Africa," Professor Trinkaus told the BBC News website.

"The question is where did they get them from? Either they re-evolved them, which is not very likely, or, to some degree, they interbred with archaic groups.

"Sex happens. I find this neither disturbing nor surprising."

I think most genetic evidence--and I stress here that I'm relying on popular accounts of the work of scientists like, for example, this one--seems to argue that sex didn't happen, at least not between Neanderthals and our ancestors, but the idea that in us there lives some faint echo of the former is one that has always appealed to me.

Posted by Ideofact at April 7, 2007 01:03 AM