Razib Khan One-stop-shopping for all of my content

July 6, 2011

Is Chris Stringer a multi-regionalist?

In an interesting piece in The Guardian on possible proto-gorilla/proto-human hybridization, the journalist lobs this grenade:

But now that the once popular “single-origin model” of the evolution of Homo sapiens has been disproved, and the previously controversial “multiregional hypothesis” has been proven by DNA evidence, perhaps we need a rethink. According to the multiregional hypothesis all modern people, including modern Africans, are the descendents of breeding and hybridising between separate ancestral groups, all at various stages of evolutionary development.

Evolutionary lice research has helped palaeoanthropologists, including Stringer, to embrace the multi-regional hypothesis. “I’m sure there is plenty more to come from the lice research,” he told me. We know that it took 4m years, 5-9m years ago, for our ancestors to completely split from archaic chimps. During that time hybrids would have been born that mated both with our ancestors and ancestral chimps.

The issue here is semantics. I think regular readers of this weblog will know to be more cautious than to contend that the “single-origin model” of our species has been “disproved,” while its inverse has been “proven.” Those are strong words in science. Additionally, I seriously doubt that Chris Stringer would identify as a multi-regionalist. Some wires ...

January 28, 2011

A ‘leaky’ model

John Farrell pointed me to this Anne Gibbons’ piece, A New View Of the Birth of Homo sapiens. Here’s some interesting passages:

The new picture most resembles so-called assimilation models, which got relatively little attention over the years. “This means so much,” says Fred Smith of Illinois State University in Normal, who proposed such a model. “I just thought ‘Hallelujah! No matter what anybody else says, I was as close to correct as anybody.’ ”

But the genomic data don’t prove the classic multiregionalism model correct either. They suggest only a small amount of interbreeding, presumably at the margins where invading moderns met archaic groups that were the worldwide descendants of H. erectus, the human ancestor that left Africa 1.8 million years ago. “I have lately taken to talking about the best model as replacement with hybridization, … [or] ‘leaky replacement,’ ” says paleogeneticist Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, lead author of the two nuclear genome studies.

I suppose ‘assimilation’ sounds too generic, but ‘leaky replacement’ seems more fitting for a building ‘super’. But it isn’t as if paleoanthropology has a Don Draper, a rogue with a way with words.

Here’s the ...

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