Over at my other weblog there is a post titled Reconstructing human origins in the genomic era, a commentary on a review paper in Nature. Here are the two bullet points I want to highlight:
- These genome-scale patterns could be best accounted for by models that involve low levels of gene flow among archaic populations before the emergence of anatomically modern humans - that is, they imply the existence of ancestral population structure.
- There is also growing evidence that some highly divergent genetic lineages might have entered our genome through hybridization between an expanding anatomically modern human population and archaic forms of humans.
Over the past year I've been talking up hybridization. Some people have expressed exasperated skepticism. After all, the consensus is Out of Africa, total replacement, right? Well, I have posted links to papers which suggest introgression before, but I want people to remember that Richard Dawkins pointed to a introgression/admixture model with a dominant African element in The Ancestor's Tale last year. Dawkins might not be a pioneering scientist in his own right, but he is someone with "sources," and it is important to see where he leans to get a sense of the direction of evolutionary science. This review paper/commentary in Nature is contingent upon the fact that I'm sure that these two individuals have access to prepress papers and research gleanings that will be more prominent within the next 6 months (keep reading Nick Wade in The New York Times).
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The paper mentionned that traces of approximately 5% admixture have been suggested/detected in europeans and west-africans.
I suppose the europeans would have mixed with neanderthals . Might they have also mixed with previously unknown pockets of erectines during the roamings in the quite vastlands of central asia ?
Who might the ancestors of the west-africans have mixed with ? African erectines ?
Do you think we'll be able to answer these questions soon or is it a bit early ?
Might they have also mixed with previously unknown pockets of erectines during the roamings in the quite vastlands of central asia ?
yes. though neandertals were extant into central asia, and possibly there were pockets even in china.
Who might the ancestors of the west-africans have mixed with ? African erectines ?
yes. though the issue there might be is that there might be ancient substructure within africa itself that wasn't eliminated. the standard 'out of africa' narrative is that a small group of africans (e.g., 100-10,000) expanded and replaced all other humans, including other hominins in africa contemporaneously. the new model would be that a small group did expand, but it absorbed genomic material from surrounding populations while predominantly replacing them.
Do you think we'll be able to answer these questions soon or is it a bit early ?
directly proportional to the rate of growth of data due to genomics. so, sooner than later.
I was reading through this paper over the weekend...
I was going to blog about it, but you beat me! (I actually used to work for one of the authors' in undergrad)