Hi Carl:
No word on that yet. They identified regions of the genome where there are (1) deep gene trees in Europe and/or Asia, (2) we share variants with Neanderthals, and (3) these shared variants are absent in Africa, and they found a lot of them. But if some variants in Neanderthals were positively selected in humans very early on then they would have spread through all humanity, and no one has scanned for those yet.
Our favorite candidate is the famous FOXP2 region, without which one has no speech. Every human has it, and the diversity hear it on the chromosome suggests that it is 42,000 years old in humans. Neanderthals have the human version (so far), so a likely scenario is that we stole it from Neanderthals.
HCH
Very nice summary—thanks.
@SilasBarta:re our careers:
I would certainly never encourage a graduate student to follow up in this area because it would be a career kiss of death. But I am at retirement age, no one is going to fire me, and most important of all I do not have federal grant support. Cochran is not an academic: his real career is in laser physics. So we enjoy a kind of freedom that few academics do.
@JanetK re skin color:
According to standard ag-sci 101 theory the number of loci makes no difference at all to the speed of change of a multi-locus trait. Six is close enough to infinity that skin color should change no faster than, say, IQ. OTOH you may be right in the real world because of the complexities of epistasis of loci.