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.