John Hawks, reviews Henn et al., and notes:
By the time we find "modern" humans in West Asia, the African population had long since diversified into regional populations. This is not news; the mtDNA evidence has suggested for several years that southern Africa and the remainder of sub-Saharan Africa were already regionally differentiated before 120,000 years ago. There have also been hints of this diversification from whole-genome evidence (including the supplement of the Neandertal genome paper last year). Here we have a clear indication that the regionality extends to every African hunter-gatherer population.
For more than a generation we've stated the conventional wisdom that Africa has more genetic diversity than the rest of the world. And yet far too often we've left it at that. With the bigger data set of Henn et al. you can get a sense that there's a fair amount of structured variation within Africa which is very interesting. It is not one amorphous undifferentiated Dark Continent. Sarah Tishkoff's recent work has been very informative in this domain, but I'm looking for what we might find out of whole genome sequencing in particular.