Pritchard’s list of selected genes also includes five that affect skin color. The selected versions of the genes occur solely in Europeans and are presumably responsible for pale skin. Anthropologists have generally assumed that the first modern humans to arrive in Europe some 45,000 years ago had the dark skin of their African origins, but soon acquired the paler skin needed to admit sunlight for vitamin D synthesis.
The finding of five skin genes selected 6,600 years ago could imply that Europeans acquired their pale skin much more recently. Or, the selected genes may have been a reinforcement of a process established earlier, Dr. Pritchard said.
It’s hard to imagine that classic natural selection – the survival of the fittest – would be responsible for such rapid evolution: just a few thousand years. I suppose it’s possible, but it would surely have to involve mutations which provide significant survival advantage, which would tend to rule out the usual suspects like being able to produce more vitamin D with pale skin. So perhaps sexual selection is involved here – which would tie in nicely with the recent speculation about blondes in Northern Europe.
Also, the possibilty that evolution continued long after the migration out of Africa, and after the distinctions between races had evolved, suggests that Steven Pinker’s answer to the Edge Annual Question (what is your dangerous idea?), that groups of people may differ genetically in their average talents and temperaments, might have been prescient.
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