— “We aren’t the same as people even 1,000 or 2,000 years ago,†he says, which may explain, for example, part of the difference between Viking invaders and their peaceful Swedish descendants. “The dogma has been these are cultural fluctuations, but almost any temperament trait you look at is under strong genetic influence.â€
— “Human races are evolving away from each other,†Harpending says. “Genes are evolving fast in Europe, Asia and Africa, but almost all of these are unique to their continent of origin. We are getting less alike, not merging into a single, mixed humanity.†He says that is happening because humans dispersed from Africa to other regions 40,000 years ago, “and there has not been much flow of genes between the regions since then.â€
[…]
in China and most of Africa, few people can digest fresh milk into adulthood. Yet in Sweden and Denmark, the gene that makes the milk-digesting enzyme lactase remains active, so “almost everyone can drink fresh milk,†explaining why dairying is more common in Europe than in the Mediterranean and Africa, Harpending says.He now is studying if the mutation that allowed lactose tolerance spurred some of history’s great population expansions, including when speakers of Indo-European languages settled all the way from northwest India and central Asia through Persia and across Europe 4,000 to 5,000 years ago. He suspects milk drinking gave lactose-tolerant Indo-European speakers more energy, allowing them to conquer a large area.
But Harpending believes the speedup in human evolution “is a temporary state of affairs because of our new environments since the dispersal of modern humans 40,000 years ago and especially since the invention of agriculture 12,000 years ago. That changed our diet and changed our social systems. If you suddenly take hunter-gatherers and give them a diet of corn, they frequently get diabetes. We’re still adapting to that. Several new genes we see spreading through the population are involved with helping us prosper with high-carbohydrate diet.â€
(via physorg.com)


