An Evolutionary Anectdote

[ed_rex]

"D.K. Belyaev and his colleagues took captive silver foxes, Vulpes vulpes, and set out systematically to breed for tameness. They succeeded, dramatically. By mating together the tamest individuals of each generation, Belyaev had, within 20 years, produced foxes that behaved like border collies, actively seeking human company and wagging their tails when approached. That is not very surprising, although the speed with which it happened may be. Less expected were the by-products of selection for tameness. These genetically tamed foxes not only behaved like collies, they looked like collies. They grew black-and-white coats, with the white face patches and muzzles. Instead of the characteristic pricked ears of a wild fox, they developed 'lovable' floppy ears. Their reproductive hormone balance changed, and they assumed the habit of breeding all the year round instead of in a breeding season. Probably associated with the lowered aggression, they were found to contain higher levels of the neurally active chemical serotonin. It took only 20 years to turn foxes into 'dogs' by artificial selection."

- Richard Dawkins, The Ancestor's Tale