Domestication works faster than we thought
Fascinating article on experiments in domestication (and on the opposite: making successive generations more aggressive). I knew from Jared Diamond’s Guns, Germs, and Steel that zebras have proved impossible to domesticate (in zoos, zebras cause more keeper deaths and injuries than, for example, lions), but it seems that we just haven’t really tried. What is quite surprising are the changes in coloration as animals become domesticated.
Dimitri Belyaev in 1984 with some of the tame silver foxes he bred in
just a few generations (Image: Ria Novosti / Science Photo Library)
I think the guy missed a bet in not selling the domesticated silver foxes as pets. The article, by Henry Nicholls in New Scientist, begins:
In 2003, while geneticist Svante Pääbo was visiting Novosibirsk, Russia’s third-largest city, he decided to look in on a famous experiment run by the Institute of Cytology and Genetics, which is based in the city. Fifty years ago, the then head of the IC&G, geneticist Dmitry Belyaev, had begun breeding silver foxes to see how easily they could be tamed. What Pääbo didn’t know, though, is that Belyaev had also set up another experiment in the 1970s involving rats. This time, one line of rats was selected for tameness and another selected for aggression.
When Pääbo saw them, he was stunned. After just 30 years of selection, the IC&G researchers had fashioned two populations that could hardly be more different. “I could take the tame ones out of the cage with my bare hands. They would creep under my shirt and seemed to actually seek and enjoy contact,” recalls Pääbo. “The aggressive animals were so aggressive I got the feeling that 10 or 20 of them would probably kill me if they got out of the cages.”
Here was a great opportunity to uncover the genetic changes responsible for the behavioural differences, Pääbo realised. Back at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, Pääbo and his team have been trying to do just this. If they succeed, their findings could have far-reaching consequences.
The zebra, for instance, is a stubborn beast, one that has thwarted all efforts to domesticate it, as have the cheetah, the African buffalo and the rhinoceros. Understanding the genetic basis of tameness might make it possible to domesticate the undomesticatable and turn exotic species into farm animals or even pets. It could also help us understand what makes some people overly aggressive – and perhaps even lead to treatments for behavioural disorders.
Most domesticated mammals are really rather different from their wild ancestors: they often have a radically different body shape, frequently sport unusual fur patterns or markings, and it is not uncommon for them to be able to breed all year round. Surely it must have taken many, many generations for all these differences to accumulate?
Charles Darwin certainly thought so, suggesting the process of domestication was “insensibly slow”. But Belyaev thought otherwise. He proposed that many of the features typical of domesticates arose because our distant human ancestors made their initial selection of wild animals on the basis of just one, rather practical characteristic: tameness. If this were the case, domestication was not only simple, it might also have taken far fewer generations than imagined…
Continue reading. It’s a fascinating article.
