Tuesday, July 25, 2006

Nice or Nasty

I am absolutely blown away by an article in the NY Times today. It's titled "Nice Rats, Nasty Rats: Maybe It’s All in the Genes," and it obliterates all kinds of conventional wisdom about animal domestication.

Here's an excerpt:
Belyaev decided to study the genetics of domestication, a problem to which Darwin gave deep attention. Domesticated animals differ in many ways from their wild counterparts, and it has never been clear just which qualities were selected for by the Neolithic farmers who developed most major farm species some 10,000 years ago.

Belyaev’s hypothesis was that all domesticated species had been selected for a single criterion: tameness. This quality, in his view, had dragged along with it most of the other features that distinguish domestic animals from their wild forebears, like droopy ears, patches of white in the fur and changes in skull shape.

Belyaev chose to test his theory on the silver fox, a variant of the common red fox, because it is a social animal and is related to the dog. Though fur farmers had kept silver foxes for about 50 years, the foxes remained quite wild. Belyaev began his experiment in 1959 with 130 farm-bred silver foxes, using their tolerance of human contact as the sole criterion for choosing the parents of the next generation.


“The audacity of this experiment is difficult to overestimate,” Dr. Fitch has written. “The selection process on dogs, horses, cattle or other species had occurred, mostly unconsciously, over thousands of years, and the idea that Belyaev’s experiment might succeed in a human lifetime must have seemed bold indeed.”

In fact, after only eight generations, foxes that would tolerate human presence became common in Belyaev’s stock. Belyaev died in 1985, but his experiment was continued by his successor, Lyudmila N. Trut. The experiment did not become widely known outside Russia until 1999, when Dr. Trut published an article in American Scientist. She reported that after 40 years of the experiment, and the breeding of 45,000 foxes, a group of animals had emerged that were as tame and as eager to please as a dog.


As Belyaev had predicted, other changes appeared along with the tameness, even though they had not been selected for. The tame silver foxes had begun to show white patches on their fur, floppy ears, rolled tails and smaller skulls.

It is a widely-held belief that all animals we could domesticate have been domesticated. I won't go into the details of why this is so (I honestly can't remember all the detail), but there are far-ranging implications if this belief is disproven.

Here's the link to the full article (registration required).

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