Re: Attn: Wildlife Biologists

From: Rin Watt <katecwatt_at_gmail.com_at_hypermail.org>
Date: Mon, 16 Mar 2009 14:37:24 -0000

from In the Blink of an Eye, by Bob Holmes

... One of the best places to see evolution in action is high in the Rocky Mountains of Alberta, Canada, home of the largest bighorn sheep in North America. Hunters can pay six-figure sums for the right to shoot a big ram, the massive, curling horns of which make it the continent's most highly prized hunting trophy. On one peak, aptly named Ram Mountain, hunting has been so intense that rams can expect to live only a year or two after their horns reach the almost-360-degree curl that makes them a legal target for hunters. Not surprisingly, this has led to intense selection in favour of males whose horns never grow to reach trophy status.
Sure enough, a study led by Dave Coltman, now at the University of Alberta in Edmonton, found that average horn size has declined by about 25 per cent over the past 30 years (Nature, vol 426, p 655). And the genetic erosion doesn't end there because larger-horned rams tend to have better genes in general. "You start taking out the prime-quality rams and the next generation will be missing those genes, because their fathers will be lower quality," says Coltman. In other words, every time they pull the trigger, hungers are working against their own long-term interests. "Its a form of artificial selection where instead of getting more of what you want you're actually going to end up with less," he says. ....
Received on 2009-03-16 07:37:29