Scientists observe 'fastest' evolution

VICTORIA, British Columbia, Aug. 4 (UPI) -- Canadian scientists say they've observed one of the fastest evolutionary responses ever while studying a fish species' ability to survive in colder water.

University of British Columbia researchers say a small fish known as the stickleback took only three years to develop a tolerance for water 5 degrees colder than what their ancestors could handle, a university release said.

Researchers transplanted marine sticklebacks, which prefer warmer water, to freshwater ponds and found that in as little as three generations -- three years -- they were able to tolerate the 5 degree F colder waters freshwater sticklebacks are happy in.

"Our study is the first to experimentally show that certain species in the wild could adapt to climate change very rapidly -- in this case, colder water temperature," study author Rowan Barrett said.

"However, this rapid adaptation is not achieved without a cost. Only rare individuals that possess the ability to tolerate rapid changes in temperature survive," he said, "and the number of survivors may not be large enough to sustain the population.

"It is crucial that knowledge of evolutionary processes is incorporated into conservation and management policy," Barrett said.