DAVIS, Calif., June 8 (UPI) -- U.S. researchers studying a tiny seashore creature say animals and plants may not be able to evolve their way out of the threat posed by climate change.
Scientists at the University of California, Davis, said the tide pool copepod Tigriopus californicus -- found from Alaska to Baja California -- showed little ability to evolve heat tolerance in a lab study.
"This is a question a lot of scientists have been talking about," said study co-author Eric Sanford, an associate professor of evolution and ecology at UC Davis. "Do organisms have the ability to adapt to climate change on a timescale of decades?"
UC Davis graduate student Morgan Kelly, the first author of the paper, collected copepods from eight locations between Oregon and Baja California in Mexico and grew the short-lived shrimp-like copepods in the lab for 10 generations, subjecting them to increased heat stress to select for more heat-tolerant animals, a UC Davis release reported Wednesday.
Kelly was able to coax only about 1 degree Fahrenheit of increased heat tolerance over the 10 generations, and in most groups the increase in heat tolerance had hit a plateau before that point.
Individual populations of the copepods are very isolated, the researchers said, meaning there is very little flow of new genes for evolutionary flexibility across the population as a whole.
"It's been assumed that widespread species have a lot of genetic capacity to work with, but this study shows that may not be so," said co-author Rick Grosberg, professor of evolution and ecology at UC Davis.
"The critical point is that many organisms are already at their environmental limits, and natural selection won't necessarily rescue them," Grosberg said.
