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17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
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Frogs Not Croaking Quite Yet
12 May 2004 (All day)
How great is the threat of climate change to biodiversity? Recent estimates based on computer modeling predict that one-third of all species could be driven extinct by 2050 (ScienceNOW, 7 January). But this approach ignores the possibility that species may evolve rapidly in response to a changing climate. Now there's some of the first concrete evidence that animals can rapidly evolve when the mercury's rising.
Yale ecologist David Skelly and colleagues studied how wood frogs in northeast Connecticut have responded to over 30 years of local climate change. In some areas, beavers have felled the trees that shade ponds. Other ponds have become shadier because people planted trees around them.
The group took a total of 150 tadpoles from ponds with various amounts of tree cover, then examined them in the lab for a suite of traits. The checklist included how well they tolerate high heat, how fast they develop at a given temperature, and what temperatures they prefer. The environment makes a big difference: For example, eggs taken from shady, cooler ponds produce tadpoles that develop faster than tadpoles from warmer ponds. They also actively seek warmer water, the team reports in the May issue of Ecology Letters.
These patterns show that frogs--often considered to be "coal-mine canaries"--can rapidly evolve new behaviors over short periods, says Skelly. He's quick to add that this doesn't imply that climate change is not a concern. But the finding highlights the importance of determining which species can rapidly adapt and under what conditions they can do it, to get a more realistic picture of the effects of climate change and to target ecological efforts more effectively.
Evolutionary ecologist Andrew Hendry of McGill University in Montreal, Canada, agrees that ignoring evolution may inflate estimates of extinction rates caused by climate change. ”But even though some populations seem able to adapt to climate change, this does not mean that evolution will save all species,” he says.