"For salmon trying to make it upriver to spawn before a hot summer hits, slow and steady loses the evolutionary race. Salmon DNA records stretching back over 30 years show that nature has increasingly selected for fish that migrate from the ocean earlier in the year. It is among the first pieces of genetic evidence that climate change is driving the evolution of a species."

"Many species have changed their migration patterns over the past few decades in response to warmer temperatures. What is difficult to tell is whether the species are changing their behaviour or evolving genetically – or both."

Sara Reardon reports for New Scientist July 11, 2012. [2]