Evolution faster in tropics than cooler regions
Monday, July 27, 2009 10:24:55 PM by IANS

Sydney, July 28 (IANS) Mammals living in the tropics are evolving faster than those inhabiting cooler regions, according to a new study.

Previously, it had been assumed that rates of genetic change in warm-blooded animals were independent of climate.

The new study demonstrates that DNA evolution occurs substantially faster in mammal

species living in warmer environments, relative to those living in cooler environments.

The study was led by Auckland University of Technology (AUT) evolutionary biologist Len Gillman and colleagues.

Gillman says that over prolonged evolutionary periods, this difference in evolutionary rate might account for the enormous accumulation of biodiversity in warmer areas like the tropics.

“The results show that species occupying warmer climates have almost 50 percent more

DNA evolution relative to those in cooler climates,” he said.

“These results come from pairs of species generally living in close proximity to each other so we would expect the effect to be far more pronounced over continental and global scales,” he said.

The study, which is the largest of its kind, involved a comprehensive global data set that included 260 mammal species, from 10 orders and 29 families.

These findings have been published in the Royal Society’s biological research journal Proceedings B.