Climate Change and Mountain Building Led to Mammal Diversity Patterns

marco_polo

Interesting research that combines paleontology and biogeography to explain patterns of mammal bio diversity, accounting for the influence of both climate change and topography, during the Miocene period.

http://www.sciencedaily.com/releases/2010/05/100505163236.htm

The prevailing notion has been that diversity is greater in mountainous regions than in lowlands simply because the topography is more complex. As mountains rise up, new habitats are created, and areas that once were continuous become fragmented. Such changes offer opportunities for new species to arise, increasing diversity.

But climate also enters in, the new study shows. During the Miocene, long-term, global cooling was interrupted by warm intervals. In the active region, diversity increased during a warm interval from 17 to 14 million years ago that coincided with intensified mountain building and volcanic activity, the analysis revealed. During subsequent cooling, diversity declined in the mountains and increased on the plains.

"This pattern suggests that the elevational diversity gradient arises during historical episodes associated with global warming and mountain building," said Badgley, an assistant professor in the Department of Ecology and Evolutionary Biology and a research scientist in the Museum of Paleontology and the Department of Geological Sciences. "This gradient is not a long-term feature of North American biodiversity."