Climate change, animal diversity studied

ANN ARBOR, Mich., Sept. 24 (UPI) -- U.S. scientists have determined climate change 8 million years ago in what's now Pakistan forced most animal species in that area into extinction.

University of Michigan paleoecologist Catherine Badgley and colleagues conducted a long-term study of fossils from northern Pakistan and determined two species of giraffe, several rhinos and five elephant relatives, along with rodents, bush pigs, horses, antelope and apes, once inhabited that region.

But when the climate shifted dramatically, most species became locally extinct rather than adapting to the new ecosystem, the scientists said.

Badgley is a member of a team that's been studying fossils in northern Pakistan for more than 30 years. The scientists determined about 8 million years ago the local climate became drier, and the prevailing vegetation changed from tropical forests and woodland to savannahs similar to ones now found in parts of Africa.

"We see quite a different ecological profile of the kinds of mammals that coexisted after this climate change than before," said Badgley, an assistant professor of ecology and evolutionary biology. "It's clear climate has had an impact on the ecological diversity of mammals in the area."

The study appears online in the Proceedings of the National Academy of Sciences.