Ann Arbor, Mich. -- The continent-hopping habits of early primates have long puzzled scientists, and several scenarios have been proposed to explain how the first true members of the group appeared virtually simultaneously on Asia, Europe and North America some 55 million years ago.
But new research using the latest evidence suggests a completely different migration path from those previously proposed and indicates that sudden, rapid global warming drove the dispersal.
Researchers from the University of Michigan, Johns Hopkins University School of Medicine and the Royal Belgian Institute of Natural Sciences present their findings in the July 25 issue of the Proceedings of the National Academy of Sciences.
Their work focuses on Teilhardina, an ancient genus that resembled the saucer-eyed, modern-day primates known as tarsiers. Like tarsiers, monkeys, apes and humans, Teilhardina was a true primate, or euprimate. In both Asia and Europe, the genus is the oldest known primate; in North America, it appears in the fossil record around the same time as another primate, Cantius. Previously, scientists had come up with four ways to explain the geographic distribution pattern.
The first is that primates originated in Africa and spread across Europe and Greenland to reach North America. Another possibility is that they originated in North America and traveled across a temporary land bridge connecting Siberia and Alaska. A third hypothesis is that primates had their origins in Africa or Asia and traveled through North America to reach western Europe. Finally, it has been suggested that the group originated in Asia and fanned out eastward to North America and westward to Europe.
In the new research, U-M paleontologist Philip Gingerich and coworkers re-evaluated the four hypotheses by comparing with unprecedented precision the times of first appearance of Teilhardina in Asia, Europe, and North America. To achieve such preci
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Contact: Nancy Ross-Flanigan
rossflan@umich.edu
734-647-1853
University of Michigan
25-Jul-2006