Froggy went a-driftin'

By Tim Stoddard|Sunday, July 01, 2001
RELATED TAGS: UNUSUAL ORGANISMS



If you want to see a truly intrepid survivor, don't bother with the TV show— just take a look at an ordinary frog. According to Franky Bossuyt and Michel Milinkovitch, evolutionary geneticists at the Free University of Brussels, Belgium, the line of ranids, or "true frogs," spent 74 million years marooned on a giant island, adrift between Africa and Asia.

When Bossuyt and Milinkovitch examined the DNA of ranid frogs from various locations in Asia and Madagascar, they found the creatures clearly shared a common ancestor. But amphibians can't survive in salt water, so the ancestor couldn't have swum from one landmass to the other. Rather, genetic evidence suggests that modern frogs arose in Madagascar and India 120 million years ago, while the two were joined as a huge detached landmass— not in Africa, as scientists had long believed. One line of frogs was stranded when Madagascar broke away. The Indian branch of the family, meanwhile, survived massive lava flows that smothered most of the subcontinent 65 million years ago. When India collided with Asia 56 million years ago, the long-suffering frogs hopped off their life raft, invaded the mainland, and eventually dispersed worldwide.




 
ADVERTISEMENT
Comment on this article
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
DSC-CV1017web
+