STATE COLLEGE, Pa., June 7 (UPI) -- A U.S. study suggests nearly all 162 land-breeding frog species living on Caribbean islands originated from a single frog species.
A Penn State University researcher determined the frogs rafted on a sea voyage from South America about 30- to 50-million years ago. Similarly, the scientists found the Central American relatives of the Caribbean amphibians also arose from a single species that arrived by raft from South America.
"This discovery is surprising because no previous theories of how the frogs arrived had predicted a single origin for Caribbean terrestrial frogs and because groups of close relatives rarely dominate the fauna of an entire continent or major geographic region," said biology Professor Blair Hedges, who directed the research.
The field work for the study required nearly three decades and some species included in the study are now believed extinct because of habitat degradation and possibly other causes, such as climate change.
Hedges -- along with coauthors Professor Emeritus William Duellman of the University of Kansas and Penn State graduate student Matthew Heinicke -- report the findings online in the Proceedings of the National Academy of Sciences. The study is to appear also in the journal's June 12 print issue.
