Large populations of frogs in Central America and the Caribbean "rafted" over the ocean from South America more than 29 million years ago, reports a new study published in the June 4 early online edition of The Proceedings of the National Academy of Sciences. Genetic analysis of eleutherodactyline frogs--species that breed out of water and lay eggs that undergo direct development on land, bypassing the tadpole stage--revealed three major and geographically defined groups of amphibians (North American, Caribbean and South American "clades"), a finding that enabled scientists Matthew P. Heinicke, William E. Duellman, and S. Blair Hedges to reject the prevailing theory that these frogs arose from land connections between North and South America.