Evolution of Sea Turtle Migrations

Each year around Christmas time, green turtles (Chelonia mydas) leave their shallow feeding grounds along the coast of Brazil and embark upon a 2000 km journey to their nesting grounds, the beaches of Ascension Island, in the mid-Atlantic. The journey takes a little more than 2 months in both directions, and is a miracle of navigation. Biologists have long wondered how the turtles manage the feat, and also why they bother to do it at all. Fifteen years ago two researchers, Archie Carr and Pa...