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...

 The Flounder's Eye

A good example of bad design is the flounder, whose popularity as an eating fish (Dover sole, for instance) comes partly from its flatness, which makes it easy to bone. There are actually about 500 species of flatfish— halibut, turbot, flounders, and their kin—all placed in the order Pleuronectiformes. The word means “side-swimmers,” a description that’s the key to their poor design. Flatfish are born as normal-looking fish that swim vertically, with one eye placed on each side of a...