dolphin... perfect adaptation Fifty million years ago, the ancestors of dolphins and whales were land animals. Then, over millions of years and through thousands of generations, changes took place in their bodies as they adapted to life in the sea. The legs disappeared and the body became a streamlined tube, ending in a powerful tail that propels it through water. The nostrils moved back on the face to become a blowhole on top of the head.   The long beak full of teeth can catch fish, or probe and poke.  A melon (that looks like a swollen forehead) aims sound waves that dolphins use like sonar. Deep within the body of modern dolphins are tiny leftover bones which used to be hips (and, a very long time ago, legs were attached to the hips). Inside their flippers are bones like our fingers.               Click here for more about dolphins!