3. Whales are mammals rather than fish, yet they live in the world’s oceans rather than on land. Because of the fact that they are mammals, scientists have believed for quite sometime that whales are descendants of land mammals.
Some interesting evidence to support this theory has recently been found. In Egypt, fossils have been found of a forty-million –year-old whale leg, kneecap, ankle, footbones, and toes. It appears from the fossil evidence that the bones were not very strong and not very large in comparison to the size of the whale.
Based on this fossil evidence, the following evolutionary path has been hypothesized. As the whale began its evolution toward the water,its legs weakened and decreased in size.Then,during it millions of years in the water , the legs slowly disappeared, leaving only the front flippers today.