Evolution Of Whales
Whales belong to the family of cetaceans. Cetaceans are actually the descendants of land animals that returned to the sea. The closest relatives of the cetaceans are hippopotamus, and also cattle and deer.
These animals slowly adapted to the water, and then completely became the water creatures.Whales closely resembled the land animals in several characteristics like the bones attached to the flippers, the forelimbs, and also the vertical movement of the spine. All these are classic characteristics of land based animals, and such features are seldom found in other sea creatures.
However, how the whale became a complete sea animal still remains a question. Whales are mammals, and not fish. There is a wide variety of genetic evidence available about the evolution of whales. Whales have come a long way from land to sea. The prehistoric whale had legs, and a long tail, and it used to live on land as well as in the sea. So, they could hunt in both the places. However, the whale was not as big when it was a prehistoric creature. It lost its tail and legs along the process of evolution, and ended up becoming a complete sea animal. The timeline for this transition is not known. Also, in what other forms the whales could have existed during this period of transition is very unclear.
Most of the evidence that is gathered about the evolution of whales comes from studying the fossils in detail. The study of whales with regard to fossils is called morphology, and it mainly concentrates on the physical features.
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