<span> descended from land animals</span>. Scientists believed that whales have evolved 50 million years ago from land dwelling ancestors who feed on fish from nearby sea. According to unearthed fossils, the early whale's body was more adapted to land but its relatives are more suited to live in water.
All food chains and webs have at least two or three tropic levels. Generally, there are a maximum of four tropic levels. Many consumers feed at more than one tropic level.
