Evidence for Evolution
Homologous vs. Analogous
Homologous: similar in structure and relative position.
Homology provides evidence for evolution because it shows a common ancestor. By studying the relative placement of bones in humans, cats, whales, and bats, for example, it is clear to see that these creatures adapted differently and eventually became separate species.
Analogous: similar in function, but not in structure.
Analogous structures provide evidence for evolution because they help us understand how animals adapted to certain environments. An example of this would be fins on sharks, and wings on penguins. Both found the need to swim, and adapted in order to survive the cruel rules of natural selection.