The existence of vestigial characteristics is often used as a kind of evidence of evolution. A vestige has no function at present. Instead, it is a shadow of past adaptations and implies a continuous series of changes—it illustrates transition, the process of loosing a trait or part over time. And change through time is evolution.
Some illustrations of vestigial characteristics include are:
- Flightless birds such as penguins, the cormorants that inhabit the Galapagos Islands, kiwis, and ostriches have rudimentary wings even though they no longer fly.
- Many marine mammals such as whales and some skakes such as the boa constrictor have rudimentary bones of the pelvic girdle and thighbone even though they do not have hind limbs.
- Many cave-dwelling species who spend their lives in darkness have eyes, incapable of sight, burried beneath their skin.
- Pigs walk on only two toes per foot but they have two more toes that are higher on the leg and never touch the ground when walking.
References:
Keeton, W. and J. Gould. 1986. Biological Science, 14th Edition. New York: WW Norton & Company.


