Richard Dawkins Vestigial Organs The Wings of the Flightless Cormorant
Vestigial organs: Whale hip bones
Vestigial organs have provided strong evidence in support of the theory of evolution. The following website provides excellent examples of vestigial features in living organisms.
http://www.livescience.com/11317-top-10-useless-limbs-vestigial-organs.html
This site explains that there are several ways to define vestigial organs which tends to cause confusion. The most acceptable definition, as provided by the Oxford English Dictionary, "defines vestigial organs as organs or structures remaining or surviving in a degenerate, atrophied, or imperfect condition or form".
Functional vs. Nonfunctional[]
There are several examples of vestigial organs. Some of this organs are still functional, whereas others have provide no function anymore.
Functional examples:
- Penguin wings: they are no longer used for flying, but they have been adapted as an excellent tool for swimming.
Nonfunctional exampls:
- The wings on flightless birds such as ostriches, emus, cassowaries, and the flightless condor.
- Ampbibian legs such as the
Has limited functionality:
- human coccyx (tailibone): we have no tail and, therefore, do not gain the benefits a tail would provide for balance. However, the coccyx provides support while sitting, it protects the bottom of the spine, and it has muscles attached to it.
Believed to be useless, but maybe not?:
- The human appendix was believed to be a vestigial organ, and perhaps is vestigial compared to what it once was. However, studies now show that the appendix may not be so useless after all.