Here’s a top ten list of useless limbs in both humans and the animal world.
As far back as 1859, when Charles Darwin published “On the Origin of Species”, there have been references to limbs that serve no purpose in humans as well as animals. They are considered vestiges of evolutionary ancestors; species of sea mammals that once walked, birds that once flew, humans that once did… things that humans do not do today. The following is a top ten list of what LiveScience calls Useless Limbs:
10. Human Appendix – said to be a leftover from long ago when humans ate only vegetables, these days the appendix is more of a donation to the medical industry so surgeons can have some practice.
9. Male Breast and Nipples – One many of us men have wondered about, other than those who enjoy some nipple tweaking during intimate moments, male nipples don’t do anything. They actually appear in the unborn fetus before the sex of the child develops.
8. Fake Sex in Virgin Whiptail Lizards – this species of lizard consists of only women and reproduces via parthenogenesis, something like cloning where an egg becomes a new lizard. Still, the some of the ladies will try to copulate and play the role of a man, even though in all practicality, there is no known purpose. (not even pleasure?)
7. The Sexual Organs of Dandelions – though not considered the sexiest of all flowers, dandelions have all the sexual organs that other flowers do – the stamen and pistil. The only catch is, they never use them, instead they reproduce via a cloning like process.
6. Wisdom Teeth – In what could be a side-effect to having better dental hygiene throughout the world, wisdom teeth were probably a welcome addition to the human jaw back when adults probably lost most of their teeth by the time they were adults. Nowadays, jaws have become smaller and these all-wise teeth often need to be removed.
5. The Blind Fish Astyanax Mexicanus – This is what happens when you are a species of fish that lives in the deep sea in total darkness for a few hundred years – you are born with eyes that don’t work.
4. The Human Tailbone – You might think that your tailbone (coccyx) has an important purpose, but medically speaking, it doesn’t. It is an artifact from a human ancestor which had a tail.
3. Erector Pili and Body Hair – It is no surprise to read that a good amount of human body hair (not all of it) is useless. But its fun to remember that goose-bumps, the erector pili that cause hairs to stand up and skin to puff up, were originally a defense to make an animal look bigger to scare off other animals. Facial hair on the other hand, that might just attract a certain mate.
2. Hind Leg Bones in Whales – 50 million years ago it is thought that whales were actually living on land and evolved into sea dwelling mammals. They see evidence of this scenario in the bone structure of a whale that still shows traces of hind legs.
1. Wings on Birds that Don’t Fly – You’ve seen the type, they’re cute, graceful, and a bit dumb, they are birds that have wings but don’t fly. But they aren’t completely useless, a nice pair of wings on a flightless bird can help with balance and help it find a date for Friday night.
Photo: quinn.anya / flickr