When you’re sick you may feel that certain body parts are more trouble than they’re worth. And in some cases, you’d be right. While the human body has evolved and adapted significantly since caveman days, a few biological traces of our prehistoric ancestors still remain with us in the form of freeloading body parts we lug around with us, but have no use for. Take a peek at the top offenders!
10. Plica semilunaris
You may not know it, but you have a third eyelid. Pull open the two more noticeable eyelids and take a look—it’s located right in the corner by the tear duct. This small third eyelid is left over from what’s known as a “nictitating membrane,” which is still present in full form in some animals including chickens, lizards and sharks.
9. Body hair
No doubt we were once hairier. Up until about three million years ago, we were covered with body hair. But by the time Homo erectus arrived, the ability to sweat meant we could shed our woolly ways.
8. Sinuses
Doctors don’t really know much about sinuses—only that we have a lot of them. Possibilities for their function range from insulating our eyes to changing the pitch and tone of our voice.
7. Adenoids
Adenoids trap bacteria, but they’re also prone to swelling and infection. Just ask any seven-year-old. Luckily, our adenoids shrink with age and are often removed, along with…
6. Tonsils
Also prone to swelling and infection. If you still have them when you reach your 30s, it’s almost an accomplishment.
5. Coccyx
More useful as a game-winning Scrabble word than as part of the anatomy, the coccyx or tailbone, is made up of several fused vertebrae left over from the days when we had tails.
4. Arrector pili
When we were hairier (see No. 9), the arrector pili made the hairs stand on end when we needed to appear bigger and scarier. Now, it just gives us goose bumps.
3. Wisdom teeth
Back in the day, when we ate mammoth meat off the bone and didn’t floss afterward, our teeth tended to fall out. Therefore, when those reserve molars, aka “wisdom teeth,” came in, they were welcomed. Nowadays, fluoride and dental plans have just made them a huge pain.
2. Appendix
Darwin claimed the appendix was useful for digestion during our early plant-eating years; it’s dwindled down to little since we started eating more digestible foods.
1. Male nipples
Because, why?
November 19th, 2008 at 11:51 pm
hey did you forgot Usman chinto
November 20th, 2008 at 12:56 am
if u (or me or science) cannot understand or decode the use of the mentioned body parts that does not mean that they are useless. The limitation of human intellectual does not mean the limitation of nature
November 20th, 2008 at 3:59 am
@kashif,
exactly,
Nothing is useless in this world, these are only useless to us because we dont know what these part are for…..
March 11th, 2009 at 12:35 am
There is this one thing, though, kashif and awahid, called science. It seems you are suggesting the appendix is some sort of mitochlorian-producing organ and we can’t detect what it does because a mass spectrometer can’t detect mystical particles. Of course, these particles would have to have no mass, and therefore the mass-energy equation (E=mc^2) would’t hold (without which we wouldn’t have nuclear fission). A particle without mass would not be affected by gravity, as it would exert none of its own.
I mean, it’s true we don’t know what some of these organs did in the past, but basically the sinuses are the only truly mysterious organ on this list, though there are various hypotheses as to their purpose.
The appendix serves no mystical purpose; after all, it can be removed with no problems /ever/ reported. If it has a purpose at all, that purpose is to get appendicitis.
January 24th, 2011 at 1:22 pm
u are lame in scinece
:p 
:0