Is there any other organ other-than the appendix that has no purpose in humans?

Question

And; shouldn't the appendix have evolved or became extinct by now like body hair? Do other omnivores have appendixs?

Answer 1

Yes many organs. (And yes, the appendix is a remnant of the cecum ... part of the digestive system in animals that digest cellulose.)

Other organs with no purpose:
- Wisdom teeth.
- Tailbone (coccyx).
- The muscles that let you wiggle your ears ... a useless feature in humans, but a remnant of the muscles used by other animals for positioning the ears towards sound.
- The plantaris muscle ... a thin useless muscle in the human calf that is used for grasping in other primates. (We know for a fact that it is useless because it's one of the muscles that surgeons harvest for reconstructive heart surgery.)
- Your big toe (toes are used for balance ... but the *size*, bone structure, muscles, nerves, etc. of the big toe reveal that it is structurally equivalent to the thumb ... i.e. it was once used for grasping).
- The plica semilunaris ... a small fold of tissue on the inside corner of your eye ... the vestigial remnant of the nictitating membrane (the "third eyelid") which is present in other animals.
- The muscles that give you goosebumps ... used for fluffing up the fur in animals in times of cold or stress.
- In the human embryo, things like gill folds and a tail.

And no they don't have to become "extinct". (Species go "extinct", organs don't ... but I understand what you mean.)

Things don't disappear the instant they become useless. They slowly become more and more useless. There is little pressure to *lose* a feature unless it is harmful.

Many things gradually do disappear, but it takes millions of years. For example, about 9% of humans are born without any plantaris muscle at all. This doesn't seem to confer any advantage or any disadvantage, so that number may go up or down in the future.

Answer 2

Now who said that the appendix didn't ahve a purpose? Doctors don't know that, they do not pay attention to evolutionary history, they just know what they can cut out without killing the patient. We don't need a second lung or a second kidney. So do they serve a purpose? Also you could apply the same analogy to breasts and gonads and wisdom teeth .
So there is a purpose, they haven't figured it out yet.
And it is in other animals, rabbits for example. It may have something to add to the digestive process.

Answer 3

The appendix actually does have a purpose. It is a part of the Immune system. All organs in the body have a purpose.

Answer 4

and wisdom teeth
and no, we wouldn't see the loss of the appendix in humans because its mere presence (usually) doesn't decrease Darwinian fitness. Traits are more likely to be selected against if they are harmful. Traits are more likely to be selected for if they increase our fitness. Traits that do neither are neither selected for or against. As for why body hair decreased, not only did we not need it once we started wearing primitive clothes, lack of it probably made people more attracive to the opposite sex. therefore those people had more babies and body hair was selected against

Answer 5

They've recently "discovered" that the appendix really does have a function in the immune system.

Not sure about other species-- I'll check back to see what others say...

Answer 6

Look around this place. The brain serves no purpose for some humans.

Anyway, visit this site: http://www.cryingvoice.com/Evolution/Vestigial.html

Answer 7

yes they are called vestigial structure
some are:
tail bone
little toe
wisdom teeth
muscles that move our ears and make our hair stand up
plica semilunaris

Answer 8

its serves a purpose, just one that other body parts take care of already.

Answer 9

How about breast nipples on a man!

Answer 10

tonsils