posted on Jul, 26 2012 @ 04:03 PM
1. Goosebumps :Humans get goose bumps when they are cold, frightened, angry, or in awe. Many other creatures get goose bumps for the same reason, for
example this is why a cat or dog’s hair stands on end and the cause behind a porcupine’s quills raising. In cold situations, the rising hair traps
air between the hairs and skin, creating insulation and warmth. In response to fear, goose bumps make an animal appear larger – hopefully scaring
away the enemy. Humans no longer benefit from goose bumps and they are simply left over from our past when we were not clothed and needed to scare our
own natural enemies. Natural selection removed the thick hair but left behind the mechanism for controlling it.
2.Jacobson’s Organ:Jacobson’s organ is a fascinating part of animal anatomy and it tells us a lot about our own sexual history. The organ is in
the nose and it is a special “smell” organ which detects pheromones (the chemical that triggers sexual desire, alarm, or information about food
trails). It is this organ that allows some animals to track others for sex and to know of potential dangers. Humans are born with the Jacobson’s
organ, but in early development its abilities dwindle to a point that it is useless. Once upon a time, humans would have used this organ to locate
mates when communication was not possible. Single’s evenings, chat rooms, and bars have now taken its place in the process of human mate-seeking.
3.Extra ear muscle : Also known as the extrinsic ear muscles, the auriculares muscles are used by animals to swivel and manipulate their ears
(independently of their head) in order to focus their hearing on particular sounds. Humans still have the muscles that we would once have used for the
very same reason – but our muscles are now so feeble that all they can do is give our ears a little wiggle. The use of these muscles in cats is very
visible (as they can nearly turn their ears completely backwards) – particularly when they are stalking a bird and need to make the smallest
movements possible so as to not frighten its future meal.
4.Plantaris Muscle :The plantaris muscle is used by animals in gripping and manipulating objects with their feet – something you see with apes who
seem to be able to use their feet as well as their hands. Humans have this muscle as well, but it is now so underdeveloped that it is often taken out
by doctors when they need tissue for reconstruction in other parts of the body. The muscle is so unimportant to the human body that 9% of humans are
now born without it.
5. Wisdom Teeth : Early humans ate a lot of plants – and they needed to eat them quickly enough that they could eat a sufficient amount in one day
to get all of the nutrients they needed. For this reason, we had an extra set of molars to make the larger mouth more productive. This was
particularly essential as the body lacked the ability to sufficiently digest cellulose. As evolution made its selections, our diets changed, our jaws
grew appropriately smaller, and our third molars became unnecessary. Some human populations have now all but completely stopped growing wisdom teeth,
while others have almost 100% likelihood of developing them.
6.Third Eyelid: If you watch a cat blink, you will see a white membrane cross its eye – that is called its third eyelid. It is quite a rare thing in
mammals, but common in birds, reptiles, and fish. Humans have a remnant (but non-working) third eyelid (you can see it in the picture above). It has
become quite small in humans, but some populations have more visible portions than others. There is only one known species of primate that still has a
functioning third eyelid, and that is the Calabar angwantibo (closely related to lorises) which lives in West Africa.
7. Coccyx (human Tail) The coccyx is the remnant of what was once a human tail. Over time we lost the need for a tail (as tree swinging was replaced
by hanging out at the local water hole grunting neanderthal gossip), but we did not lose the need for the coccyx: it now functions as a support
structure for various muscles and a support for a person when he sits down and leans back. The coccyx also supports the position of the anus.
8. Appendix: The appendix has no known use in modern humans and is often removed when it becomes infected. While its original use is still speculated
on, most scientists agree with Darwin’s suggestion that it once helped to process the cellulose found in the leaf-rich diet that we once had. Over
the course of evolution, as our diet has changed, the appendix became less useful. What is particularly interesting is that many evolutionary
theorists believe that natural selection (while removing all of the abilities of the appendix) selects larger appendices because they are less likely
to become inflamed and diseased. So unlike the little toe, which may eventually vanish and is equally useless, the appendix is likely to stay with us
for a long time – just hanging around doing nothing.