1. In plant-eating vertebrates, the appendix is much larger
than in humans. Its main function is to
help digest a largely herbivorous diet. The human appendix is a small pouch
attached to the large intestine where it joins the small intestine and does not
directly assist digestion. Interestingly, it has been noted by paleontologist
Alfred Sherwood Romer in his text “The Vertebrate Body (1949)” that the major
importance of the appendix “would appear to be financial support of the
surgical profession,” referring to, of course, the large number of
appendectomies performed annually. In 2000, in fact, there were nearly 300,000
appendectomies performed in the United States, and 371 deaths from
appendicitis. Any secondary function that the appendix might perform certainly
is not missed in those who had it removed before it might have ruptured.
2. The subject of the
male nipple is a sensitive, and maybe confusing, topic to many. Those who wish
to invalidate evolutionary theory might pose the question, “Was man descended
from woman?” Both men and women have
nipples because in early stages of fetal development, an unborn child is
effectively sexless. Nipples are present in both males and females; it is only
in a later stage of fetal development that testosterone causes sex
differentiation in a fetus. All mammals, male and female, have mammary glands.
Male nipples are vestigial; they may perform a small role in sexual stimulation
and a small number of men have been able to lactate.
3. With all of the
pain, time, and money that are put into dealing with wisdom teeth, humans have
become just a little more than tired of these remnants from their large jawed
ancestors. But regardless of how much they are despised, the wisdom teeth
remain, and force their way into mouths regardless of the pain inflicted. There
are two possible reasons why the wisdom teeth have become vestigial. The first
is that the human jaw has become smaller than its ancestors – and the wisdom
teeth are trying to grow into a jaw that is much too small. The second reason
may have to do with dental hygiene. A few thousand years ago, it might be
common for an 18 year old man to have lost several, probably most, of his
teeth, and the incoming wisdom teeth would prove useful. Now that humans brush
their teeth twice a day, it’s possible to keep one’s teeth for a lifetime. The
drawback is that the wisdom teeth still want to come in, and when they do, they
usually need to be extracted to prevent serious pain. On the bright side, I never got my wisdom
teeth and, therefore, avoided pain and expense.
On the darker side, does that mean I have no wisdom?
4. The fused vertebrae are the only vestiges that are left of
the tail that other mammals still use for balance, communication, and in some
primates, as a prehensile limb. As our ancestors were learning to walk upright,
their tail became useless, and it slowly disappeared. It has been suggested
that the coccyx helps to anchor minor muscles and may support pelvic organs.
There have been documented cases of infants born with tails, an extended
version of the tailbone that is composed of extra vertebrae. In those cases, the tailbone has been
surgically removed with little or no adverse effects. Nevertheless, there are no adverse health
effects of such a tail, unless perhaps the child was born in the Dark Ages. In
that case, the child and the mother, would’ve been considered witches and
killed instantly.
5. The erector pili
are smooth muscle fibers that give humans “goose bumps”. If the erector pili are activated, the hairs
that come out of the nearby follicles stand up and give an animal a larger
appearance that might scare off potential enemies and a coat that is thicker
and warmer. Humans, though, don’t have thick furs like their ancestors did, and
our strategy for several thousand years has been to take the fur off other warm
looking animals to stay warm. It’s ironic actually that an animal, sensing
danger is near, would puff up its coat to look scarier, but the human hunter
would see the puffier coat as a warm prize, leaving the thinner haired weaker
looking animals alone. Of course, some body hair is helpful to humans; eyebrows
can keep sweat out of the eyes and facial hair might influence a woman’s choice
of sexual partner. All the rest of that hair, though, is essentially
useless. Unless you count all the money
spent on depilation, waxing, shaving, lasers, and other methods.
6. Your sinuses are basically pockets of air that reside
inside your face. The biological role of sinuses is often a topic of heated
debate, but there is little-to-no-consensus on their actual purpose. One thing
everyone can agree on is that there is nothing worse than a sinus headache,
except when your sinuses get infected.
7. The human ear has all kinds of strange things going on
with it. For one thing, there’s an entire group of muscles attached to our ears
that, for most monkeys, are used to move the ears like satellite dishes trying
to pick up a signal. For us, however, they just sit there – not moving anything
– suggesting that they’ve lost their biological function. Except, of course,
for those who can wiggle their ears, in which case, they serve the purpose of
making you look like a fool. It’s worth pointing out that chimps, like us, also
have these underdeveloped muscles and therefore lack the capacity for
ear-movement, as well. Furthermore, in
about 10% of the population, the outer rim of the ear called the helix has been
known to show signs of vestigial features. In the ear a thickening of the helix
called “Darwin’s tubercle” occurs at the juncture of the upper and middle
thirds of the ear – a feature common to many mammals.
8. Your plica
semilunaris – what many believe to be a vestigial remnant of your third
freaking eyelid – is the small fold of tissue located on the inside corner of your
eye (not the little bump in the very innermost corner but the small flap next
to it). Your plica semilunaris are the vestigial remnants of what are
referred to as “nictitating membranes”, which are most commonly found in birds,
reptiles, and amphibians. In a masked lapwing the membrane is typically
translucent, and serves to moisten the eye, clear debris, and help stare down
weeping angels. Humans, sadly, are not equipped with these functioning third
eyelids, but don’t let that stop you from standing in front of a mirror and
willing yourself to make them move.
9. Tonsils are one of the most removed parts of the human
body. Tonsils are nothing but a collection of the lymphoid tissues present on
each side at the end of the throat. Though they are vestigial, they still
perform a simple function of fighting against the preliminary infection in the
throat and the bacterial fighting effect in the sinusoids causes it to
swell. Doctors mostly recommend surgery
for the removal of the tonsils to avoid further throat infection. However,
removal of tonsils can be dangerous at times and cause vocal problems to
people. On the bright side, when your
tonsils are taken out, you can eat all the ice-cream you want. That’s something.
10. The fifth toe in the leg has nothing to do other than
getting people injured. The fifth toe was used for hanging on trees and
swinging around the branches in the primitive primates. This body part was
bigger than what it is now and the reduction of its size is what makes it
obsolete. Also, as we humans walk on our foot, the fifth toe now has nothing to
do with this part for balancing or mobility in any way.
