Not every part of the human body has a role. Because of the evolution and our lifestyle changes throughout millions of years, some parts of our body that once served a specific function have now become virtually useless. There are even a few that has no real purpose at all. These are called “vestigial organs.”
Coccyx or tailbone
Our ancestors millions of years ago used to balance their gaits by using their tails. Obviously, as humans learned to walk with two legs, the tail became useless and is now fused to the end of the vertebral column, which is now the coccyx or the tailbone.
Male nipples
Why do men have nipples? Well, it starts all the way from the womb — basically, every fetus began as a female, and the nipples appeared already even before the gender was determined. When the Y chromosomes testosterone begins to work its way, it will lead to the development of the male sex organs, which eventually take over the female ones. Yes, you read it right — every one of us, including guys, started out as females, and the male nipple is a vestige of the men’s former female selves in the womb.
It is interesting to note that although the instances are very rare, men can lactate and even suffer from breast cancer.
Wisdom teeth
Over time, the human jaw has become smaller than our mouths won’t have any room for more teeth to grow. There are many other factors (such as poor dental hygiene) why wisdom teeth occur in many individuals. And we all know very well that wisdom teeth are unbearably painful for some people, especially when they’re pulled off.
Ancient humans needed larger jaws for chewing their plant-based diet to effectively digest cellulose – a substance that makes up the cell walls of plant cells.
Appendix
Our evolving diets and eating habits are most likely to blame on why the appendix has played virtually no part in our digestive system. According to scientists, the appendix may have served a function when our ancestors’ diet was made up of plants and lots of roughage. The appendix nurtures bacteria — the good kind, that is — which keep the gut healthy and free from infections brought about by eating raw foods.
As you can see in certain animals such as rabbits, their appendices are rather large, simply because they are utilized to the hilt. They greatly help in the digestion of indigestible matter (like fiber) in plants, grasses, and even wood. It could be that our ancestors’ appendices used to be large too.
Nowadays, we eat a lot of cooked and processed foods, which has rendered the appendix shrunken and become obsolete. A lot of people believe that the virtual uselessness of the appendix has caused it to become infected and inflamed, which unfortunately leads itself to be ruptured. This condition, commonly called appendicitis, happens to one in every fifteen people in the world.
Body hair and goosebumps
Our ancestors used to be really hairy. Their copious body hair would automatically stand stiff and erect whenever they were cold or being confronted or threatened, making them appear bigger and more intimidating. It also insulated them against the cold. Nowadays though, does a body hair serve any decent purpose at all?
Darwin’s tubercle
Darwin’s tubercle or Darwin’s point is a small fold of skin in the outer part of the ear. It is a congenital condition, and it is more common among many Europeans and Native Americans. Some people claim that having this body part is a sign of intelligence. Although it is not sure what was the former purpose of Darwin’s point, scientists suggest that the extra skin may have been a joint that allowed the ear to wiggle. Some animals have this feature too, which they flop or swivel in order for them to hear better. Maybe some people with Darwin’s tubercle can wiggle their ears, but it doesn’t do much to improve their hearing.
Vestigial tissue in eyes
Human eyes have two vestigial tissues.
There’s a small tissue in the corner of a human eye, which at some point in the past, served as a third translucent eyelid. This remnant tissue called plica semilunaris, protected and moistened the eyes. It is still functional in many mammalian species in the form of the nictitating membrane.
The other vestigial tissue is a smooth muscle, located between two certain gaps inside the skull. It is called the Muller’s muscle after its discoverer Johannes Peter Müller. It is critical to orbital wall structure in some animal species but serves no purpose in humans.
Vestigial muscles in arms
Located between two muscles in the forearm, is a small tendon known as palmaris longus muscle. About 86% of the population has this rudimentary muscle. It served an important function back when our ancestors used to live in trees. But when humans started inhabiting the ground, it lost its active function. In modern humans, it is considered a vestigial organ since it does not add to grip strength.
There’s a vestigial skeletal muscle in the posterior neck triangle, present in a small number of individuals. About 2-3 percent of the total population has it, but it is found in many mammals including apes and orangutan.
Vestigial molecules
Vestigial structures aren’t limited to the organ level, humans also have molecules we no longer require or use. A pseudogene –zombie genes which no longer have any functionality—L-gulonolactone oxidase, which used to code for an enzyme that synthesized Vitamin C in our ancestors. At some point in the past, the gene was mutated and no longer remained functional.
The vestigial muscle in the leg
A thin muscle and a long tendon combine to form a vestigial muscle called the plantaris muscle. Present in 87-90 percent of the population, this tendon’s function in the motion of legs and ankles in negligible, making it a redundant and rudimentary muscle. This tendon is used in grafts.
It is also known as “the freshman’s nerve” because freshman medical students often misidentify this tendon as a nerve.
Prenasal Sinuses
There are four small pockets of air surrounding the nasal cavity – the area behind the nose, right in the middle of the face. So far as scientists can tell, these pockets serve no purpose whatsoever.
They are hotspots of inflammation and infection though. They get stuffed when you have a cold or an allergy. If the inner lining of sinuses gets infected it leads to sinusitis – an inflammation that causes fever, headache and plugged nose. These prenasal sinuses are also susceptible to cancer.
Tonsils
At the junction between air passageway and digestive tract, there are folds of tissues present called tonsils. They are supposed to serve a role in the immune system but apparently, the only role they serve today is getting inflamed and infected. Their infection leads to tonsillitis, a condition only cured by surgically removing tonsils altogether, making them similar to appendix in some ways.