The human body is a pretty amazing thing. Unless you’re a surgeon or a serial killer you will probably never fully appreciate all the crazy organs that people have and the myriad tasks they accomplish every minute of every day. But as well-evolved as our bodies are, there are a few bits and pieces we could do without. With that in mind, we thought we would take a trip around the body this week to talk about some of its most useless organs.
1. Male Nipples
Let’s deal with male nipples right off the bat. The only reason they exist is because even the manliest man you will ever meet began life in his mother’s womb as a female. When the developmental process gets started all babies, boy or girl, follow the same plan. It is only later that male genes on the Y chromosome kick in and plant the seeds of beards and all the rest of what makes a man a man. The result is that men end up with a pair of purely decorative chest ornaments that serve only as a target for adolescent pain-inducement before the brain is fully developed.
You may not know it, but you have a tail. It is a remnant from when our ancestors used to run along branches and swing through trees. Back then it aided in balance and since then it has become essentially a 5th limb for some species of new-world monkeys, allowing them to grip branches and hang hands-free. That is great for the monkeys, bu all it is for most people is a lump of fused vertebrae tucked inside the skin at the base of our spines. For an unlucky few it sticks out and makes them self-conscious. It’s only real function these days is as a dominant scrabble word.
3. Wisdom Teeth
In the land of long-ago your forebears lived harsh lives. They had to chew tough meat right off the bone whenever they could get it. They also had to catch that meat and risk getting a few teeth knocked out in the process. For that reason humans evolved an extra couple pairs of molars to come in later in life to fill in the gaps. However, now that we have toothbrushes and the like wisdom teeth generally do more harm than good. The most joy they ever bring these days is to the friends of people who just had them removed.
4. Erector Pili
Aside from eliciting the occasional chuckle from less mature readers of science blogs, the erector pili are another part of the body that serves no useful function. These are the organs that cause your skin to get all bumpy when you’re cold or afraid. Back when we were covered in body hair, they made that hair stand up to help us hold in extra warmth or to look big and mean. You may have seen an angry dog using its erector pili to raise the hair on the back of its neck during a barking fit. Since humans aren't typically fur-covered anymore, the effect is a little less dramatic.
5. Plica Semilunaris
Our last useless organ is so obscure that Microsoft Word thinks it’s a spelling mistake. It is the plica semilunaris, more common called your third eyelid. It sits in the inside corner of your eye near the tear duct and you can only really see it if you pull your eye wide open. It used to protect our eyes while letting us still see the world when our ancestors lived underwater. Watch a video of a crocodile about to submerge itself and you will see these transparent eye-covers in action. Unfortunately, in humans they have withered to the point of uselessness, although it would be really cool if they still worked. Built-in ski goggles anyone?
Honourable Mention: The Appendix
One organ you may have expected to find on this list is the appendix; that small dangling protuberance at the point where your small and large intestines meet. Granted they do have a tendency to become infected and 1 in 20 people get them removed with no apparent problems, but your appendix isn’t useless. Recent research has shown that the appendix is a storehouse for some of the beneficial bacteria we learned about in a previous article. The bacteria lie in wait until things go haywire in your large intestine before riding to the rescue. If the appendix were as useless as everyone used to think, it wouldn’t have hung around the evolutionary toolshed for 80 million years and involved in countless other species of animals. So give your appendix the credit it deserves… Unless it gets infected. Then cut it out like a bad habit.