Your “third eyelid,” or the plica semilunaris, is that little extra area of tissue on the inner-corner of your eye. You can liken this to that creepy sideways eyelid-thing that birds and reptiles have. It serves to “moisten the eye and clear debris.”
Try this out: with your palm up, touch your pinky to your thumb and tip your hand slightly up. If you see a raised tendon, then you have a vestigial (or a part of the body that became useless over time, due to evolution) muscle called the palmaris longus, which was used by our ancestors as an aid for gripping and hanging from trees. If you don’t see it, then you’re part of the 10% of humans who don’t have it.
Goosebumps are left over from a time when humans had much more body hair. When cold, goosebumps served to fluff up our natural winter coats and keep us warmer, but since we have man-made winter coats now, there’s really no need for goosebumps.
If you’ve ever had appendicitis, then you know that the appendix mostly just causes a lot of problems. It serves little to no purpose in modern humans, as it was thought to aid in the digestion of large amounts of cellulose in plants from when humans ate a plant-heavy diet. Nowadays you can get it removed and not notice a single difference.
Wisdom teeth are another example of something leftover from our plant-eating days. Plant-heavy diets, as well as the consumption of raw meats, required a lot more chewing room in our mouths. However, as we began cooking our food, our jaws started shrinking due to the intake of softer foods.
Believe it or not, the human brain has actually been shrinking in size over time, meaning that humans may actually be getting dumber. Yup, that’s right, modern technology may be acting as a safety net of sorts that makes it less necessary for humans to be more intelligent and independent.
Another theory, however, is that the brain getting smaller is a sign that the human brain is becoming more efficient and working more quickly, all while taking up less space.
Most are aware that they have a tiny, useless tailbone (otherwise known as the coccyx), but what they heck was it used for? It’s believed that humans lost their tails when they gained the ability to walk, as they’re mainly used as an aid for balance in other species.
Other species have what’re called the auriculares muscles, which are used to move the ears without having to turn the head. Early humans had the ability to move the external ear in order to “augment our peripheral hearing.” All that’s left over of that trait is the ability for some to wiggle their ears.
While body hair kept our ancestors from freezing, it’s mostly just a pain in the butt for modern-day humans now that we have indoor heating. Eyebrows do help to keep the sweat out of our eyes, but the rest of it? Mostly useless.