10 – Plica Semilunaris,
- You know how cats and reptiles have those kinda-cool-but-kind-gross third eyelids? Well, so did humans once upon a time! A tiny folded fragment of our third eyelid is known as the plica semilunaris and can be found next to our tear duct.
- It plays no role in our survival and doesn’t affect our vision. It would play a marginal role in tear drainage and sweeping debris away from the eye – if it wasn’t so damn tiny!
9 – Auricular Muscles and Darwin’s Tubercle,
- Anterior, posterior, and superior auricular muscles are the muscles surrounding the outer ear. Some animals use them to swivel their ears towards the direction of sound, but since humans can’t do this – well, I certainly can’t; I don’t know about you – they serve no purpose.
- Wiggling our ears is a neat party trick, but probably won’t contribute to our survival as a species.
- Another vestigial feature of the ear is Darwin’s tubercle. It’s a small fold of skin, a thickening of the helix, that appears on ten percent of people’s upper ears. It’s thought to be a remnant from when we had larger-shaped ears that could swivel.
8 – Subclavius Muscle,
- This small muscle stretches under the shoulder from the first rib to the collarbone. It plays a small role when we depress our shoulders, but would be a lot more useful if humans still walked on all fours.
- Interestingly, some people have one subclavius muscle, others have none, and a few overachievers have two. Clearly this is a nonessential muscle if so many get by without it.
7 – Male Nipples,
- All human foetuses develop nipples them before gender is determined. This is why males have them; they’re a holdover from when we weren’t sure what team we’re going to be put on.
- Although it’s rare (and disconcerting!), men, like women, have mammary glands and so are technically capable of lactating. They can also develop breast cancer.
- Otherwise, male nipples are pretty much functionless. They’re a sensitive, though useless, aesthetic adornment.
- Nowadays, they are brought up in #FreetheNipple debates to illustrate the double standard sexualisation of the female nipple.
6 – Pyramidalis Muscle,
- The Pyramidalis is a tiny, triangular muscle that attaches to the pelvis in two places. It’s pouch-like and is thought to be a relic from when we were pouched marsupials.
- This is another disappointing evolutionary development. I mean, think of the additional storage we’d have if we had pouches. Pockets in clothes would be unnecessary and women wouldn’t have to store things in their cleavage.
- The Pyramidalis muscle is absent in twenty percent of the population. Sometimes it’s absent on only one side; sometimes both. It makes no difference, though, as the lower end of the rectus will just become proportionately larger to compensate.