Every part of our body has meanings and although not all parts are still useful. There are a lot of parts that we now refer to as vestigial parts of the body not because they are absent but because they are currently not functioning that way. So let's discuss some maybe useless parts of our body.
I will like to start with the Auricular muscles which is found in the close to ear helps the ear to wiggle. This is why some people have the ability to wiggle their hear but this muscle isn't functional again like it is for other animals like dogs and cats. It is used to pick sounds allowing the ear to follow the sound. Our ancestors ears were able to move up a bit with sounds but have largely lost the function thereby causing them to become vestigeal but the part in our brain responsible for this still have some activity when we hear sounds.
Have you heard of Plica Semilunaris? it is the vertical line found in the medial side of the eye area. Unlike reptiles and some animals that have three eyelids with the third one being the Nictitating membrane, we do not have it neither is it found in our closest relatives but the plica semilunaris is the remnant of it since we have sufficient moistening in the eye, we do not need the Nictitating membrane which is a moistener.
We know we do not need moisteners but what about Male Nipples? Some times I ask myself its function but then I realize that while the female nipple is good for breastfeeding, the male nipple is not completely useless as it can be stimulated. Since it is an erogenous zone, it is very important but do you know that some people can have something similar to a nipple in their nipple line just like dogs or cats and it can even be found in the armpit, we refer to this as atavism.
Let's see Goosebumps which is a product of the Arrector pili muscles. So many of us can have goosebumps when we are cold or we experience some type of threat. The Arrector Pili Muscles would cause the hair to stand erect when we experience these things but since we do not have hairs like other hairy animals, it is not fulfilling its purpose. It's purpose in other animals like cats and dogs is to increase the size of the animals but since we do not have so much hairs on our body, our size isn't increased.
We also have primitive tail and it is known as the Coccyx. It is a vestigial structure and our closest siblings the great apes do not have tails since they do not need it to cling to trees and climb them. When we began to work bipedally, our tail became useless and it became vestige. Another part of the body that has been modified is the human feet. It has been modified for ambulation and for running. Our feet has double arches with one going from front to back known as the longitudinal arch, and another arch going from side to side and they are able to reduce muscle usage. Compared to gorilla with flat foot, we are able to run while they can't.
We have a lot of body parts that are still useful and some are now vestigial because we do not need them again. One part of the body we thought was vestigial is the appendice but we have learned that it is very good for keeping our good gut bacteria which helps our gut.
For Further Reading
https://www.mayoclinic.org/diseases-conditions/appendicitis
https://pmc.ncbi.nlm.nih.gov/articles/PMC5775970/
https://www.ncbi.nlm.nih.gov/books/NBK470359/
https://www.aao.org/education/image/advancement-of-plica-semilunaris-onto-bulbar-conju-2
https://www.healthline.com/health/mens-health/why-do-men-have-nipples
https://www.unsw.edu.au/newsroom/news/2019/09/why-do-men-have-nipples
https://www.nih.gov/news-events/nih-research-matters
https://www.elsevier.com/resources/anatomy/integument/dermis
https://www.nhs.uk/conditions/tailbone-coccyx-pain/
https://www.ncbi.nlm.nih.gov/books/NBK549870/
