Goosebumps are the result of flexing muscles at the base of each hair follicle. There are two reasons humans get goosebumps. The first happens when someone is cold. The second is when you’re scared and works much like a cat’s fur when it feels threatened – by raising the hair when we’re ready to fight it made us appear bigger. At least it would work in theory if we were covered in fur or thick hair.
Humans are the only species on Earth that has exposed lips. No animal shows interior skin on their mouth like we do.
At some point in our ancestral history, our ears moved directionally. Like a horse’s, we could move them around to be able to hear things better. While that ability is mostly gone, we all still have the auriculares muscle which surrounds the outer ear.
Although wisdom teeth are now simply painful and frail, they once served a very important purpose. A long, long time ago, pre-humans were primarily herbivores, which meant they ate a lot of greens. Because green vegetation takes longer to digest, it needed to be chewed more, and wisdom teeth gave the extra surface area needed to grind the greens into pulp.
Although the appendix does seem to produce some good gut germs to help the digestive system, we don’t really need it and those that have it removed suffer no real consequences. It seems it is simply left over from a previous version of us.
No animal on Earth has breasts quite like a human does. It seems like they evolved after we started walking upright. They began to become rounder and bigger much like so many of the boobs we see today. Not that anybody is paying attention to stuff like that — wink wink. Facts via Ebaumsworld