Our bodies are weird, as the farts that half of you will inadvertently release while reading this can attest. And though we all live in one, there's a lot about our bodies that we still don't understand. Why do we faint at the sight of blood? Why do teenagers break out into a pimply mess just when they've reached the point where they want to attract the opposite sex instead of making them run away in disgust?
Usually, the answer is that society evolves faster than biology, and quirks that helped us survive in the woolly mammoth days are now a pain in the ass. For example ...
6Acne Might Have Kept You A Virgin Until You Were Strong Enough To Raise Kids
Acne doesn't seem to serve any purpose beyond making the lives of teenagers even more miserable. A bad case of it pretty much guarantees that you have plenty of spare time to do your math homework, because no one wants to date someone who looks like an alien life form is slowly taking over their face. And despite your mom insisting that you were still beautiful, that may have been nature working exactly as intended.
Nature is a dick.
According to one theory, there was a time when a pimply mess on your face kept the opposite sex away while you went through the process of becoming a finely-tuned reproductive machine. Adolescence produces an interest in sex, but it doesn't magically provide you with the experience and maturity required to raise a child (or to defend it from wolves, if we're thinking in terms of evolution here).
So acne provided a buffer period, giving sexually-motivated adolescents time to learn how to be responsible. Because while bad parenting today merely means a visit from the government and/or a reality show contract, historically it meant dead children, which was a huge waste of resources -- and also prevented people from passing on their genes. Destroying the topography of a teen's face may have been nature's way of buying them time to realize they wouldn't make it as a wandering cave artist, get their hunting and gathering act together, and give their eventual offspring a better chance of survival.
Nature could have simply delayed sexual maturity, but nature likes watching you masturbate.
Another theory suggests that acne also made younger males look like less of a sexual threat to older men in the community, which protected them from harm until they were old enough to protect themselves. An older guy would look at some pimply-faced kid and conclude that the dweeb had no chance of stealing away his woman, and thus wasn't worth the hassle of bullying. Theorists are still working on how to make this theory jibe with everything we know about high school bullies.
So that smattering of acne you saw in the mirror every morning as a teen may have been millions of years of evolution telling you that you were too much of a wuss to get laid or avoid harassment. In other words, your mom couldn't have been more wrong.
5Contagious Vomiting Made Sure We Didn't All Get Poisoned
Let's say you're at a party where alcohol is served, which we're told is a popular thing these days. Eventually, someone has one more Jell-O shot than their body can handle, and all the messy contents of their stomach come out to give the kitchen floor a slick coat of acid and regret. An onlooker sees the vomit and starts to look sick themselves, and after they puke, the two puddles of upchuck start to make you feel queasy too, even though you haven't had a single drop of alcohol (you're a recovering alcoholic, forced to quit after drinking ruined your career and marriage). The next thing you know, you're looking at some half-digested Funyuns and trying to calculate how much the host is going to charge you to have his dog professionally bathed.
Cracked Tip: Gin washes out much easier than bourbon.
It's easy to assume that contagious vomiting, also known as Stand By Meing, is triggered by the fact that vomit is gross. But your body actually tries its hardest to avoid vomiting, because it's terrible for you. You lose electrolytes and fluids, stomach acid erodes your teeth, and the vomit can clog up your breathing passages. However, it's also an extremely effective way to expel poison or far too many mixed drinks from your body.
So the theory is that social vomiting, in addition to being a great name for a punk band, is an extension of that defense mechanism. Back when we foraged for food in groups, there was a constant risk of eating something that was spoiled or poisonous, because eating used to be a trial-and-error process. Since we shared our meals, one person having an adverse reaction meant there were good odds that everyone else in the group was going to get sick too.
It took a lot of caveman to eat one velociraptor.
So social vomiting could have evolved as a disgusting cautionary reflex to expel any toxins that might have been ingested before they incapacitated everyone and left the tribe vulnerable. And now we use it as a hilarious signal that it's time for everyone to quit voluntarily drinking poisonous alcohol for the evening. There's no better proof that we've conquered nature than that.