Evolution is a fickle mistress. On the one hand, we can't complain, since humans ended up with opposable thumbs and huge brains (and relatively hairless). On the other hand, we can't fly and our heads hurt if we eat ice cream too fast.
But some of the everyday annoyances that drive us crazy are exactly what made modern humanity possible. For example ...
#5. Getting Kicked in the Junk Hurts Because It Makes Sperm Work Better
As decades of America's Funniest Home Videos have taught us, the only thing funnier than seeing someone else get hit in the junk is a baby who's scared by his own farts. But the hilarious act of hitting a man in the ballsack reminds us of a baffling evolutionary defect -- after all, when's the last time you've seen a shark rolling around on the beach because it got nailed in the balls? And you would have seen it if it'd happened, somebody would have put that shit on YouTube.
Or maybe one of the more specialized porn sites.
Well, the human crotch has two problems: One, unlike with some animals, the nuts are on the outside of the body. And two, the family jewels are so disproportionately sensitive to pain that just the thought of a wayward hit to the groin will have you doing a crotch block. But why?
It Has to Be That Way Because:
Scientists think a big part of it is the fact that sperm really prefers hanging out at lower body temperatures, and the last time we checked, lower body temperatures are impossible to accomplish from the inside of the body without some kind of weird crotch-mounted air conditioning. So, the sperm has to be suspended in orbs out where the air can get to them (this is why, as we mentioned recently, a laptop can cook a man's sperm to death).
"It just felt as if my scrotum cried out and then was silenced suddenly."
It's not until you get aroused that things tighten up downstairs, and the best part is that it's actually the woman's (or guy's?) body heat that jump-starts the process that will eventually end with a baby or a mess or both. Because even though sperm production is best at lower temperatures, ejaculation requires some hopped up, crazy-excited spunk. So at the key moment, the testicles retreat, get hot, and you probably know the rest. You also might have figured out that this retreat kind of protects the dangly parts during sex, which is a win-win for everyone.
Which brings us to extreme ball sensitivity. What's the deal with that? Well, it's not that other animals just love being smacked in the balls, it's that, well, try it. Go find a bull and try to nail it in the nuts with a dodge ball. You can't, can you? Its legs and tail are in the way.
And with that, a beautiful sport was born.
Humans, however, decided at some point that walking upright would be a great idea, so now we have the perfect storm of external testicles and a posture that literally has us walking balls-first into danger.
#4. We Need Dentists and Braces Because We Evolved Big Brains
Don't let Hollywood fool you, guys -- most people in this world are sporting teeth that are as crooked as an Illinois governor. If you see someone with a perfect set of chompers, either they or their parents shelled out some dollars to make it happen. The rest of us have more teeth than our little orifices can handle, which is why some of us end up with snaggletooths and fangs and whatever is going on with Steve Buscemi's mouth.
Complete dental anarchy?
Not to mention the nightmare that is wisdom tooth removal -- those bastards try to cram their way into the jaw so tightly that nothing short of surgery can remove them. Again, it seems like a straight design flaw -- why in the hell would you not have room in your mouth for your own teeth?
It Has to Be That Way Because:
Before humanity got a taste for flesh, vegetation was our only source of nutrition. But the thing about roots and leaves and nuts is that you need a lot of it to get enough protein to keep on living. So imagine the teeth it would take to grind down that kind of diet all day long. You can go look at a horse, if it helps.
Oh hey, we loved you in Reservoir Dogs, Mr Buscemi.
Once our big ol' Chiclet teeth had their way with wood pulp or whatever else we were managing to swallow for sustenance, our digestive systems went to work. Digesting all of those twigs and shit sapped whatever energy we had left -- which left zilch for our brains.
And then something happened. Someone somewhere figured out, "Hey, meat!" And then they learned how to cook it. Beginning about 2.3 million years ago, humanity started getting enough protein to direct a little more to the brain and a little less to the shitter. It didn't take too long to figure out tools that made our fangs even more worthless.
As a result of this softer brain-fuel diet, our jaws are shrinking, crowding out the worthless teeth and inflicting headgear on scores of awkward preteens. At least we have the brain power to generate the income that it takes to pay for the headgear, though.
And the strong tool-using hands to bully someone into a miserable childhood.
#3. We Choke on Food Because We Evolved the Ability to Speak
Quick! When was the last time you had to give your dog the Heimlich maneuver? Never? (Please say never.) The idea of animals choking to death is as foreign as the idea of humans who can lick clean their own crotch, yet more than 3,000 people a year manage to accidentally choke to death.
Eating in a hurry, eating while laughing or just plain old not chewing enough can end it all within minutes. How in the hell did we evolve so that you can kill a healthy man just by tickling him while he's trying to swallow some falafel?
"My other technique involves asking the victim for the time while he's carrying a scalding hot drink."
Ask your larynx. You can literally do that, because you have one, and it happens to be the reason you can't breathe and swallow at the same time.
It Has to Be That Way Because:
You hopefully already know that the only reason you can talk is because you have vocal cords (or folds), which are located a couple of inches down your throat, in your larynx. The cords are down there instead of, say, right at the back of your mouth, because being down there lets you make a much wider range of sounds (think of your head as a musical instrument). That design means that instead of crude grunts, you can spit the kind of sick rhymes that let humans consistently win battle raps against almost every other species on earth.
But this kitty can play the trumpet real fine.
But that setup also lets food get caught in there, and stops you from breathing in the process.
You know from basic biology that inside your neck meat are two tubes. One, the esophagus, sits in the back of your throat and carries food down to the digestion parts. The other, the larynx, sits on top of the trachea, which takes air down to your breathing parts. Because the larynx is positioned down in the throat a bit to give us the ability to say fancy words to each other, the air tube can't connect directly to our sinuses (which would let us keep breathing through our nose whether or not we had a doughnut crammed in the other tube). Instead, the two tubes share a little hallway before branching off to go their separate directions, and one hunk of bratwurst can block them both.
And that's exactly what will happen if a chunk of food starts to go down the wrong tube -- you'll choke, and choking is our mechanism to prevent something much worse, which is aspiration pneumonia, otherwise known as "French Fry in the Goddamned Lung Syndrome." Which will kill you dead.
"We've identified the fry. It was a 9-centimeter hollow-point with extra salt."
So choking is unique to humanity, but so is our ability to talk to each other. It's not a bad trade-off if you can remember to chew your damned food.
#2. Pregnant Women Get Morning Sickness to Avoid Parasites
If there's one thing Cracked knows a lot about, it's pregnancy. And the first thing we'll tell you about pregnancy is that it's no walk in the park for people who enjoy digesting their food as God intended. For about 80 percent of pregnant women, however, the first three months of pregnancy are a vomitathon. Just full on all-throw-up, all the time. Some women don't even make it through the pregnancy without getting hospitalized for dehydration. Surely the act of ejecting the nourishment that keeps you and your baby alive is an evolutionary mistake, right?
"It was an unusual case of birth-by-mouth."
It Has to Be That Way Because:
The food available to prehistoric women wasn't going to include a prenatal vitamin, non-caffeinated chai with fresh fruit, yogurt and granola. Our great-to-the-power-of-a-thousand grandmothers got to choose from what was on the ground and in the trees -- berries, eggs, wild fruits and fetid animal carcasses.
Enter morning sickness. It turns out the foods that were most likely to carry parasites in our pre-cooking days are the exact same foods that often trigger morning sickness today: red meat, eggs, poultry and fish. In other words, the human body came up with a kickass adaptation to keep the human race going -- scare pregnant women away from dangerous foods by making them vomit at the smell of them. It's a particularly effective adaptation when you realize that nausea is usually strongest during the first few months of the pregnancy, when the fetus is at its most vulnerable.
"I'm fatally allergic to people pressing their face against my womb and cooing."
Women who live in societies that don't use a lot of animal products tend to not get morning sickness at all. Zero. It's not even a concept in their cultures. We don't have the names of those cultures handy, but we're going to guess they're pretty skinny.
#1. Our Spines Don't Heal Thanks to Our Big Brains
Christopher Reeve falls off a horse, and instantly he's paralyzed forever. When you see an athlete go down with a back injury, everybody in the stands holds their breath while the trainers strap the guy to a board, everyone praying that it's not the spine.
Broken bones? No problem. Punctured lung? It's bad, but it will heal. But not the spine. Once the spine is damaged, it's all over. But why?
It's certainly not like that for all creatures -- newts and baby opossums can rebuild their nervous systems with comparative ease. Hell, our lizard cousins voluntarily sever, then regrow, their spinal cords as part of an amazing screw-you escape mechanism.
And nature's most efficient weight loss method.
It's not like human nerves can't heal -- when nerves in the central nervous system are injured, they actually try to regrow right away. As far as they're concerned, all they need is a little chicken noodle soup and a hug and everything will be fine again. But the central nervous system won't let them. Our own bodies abort the regeneration, leaving us paralyzed.
OK, evolution better have a freaking good reason for this.
It Has to Be That Way Because:
The answer is that Mother Nature miraculously managed to cram 2.5 square feet of brain surface into our skulls without making us all look like Burton-inspired Martians. That structure, and the rest of the central nervous system, is unbelievably complex and unbelievably specific in its design. If your face gets damaged from a broken beer bottle and the skin cells don't grow back quite right, it just means you have a kickass scar. But if your central nervous system doesn't grow quite right, suddenly your limbs don't work. There is no margin for error.
This is not a kickass spine scar. This is the tragic image of a woman who can't lower her arms.
So, rather than risk these nerves going rogue and screwing up the whole system, the body just gives them one set of strict blueprints to follow, and if anything goes wrong with that plan (i.e., you fall off a motorcycle and sever your spine), then that's it. Like most of the parts in your laptop, it's just too complex to fix, and unfortunately we haven't figured out how to just do a warranty replacement.
That was the price to pay for having the kind of brain that lets us invent motorcycles in the first place. And also ways to let paralyzed people control shit with their minds.
"Eat shit, evolution!"
And check out why your body hates you in 5 Ways Your Brain Is Messing With Your Head and 6 Ways Your Body Loves to Screw You (Explained by Science).