It must have been really hard to make sense of the world before anybody knew how evolution worked. This would be especially true for anything having to do with sex -- our bodies seem to have either been designed by a dysfunctional committee or a very cruel prankster. A man can live with a penis all his life and, gazing upon it for the last time, still think, "Yeah, that looks weird."
But thanks to science, we're slowly figuring out why each of these oddities survived natural selection.
The best thing about animal penises is that you usually have to go out of your way to see one (bulls and elephants aside). Because most critters walk on all fours, their junk always remains tastefully hidden under layers of skin and fur. It doesn't work that way with humans, though. If anything, our entire society is built around the idea of making our dicks less noticeable than they naturally are.
Some ways are more effective than others.
But prominently-displayed genitalia is actually an evolutionary advantage and a possible reason why humans walk on two legs. There is a theory that claims that it's because bipedalism changed how both sexes signal their sexual availability to each other.
First, walking upright instead of on all fours meant that human dongs were suddenly on full display, which cut through all the bullshit when it came to mating. When an early human walked up, dick standing proudly in the breeze, a female knew exactly what his intentions were and could quickly tell him to either fuck off or fuck on.
And sometimes "Fuck you, creep!"
For women, though, bipedalism had the opposite effect -- a female's parts are suddenly hidden from view when she's no longer on all fours. That made it harder for males to judge when a woman was ovulating (which is not the case in other primates). This might have encouraged monogamy (since the guy would need to pay closer attention to more subtle sexual cues) but also resulted in a lot more sex.
To play it safe, they would engage in sexual activity all the time, not just during mating season which is what almost every other animal does. It soon ushered in an era of 'round-the-clock pounding that eventually helped our species populate the planet. And then some bastard invented pants and ruined it for everyone.
Humans get so upset about cheating that it fuels most of our songwriting output. But monogamy (and therefore the concept of "cheating") is very rare in the animal kingdom. In fact, the human baby-gravy cannon looks the way it does because evolution assumed that our women were going to be giving it away to any caveman that comes around to borrow a cup of rocks.
According to one controversial theory, the shape of the penis is an evolutionary mechanism for displacing any rival semen that might have found its way into a female's vagina while she was "out shopping with a friend."
"I missed the 'Caution: Wet Floor' sign, slipped, and then-"
That nice little mushroom-shaped cap on top of the penis is known as the glans. Now, the reason it is so pronounced in comparison to other animals is that it allows a thrusting male to plug a vagina and scoop out any unfamiliar instant-baby batter before it reaches the cervix. It's sort of a plunger type action -- do we have to show you an animated GIF to make it clear? Because we're not doing that.
Here's a GIF of an actual plunger; work it out from there, you perverts.
This is supposedly why males tend to have rougher, more penetrative sex when they suspect that their SO might have been unfaithful. It's their bodies' way of making sure to thoroughly clean out their personal semen repository. You know what -- we're slowly realizing that sex is one of those things that you probably enjoy more if you don't know the history. Oh, well, too late to stop now ...
Masturbation would seem to be a flaw in the reproductive system, a form of cheating at the game. Instead of procreating with a fertile partner, we literally take matters into our own hands with a process that has zero chance of making a baby unless the masturbation session is immediately followed by a very unlikely series of accidents.
"I was in the mall bathroom, and this lady missed the 'Caution: Wet Floor' sign, slipped, and then-"
"But don't all animals masturbate?" you say. "I just went to the zoo and the monkeys were playing their dicks like banjos!" Actually, no -- while probably every animal stimulates its sex organs every now and then, it's rarely to completion. Humans are the only species observed who do it all the way, and with such impressive frequency. How the hell did the species not immediately go extinct as soon as we discovered it? All that precious sperm was suddenly being wasted, right?
Not to mention all the tissues and fancy lotions.
Well, it's only wasted in the sense that milk is wasted if you don't use it before it spoils. Sperm actually has a Best By date -- maybe only a week or so. Sperm that is a few weeks/months old can actually lead to some serious health risks in your progeny, which is why animals like mice expel it from their bodies with urine every few days to keep it fresh (which is what humans males will do, if they abstain). As for the rest, well, they jerk off.
It's the healthy thing to do!
That's the theory anyway, that we masturbate to flush the old sperm out of our systems, and force our bodies to cook up a fresh new batch of motile swimmers rather than waiting for our bodies to literally piss them away.
Monogamy is another practice we take for granted as natural (or "traditional," depending on what debate you're having) but that seems to fail the evolutionary math test. Wouldn't humans produce more offspring if each male knocked up as many females as possible? There are still lots of cultures that function that way, so why did "one man, one woman" become the norm in modern society?
It may have been as simple as avoiding sexually-transmitted diseases.
Centers for Disease Control and Prevention
"We had to start inventing new letters to cover all the types of hepatitis you have."
For our ancestors who weren't blessed with contraception, the number of sexual partners, apart from being directly proportional to the fun they had, was also directly proportional to their chances of dying of a junk disease. Some Canadian and German researchers investigated the matter and concluded that in advanced agricultural societies (that is, where lots of people lived in closer proximity) STDs could spread rapidly enough to potentially wipe out entire groups. But the diseases could be contained if mating was limited to two partners, so societies that favored monogamy would have an advantage.
This would seem to imply that the magical feeling we call "love" may just be an elaborate justification for not wanting our genitalia to burn when we pee. But we would be irresponsible to leave it at that -- the reality is that humans are complex creatures and nothing we do can be boiled down to one simple, shocking evolutionary fact. Each of these is just one part of a (very weird) whole that is human sexuality. Which includes the theory that ...
Calling a stiff penis a "boner" might just be a colorful metaphor in the human world, but in the animal kingdom, it's a cold statement of fact. Most mammals, including our closest primate cousins, have an actual bone in their dicks called the baculum which basically lets them stick it in even when they aren't in the mood.
Didier Descouens/Wiki Commons
That arrow is pointing to what is scientifically known as "The Bone Zone."
Way, way back, proto-humans also had those dick-bones but evolution eventually replaced them with a complicated system of blood flow and hydraulics that can just fail for no apparent goddamn reason. Dick move, nature. Then again, it all actually had a valid purpose.
Losing the bone from our boners made our penises more flexible, which helped facilitate sex in a variety of different positions. It's like, have you ever seen a rigid drain snake? Of course not. Those things need to be flexible to navigate through the twisting, turning maze of your plumbing. It's exactly the same with the human schlong; its rubberiness allows us to reach every nook and cranny of a human female's "plumbing."
This GIF actually fits nicely for this entry too.
In other words, the Reverse Cowgirl, the Spoons, the Piledriver, basically the entire Kama Sutra all owe their existence to this mutation. Natural selection would have resulted from the fact that the first guys who could suddenly do all of those things were presumably very popular.
Dibyajyoti Lahiri sometimes talks to himself on Twitter.
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