5 December 2005
Evolution And The Penis
by Paul A.
I read once about an old aboriginal custom of matching women to men on the basis of penile and vaginal compatibility. Small, "deer" men were matched with deer women and the large, "buffalo" men were matched with buffalo women. How they came to determine just who was a "deer" woman and who was a "buffalo" woman was never disclosed and I can imagine a few "deer" women would have been somewhat dismayed at their designation. On the face of it I suppose this seems reasonable. Why have deer boy with buffalo girl when buffalo boy is the only man for the job? But it begins to break down when one remembers that the vagina is highly expandable. With a modicum of foreplay, deer woman can easily take on buffalo boy and may well prefer the experience. Those sensible communal minded natives no doubt came to this arrangement when they realized that deer boy would never make it in the open market. This was clearly a deer boy driven agenda.
This raises an interesting question. If the ideal size is larger than average, why isn't the average man larger? I suppose one could dismiss the question by answering "God likes to mess with our heads," but there is a genuine conundrum here. Our bodies have been sculpted over millennia by evolution to perfectly match form to function. And of all the forces driving evolution, none is sharper than female sexual selection. If women prefer to have sex with men with large dicks then the genes for large penises should quickly spread through the population. Every man should be packing a whopper. So why aren't they? Well, there are several theories.
- Woman really don't like 'em big. This, of course, is a total lie. When was the last time you saw a five inch dildo?
- Women may like a large penis but they're stuck with guy they get. Someone's got to end up with deer boy, right? Well, yes, but deer woman can also screw buffalo man on the side and con deer man into raising buffalo son. Think this doesn't happen? Wrong! It's been estimated that 15 percent of children in Britain are the offspring of someone other than their stated father. Studies have shown that women are more inclined to cheat at the peak of their ovulation. Even if the rate of cuckoldry were only 5 percent, buffalo man genes would dominate the population within 12 generations (in evolutionary terms, a blink of an eye).
- Every man is already packing a whopper. This is actually true and lends some credence to the idea that there is selective pressure favoring larger penis size. After all, our closest relatives, the bonobo chimps, have penises that are substantially smaller than ours at 3 inches (and they're proud of them too). Gorillas at 1.5 inches would be the laughing stock of the shower room if they couldn't beat you to a pulp for even looking. Compared to most mammals, even deer boy is hung like a stallion. Evolutionary biologists have theorized that our relatively large penis size has evolved as part of ongoing selective pressures. Plausible enough. But again, we're talking sexual selection here, something vastly more powerful than adaptive selection. If the ideal penis size is eight inches, the top of the bell curve should be eight inches. The fact that it's not tells us that something else must be happening.
- There may be selective pressure favoring bigger dicks but there are also selective pressures mitigating their size. Aha! This must be it. There is a limit to even runaway adaptation - a cost to every extra ounce of flesh we carry on our bones. It has to be fed and oxygenated. Limited resources tend to keep a lid on such extravagances. There's also a physical limit to what women could realistically accommodate. And a limit to what men can have hanging. Buffalo man with his big floppy dick may be the subject of every woman's fantasy but sadly, buffalo man didn't make it when the hunting party was forced to flee through the brambles (ouch). So okay, twelve inch dicks are probably out. But what about an eight inch dick? Okay... brambles again, but why not a big dick that collapses to a nub when not aroused? And how about thickness? In any size survey, women invariably choose girth over length. Why isn't the penis thicker?
- The genes for dick size are passed down through the mother. Deer woman may sleep with buffalo man but give birth to... sigh... deer boy. Proponents of this theory (this is a bar table theory only. No serious scientist would advance it) speculate that the genes for penis size, like the gene for hemophilia, are located on the X chromosome. Because a woman has two X chromosomes and a man only one, a woman may mate with buffalo man but his buffalo dick genes will lose out in the long run. But anyone who knows anything about Mendelian genetics will recall that that while none of buffalo man's sons will have his buffalo dick genes, half of his daughters will. And so will half of their sons. All things being equal, as long as women prefer buffalo dicks, buffalo dick genes should propagate.
- Dick size isn't genetic at all. It's determined by hormones in utero. We are all, by default, female. What turns a relatively tiny clitoris into a strapping great dick are androgens - male hormones, generated at a critical point in gestation. In fact there are women who are genetically male but phylogenically female because of a mutation that renders them androgen insensitive. There are also studies that suggest homosexuality in rats can be induced by exposing the mothers to stress at a critical point in gestation. Which is all fine and dandy, but the problem with applying this to dick size is that while the mother's hormones have an influence on gestational development, masculinization is turned on by the fetus itself, through a complex interplay of its own genes. While it's possible that because your mother was late for work at a critical juncture, you now have a piddly dick, dick size in the larger population is still genetically determined.
So where does this leave us? None of these theories by themselves can explain why we're not all walking around with whoppers in our pants. But perhaps the final result involves an interplay of all the factors. Women may prefer big dicks, but their choice of mate is more varied and complex. As one woman said to me, it's not what's inside you, it who's inside you. This would go for the men they choose to have affairs with as well. In other words, dick size is a factor, but it's not the factor. Other adaptive pressures come into play and before you know it you've got a bunch of deer boys running around. Either that or maybe God really is just messing with our heads.