It’s not that there is one gene for the micropenis. There are hundreds of genes that affect penis size, probably. At least dozens. And if you happen to inherit most of them you end up with a really tiny one. Your father maybe just had one that was slightly smaller than average but your mom may have been carrying genes for even smaller ones and you got unlucky. You probably won’t end up mating and passing on those genes but everyone else who just has a few of them (not enough to make it super tiny) can get laid and pass them on just fine. Especially if those genes have multiple effects, some of which are positive, which is likely.
People often forget that the opposite sex can carry and pass on genes that are neutral or even helpful to them but detrimental to you. That’s a big way these “bad” traits can remain in a population. If a couple has a girl then it’s a positive gene to pass on, if they have a boy then it’s negative. There is pressure to remove it on the male side of things but not on the female.
If based on natural selection, the other Redditors have answered it.
However if you are asking from a survival POV, my rationale is we (humans) tinker too much.
We have medications and procedures that allows us to prolong/sustain life, promote passing on of genetic diseases and defects.
It’s a slippery slope to start going down so will leave it at that.
I am however GLAD for the tinkering as it has prolong my life but flip side is my kids have a 50/50 chance of having it which will not be known until exposure happens.
This is because a micropenis is not a simple genetic trait like blue eyes or a big nose.
Instead a micropenis will often occur because of a failure of the gonads to produce enough sex hormone for the penis to fully develop, and that in turn would be due to a problem with the pituitary gland or the hypothalamus.
So it isn’t like people with a micropenis are breeding true, instead it is simply that some people have genetics which make them somewhat more likely to have pituitary or hypothalamus problems that result in a micropenis. Those problems are very rare to occur, less than 1% of the population, and so they aren’t impactful enough to be completely eliminated through natural selection. Someone could have genetics that make them more likely to have a micropenis and yet it is overwhelmingly likely they still have normal genitalia despite that. All the equipment would work fine and until relatively recently everyone would be completely unaware there was increased risk!
A lot of things in biology are like this. For example some people have genetics which make them significantly more likely to have heart attacks than the population at large. Yet that trait isn’t completely removed from the population via natural selection because while they have significantly higher risk the actual prevalence of the issue is still very low. Even if they have three times the chance of the average person to have a heart attack, three times a slim chance is still very unlikely.
Latest Answers