Since acne is considered an undesirable trait, why is it still prevalent

Acne is not mostly a genetic trait....acne is caused by the buildup of excess sebum on the skin and all the dirt and oil which erupts bacterial infection and causes a pimple. You can't apply Darwin's theory because he focuses on genetic traits. Ex. A peacock has wild beautiful feather is something that can be passed down but acne can almost be considered an acquired trait and by that you can't pass it on.

Acne is not a trait, it's a condition caused by bacteria. Since acne has no real effect on reproductive success, there is no selective pressure against it, so acne stays. Most acne occurs in young teens, and this population isn't reproducing at this age. But even in older individuals, you don't pick a mate because they are acne free.

well acne isn't only caused by genetics, there are other factors which can cause acne too.

besides, most acne clears up by the time you reach the stage where you want to start a family, so when you find your special someone, or 'mate' referring to Darwin, acne generally isn't an issue as by the time people start trying for babies, they've already left their 'acne stage' therefore it wouldn't 'put anybody off' so to speak.

Unless acne kills you off before you can reproduce the disorder will persist. It is simple as that. For a more serious example take the case of sickle cell anemia, a crippling disorder of hemoglobin structure. It has persisted for centuries and still does; why? because the sufferers are still capable of reproduction. Reproduction is the key factor in evolution, not any specific phenotypes.

The answer is that in early hominids, it apparently did not produce enough of a hindrance to mating to to affect natural selection one way or another. In males of mating age, it would have been obscured by facial hair. And in females, well, the mere fact that they are female generally overrides a little acne. (We males are like that.). It's mostly in modern society ... probably in the last 50 years or so of bombardment of images of "ideal" beauty (where every blemish can be 'cured' with a little Photoshop)... that this becomes an issue at all. But that's not nearly enough time for natural selection to have any effect in humans, especially since we are now mating much later in our post-acne-affected years, than our prehistoric ancestors did.


Hang in there, it gets better. I had really bad acne (probably worse than yours) from 12 to about 18, but then dramatically improved to the point where it hardly bothered me. It it was completely cleared up by my early 20s. In the meantime, there are a lot more really good cleansing products and medications out there that were not available in my time.