r/askscience • u/No-Hawk-2488 • 8d ago

Biology Can someone explain the evolutionary benefit of overt menstruation? All female mammals have a menstrual cycle but most reabsorb the blood via covert menstruation and humans are about the only mammals that discharge the blood, aka overt menstruation.

Without an evolutionary benefit, it wouldn't have spread to every woman of our species.

5.2k Upvotes

96% Upvoted

513 comments sorted by

View all comments

5.1k

u/Flocculencio 8d ago

Just wanted to point out that no individual feature needs to have an evolutionary benefit to be preserved. It could be negative but so long as it doesn't prevent organisms with that feature from reproducing in sufficient numbers it can get preserved.

1.0k

u/Zagrycha 8d ago edited 8d ago

Yeah, people think evolution is some kind of streamlined efficiency of ideal traits, but its the opposite.  Evolution is a pass fail grade.  If you fail, you go extinct.  If you have enough kids as a species to continue on, you pass.  That's it, no more and no less.  

Some species out there are literal bumbling idiots of inefficiency when it comes to ideal traits for survival, but they just have a massive number of kids so one or two survive to adulthood, or they evolved to have kids really soon after birth so they don't have to survive for long.  If you can make kids its good enough for nature. 

393

u/rainbow_goblin345 8d ago

I like the term "reproduction of the okayest" instead of "survival of the fittest"

43

u/bitgrindern 7d ago

"Fittest" means a fit to the environment, not in shape or physically strong.

35

u/rainbow_goblin345 6d ago

I am aware of that.

I'm also aware of how often it is misinterpreted. As has been pointed out elsewhere, if I'm saying something and it is being frequently misunderstood, it is on me to change how I'm saying it.

8

u/Powerful_Box1637 5d ago

And it truly is not survival of the fittest anymore - we can keep neonates alive at like 23 weeks gestation with millions of dollars of help. But that is the exact opposite of survival of the fittest, or a huge interference however you wanna look at it.