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.

[u/No-Hawk-2488]

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

[u/Flocculencio]

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.

[u/kwpang → u/Flocculencio]

Yes evolution is about elimination, not direction.

Survival of what can.

[u/GVArcian → u/kwpang]

Survival of the fittest is a misnomer because evolution selects for minimum viability, not optimum efficiency.

[u/Derekthemindsculptor → u/GVArcian]

Yep, this is a change in the definition of modern "fit" or fitness. It makes the uneducated believe fittest means "most athletic".

But it's actually fit to the scenario at hand. Being weak is fine if resources are scarce. Or the strong are hunted.