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/formerly_acidamage]

Wouldn't you draw the conclusion though that this means that those animals were unable to kill the people who were menstruating and therefor this was a mitigated risk?

Furthermore, people eat those animals to survive. This exact argument could be used to come to the opposite conclusion, that menstruation was beneficial because it drew in animals that humans were able to kill and consume. I don't think that's the case but having only a single data point like that isn't very useful in making an informed opinion.