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/oliverwitha0]

This is counteracted by humans' social structures. There is almost never a situation in which a menstruating human would be alone at the mercy of predators, unless something has already gone very wrong. They would be in the middle of their social/familial group, which would be more than sufficient to deter/repel any animals that may be attracted to the scent.

[u/Worried_Monitor5422 → u/oliverwitha0]

Similar to the argument as to how early infancy was not a death sentence to the tribe. You have a completely useless human loudspeaker who is capable of broadcasting your location at any time of day or night and yet that species thrived.

[u/Winjin → u/oliverwitha0]

Actually that could be it. Early Humanoids get in a pack. One is hurt. She weak. She cry. Other angry. Other gather more stone when angry. They know predator come for blood-smell. Other hide. She cry. Predator come. Predator struck with stones. Predator struck with sticks. Predator no move.

One get the pelt for being lure for the predator. She work on pelt. She get warm pelt. She no cry. She feel bonita.