Incorrect. Most life forms don't need menstruation in their process of reproducing. Only human with the obviously visible bleeding, and human is the destroyer of most life forms. Menstruation is the remove of unhealthy embryo in the newest theory, and human female don't need menstruation to get pregnant.

Rather to say, menstruation removed many embryos, so they became more difficult to get pregnant, you can just check about the medical science of those pedophiles raping case.(7 years old child get pregnant...etc)

I have a theory that since human have so many odd sexual behaviors (like pedos), cannot make sure the quality of embryos, menstruation is a selector to remove these unhealthy embryos.