Ha ha, it is not always the case and sometimes it is before, sometimes during and sometimes after 🤢, but girl's gotta do what a girl's gotta do 😋.

Regarding preservation of the species - that theory would work if female had capacity to reproduce as long as a male, but no woman after about 50 can reproduce, while man can as long as he is alive. If reproduction was the factor, females would be dying very soon after 50, so that resources are preserved for the next generation but what actually happens is the opposite. I believe that XX and XY actually have the biggest influence since Y misses one whole segment of chromatin material 😬. That and a high levels of estrogen that females have for good part of their lives which protects their cardiovascular system.