SpankAPlankton t1_iwy3du5 wrote

Why do human females have menstrual periods when most female animals simply reabsorb their uterine lining if they don't become pregnant? I can't think of any evolutionary advantage to this often incapacitating process. Back in the prehistoric days, it would've hindered many women's ability to gather food, run from dangerous situations, take care of other offspring, and other things they'd need to do to survive.