Mormon polygamists shared the flaws of the fruit fly

It was during this period that polygamy was slowly being phased out under pressure from state legislators. The results were clear: the more women partnered with a man, the fewer children each of those women had. Exactly why is not clear. Like the Soay rams, men may simply not have had the stamina. Wade says: "It could be owing to competition between women within a plural marriage for shared resources, or it could be owing to other unknown factors." Neither was polygamy a great deal for males. For every man who had multiple wives, there were many who had none. "For every male that has three mates, there must be two who have none," said Wade. "If a male has even more mates, then the disparity among male reproductive haves and have-nots can become quite high."