Humans Have Been Polygamous For Most Of History, FuturePundit notes, citing Genes expose secrets of sex on the side:
Men and women differed in their participation in reproduction, the researchers report. More men than women get squeezed out of the mating game. As a result, twice as many women as men passed their genes to the next generation.‘It is a pattern that’s built up over time. The norm through human evolution is for more women to have children than men,’ said Jason Wilder, a postdoctoral fellow in UA’s Arizona Research Laboratories and lead author on the research articles. ‘There are men around who aren’t able to have children, because they are being outcompeted by more successful males.’
Co-author Michael Hammer, a research scientist in UA’s Arizona Research Laboratories, said, ‘We may think of ourselves as a monogamous species, but we’re coming from an evolutionary history that’s probably slightly polygamous. If we’re shifting toward monogamy, it’s so recent it hasn’t left an imprint on our genome.’
Or the same reproductive behavior is continuing, but in a culturally accepted fashion, Wilder said. ‘The modern version that we generally don’t find offensive is that men tend to remarry and have more children much more often than women do.’
Since I just finished reading Under the Banner of Heaven (about early Mormon history and modern fundamentalist Mormons), and I’m currently reading about the Mongols, I find this remarkably apropos.