From Scientific American:
Researchers report genetic evidence bolstering the socially contentious idea that polygyny—the mating practice where some males dominate reproduction by fathering children with several women—was the norm for sexual behavior throughout human history and prehistory. Because polygyny means other men father few or no children, the study, published today in PloS Genetics, also shows that, on average, women bequeath more genes to their offspring than men do.
The proportion of female to male genes passed on is not yet known. “Our follow-up work is to get a better estimate, but we believe it’s at least two to one, if not more,” says senior study author Michael Hammer, a geneticist at the University of Arizona in Tucson. “This is good science, and even more notable is the increasing light it sheds on our own human nature,” says David Barash, evolutionary psychologist, University of Washington in Seattle.
The study, which examined genetic material (DNA) from six geographically diverse populations—Biaka from Central African Republic, Mandenka from Senegal, San from Namibia, French Basque, Han Chinese and Melanesians from Papua New Guinea—provides independent corroboration of what many animal studies have shown and evolutionary biologists have long claimed: basic human biology is polygynous, Barash notes. “Monogamy is a recently inspired cultural add-on.”