How did human sexuality evolve? Researchers are undecided as to whether our sexual basis lies in monogamy, polygamy, or polyamory. Some fossil remains tend to indicate monogamy, while many genetic analyses support polygamy. A group of scientists from University of Arizona compared X-chromosome data against autosomes of six different human societies to determine male vs. female effective population size. The genetic evidence suggests that the male-female ratio is biased in favor of multiple women, supporting the idea that polygyny was the dominant mating system during the past 10,000 years of human evolution. However, some anthropologists argue that polygyny could have been the result of the emergence of agriculture, which favors patrilocal societies. The jury is still out on whether or not this genetic data can be used to infer the origins of human sexual systems.