14 DAY TRIAL // A mathematical model developed by University of Tennessee in Knoxville distinguished professor of ecology, evolutionary biology and mathematics, Sergey Gavrilets, demonstrates that a sexual revolution of sorts must have occurred in our species' past, which made humans predominately monogamous.
In the distant past, alpha and beta males most likely chose whatever female partners they wanted, mated with them, and then left them to look after the offspring, similarly to what scientists are now seeing in chimps and bonobos. Yet, our species took a different path at one point.
It could be that males of inferior status, who could not take on the alpha male directly, started courting women by providing food on a continuous basis. These women may have become faithful to those men, leading to a situation where evolution favored this type of pair bonds.
Little by little, the alpha males disappeared, allowing for both monogamous couples and the development of social norms to keep the old hominin groups in check, and to punish offenders, Time reports.