The study, published in the Proceedings of the National Academy of Sciences, helps answer long-standing questions in evolutionary biology about how the modern family, which is characterised by intense, social attachments with exclusive mates, emerged following earlier times of promiscuity.
According to the researchers, when women started choosing weak men as mates and remaining faithful to them, it gradually resulted in pair-bonding.
The transition also witnessed a reduction in male-to-male competition in favour of providing for females and providing close parental involvement, said study author Sergey Gavrilets of the National Institute for Mathematical and Biological Synthesis
"Once females begin to show preference for being provisioned, the low-ranked males' investment in female provisioning over male-to-male competition pays-off," he was quoted as saying by LiveScience
The study showed mathematically that the most commonly proposed theories for the transition to human pair-bonding are not biologically feasible.
However, the research advances a new model showing that the transition to pair-bonding can occur when female choice and faithfulness, among other factors, are included, the scientists said.
The result is an increased emphasis on provisioning females over male competition for mating. The effect is most pronounced in low-ranked males who have a low chance of winning a mate in competition with a high-ranked male.
Thus, the low-ranked male attempts to buy mating by providing for the female, which in turn is then reinforced by females who show preference for the low-ranked, "provisioning" male, said Gavrilets, who is also a professor at University of Tennessee-Knoxville. (More)
