Scientists in Britain have been puzzled by the question of how monogamy come about in the first place. But they have apparently found the answer.

Christopher Opie, an anthropologist at the University College London:

Humans have ended up monogamous to some extent, it’s the predominant way we live. What we have now is an evolutionary pathway for the emergence of monogamy.

According to studies conducted, there are three things that could explain why certain species stick to having one spouse during their lifetime.

The first is that two is better than one. If offspring are in the picture, two parents may find it easier to deal with the demands that children bring. Secondly, there is a concept called “mate guarding,” implying that males need to stay close to their significant other to protect them and ward of rivals. And lastly, males stick with females to protect their offspring from other males “who want to kill existing offspring so that females become fertile again and can be impregnated.”

Opie and his team came up with the following hypothesis. They took a family tree of 230 animals and collected information from their mating behaviour, rates of infanticide and paternal care. They then simulated evolution from 75 million years ago to today. “As the simulation ran, it showed how monogamy rose and fell for different species.” After running the programme numerous times, they found that the evolution of monogamy in primates was preceded by one thing only: “Infanticide by males.”

You do not get monogamy unless you already have infanticide, and you do not get a switch to paternal care if you don’t already have monogamy. Monogamy is only one strategy for dealing with infanticide. But it’s not the only one. Chimps mate with all the males in their group to confuse paternity so males won’t attack. But in others, humans included, males stick with females to protect them.

[Source: The Guardian]