Scientists have long wondered why a small minority of mammals, including some humans, have evolved into monogamous creatures, and two studies provide new information but give different answers.
One group of scientists that looked only at primates found that the impulse for males to protect their offspring from infanticide by rival males was the trigger for monogamy. That study was published in Proceedings of the National Academy of Sciences.
The other study, which focused on more than 2,500 species of mammals, said males form pairs with females to protect their mates. That situation arose, the studypublished in the journal Science said, because females lived spread apart from one another, making the risk of leaving a vulnerable female too great.