By SETH BORENSTEIN, Associated Press
WASHINGTON (AP) — Only a few species of mammals are monogamous, and now two scientific teams think they've figured out why they got that way. But their answers aren't exactly romantic.
One team looked just at primates, the animal group that includes apes and monkeys. The researchers said the exclusive pairing of a male and a female evolved as a way to let fathers defend their young against being killed by other males.
The other scientific team got a different answer after examining about 2,000 species of mammals. They concluded that monogamy arose in mammals because when females were spread out geographically, males had trouble guarding them against competitors unless they stuck close by.
The studies are published online Monday in the journals Science and the Proceedings of the National Academy of Sciences.
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