Title: The evolution of social monogamy in mammals Authors: D. Lukas1*, T. H. Clutton-Brock1 Affiliations:

The evolution of social monogamy has intrigued biologists for over a century. Here, we show that the ancestral condition for all mammalian groups is of solitary individuals and social monogamy is derived almost exclusively from this social system. The evolution of social monogamy does not appear to have been associated with a high risk of male infanticide and paternal care is a consequence rather than a cause of social monogamy. Social monogamy has evolved in non-human mammals where breeding females are intolerant of each other and female density is low, suggesting that it represents a mating strategy that has developed where males are unable to defend access to multiple females. One Sentence Summary: Social monogamy evolved in solitary mammals as a male mating strategy and is not a consequence of selection for paternal care