Why some animals forgo reproduction in complex societies

In complex societies, some animals forgo breeding and help others raise young. Although this behavior at first seems maladaptive, evolutionary biologists have developed theory that explains when and how it can evolve. For example, if it helps kin raise more young or if dispersing to breed elsewhere is risky, an individual may cooperate with nearby breeders. After two decades of work on the social behavior of coral reef fish, Peter Buston of Boston University and Marian Wong of University of Wollongong, Australia, have shown that this behavior can unfold under a third scenario: If conflict with dominant breeders is especially risky, then subordinates will politely wait their turn to breed, rather than risk a fight. Buston and Song explain their experimental and observational work in this feature, and then outline how their work influences current theory.