Allowing nature to be nurture : a comment on Bailey et al.

In their recent review, Bailey et al. (2017) make the compelling case that indirect genetic effects (IGEs) should be more widely incorporated into behavioral ecology research. IGEs occur whenever the trait of one individual is affected by the genotype of another “interacting” individual, usually via one or more “social cues.” IGEs create an additional source of heritable variation that can influence an individual’s trait expression above and beyond any direct contributions of its genotype (direct genetic effect [DGE]) and the environment (Lynch and Walsh 1998). When conspecifics interact, as is the case for behavioral interactions, they make up part of an individual’s “social environment” and because these interacting partners are themselves genetically variable, additional heritable variation can be generated. So why does this matter? A key outcome of IGEs is that traits affected by them can evolve not only due to direct genetic variation but also due to evolution of the social environment itself (Wolf et al. 1998)