Does Mother Nature Punish Rotten Kids?

Abstract

The theory of parent-offspring conflict predicts that mothers and their offspring may not agree about how resources should be allocated among family members. An offspring, for example, may favor a later weaning date than does its mother. Despite a parent's physical superiority, it may be that offspring are able to manipulate their parents' behavior. In this paper, we investigate a two-locus population genetic model of weaning conflict in which offspring can attempt to extort resources from their parents by reducing their own chances of survival if their demands are not met. We find that the frequency of recombination between the genes controlling maternal behavior and those controlling juvenile behavior determines the evolutionary outcome of this genetic conflict. When these genes are tightly linked, the mother will be able to get her way. When they are not, offspring can successfully "blackmail" their parents into providing additional resources.