Mating Systems and the Resolution of Intrafamily Conflict in a Marine Snail

University Of California-Davis, Davis CA

Investigators

Abstract

The resolution of ecological and genetic conflicts of interest governs virtually all social relationships, from genes to societies. Families represent a universal and especially intense arena for cooperation and conflict: fathers and mothers, sons and daughters, and brothers and sisters may often die for each other, but given the right circumstances, they will also kill each other. The development of kin selection theory 40 years ago provided the foundation for analyzing the resolution of conflicts between family members, clarifying how and when pairs of relatives of any species should and should not help each other. However, social conflicts rarely involve isolated pairs of relatives. Instead, the conflicts play out on a matrix of interactions between different family members, and beyond. This proposal focuses on the resolution of multiway intrafamily conflicts in a remarkable marine snail, in which females enclose their offspring in "nurseries" that they attach to males. As the offspring develop, they cannibalize each other, an extreme form of sibling competition for resources provided by their mother. Because females mate with several males, the offspring within a nursery are usually a mixture of full- and half-brothers and sisters. This widespread habit of multiple mating by females increases the scope for conflict between parents and offspring, and among the offspring. Theory predicts that offspring should consume their half-sibs before their full sibs, and testing this prediction using experiments and genetic analyses is a major goal of this proposal. In addition, the studies in this proposal will use experiments to determine whether females control the mixture of full- and half-siblings, so as to adjust the rates of cannibalism within nurseries. The research involves extensive international collaboration with colleagues and students in Mexico. The project will support infrastructure, including a molecular ecology website and associated workshops, and a multi-user genetics facility used to train students and postdoctoral researchers in state-of-the-art molecular analysis. NSF support over the last three years has supported the training of 6 Ph.D. students (3 women, 1 Hispanic), 4 postdocs (1 woman, 1 Hispanic), and 9 undergraduates(5 women, 1 minority). This proposal will support the training of a comparable number of young scientists, giving them multidisciplinary training at the interface of behavior, ecology, evolution, and marine biology.