Do animals avoid inbreeding? Revisiting a classic idea from the ground up

Inbreeding can be costly, as offspring produced by matings between close relatives often have reduced fitness. Given these costs, evolutionary biologists commonly assume that animals will avoid mating with relatives.

However, evolutionary theory predicts that animals will tolerate, or even prefer, mating with relatives under a broad range of conditions. The aim of this project is to resolve this mismatch between empirical and theoretical expectations.

Specifically, this project aims to determine if, when and how animals avoid inbreeding using an experimental framework designed to overcome the current limitations in the way that inbreeding avoidance is usually studied.

Specifically, this project will use 17 species of Poeciliids, a diverse group of closely related freshwater fish, to quantify the costs of inbreeding and determine whether and how inbreeding is avoided either before (through mate choice) or after (through female-sperm interactions) mating.

Importantly, the proposed project will assess the costs of inbreeding and avoidance strategies in both females and males under a range of experimental conditions to generate a robust understanding of when and how animals attempt to avoid inbreeding.

By incorporating experimental approaches into a comparative framework, the proposed project promises to resolve a central outstanding topic in evolutionary biology and have far-reaching implications for the way we manage conservation breeding programmes for endangered species.