When and why do natural and sexual selection align?

Does sexual selection promote, or inhibit, adaptation by natural selection?

A wealth of laboratory studies provide insight into when and why sexual selection increases or reduces male and female mean fitness.

However, the extent to which these processes scale up to influence higher level patterns - in particular, population persistence – is a major unresolved challenge. Key to resolving the problem is the connection between sex-specific adaptation and population demography.

This project will bridge approaches from evolutionary genetics and population ecology, using fruit flies as a model, to understand the demographic mechanisms that mediate sex-specific effects on adaptation.

First, I will use a large scale response-surface experiment in ecological time to understand how male and female density influence demography, and how these effects are mediated by sex-specific nutrition.

Next, I will use experimental evolution to understand how adaptation by sexual selection, natural selection, and their combination influences evolution of two-sex demographic parameters.

Together, these work packages will indicate not only the extent to which each sex contributes to population growth, but also how this contribution changes in response to the form of sex-specific selection.

This work will provide insight into the demographic mechanisms that mediate the wide range of effects sexual selection can have on population persistence, relevant for all sexually reproducing organisms.