Sexual selection has generated much of the spectacular diversity of form that we see in animals and plants, from the bright colours of birds and fish to the exaggerated horns and mandibles of insects.

Charles Darwin recognised that sexual selection acts both via competition among members of the same sex for access to mates, and by mating preferences. Sexual selection can thus act on both male and female traits, ultimately driving evolutionary changes in those that serve as weapons in mating competition and ornaments for attracting mates.

We are particularly interested in the benefits individuals can accrue through mate choice, which can be direct in the form of resources required for reproduction, or indirect in the form of genes that affect offspring survival and reproduction. For example, our research addresses the mechanisms underlying indirect benefits of mate choice, including work on how mutations throughout the genome affect the acquisition and allocation of resources, and how limiting resources such as nutrients, vitamins and carotenoids affect the expression of sexually selected traits, thereby providing choosers with reliable information on mate quality.

Sexual selection can also occur after mating, in the form of sperm competition and female control over which male’s sperm fertilize their eggs. The selection pressure this generates has far-reaching consequences for the behaviour, morphology and reproductive physiology of animals.

Our research also focusses on the evolution of genital traits that are required to deliver sperm and encourage females to retain them. We are interested in how sperm competition fuels the evolution of ejaculate traits such as sperm morphology, swimming speeds and their competitive fertilisation abilities. Our work is showing that females can exert subtle physiological control over fertilisation events, for example by differentially accepting or attracting sperm from different males.

We study these aspects of sexual selection in a range of species, from prehistoric vertebrates like Dimetrodon, to native species like the ornate dragon lizard, frogs, trapdoor spiders and a range of broadcast spawning marine invertebrates. We also make extensive use of laboratory model species, including vertebrates such as house mice, and invertebrates such as crickets, seed beetles, dung beetles, Drosophila and acarid mites and single celled algae.