We study how sperm number and morphology is shaped by sperm competition across the animal tree of life. We also examine how fertilization mode (i.e., internal vs. external fertilization) influences the evolution of sperm morphology in animals.

We examine genital evolution and co-evolution between the sexes, comparing genital shapes and rates of evolutionary diversification. Previous work focused on pinnipeds and dung beetles, but we are now turning our attention to aquatic organisms.

We examine the role of ecological factors, parental care, and sexual selection in driving the evolution of mating systems in animals. 

Cooperative breeding is complex social system where some group members breed and others forgo their own reproduction and instead assist in providing care for offspring off the breeding individuals. We study how cooperative breeding evolves in Tanganyikan cichlids.  

We examine how brain size is related to cognitive performance and the ecological and social factors that drive brain size diversification. Our work on brain evolution is an ongoing collaboration with Niclas Kolm's lab. 

We are studying how eyespots and other distinct markings evolve in aquatic animals. To do this, we combine phylogenetic comparative studies with experimental approahces using lab and field populations sharks and fishes.