I currently have two main research focuses:
Mate choice and the environment
Choosing the right mate is hugely important for all sexual animals: mates vary widely in quality, so there are strong reproductive benefits to choosing high-quality partners. However, despite the benefits of choice, we see huge variation in how strongly some mates are preferred over others, both between and within species. One key reason for this variation is that the costs and benefits of being choosy vary across different environments and contexts. For example, it might be better to mate quickly and forego choice when the cost of travelling between mates is high (see right).
I study which environmental factors most strongly influence animal mate choice. This involves two approaches. First, I am collecting data from published studies of animal mate choice across as many species as possible, which I will analyse in order to determine which environmental factors most strongly influence the patterns of mate choice across species. Second, I use experimental evolution to test whether mate choice evolves in the lab in response to consistent changes in the environment over multiple generations. I use populations of the Indian meal moth, Plodia interpunctella, which have been reared under experimentally-altered population sex ratios for over 130 generations.
The evolution and function of animal genitalia
Animal genitalia exhibit an extraordinary amount of morphological diversity between species, despite all having to fulfil the same basic function: to transfer or receive gametes during mating. I am interested in how selection drives the evolution of genital traits, and the functional processes driving such selection.
I have examined genital evolution in several insect species. For example, in the cowpea seed beetle Callosobruchus maculatus, the male’s penis is covered in hundreds of sharp spines which injure the female reproductive tract during mating (see right). In this species mating is therefore generally harmful to females. I have examined how the morphology of the female reproductive tract evolves to reduce the harm females receive during mating. To do this I used micro-CT X-Ray scanning (in collaboration with Leigh Simmons and Kathryn McNamara at the University of Western Australia) to measure the thickness of female reproductive tract tissue in three dimensions, showing that female tract thickness and male penis spine length have co-evolved across seed beetle populations (see here). I have also used micro-CT to visualise female tract injuries at different stages of mating (here).
Right: Micro-CT scan showing the penis of the
cowpea seed beetle Callosobruchus maculatus