Research theme:

How do parasites influence the evolution of host reproductive strategies?

We’re interested in understanding the role that parasites play in the evolution of sex and mating strategies, and in turn, the role that host mating strategies play in the epidemiology and evolution of sexually transmitted infections. We’re also interested in the evolution of sex ratio.

Key findings

Evolution of sex

Selection for sex should peak at intermediate levels of host diversity due to ecological feedbacks. At low diversity, the sexual population is unable to avoid disease much better than clonal individuals. At high diversity, the sexual population is very good at resisting parasites, but this reduces disease prevalence to low levels and allows faster-growing clonal lineages to invade. From Ashby & King (2015, J Evol Biol).

Parasite-mediated sexual selection

Coevolutionary cycling of host mate choosiness (blue) and the virulence of a sexually transmitted infection (red). From Ashby & Boots (2015) PNAS.

Sex ratio