On the evolutionary origins and consequences of XY and ZW sex-determining systems

Speaker: Professor Charles Mullon, University of Lausanne
Series: Zoology Departmental Seminar Series

Why do some species evolve XY sex determination and others ZW, and how does this affect sex chromosome evolution? I will present models showing how trade-offs between male and female reproduction can drive the evolution of separate sexes and their genetic basis. These models identify conditions that favour XY systems, helping to explain their prevalence in flowering plants. I will then show how sexual antagonism and variation in male mating success influence the suppression of recombination, causing sex chromosomes to evolve differently in XY and ZW systems. Together, these results connect reproductive ecology to the origins of sex determination and the evolution of sex chromosomes.