I am greatly interested in the evolution of sex-determining systems. Consistently with the sex-ratio theory, these systems were thought to be stable insofar as they ensure an equal sex-ratio, but empirical research has shown that they are subject to rapid changes. Different mechanisms were proposed to explain the great diversity and the instability of sex-determining systems. My PhD will focus on the effect of sexually antagonistic selection on the instability of sex determining systems. I will run individual-based simulations allowing to investigate different parameters (e.g. recombination and mutation rate) that might affect the dynamics of this process.