EvoLunch Seminar: Ksenia Khudiakova (Institute of Science and Technology Austria)

If a mutation participates in epistatic interactions, its fitness effect depends on the genetic background. As genetic backgrounds fluctuate over evolutionary time, the same mutation can experience changing selection coefficients. I model this process under a stabilizing selection fitness landscape at evolutionary equilibrium, defined by a balance between deleterious and compensatory fixations. It turns out that the dynamics is well-approximated by the Ornstein-Uhlenbeck process, for which many quantities are known analytically. I then compare the model’s predictions with experimental patterns of background-dependent change in mutation effects reported in Park et al. (2022).