Diminishing-returns epistasis among random beneficial mutations in a multicellular fungus.

ABSTRACT: Adaptive evolution ultimately is fuelled by mutations generating novel genetic variation. Non-additivity of fitness effects of mutations (called epistasis) may affect the dynamics and repeatability of adaptation. However, understanding the importance and implications of epistasis is hampered by the observation of substantial variation in patterns of epistasis across empirical studies. Interestingly, some recent studies report increasingly smaller benefits of beneficial mutations once genotypes become better adapted (called diminishing-returns epistasis) in unicellular microbes and single genes. Here, we use Fisher's geometric model (FGM) to generate analytical predictions about the relationship between the effect size of mutations and the extent of epistasis. We then test these predictions

SUBMITTER: Schoustra S 

PROVIDER: S-EPMC5013798 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature