--- res: bibo_abstract: - Fitness interactions between mutations can influence a population’s evolution in many different ways. While epistatic effects are difficult to measure precisely, important information is captured by the mean and variance of log fitnesses for individuals carrying different numbers of mutations. We derive predictions for these quantities from a class of simple fitness landscapes, based on models of optimizing selection on quantitative traits. We also explore extensions to the models, including modular pleiotropy, variable effect sizes, mutational bias and maladaptation of the wild type. We illustrate our approach by reanalysing a large dataset of mutant effects in a yeast snoRNA (small nucleolar RNA). Though characterized by some large epistatic effects, these data give a good overall fit to the non-epistatic null model, suggesting that epistasis might have limited influence on the evolutionary dynamics in this system. We also show how the amount of epistasis depends on both the underlying fitness landscape and the distribution of mutations, and so is expected to vary in consistent ways between new mutations, standing variation and fixed mutations.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Christelle foaf_name: Fraisse, Christelle foaf_surname: Fraisse foaf_workInfoHomepage: http://www.librecat.org/personId=32DF5794-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0001-8441-5075 - foaf_Person: foaf_givenName: John J. foaf_name: Welch, John J. foaf_surname: Welch bibo_doi: 10.1098/rsbl.2018.0881 bibo_issue: '4' bibo_volume: 15 dct_date: 2019^xs_gYear dct_identifier: - UT:000465405300010 dct_isPartOf: - http://id.crossref.org/issn/17449561 - http://id.crossref.org/issn/1744957X dct_language: eng dct_publisher: Royal Society of London@ dct_title: The distribution of epistasis on simple fitness landscapes@ fabio_hasPubmedId: '31014191' ...