Inferring the Distribution of Fitness Effects (DFE) of Newly-Arising Mutations Using Samples Taken from Evolving Populations in Real Time
The DFE characterizes the mutational “input” to evolution, while natural selection largely determines how this input gets sorted into an evolutionary “output”. The output cannot contain novel genetic material that is not present in the input and, as such, understanding the DFE and its dynamics is crucial to understanding evolution generally. Despite this centrality to evolution, however, the DFE has remained elusive primarily due to methodological difficulties. Here, we propose and assess a novel framework for estimating the DFE which removes the biasing effects of selection statistically. We propose a statistic for characterizing the difference between two inferred DFEs, taken from two different populations or from the same population at different time points. This allows us to study the evolution of the DFE and monitor for structural changes in the DFE.
KeywordsAdaptive evolution Fitness mutation Population genetics Cumulant expansion Empirical characteristic function
We thank Guillaume Martin, Thomas Burr, Paul Sniegowski, Tanya Singh, Thomas Bataillon, and Eduarda Pimentel for helpful discussions, and three anonymous referees. PG carried out some of this work while visiting Aarhus University, Denmark. PG received financial support from NASA grant NNA15BB04A.