Philip John Gerrish

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.