The polymorphism frequency spectrum of finitely many sites under selection.

摘要: The distribution of genetic polymorphisms in a population contains information about evolutionary processes. Poisson random field (PRF) model uses the polymorphism frequency spectrum to infer mutation rate and strength directional selection. PRF relies on an infinite-sites approximation that is reasonable for most eukaryotic populations, but becomes problematic when θ large (θ ≳ 0.05). Here, we show at rates characteristic microbes viruses induces systematic biases lead it underestimate negative selection pressures erroneously positive We introduce two new methods extend our ability θ: finite-site modification technique based diffusion theory. Our can be used not only “weighted average” acting gene sequence, also across sites. evaluate accuracy methods, as well original approach, by comparison with Wright–Fisher simulations.