RT Journal Article
SR Electronic
T1 Transition densities and sample frequency spectra of diffusion processes with selection and variable population size
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 014639
DO 10.1101/014639
A1 Daniel Živković
A1 Matthias Steinrücken
A1 Yun S. Song
A1 Wolfgang Stephan
YR 2015
UL http://biorxiv.org/content/early/2015/02/02/014639.abstract
AB Advances in empirical population genetics have made apparent the need for models that simultaneously account for selection and demography. To address this need, we here study the Wright-Fisher diffusion under selection and variable effective population size. In the case of genic selection and piecewise-constant effective population sizes, we obtain the transition density function by extending a recently developed method for computing an accurate spectral representation for a constant population size. Utilizing this extension, we show how to compute the sample frequency spectrum (SFS) in the presence of genic selection and an arbitrary number of instantaneous changes in the effective population size. We also develop an alternate, efficient algorithm for computing the SFS using a method of moments. We apply these methods to answer the following questions: If neutrality is incorrectly assumed when there is selection, what effects does it have on demographic parameter estimation? Can the impact of negative selection be observed in populations that undergo strong exponential growth?