Wolfgang Stephan

Early split between African and European populations of Drosophila melanogaster

The paper compares demographic scenarios between African and European Drosophila melanogaster populations using new genomic data, finding that gene flow improves model fit and suggests an older divergence time.

Transition densities and sample frequency spectra of diffusion processes with selection and variable population size

The paper develops methods to compute the sample frequency spectrum under selection and variable population size, and applies them to assess the effects of selection on demographic parameter estimation and detect negative selection in growing populations.