  We study the impact of a hard selective sweep on the genealogy of partially
linked neutral loci in the vicinity of the positively selected allele. We
consider a sexual population of stochastically varying size and, focusing on
two neighboring loci, derive an approximate formula for the neutral genealogy
of a sample of individuals taken at the end of the sweep. Individuals are
characterized by ecological parameters depending on their genetic type and
governing their growth rate and interactions with other individuals
(competition). As a consequence, the "fitness" of an individual depends on the
population state and is not an intrinsic characteristic of individuals. We
provide a deep insight into the dynamics of the mutant and wild type
populations during the different stages of a selective sweep.
