Genealogies of two linked neutral loci after a selective sweep in a large population of stochastically varying size

TL;DR

This paper analyzes how a strong selective sweep affects the genealogies of two linked neutral loci in a large, stochastically varying population, providing an approximate formula for the neutral genealogy post-sweep.

Contribution

It introduces a novel model considering ecological parameters and population variability to derive genealogies of linked neutral loci after a selective sweep.

Findings

Derived an approximate formula for neutral genealogy after a sweep

Provided insights into population dynamics during the sweep

Highlighted the dependence of fitness on population state

Abstract

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.