Interference of Competing Beneficial Mutations on Recombining Chromosomes

Finding signatures of selective sweeps in genomes is a major goal of current population genomics, as it allows estimating the rate of beneficial mutations going to fixation and identifying the genes involved in selection. Models of recurrent selective sweeps traditionally assume that in chromosomal regions of normal recombination rates at most one beneficial allele is on the way to fixation. We review and extend here the theoretical studies on interference between closely linked beneficial mutations suggesting that this assumption may be violated. We show that interference between beneficial mutations may lead to substantially increased fixation times even in chromosomal regions of normal recombination rates. Furthermore, we discuss how interference can be detected in population genomic studies by analyzing genetic footprints of selective sweeps, and search for empirical evidence of interference in published datasets.