Selective sweeps for recessive alleles and for other modes of dominance

J Math Biol. 2011 Sep;63(3):399-431. doi: 10.1007/s00285-010-0382-4. Epub 2010 Nov 13.

Abstract

A selective sweep describes the reduction of linked genetic variation due to strong positive selection. If s is the fitness advantage of a homozygote for the beneficial allele and h its dominance coefficient, it is usually assumed that h=1/2, i.e. the beneficial allele is co-dominant. We complement existing theory for selective sweeps by assuming that h is any value in [0, 1]. We show that genetic diversity patterns under selective sweeps with strength s and dominance 0 < h < 1 are similar to co-dominant sweeps with selection strength 2hs. Moreover, we focus on the case h=0 of a completely recessive beneficial allele. We find that the length of the sweep, i.e. the time from occurrence until fixation of the beneficial allele, is of the order of √(N/s) generations, if N is the population size. Simulations as well as our results show that genetic diversity patterns in the recessive case h=0 greatly differ from all other cases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles*
  • Computer Simulation
  • Genes, Recessive*
  • Genetic Variation
  • Models, Genetic*
  • Selection, Genetic