Invasion and fixation of sex-reversal genes

J Evol Biol. 2007 May;20(3):913-20. doi: 10.1111/j.1420-9101.2007.01311.x.


We simulated a meta-population with random dispersal among demes but local mating within demes to investigate conditions under which a dominant female-determining gene W, with no individual selection advantage, can invade and become fixed in females, changing the population from male to female heterogamety. Starting with one mutant W in a single deme, the interaction of sex ratio selection and random genetic drift causes W to be fixed among females more often than a comparable neutral mutation with no influence on sex determination, even when YY males have slightly reduced viability. Meta-population structure and interdeme selection can also favour the fixation of W. The reverse transition from female to male heterogamety can also occur with higher probability than for a comparable neutral mutation. These results help to explain the involvement of sex-determining genes in the evolution of sex chromosomes and in sexual selection and speciation.

MeSH terms

  • Animals
  • Evolution, Molecular
  • Female
  • Genetic Drift
  • Genetic Speciation
  • Genotype
  • Male
  • Models, Genetic*
  • Mutation
  • Population Density
  • Sex Chromosomes
  • Sex Determination Processes*
  • Sex Ratio