Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Hill-Robertson Interference Maintained by Red Queen Dynamics Favours the Evolution of Sex (#314)

Jack Da Silva 1
  1. University of Adelaide, Adelaide, SA, Australia

Although it is well established theoretically that selective interference among mutations coexisting on different genetic backgrounds (Hill-Robertson interference) favours meiotic recombination, genome-wide mean rates of mutation and strengths of selection appear too low to support selective interference as the mechanism favouring recombination in nature. A possible solution to this discrepancy between theory and observation is that selection is intermittently very strong due to the antagonistic coevolution between a host and its parasites. The Red Queen theory posits that such coevolution generates negative fitness epistasis among loci, which in turn generates negative linkages among alleles that favour recombination. However, Red Queen dynamics without epistasis may provide the ecological conditions that maintain strong and frequent selective interference. This hypothesis is developed here using recursion equations to simulate Hill-Robertson interference with Red Queen dynamics. A method is developed that allows the frequencies of haplotypes with an arbitrary number of loci to be calculated after recombination. Simulations show that an allele for recombination at a modifier locus is most strongly favoured when there are many selected loci and when the strength of selection, the mutation rate and population size are moderately large. Recombination is also most strongly favoured when a host and its parasites have similar evolutionary dynamics.