Data from: Relative effects of segregation and recombination on the evolution of sex in finite diploid populations

The mechanism of reproducing more viable offspring in response to
selection is considered as a major factor influencing the advantages of
sex. In diploids, sexual reproduction combines genotype by recombination
and segregation. Theoretical studies of sexual reproduction have
investigated the advantage of recombination in haploids. However, the
potential advantage of segregation in diploids is less studied. The
present study aimed to quantify the relative contribution of recombination
and segregation to the evolution of sex in finite diploids by using
multi-locus simulations. The model calculated the mean fitness of a
sexually or asexually reproduced offspring to describe the long-term
effects of sex. The evolutionary fate of a sex or recombination modifier
was also monitored to investigate the short-term effects of sex. We
considered two different scenarios of mutations in finite populations to
investigate the evolution of a sex or recombination modifier: (1) only
deleterious mutations were present and (2) a combination of deleterious
and beneficial mutations. Results showed that the combined segregation and
recombination strongly contributed to the evolution of sex in diploids. If
deleterious mutations were only present, segregation efficiently slowed
down the speed of Muller's ratchet. As the recombination level was
increased, the accumulation of deleterious mutations was totally inhibited
and substantially contributed to the evolution of sex. The presence of
beneficial mutations evidently increased the fixation rate of a
recombination modifier. We also observed that the twofold cost of sex was
easily to overcome in diploids if a sex modifier caused a moderate
frequency of sex.