Computer experiments on the evolution of sex: the haploid case.

We have conducted a set of computer experiments that investigate the conditions under which sexual reproduction can evolve. In these experiments, haploid genomes are treated as integer strings able to undergo mutation and, in the case of sexual strings, recombination, with string sequence (the genotype) determining fitness. Our results indicate that the likelihood of a rare sexual mutant spreading through an otherwise asexual population is small when sexual reproduction entails the classical two-fold cost of males. However, our results indicate that when mutation rates are not excessively high, sexual reproduction constitutes a more efficient fitness optimization algorithm, allowing a sexual population to adapt more quickly to its environment than an asexual population.