Fitness dependence preserves selection for recombination across diverse mixed mating systems

Meiotic recombination and the factors affecting its rate and fate in nature have inspired many theoretical studies in evolutionary biology. Classical theoretical models have inferred that non-zero recombination can be favoured under a rather restricted parameter range. Thus, the ubiquity of recombination in nature remains an open question. However, these models assumed constant (uniform) recombination with an equal rate across all individuals within the population. Models of fitness-dependent recombination, with the rate varying among genotypes according to their fitness have shown that such a strategy can often be favoured over the best constant recombination. Here we use simulations to show that across a range of mating systems with varying frequencies of selfing and clonality, fitness-dependent recombination is often favoured even when any non-zero constant recombination is disfavoured. This recombination-protecting effect of fitness dependence is strongest under intermediate rates of selfing or high rates of clonality.