ABSTRACT
Sexual conflict involving male coercion has been suggested as a possible mechanism for the maintenance of costly sexual reproduction, offering a potential resolution to the ‘paradox of sex’. However, the potential for sexual conflict to promote sexual reproduction may depend on ecological and genetic factors that influence the dynamics of sexually antagonistic coevolution. We investigated the conditions whereby male coercion could impede the invasion of asexual mutants and prevent transitions from sexual to asexual reproduction using a series of individual-based simulation models that vary in the ecology and genetic architecture of sexual antagonism. We show that a mutant allele that gives virgin females the ability to reproduce parthenogenetically easily invades obligately sexual populations over a broad parameter range via the fecundity advantage of occasional reproduction before mating. However, male coercion prevents transitions from facultative to obligate asexuality unless females evolve effective resistance. The potential for loss of sex can therefore depend on the dynamics of sexual arms races. Our results reveal the complementary roles of mate scarcity and female resistance in promoting the spread of asexual strategies. Our results also suggest that the costs and limitations of female resistance can be key factors in the maintenance of sexual reproduction, and that males’ ability to overcome female resistance can turn sex into an evolutionary trap.