E&ERC PhD candidate Nathan Burke won 1st prize in the National Evolutionary Synthesis Center's 2015 evolution film festival with his video "Escaping the Sex Trap" Congratulations Nathan
Almost all multicellular organisms reproduce sexually, but it isn’t entirely clear why this should be the case. Since sex is associated with a number of large costs, evolutionary theory predicts that organisms that reproduce asexually (clonally) should avoid these costs and thereby outcompete and outnumber organisms that reproduce sexually. Why there is such a mismatch between this theoretical prediction and biological reality is one of the most puzzling paradoxes in evolutionary biology. It is assumed that for sex to be so common, it must confer very large benefits to cancel out the costs. But it’s unclear whether such benefits exist. My research tests whether sex might be common not because it confers some yet-to-be-discovered benefit, but because it is an evolutionary trap maintained by sexual conflict. According to this hypothesis, harmful males, by coercing females to mate against their evolutionary interests, ensure that costly sex persists and clonal reproduction is inhibited. My research on the spiny leaf stick insect - a phasmatid capable of both sexual and asexual reproduction - suggests that females might be able to escape this sex trap and maintain asexual reproduction by producing weak pheromonal signals that do not attract males and by strongly resisting matings. This research raises some intriguing questions: Are coercive males responsible for the dominance of sexual reproduction? Can female resistance lead to the extinction of males and the loss of sex?