Abstracts (first author)
Reproductive assurance drives mating system transitions to selfing
Evolutionary transitions from outcrossing to selfing are thought to occur because selfing reproductively assures the persistence of populations when mates or pollinators are unreliable. Direct evidence for reproductive assurance is however equivocal, in particular because outcrossing can easily overcome the adaptive benefits of selfing. To test for the impact of reproductive assurance by selfing, we performed invasion experiments of hermaphrodites into predominantly male-female populations of the nematode Caenorhabditis elegans. The invasion and fixation of selfing resulted in adaptation when populations evolved in a new environment that hindered mating. In contrast, when selfing failed to invade, adaptation to the novel environment was compromised because mating was possible. Using Monte Carlo simulations we further explored the factors that might have influenced the invasion dynamics of selfing. We confirm that reproductive assurance was responsible for the experimental transition from outcrossing to selfing.