Waiting for love but not forever: Modeling the evolution of waiting time to selfing in hermaphrodites

Although mixed mating systems involving both selfing and outcrossing are fairly common in hermaphrodites, the mechanisms maintaining still unknown many cases. In some species, individuals that have not yet found a partner delay self-fertilization for time. This “waiting time” to (WT) can exhibit heritable variation between is subject two opposing selection pressures: waiting longer increases density-dependent probability encounter mate within time thereby chance avoid inbreeding depression (ID) offspring, but also risk of dying before reproduction. It has long been hypothesized fluctuations population density thus availability lead stable intermediate WTs, our knowledge there so far no quantitative models take into account joint evolutionary dynamics ID. We use an individual-based model mathematical approximation explore how delayed evolves response fluctuations. find at high density, when meet often, WT evolution dominated by genetic drift; densities, strong ID causes increase; low purged approaches zero. Positive feedback loops drive system either complete or outcrossing. Fluctuating slow down convergence these alternative states. However, mating, sense polymorphism WT, times, was never observed. Thus, additional factors need be explored explain persistence selfing.