Evolution of Reproductive Efficiency in Caenorhabditis elegans Under Obligatory Outcrossing

Abstract Radical shifts in reproductive systems result radical changes selective pressures acting on traits. Nematode Caenorhabditis elegans constitutes one of rare model where such can be experimentally induced, providing an opportunity for studying the evolution phenotypes real time. Evolutionary history predominantly selfing reproduction has led to degeneration traits involved outcrossing, making it inefficient. Here, we introduced obligatory outcrossing into isogenic lines C. and allowed replicate populations evolve under new system. We predicted that they should higher efficiency, leading increased fitness relative unevolved ancestors. To test this prediction, assayed both ancestral evolved populations. control potentially confounding effect adaptation laboratory conditions, also with wild-type (selfing) In five experimental blocks, measured competitive 12 (6 6 selfing) after ca. 95 generations evolution, along their respective On average, found by 0.72 SD (± 0.3 CI) 0.52 0.35 populations, suggesting further conditions types. Contrary predictions, increase was not significantly no detectable changed Importantly, results individual varied strongly between some cases even differing direction. This emphasises importance replication avoiding reporting false findings.