Data from: Selfing can facilitate transitions between pollination syndromes

Pollinator-mediated selection on plants can favor transitions to a new pollinator depending on the relative abundances and efficiencies of pollinators present in the community. A frequently observed example is the transition from bee pollination to hummingbird pollination. We present a population genetic model that examines whether the ability to inbreed can influence evolutionary change in traits that underlie pollinator attraction. We find that a transition to a more efficient, but less abundant pollinator is favored under a broadened set of ecological conditions if plants are capable of delayed selfing rather than obligately outcrossing. Delayed selfing allows plants carrying an allele that attracts the novel pollinator to reproduce even when this pollinator is rare, providing reproductive assurance. In addition, delayed selfing weakens the effects of Haldane's sieve by increasing the fixation probability for recessive alleles that confer adaptation to the new pollinator. Our model provides novel insight into the paradoxical abundance of recessive mutations in adaptation to hummingbird attraction. It further predicts that transitions to efficient but less abundant pollinators (such as hummingbirds in certain communities) should disproportionately occur in self-compatible lineages. Currently available mating system datasets are consistent with this prediction and we suggest future areas of research that will enable a rigorous test of this theory.传粉者介导的植物选择偏好向新传粉者类群的演化过渡，其选择方向取决于群落内现有传粉者的相对丰度与传粉效率。其中一类被频繁观测到的过渡模式，便是从蜂类传粉转向蜂鸟传粉。我们构建了种群遗传学模型，用以探究近交能力是否会影响传粉者吸引相关性状的演化变化。研究结果表明，若植物具备延迟自交（delayed selfing）能力而非专性异交，那么在更宽泛的生态条件下，向更高效但丰度更低的传粉者类群的过渡会受到自然选择的青睐。延迟自交可使携带吸引新型传粉者等位基因的植物，即便该新型传粉者较为稀少时仍能完成繁殖，从而提供繁殖保障。此外，延迟自交还会通过提升赋予植物对新型传粉者适应性的隐性等位基因的固定概率，削弱霍尔丹筛（Haldane's sieve）的作用效应。 本模型为“蜂鸟传粉适应性演化中隐性突变异常丰富”这一悖论提供了全新的研究视角。研究进一步预测，向高效但丰度较低的传粉者类群（如部分群落中的蜂鸟）的演化过渡，应不成比例地更多发生在自交亲和的演化支系中。当前可用的交配系统数据集与这一预测相符，我们还提出了可用于严格检验该理论的未来研究方向。