DISSERTATION RESEARCH: Experimental Evolution of Mating System under Varying Pollinator Availability in Mimulus guttatus

植物交配系统的进化一直是进化生物学史上一个备受关注的话题。尽管对交配系统的变化有广泛的描述，但对交配系统转变的具体机制仍有很大的未知。本研究将以黄猴花（Mimulus guttatus）为模型系统，提供从异交到自花受精过渡过程中最直接的进化变化的全面量化。第一个目标是探索在经历相反传粉者制度的种群中随时间的表型和遗传变化：丰富的大黄蜂（Bombus）传粉者与无传粉者。这种转变以前从未在实验室中使用实验进化直接观察到。第二个目标是研究Bombus和Mimulus之间的机制关系；确定蜜蜂授粉群体中的特定选择压力，例如传粉者偏好对自然选择的贡献。这些研究将检验在传粉者限制下自花受精的机制进化，这在今天至关重要。人类活动通过景观改造和气候变化改变了植物与传粉者的相互作用。此外，在项目过程中，本科生将在项目实验设计、数据收集、分析和结果传播方面接受专门的培训和指导。

The evolution of plant mating systems has been a topic of great interest throughout the history of evolutionary biology. Despite the extensive description of mating system variation, a great deal remains unknown about the specific mechanisms involved in mating system transitions. The proposed studies will provide a comprehensive quantification of the most immediate evolutionary changes in the transition from outcrossing to self-fertilization using Mimulus guttatus, the yellow monkeyflower, as a model system. The first objective explores phenotypic and genetic changes over time in populations experiencing opposing pollinator regimes: abundant bumblebee (Bombus) pollinators vs. no pollinators. This transition has never before been observed directly in the laboratory using experimental evolution. The second objective will investigate the mechanistic relationship between Bombus and Mimulus; identifying specific selective pressures in bee-pollinated populations such as the contribution of pollinator preference to natural selection. These studies will examine the mechanistic evolution of self-fertilization under pollinator limitation, vitally important in today?s changing world as human activities alter plant-pollinator interactions through landscape modification and climate change. In addition, during the course of the project undergraduate students will receive specialized training and mentorship in project experimental design, data collection, analysis, and dissemination of results.