The genetic architecture of local adaptation and reproductive isolation in sympatry within the Mimulus guttatus species complex

The genetic architecture of local adaptation has been of central interest to evolutionary biologists since the modern synthesis. In addition to classic theory on the effect size of adaptive mutations by Fisher, Kimura and Orr, recent theory addresses the genetic architecture of local adaptation in the face of ongoing gene flow. This theory predicts that with substantial gene flow between populations local adaptation should proceed primarily through mutations of large effect or tightly linked clusters of smaller effect loci. In this study, we investigate the genetic architecture of divergence in flowering time, mating system-related traits, and leaf shape between Mimulus laciniatus and a sympatric population of its close relative M. guttatus. These three traits are probably involved in M. laciniatus’ adaptation to a dry, exposed granite outcrop environment. Flowering time and mating system differences are also reproductive isolating barriers making them ‘magic traits’. Phenotypic hybrids...自现代综合进化论（modern synthesis）确立以来，局部适应的遗传架构一直是进化生物学家的核心研究议题。除费希尔（Fisher）、木村资生（Kimura）与奥尔（Orr）提出的适应突变效应量经典理论外，新近的理论针对持续发生基因流（gene flow）情境下的局部适应遗传架构展开了探讨。该理论预测，当种群间存在显著基因流时，局部适应主要通过大效应突变或紧密连锁的小效应位点簇实现。本研究探究了裂叶猴面花（Mimulus laciniatus）与其近缘物种斑点猴面花（Mimulus guttatus）的同域种群之间，在开花时间、交配系统相关性状以及叶片形状上的分化遗传架构。这三类性状大概率参与了裂叶猴面花对干燥、裸露花岗岩露头生境的适应过程。此外，开花时间与交配系统差异同时构成生殖隔离屏障，使其成为神奇性状（magic traits）。表型杂种……