DISSERTATION RESEARCH: The role of selection, gene flow, and range limits in determining adaptive phenotypes

根据遗传变异、自然选择的强度以及来自附近种群的基因流动的数量和性质，物种范围限制可以是适应性多样性高或低的区域。本研究采用田间实验的方法，研究了内华达山脉一年生植物Mimulus laciniatus的基因流和选择在适应多样性中的作用。初步数据揭示了气候适应在低海拔和高海拔范围的限制。沿着这些范围限制确定选择性质的实验正在进行中，而实验交配将提供对基因流动的作用的理解，从远的和近的种群，在范围边缘的适应潜力。最后，遗传标记（微卫星）被用于估计物种范围内的基因流动和种群规模。除了提供关于范围限制的进化的基本见解外，这项研究还将在气候变化导致栖息地日益温暖的时候为物种管理和保护工作提供信息。山地系统拥有令人印象深刻的植物物种多样性。了解遗传多样性、基因流动和气候适应如何相互作用，可能有助于制定更广泛地保护这些独特植物群的策略。此外，该项目继续支持本科生，包括许多科学界代表性不足的群体的成员；学生以研究助理的身份参与，并经常开发自己的独立研究项目。

Species range limits can be areas of high or low adaptive diversity depending on genetic variation, the strength of natural selection, and the amount and nature of gene flow from nearby populations. In this study, field experiments are used to understand the role of gene flow and selection in the adaptive diversity of Mimulus laciniatus, a Sierra Nevada annual plant with a restricted, well-defined geographic range. Preliminary data reveal climate adaptations at low- and high-elevation range limits. Experiments to determine the nature of selection along these range limits are ongoing while experimental matings will provide an understanding of the role of gene flow, from both far and nearby populations, on adaptive potential at range edges. Finally, genetic markers (microsatellites) are being used to estimate gene flow and population sizes across the species range. In addition to providing basic insights about evolution at range limits, this research will inform species management and conservation efforts at a time when climate change is resulting in increasingly warmer habitats. Mountain systems host an impressive diversity of plant species. Developing an understanding of how genetic diversity, gene flow, and climate adaptation interact may contribute to strategies aimed more broadly at conserving these unique floras. Additionally, this project continues to support undergraduates, including many members of underrepresented groups in science; students participate as research assistants and often develop their own independent research projects.