Dissertation Research: Determining the Mechanisms of Recurrent Cline Evolution in White Clover (Trifolium repens)

调查适应的空间和时间尺度已被证明是困难的，因为生态重要特征的分子基础往往是复杂的。该项目研究了白色三叶草的适应过程，使用五个独立的地理梯度，在一个很好的特点称为氰生成（氰化物释放后，组织损伤）。具体来说，这项工作比较了整个三叶草基因组的遗传变异，在两个基因的变异基础氰，了解自然选择的程度，基因流，和其他过程是跨梯度保守的目标。还将研究每个梯度中的自适应变化的起源。此外，生态实验将被用来确定生态权衡，保持种群内的蓝藻变化。了解创造和维持生态重要性变化的过程是预测物种对环境变化的反应和制定未来政策的基础。这个建议调查这些过程在一个易处理的自然系统。这项工作将回答有关适应的广泛问题，同时为预测物种反应提供有用的案例研究。该提案对本科生和高中生进行了大量的教育推广，使用三叶草氰生成作为理解遗传学和生态学之间联系的基本教学工具。该项目还将在实验室和实地环境中为青年科学家和高中教师提供培训。

Investigating the spatial and temporal scales of adaptation has proven difficult because the molecular basis of ecologically important traits is often complex. This project examines in white clover the process of adaptation using five independent geographical gradients in a well-characterized trait called cyanogenesis (cyanide release after tissue damage). Specifically, this work compares genetic variation throughout the clover genome to variation in the two genes underlying cyanogenesis, with the goal of understanding the degree to which natural selection, gene flow, and other processes are conserved across gradients. The origins of the adaptive variation in each gradient will also be investigated. Further, ecological experiments will be used to identify the ecological trade-offs that maintain cyanogenesis variation within populations. Understanding the processes that create and maintain ecologically important variation is fundamental in making predictions regarding species responses to changing environments and establishing future policy. This proposal investigates these processes in a tractable natural system. This work will answer broad questions about adaptation while providing a useful case study for predicting species responses. This proposal carries a large educational outreach component for undergraduates and high school students, using clover cyanogenesis as a basic teaching tool for understanding the connection between genetics and ecology. The project will also provide training to young scientists and high school teachers in laboratory and field settings.