Dissertation Research: Feedback between ecological interactions and evolutionary processes in a trophic cascade

营养级联，即捕食者抑制食草动物从而间接使植物受益的生态相互作用，是研究最广泛的多物种相互作用之一。本研究将探讨营养级联如何影响常见猴花植物（Mimulus guttatus）的自然选择和进化。将在野外对节肢食草动物和掠食性蜘蛛的存在进行控制，并测量几种遗传可变植物性状的反应，以评估与这些处理相关的选择压力的变化。植物性状的变化也有可能影响营养级联的强度。这种反馈机制的重要性将直接衡量，通过在下一季的每个处理中种植每个处理的植物后代，以及间接衡量，通过使用人工选择来操纵植物性状，然后将选择的品系放入每个处理中。了解生态群落中复杂的多物种相互作用仍然是生态学的一个关键挑战。这项研究的智力价值在于，它将增加我们对复杂生态群落中遗传变异、自然选择和多物种相互作用之间相互作用的理解。这项研究的更广泛的影响包括培训学生，它将为管理自然和农业系统中的物种多样性和遗传多样性产生重要的见解。了解不同物种之间的可变相互作用和物种内部存在的遗传变异之间的潜在反馈，也将有助于预测物种多样性和遗传多样性被人类改变时生态群落将如何变化。

Trophic cascades, ecological interactions in which predators suppress herbivores and so indirectly benefit plants, are among the most widely studied multi-species interactions. This research will examine how trophic cascades affect natural selection and evolution of the common monkey flower plant (Mimulus guttatus). The presence of both arthropod herbivores and predatory spiders will be manipulated in the field and responses of several genetically-variable plant traits will be measured to assess changes in selection pressures associated with those treatments. Changes in plant traits also have the potential to influence the strength of trophic cascades. The importance of this feedback mechanism will be measured directly, by growing offspring of plants from each treatment in every treatment the following season, and indirectly, by using artificial selection to manipulate plant traits and then placing selected lines into each treatment. Understanding complex multi-species interactions in ecological communities remains a key challenge for ecology. The intellectual merit of this research is that it will add to our understanding of the interplay between genetic variation, natural selection, and multi-species interactions in complex ecological communities. The broader impacts of the research include student training, and that it will generate important insights for managing both species diversity and genetic diversity in natural and agricultural systems. Understanding potential feedbacks between the variable interactions among different species and the genetic variation present within species will also help in predicting how ecological communities will change as species diversity and genetic diversity are altered by humans.