DISSERTATION RESEARCH: Local adaptation of stress physiology in Rana Sylvatica

环境诱导的应激在生物体的生活史中是常见的，并且在很大程度上，生物体对这些应激源的反应决定了成功的生存和繁殖。因此，为了了解环境和生物体性能之间的反馈，必须确定生物体是否以及如何适应其表型反应以适应常见的应激源，如捕食者。这些对压力源的反应可能以生物体当前和未来的性能为代价。该项目旨在确定沿幼虫捕食风险梯度生活的林蛙（Rana sylvatica）种群是否以及如何对应激反应进行局部适应。该项目将采用一种普通的花园方法，结合应激激素控制，测试两种可能的适应机制，这两种机制将降低高捕食者池塘的应激成本：减少对捕食者的应激激素产生，减少对循环应激激素的生理反应。如果长期对捕食者的持续存在做出反应的成本大于收益，那么研究人员预计，在高捕食者池塘中生活的蝌蚪要么会减少应激激素的产生，要么会减少对实验中升高的应激激素的反应。这个项目的结果将有助于我们对环境压力对生物体的影响的总体理解，并提供对两栖动物如何能够（或不能）应对长期环境挑战的见解。此外，该项目将提供机会，让本科生参与初级研究，并向当地土地所有者提供有关其池塘和湿地所支持的两栖动物和其他生物的公共宣传和教育。

Environmentally-induced stress is common in the life histories of organisms, and, to a large extent, the organism's response to those stressors determines successful survival and reproduction. Therefore, in order to understand feedbacks between environment and organism performance, it must be determined whether and how organisms adapt their phenotypic responses to commonly encountered stressors such as predators. These responses to stressors may come at both current and future costs to the organisms performance. This project aims to determine whether and how local adaptation of the stress response occurs in populations of wood frogs (Rana sylvatica) that live along a gradient of larval predation risk. Using a common-garden approach coupled with stress hormone manipulation, the project will test for adaptation in two potential mechanisms that would reduce the costs of stress in high-predator ponds: reduction of stress hormone production to predators, and reduction of physiological responsiveness to circulating stress hormones. If the cost of chronically responding to the constant presence of predators is greater than the benefit, then investigators expect that tadpoles from populations in high-predator ponds will exhibit either reduction of their production of stress hormones or reduction in their response to experimentally-elevated stress hormones. The results from this project will contribute to our general understanding of the effects of environmental stress on organisms as well as provide insights into how amphibians in particular are able (or unable) to cope with chronic environmental challenges. In addition, this project will provide opportunities for involving undergraduates in primary research, as well as incorporating public outreach and education to local landowners regarding the amphibians and other organisms their ponds and wetlands support.