DISSERTATION RESEARCH: Local adaptation of stress physiology in Rana Sylvatica

环境诱导的应激在生物体的生命历史中是常见的，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，为了理解环境和生物体表现之间的反馈，必须确定生物体是否以及如何适应常见的应激因素，如捕食者。这些对应激源的反应可能会以生物体当前和未来的表现为代价。该项目旨在确定是否以及如何在沿幼虫捕食风险梯度生活的林蛙种群中发生应激反应的局部适应。使用普通花园方法和压力激素操作，该项目将测试两种潜在机制的适应性，这两种机制将降低高度捕食者池塘的压力成本：减少对捕食者的应激激素产生，以及降低对循环应激激素的生理反应。如果长期对捕食者的存在做出反应的成本大于收益，那么研究人员预计，来自高度捕食者池塘种群的蝌蚪要么会减少应激激素的产生，要么对实验中升高的应激激素的反应会减少。该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了解，并为两栖动物特别是如何能够(或无法)应对长期的环境挑战提供见解。此外，该项目将提供让本科生参与初级研究的机会，并向当地土地所有者提供关于他们的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.