DISSERTATION RESEARCH: Adaptation to variable ultraviolet radiation threats in alpine Daphnia populations.

生物如何通过自然选择进化以耐受环境中的压力？在这个项目中，研究人员试图了解淡水动物是如何进化到能够耐受高山生态系统中清水池塘中有害的紫外线辐射的。研究人员将重点放在华盛顿州奥林匹克国家公园高山池塘中广泛分布的浮游动物蚤状水蚤上，这些池塘对紫外线辐射具有一定的耐受性。调查人员进行了三方面的调查：1）了解不同种群对紫外线辐射的耐受性如何变化，2）了解紫外线辐射耐受性是否是一种诱导性状，和3）利用遗传学和分析方法阐明自然选择在水蚤种群适应环境中紫外线辐射威胁方面的作用。全球气候的间接影响据了解，水下紫外线辐射状况的变化比臭氧洞的影响更大。该项目将扩大我们对浮游动物种群如何进化以在高紫外线辐射暴露下持续存在的理解。这将作为一个预测模型，预测其他种群在气候变化和管理战略面前可能或可能无法坚持下去。因此，该项目的智力贡献是双重的，特别是为我们了解和预测浮游动物对高山栖息地环境压力的反应提供了信息，并更广泛地阐明了在全球气候变化时代，种群如何适应可变环境压力的进化过程。

How do organisms evolve via natural selection to tolerate stresses in their environments? In this project the investigators seek to understand how freshwater animals have evolved to tolerate harmful ultraviolet radiation in the clear-water ponds of an alpine ecosystem. The investigators focus on the widespread zooplankton Daphnia pulex in alpine ponds that span a range of transparencies to ultraviolet radiation in Olympic National Park, WA. The investigators pursue three lines of inquiry: 1) to understand how tolerance of ultraviolet radiation varies among populations, 2) to understand whether the tolerance of ultraviolet radiation is an inducible trait, and 3) to use genetic and analytical methods to elucidate the role of evolution by natural selection in adapting populations of Daphnia to the ultraviolet radiation threats in their environment.The indirect effects of global climate change on underwater ultraviolet radiation regimes are understood to be stronger than the effect of the ozone hole. This project will expand our understanding of how a zooplankton population has evolved to persist in the presence of high ultraviolet radiation exposure. This will serve as a predictive model for how other populations may or may not be able to persist in the face of climatic changes and management strategies. The intellectual contributions of this project are therefore twofold, specifically informing our understanding and predictions of zooplankton responses to environmental stress in alpine habitats, and more broadly illuminating the evolutionary process of how populations adapt to variable environmental pressures in an era of global climate change.