DISSERTATION RESEARCH: Comparative thermal physiology and evolution of Australo-papuan Eugongylus skinks: testing Janzen's hypothesis for gradients in species diversity

了解温度生理学对于理解许多生物现象是必要的，例如生长的时间和空间模式，物种多样性和范围大小。热生理学的比较研究也深入了解内在的生理限制如何影响物种形成的倾向，并解释宏观进化模式，如纬度多样性梯度。拟议的研究将检查温度的反应和性状的一组相关的森林蜥蜴跨越广泛的纬度梯度（热带新几内亚温带塔斯马尼亚）和山地和低地类群之间，所有在系统发育的背景下。中心的预测是，热耐受性的宽度将在低纬度比高纬度和更广泛的物种在高海拔比低海拔。耐热性和其他生理参数的测量将被认为是与地理数据的关系，以测试假设，热带类群更容易地形隔离，因此，由于生理限制的物种形成。该项目旨在阐明一个主要的宏观进化模式，纬度多样性梯度负责的机制，但它也有保护的影响。为了尽量减少生物多样性的损失，必须根据脆弱性确定保护区的优先次序，以此来管理生态系统，这就要求查明影响环境变化敏感性的因素。敏感性受物种的内在特征控制，例如生理限制。当外推到可能导致范围转移或减少的新情况时，整合生理特征的机械物种分布模型可能提供更大的预测能力。通过这项研究估计的物种的热生理特性将被纳入这些模型，以评估哪些物种可能是最脆弱的即将到来的气候变化，从而确定保护的优先事项。

An understanding of temperature physiology is necessary to comprehend many biological phenomena, such as temporal and spatial patterns of growth, species diversity, and range size. Comparative studies of thermal physiology also yield insight into how intrinsic physiological limits affect the propensity for speciation and explain macroevolutionary patterns, such as the latitudinal diversity gradient. The proposed research will examine temperature responses and traits for a set of related forest lizards across an extensive latitudinal gradient (tropical New Guinea to temperate Tasmania) and between montane and lowland taxa, all in a phylogenetic context. Central predictions are that thermal tolerance breadths will be narrower in species at lower than high latitudes and wider for species at high compared to low altitudes. Measurements of thermal tolerance and other physiological parameters will be considered in relation to phylogeographic data to test the hypothesis that tropical taxa are more prone to topographic isolation and hence speciation due to physiological limits. This project seeks to explicate mechanisms responsible for a major macroevolutionary pattern, the latitudinal diversity gradient, but it also has implications for conservation. To minimize biodiversity loss, ecosystems must be managed by prioritizing conservation areas based on vulnerability, which requires that factors governing sensitivity to environmental change be identified. Sensitivity is controlled by intrinsic traits of a species, such as physiological limits. Mechanistic species distribution models that integrate physiological traits may provide greater predictive power when extrapolating to novel situations likely to cause range shifts or extinctions. Thermal physiological traits of species estimated through this research will be incorporated into such models to assess which species might be most vulnerable with impending climate change and thus identify conservation priorities.