Postdoctoral Research Fellowships in Biology for FY 2009

本行动资助NSF 2009年度博士后研究奖学金。该奖学金支持杰森·布朗的一项名为“将物种分布模型、地理信息系统和聚合系统发育方法整合到系统地理学研究中”的研究和培训计划。这项研究的主办机构是密歇根大学，赞助科学家是蕾西·诺尔斯。整合物种分布模型、聚结系统和地理信息系统为生物地理学提供了一个新的视角，可以大大提高我们对当前和历史物种分布模式的理解。更好地了解这些因素对两栖动物（该项目的重点分类群）的保护尤为重要，因为在过去的25年里，许多两栖动物的数量急剧减少。物种分布模型是利用各种气候和地理变量（如温度、降雨）预测物种分布的计算方法。由此产生的模型根据物种的生态耐受性生成栖息地适宜性图，指出高适宜性和低适宜性的区域。这使得物种分布被视为适宜和不适宜栖息地的梯度；从而更准确地反映特定景观的扩散潜力。利用这些“扩散景观”、基于聚结的系统发育和地理信息系统，本研究(1)估算了谱系谱系之间的现实扩散网络，然后可以用来估算每个目标物种在几个时间时期的关键扩散路线；(2)使用修改的“扩散景观”来测试不同时间时期的生物地理学假设。该中心的培训和教育目标包括计算机编程、理论生物地理学和假设检验、聚结系统发育，以及继续发展地理信息系统方面的专门知识，特别强调发展一种评估物种传播网络的严格和有凝聚力的方法，以及可靠性的统计测试。这项研究的广泛影响是更好地了解物种分布，以便在保护和恢复项目中加以考虑。

This action funds an NSF Postdoctoral Research Fellowship for FY 2009. The fellowship supports a research and training plan entitled "Integrating species distribution models, Geographic Information Systems and coalescent phylogenetic methods into phylogeography studies" for Jason Brown. The host institution for this research is the University of Michigan, and the sponsoring scientist is Lacey Knowles.Integrating species distribution models, coalescent-based phylogenies and geographic information systems provides a novel perspective on biogeography and could substantially improve our understanding of current and historic species distribution patterns. A better understanding of these factors is particularly important for the conservation of amphibians (the focal taxa of this project), many of which have dramatically declined in the past quarter-century. Species distribution models are calculations that predict the distribution of a species using various climatic and geographic variables (e.g. temperature, rainfall). The resulting model generates a habitat suitability map based on a species' ecological tolerance, indicating areas of high and low suitability. This allows species distributions to be treated as gradients of suitable and unsuitable habitat; thereby more accurately reflecting the dispersal potential across particular landscapes. Using these "dispersal landscapes," coalescent-based phylogenies and geographic information systems, this research (1) estimates realistic dispersal networks between genealogical lineages, which can then be used to estimate key dispersal routes for each target species at several periods in time, and (2) uses modified "dispersal landscapes" to test biogeographic hypotheses at different periods in time.The training and education objectives in include computer programming, theoretical biogeography and hypothesis testing, coalescent phylogenetics, and a continued development of expertise in Geographic Information Systems, with particular emphasis on the development of a rigorous and cohesive method for evaluating species dispersal networks, and statistical tests of reliability. The broader impacts of this research are to better understand species distributions for consideration in conservation and restoration projects.