Postdoctoral Research Fellowships in Biology for FY 2009

这一行动为NSF 2009财年博士后研究奖学金提供了资金。该奖学金支持杰森·布朗的一项研究和培训计划，名为“将物种分布模型、地理信息系统和联合系统学方法整合到系统地理学研究中”。这项研究的主办机构是密歇根大学，赞助科学家是Lacey Knowls。整合物种分布模型、基于聚合体的系统发育和地理信息系统为生物地理学提供了一个新的视角，并可以极大地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于保护两栖动物(该项目的重点分类群)尤为重要，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、降雨量)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了栖息地适宜性地图，指明了高适宜性和低适宜性区域。这使得物种分布可以被视为适合和不适合栖息地的梯度，从而更准确地反映出特定景观的扩散潜力。利用这些“扩散景观”、基于融合的系统发育和地理信息系统，这项研究(1)估计了谱系之间现实的扩散网络，然后可以用来估计每个目标物种在几个时期的关键扩散路线，以及(2)使用改进的“扩散景观”来检验不同时期的生物地理假说。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、融合系统发生学和地理信息系统专业知识的持续发展，特别强调开发一种严谨和连贯的方法来评估物种扩散网络，以及可靠性的统计测试。这项研究的更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.