International Research Fellowship Program: When Does Nature Favor Chaos?: Metapopulation Dynamics, Life History Evolution, and Multi-Level Selection

国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。该计划的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持Jeffrey A.Fletcher博士与加拿大不列颠哥伦比亚省温哥华不列颠哥伦比亚大学Letisa Aviles博士合作的为期22个月的研究奖学金。该项目涉及集合种群动态、生活史进化和多水平选择。群居蜘蛛和疟疾寄生虫是高度分化的集合种群系统的两个例子，在这种集合种群系统中，偏向的性别比例和快速的局部增长可能与内在的动态不稳定性和多层次的选择有关。考虑到这样的模型系统以及经验和理论方法的结合，PI和宿主将探索：(1)允许局部混沌动态演变和进化稳定的因素；(2)不同程度的种群细分以及灭绝和再殖民的速度如何影响影响种群动态的生活史特征的多水平选择；(3)种群划分之间和群体内的自然选择如何改变种群规模和性别比例，以达到特定的局部种群增长率。这些问题的研究包括：(1)基于个体的计算机模拟模型，包括性别比例和窝卵大小的共同进化特征，以及不同程度的种群细分；(2)利用现有的人口普查时间序列数据以及有关生活史特征和种群细分程度的现有文献进行的跨物种研究；(3)对各种相关的热带社会蜘蛛物种的协作实证研究。该项目预计将耗时两年，包括两个月的拉丁美洲之旅。这项工作的预期成果包括：(1)开发可共享的软件，研究选择水平、生活史特征和种群动态之间的关系；(2)加强对生活史特征如何影响其他高度细分的种群中种群动态的理解，包括生活在高度分散环境中的濒危物种和寄生在宿主(如疟疾)中的寄生虫；(3)本科生和研究生参与这一项目；以及(4)通过课堂客座讲座和为不同教育水平的听众举办的研讨会来分享研究结果。

0402136FletcherThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-two-month research fellowship by Dr. Jeffrey A. Fletcher to work with Dr. Leticia Aviles at University of British Columbia in Vancouver, British Columbia, Canada.This project is about metapopulation dynamics, life history evolution and multilevel selection. The social spiders and malaria parasites are two examples of strongly subdivided metapopulation systems where biased sex ratios and fast rates of local growth may be associated with intrinsic dynamical instability and multiple levels of selection. With such model systems in mind and a combination and empirical and theoretical methods, the PI and host will explore: (1) the factors that allow locally chaotic dynamics to evolve and be evolutionary stable, (2) how different degrees of population subdivision and rates of extinction and recolonization influence multilevel selection on life history traits that affect population dynamics; and (3) how natural selection acting among and within groups partitions changes in brood size and sex ratio to arrive at a particular local population growth rate. These questions are investigated with: (1) an individual-based computer simulation model with coevolving traits for sex ratio and clutch size, and variable degrees of population subdivision; (2) a cross-species study using existing population census time series data as well as existing literature on relevant life history traits and degrees of population subdivision; (3) collaborative empirical studies on various related species of neotropical social spiders. This project is expected to take two years and involve two month-long trips to Latin America. Expected outcomes of this work include: (1) development of sharable software to study the relationship between levels of selection, life history traits, and population dynamics; (2) enhanced understanding of how life history traits influence population dynamics in other highly subdivided populations including endangered species living in highly fragmented environments and parasites living in hosts (e.g. malaria); (3) involvement of undergraduate and graduate students in this project; and (4) sharing findings through guest lectures in classrooms and seminars for audiences of various educational levels.