MIP: Addressing the Role of Community Ecological Interactions in Population Niche Evolution along Hot Spring Thermal Gradients

了解决定地球上生物多样性起源和分布的因素是生态学和进化论的一个基本目标。虽然一组生物的潜在分布完全由其进化的环境容忍极限决定，但其实际实现的分布还取决于它与其他群落成员相互作用的结果。蒙大拿大学的Scott R.Miller博士获得了一项拨款，用于研究相互竞争的光合作用微生物(蓝藻和绿色非硫细菌)之间的相互作用如何塑造它们在黄石国家公园两个特征良好的温泉环境梯度(白溪和兔溪)上实现的分布模式。项目1将环境基因表达分析与实验室生理学实验相结合，以解决进化论的核心原则，即竞争物种的进化是为了减少竞争，方法是测试绿色非硫细菌在与竞争蓝藻高度分布重叠的地区是否表现出资源利用的遗传编程转变。项目2结合了遗传和生理方法来解决为什么不同的泉水蓝藻聚球藻B的丰度不同：这种蓝藻在Rabbit Creek的实际分布范围是White Creek的两倍。这些已实现分布上的差异是否是春天之间聚球菌B之间温度表现的不同程度遗传决定的差异的结果，以及生物在春天之间迁移能力的限制或竞争对手的排斥是否导致了这些差异。生态变异如何在群落内和群落之间分配，以及生态相互作用本身如何促进竞争生物的进化特征，这些问题在生态学和进化论中由来已久，但微生物在这些问题上的进展历来受到技术限制的阻碍。解决这些问题对我们理解微生物群落的组成和功能，以及它们如何应对环境变化具有重大意义。总而言之，这些项目有望从一个新的微生物角度对这些问题提供新的见解。因此，研究计划涉及将微生物生理学和基因组多样性与环境过程相结合的关键计划目标，以确定群落内生物相互作用的机制基础，并揭示微生物在时间和空间上的分布模式。该奖项通过支持研究生和本科生的培训，以及黄石温泉的皮？S温泉生物学课程，实现了研究和教育的整合。黄石温泉生物学课程是一门二年级课程，将这些温泉作为一个天然的教学实验室，提供动手操作的微生物研究体验。外展部分包括继续关注这些微生物群落，通过国家自然基金会国家Chautauqua研讨会暑期计划，为大学和高中教师举办的皮耶？S年度野外黄石温泉生物学课程。

Developing an understanding of the factors that determine the origins and distribution of biological diversity on the planet is a fundamental goal of ecology and evolution. Whereas the potential distribution of a group of organisms is determined solely by its evolved limits of environmental tolerance, its actual realized distribution also depends upon the outcome of its interactions with other community members. A grant has been awarded to Dr. Scott R. Miller of The University of Montana to investigate how interactions among competing photosynthetic microorganisms (cyanobacteria and green non-sulfur bacteria) have shaped their realized distribution patterns along two well-characterized hot spring environmental gradients (White Creek, Rabbit Creek) in Yellowstone NP. Project 1 integrates environmental gene expression analyses with laboratory physiology experiments to address the central tenet of evolutionary theory that competing species evolve to reduce competition by testing whether green non-sulfur bacteria exhibit a genetically-programmed shift in resource utilization in regions of strong distribution overlap with competing cyanobacteria. Project 2 combines genetic and physiological approaches to address why the different springs differ in the abundance of the cyanobacterium Synechococcus B: the realized distribution of this cyanobacterium is twice as broad at Rabbit Creek compared with White Creek. It will be determined whether these differences in realized distribution are the result of different amounts of genetically-determined variation in temperature performance among Synechococcus B between springs, and whether either limitations in the ability of organisms to migrate between springs or exclusion by competitors contribute to these differences.The questions of how ecological variation is distributed within and between communities, and how ecological interactions themselves contribute to the evolved traits of competing organisms, are longstanding in ecology and evolution, but progress on these questions has been historically hampered for microorganisms by technological limitations. Addressing them has major implications for our understanding of how microbial communities are assembled and function, and of how they may respond to environmental change. Together, these projects promise fresh insights into these questions from a novel microbial perspective. The research plan thereby addresses key program goals of integrating microbial physiology and genomic diversity with environmental processes to determine the mechanistic basis of biotic interactions within communities and to reveal the patterns of microbial distribution in time and space. The award enables the integration of research and education through support for both graduate and undergraduate student training, as well as through the PI?s Biology of Yellowstone Hot Springs course, a sophomore-level offering which uses these hot springs as a natural teaching laboratory to provide a hands-on microbiological research experience. Outreach components include a continued focus on these microbial communities in the PI?s annual field-based course for college and high school instructors on the biology of Yellowstone hot springs through the NSF National Chautauqua Workshop summer program.