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的一个基本目标。虽然一组生物的潜在分布仅由其进化的环境耐受极限决定，但其实际实现的分布也取决于其与其他群落成员相互作用的结果。蒙大拿大学的Scott R. Miller博士获得了一笔赠款，用于研究在黄石国家公园两个具有良好特征的温泉环境梯度（白溪，兔溪）中，竞争的光合微生物（蓝藻和绿色非硫细菌）之间的相互作用如何形成其实现的分布模式。项目1将环境基因表达分析与实验室生理学实验相结合，通过测试绿色非硫细菌在与蓝藻竞争的强分布重叠区域是否表现出资源利用的遗传程序转变，来解决进化理论的核心原则，即竞争物种进化以减少竞争。项目2结合了遗传学和生理学的方法来解决为什么不同的泉水中蓝藻藻B的丰度不同：这种蓝藻的实际分布在兔溪的范围是白溪的两倍。这些已实现分布上的差异是否由不同数量的遗传决定的B型聚球菌在不同的弹簧之间的温度表现差异造成的，以及生物在不同的弹簧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，将被确定。生态变异是如何在群落内部和群落之间分布的，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中是长期存在的，但在这些问题上的进展一直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是如何聚集和运作的，以及它们如何应对环境变化具有重要意义。总之，这些项目有望从新的微生物角度对这些问题有新的见解。因此，研究计划解决了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项目目标，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，以及通过PI？这是一门二年级的课程，将黄石温泉作为一个自然教学实验室，让学生亲身体验微生物学的研究。外展组成部分包括继续关注PI中的这些微生物群落。通过美国国家科学基金会（NSF）国家肖托夸研讨会暑期项目，为大学和高中教师提供黄石温泉生物学的年度实地课程。

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.