CAREER: Exploring Mutualism Stability in a Community Context

生态学中的一个主要问题是，互惠关系如何在时间和空间上保持稳定，因为进化应该有利于那些利用伴侣获得利益而不提供回报的个体。本研究的总体假设是，第三方影响互惠配对的相容，从而最终形成共生的专一性和互惠稳定。为了验证这一假说，我们将以真菌-蚂蚁-微生物共生的四方系统为模型系统，将密集采样和分子生态学技术与共生体分析和宿主-共生体切换实验相结合。具体地说，这个项目将研究：i)在真菌生长的蚂蚁-微生物共生的进化史上微生物共生体之间的相互作用模式，ii)第三个互助者对两方互惠关系的兼容性/稳定性的影响，以及iii)寄生虫通过协调合作伙伴的利益在稳定互惠关系中的作用。从单个细胞的功能到改变生态系统动态，互惠关系塑造了生物组织的各个层面。这项拟议的研究将探索有助于稳定或导致互惠关系不稳定的因素。互惠共生是生命史上的一个主要主题；因此，这项工作将提供对推动生物复杂性和多样性的机制的见解。此外，通过将研究和教育结合起来，该项目将对各级培训和教育产生直接和持久的影响。这些影响将通过开发本科和研究生一体化课程、将吸引数百名K-12学生的互动展品以及通过Delta实习计划为年轻教师提供培训计划来实现，该计划旨在整合生物科学复杂前沿的教学和研究。

A major question in ecology is how mutually beneficial relationships remain stable over time and space, as evolution should favor those individuals that exploit their partners to obtain benefits without providing rewards in return. The overarching hypothesis of this research is that third parties influence the compatibility of mutualist pairings, and thus ultimately shape symbiont specificity and mutualism stability. To test this hypothesis the quadripartite fungus-growing ant-microbe symbiosis will be used as a model system, and the research employed will combine intensive sampling and molecular ecology techniques with symbiont assays and host-symbiont switching experiments. Specifically, this project will examine: i) the patterns of interactions among microbial symbionts across the evolutionary history of the fungus-growing ant-microbe symbiosis, ii) the impact of a third mutualist on the compatibility/stability of a bipartite mutualism, and iii) the role of parasites in stabilizing mutualisms by aligning the interests of cooperative partners. Mutualistic relationships shape all levels of biological organization, from the functioning of individual cells to altering ecosystem dynamics. The proposed research will explore the factors that help stabilize, or contribute to the instability of, mutualism. Mutualism is a major theme in the history of life; thus this work will provide insights into mechanisms that drive biological complexity and diversity. In addition, by integrating research and education, this project will have immediate and long lasting impacts in training and education at all levels. These impacts will be realized through development of an integrative undergraduate and graduate course, interactive exhibits that will engage hundreds of K-12 students, and a training program for young faculty via the Delta internship program to integrate teaching and research at the complex frontiers of biological sciences.