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.
