EAGER: Surveying impacts of community context on adaptive mutational landscapes

Species evolve in communities with other species. However, tracking evolution in those complex communities is difficult. This project will examine how community context alters species evolution. Using new techniques in whole-genome analyses, this research will determine how different communities alter the fitness effects across the entire genome. This research bridges the fields of ecology, evolution, and microbiology to provide insight into how the evolutionary process may occur in the complex communities. Analysis tools will be developed and made publicly available through this research and the insights gained may be relevant for conservation and management of ecosystems facing environmental change. In addition, the research will enable training for graduate and undergraduate students in laboratory and computation skills. Moreover, the researchers will conduct educational outreach to local high schools on antibiotic resistance, a topic at the intersection of microbiology and evolutionary biology. The ability of a population to adapt is reliant on mutational input. Possible mutations define the mutational neighborhood. This research will document how the mutational neighborhood evolves with community context over time. Using experimental evolution in microbial communities and transposon-insertion sequencing, the project will directly measure how the mutational neighborhood in bacteria can be predicted by species interactions. Three ecological scenarios will be explored. They include predation, competition, and a combination of predation and competition. Transposon insertion libraries in ancestral and the evolved populations will be assayed for frequency changes across the scenarios. Computational tools will be developed that calculate mutational neighborhood measures using a Shannon entropy approach. These neighborhoods will be compared across contexts. This project will provide new insights into the evolutionary process in a community context and generate new analytic tools. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.