RII Track-4: Evolutionary Genomics of Multispecies Ecological Interactions

University Of Mississippi, University MS

Investigators

Abstract

Ecological communities are comprised of different species populations that interact with one another. A central goal of the field of community ecology is to understand the outcomes of these various species interactions. Given that organismal traits govern the interactions between species, an understanding of how traits evolve in a community context is critical for a clearer picture of the dynamics of ecological communities. The aim of this research to understand the evolution of these traits in multispecies communities, and to determine if and how evolution differs in pairwise vs. more diverse species combinations. Experimental evolution is a powerful tool for the study of evolution in the laboratory. By subjecting organisms with rapid generation times to selection pressures, investigators can observe evolutionary changes at both the phenotypic and genotypic level in real time. In this project, the PI will experimentally evolve predator-prey interactions between roundworms and two species of bacteria to quantify changes in their interactions. With collaborators at New York University, the PI will gain training in methods to produce and analyze genomic DNA sequence data of evolving populations of the predatory roundworms, allowing for linkages between genetic and community-level changes. Findings will further our understanding of how genetic evolution proceeds in ecological communities and contribute to our understanding of the forces structuring biodiversity across scales of organization. Species interactions are a ubiquitous feature of ecological communities. As such, understanding the outcomes of these interactions provides important information for the maintenance of biodiversity. Since the outcomes of the interactions are often mediated by organismal traits, understanding how these traits, and thus interactions, evolve over time will be key to understanding biodiversity dynamics over time. Linking the underlying genetic variation to these community level phenotypes (i.e., species interactions) is the goal of this proposal. This project will use an experimental ecological module with the model organisms Caenorhabditis elegans (nematode), Myxococcus xanthus (bacteria), and Escherichia coli (bacteria) to study evolving communities. With these genetically tractable species, this project will simultaneously measure both phenotypic (ecological) and the underlying genomic changes in the DNA. Activities of this fellowship include the training of the PI in genetic and genomic analyses of Caenorhabditis nematodes, top predators in the experimental system, to link phenotypic changes in model communities to the underlying genetic changes. With collaborators at the host institution (New York University), genomic sequence data from populations of C. elegans nematodes evolved in different ecological settings will be generated and analyzed to determine how patterns of genomic evolution vary across these scenarios. Results from this research will provide insight into whether and how the genomic targets of selection are qualitatively different in pairwise vs. multispecies community interactions. The proposed research will contribute to understanding the linkages between evolutionary genetics, community ecology, and the scales of biological organization (i.e., genomics and communities). 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.