Coevolution - the process by which interacting species undergo reciprocal evolutionary change - is one of the major driving forces underlying the generation and maintenance of biodiversity. Research over the past decade has shown that spatial heterogeneity can influence coevolutionary interactions. However, a complete, mechanistic understanding of the influence of spatial heterogeneity on coevolution is still needed. The proposed research combines theoretical and empirical approaches to rigorously evaluate how spatial heterogeneity in resource availability and dispersal among habitat patches influence coevolution. It utilizes the bacterium Escherichia coli and the bacteriophage T7, a viral parasitoid of E. coli, as model coevolving organisms. Experiments in which dispersal and resource availability are directly manipulated will be combined with theoretical models that incorporate details of the host-parasitoid interaction to provide both qualitative and quantitative predictions of how dispersal across a heterogeneous landscape influences coevolution. This research provides a crucial middle ground between the relative simplicity of current mathematical models and the complexity of field studies. This research will add to our understanding of the geographic mosaic theory of coevolution and metacommunity theory, which underlie much of the work on habitat fragmentation in conservation biology. This work will also increase our understanding of coevolving microbes, which perform many crucial ecosystem services and which have been vastly understudied. Finally, the research will contribute to our general knowledge of how spatial heterogeneity influences the ecology and evolution of interacting organisms.
