A current challenge in coevolutionary biology and community ecology is to understand how networks of interacting species evolve in different ways in different environments. The importance of this challenge is increasing, as the species composition of many ecosystems is rapidly changing worldwide. We need to understand the extent to which the interactions between networks of species can change under different ecological conditions and how those changes may be structured genetically by the phylogenetic history of lineages. The proposed work will evaluate how networks of interacting plants and insects differ in structure across geographic landscapes as populations evolve and diverge. The work will focus on the specific problem of how a four-species network of two closely-related plant species and two closely-related moth species differ genetically and ecologically in four environments in California. Objective 1 will evaluate how the moths Greya politella and G. obscura (Prodoxidae) differ along the Coast Ranges of California in their use of the woodland stars, Lithophragma parviflorum and L. heterophyllum (Saxifragaceae). Objective 2 will evaluate whether differences among habitats in how moths use these two plant species are determined genetically or by local ecological conditions. Objective 3 will use molecular markers to assess whether similarity in network structure among some habitats results from the shared phylogenetic history of those populations.
Overall, the integration of ecological and molecular approaches in the proposed work will provide a direct evaluation of how the diversification of lineages and local ecological conditions collectively contribute to geographic differences in the organization of biological communities. This research will also aid in training undergraduate students in all aspects of scientific research. Undergraduate students will gain molecular, greenhouse, and field skills while learning about experimental design, data analysis, and manuscript preparation. Results of this work will be presented at national meetings.
