The evolution of individual species is not independent of interactions with organisms. Indeed, coevolution, reciprocal evolution resulting from interactions between species over time, is increasingly being viewed as one of the major processes organizing the earth's biodiversity. The geographic mosaic theory of coevolution states that such coevolutionary interactions are highly dynamic in space and time. Associated theoretical models also indicate that the degree to which geographical patterns of inter-population gene exchange within a species (gene flow) are similar (symmetrical) between interacting species influences both local and global coevolutionary patterns. The proposed research has two primary objectives. First, it will utilize recent advances in statistical genetics and graphical modeling to develop new analytical procedures for obtaining a geographically explicit summary of gene flow within a species and for testing the symmetry of gene flow between species. Second, it will use these procedures to test predicted differences in the symmetry of gene flow in mutually beneficial (mutualism) and antagonistic (host-parasite) relationships using model plant-pollinator and plant-herbivore systems. This research thus melds theoretical and empirical approaches to gain important insight into fundamental differences in gene flow dynamics in mutualistic versus host-parasite systems, differences that may influence the geographic patterning of coadaptation in plant-insect relationships. Broader impacts of the project include the education and training of undergraduate and graduate students as well as novel outreach activities and internships involving high school science teachers.
