View Program - 2022 Population, Evolutionary, and Quantitative Genetics Conference

Plant-pollinator interactions have long been appreciated as a key driver of flowering plant evolution. Notably, much of the existing empirical evidence highlights pollinators as selective agents shaping floral trait adaptation and species diversification. We seek to expand our understanding of the evolutionary significance of plant-pollinator interactions by emphasizing how pollinators can impact plant evolution through control of gene flow via pollen dispersal. We use population genetic tools to test the hypothesis that since pollinators control gene dispersal via pollen flow, plant population genetic structure will reflect variation in pollinator movement. The relationship between the Texas wildflower, Phlox drummondii, and its primary pollinator, Battus philenor, provide an excellent system to explore this prediction. Field observations indicate B. philenor is the most frequent and effective visitor to P. drummondii, that no mechanism for long-distance seed dispersal exists, and that B. philenor moves broadly across their shared range. Therefore, movement of B. philenor is likely a significant factor driving dispersal both within and between populations of P. drummondii. To test this expectation, we generated genome-wide molecular markers using restriction-site associated DNA sequencing and characterized patterns of genetic variation in both species. By sampling co-occurring populations of plant and pollinator, we infer patterns of pollinator movement and test pollinator impact on genetic connectivity of plant populations in a spatially explicit context. Our work aims to generate new understanding of the role of pollinators in plant evolution as well as to characterize how pollinator loss under changing climate might impact plant persistence.

The role of pollinators in shaping plant population genetic structure