The process of species formation fascinates me. I am particularly interested in understanding the role of natural selection in causing diverging plant populations to become species. Pursuing this goal entails investigating fundamental questions of evolutionary biology such as: What is the genetic basis of adaptations? What is the role of migration and genetic drift during the evolution of traits? What is the strength of selection acting on an adaptive allele? And what is the mechanism underlying selection? I address these questions using an interdisciplinary approach that incorporates functional molecular biology experiments, population genetic analyses, pollinator behavior trials, and field reciprocal transplant experiments.
Much of my research has been done on the native Texas wildflower Phlox drummondii. Flower color variation in Phlox is a classic example of reinforcement, the process in which reduced hybrid fitness generates selection for the evolution of reproductive isolation between emerging species. I have begun to develop Phlox as a modern system for evolutionary and ecological genetic studies. There is a rich knowledge of natural history and ecology in this system that is informative for designing a plethora of innovative projects. I plan to expand my studies in this system to a broad array of topics including the evolution of plant mating systems, adaptive constraints of pleiotropy, and plant-pollinator interactions.