How frequently, and under what conditions, does evolution take the same path? When independent populations evolve the same characteristics, are the underlying genetic changes similar or different? Advances in genetic techniques are finally allowing answers to these fundamental questions about the way evolution works. However, these issues have not yet been explored in hybridizing lineages, despite the fact that hybridization (mating and cross-fertilization between different species) is widespread in wild plants, animals, and fungi. This project examines replicate populations of experimental hybrid sunflowers which have been evolving in the field in Texas. Morphological and physiological measurements will determine whether they are converging or diverging in their traits, and new genetic DNA sequencing techniques will be used to determine whether the genetic basis of trait changes are similar or different across the replicates.
The proposed research is the first to experimentally examine not only the repeatability of hybrid evolution, but also to characterize its genetic architecture in the wild. It will answer fundamental questions about the way that evolution produces biodiversity, and will inform plant and animal breeding efforts. The project will also impact science education in several ways, including: (a) outreach to K-12 science classrooms and (b) integration of research and education via training of fifteen undergraduate students (many from underrepresented groups), two technicians, and one postdoctoral fellow. Public outreach via a new Evolution in Action website will include a lay introduction to experimental evolution studies and will demonstrate real-time evolution via regular updates on the traits and genetics of the experimental populations.
