Postdoctoral Fellowship: PRFB: Biodiversity in hybrid systems: Exploring the hybrid bridge hypothesis

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2025. The fellowship supports research and training of the fellow that will contribute to biology in innovative ways. The research focuses on gall wasps-- tiny insects that form protective growths, or galls, on oak trees. These wasps often specialize on particular oak species, but when related oak species hybridize (interbreed), the new, hybrid trees may provide opportunities for wasps to shift from one parent oak species to the other by using the hybrid trees as a “bridge”. The study of hybridization is gaining importance as species introductions and range shifts increase opportunities for species to interbreed that would otherwise remain isolated. Clarifying how hybridization in plants can affect insect diversity may be crucial, therefore, for understanding the great biodiversity of insects that is observed today. These findings will contribute to our understanding of how biodiversity is generated and maintained, particularly in the face of environmental change. Furthermore, the fellow will leverage their experiences working at a federal agency (U.S. Geological Survey) to create resources for students interested in pursuing a career in the federal government. Hybridization plays an important role in generating and maintaining biodiversity, particularly in plants. The hybrid bridge hypothesis posits that hybridization in plant hosts can facilitate host shifts in associated insect parasites. If hybrid hosts can form a bridge through which host shifting can occur, this can 1) facilitate host shifts between parent species or 2) generate new species if the insects become locally adapted to their new host. To provide an empirical test of these possible outcomes, oak trees (Quercus spp.) and their specialized cynipid gall wasp parasites (Hymenoptera: Cynipidae) will be used as a model system. The fellow will use a multi-faceted and multi-scale approach, including a continent-wide comparative analysis, genomic analysis of a known hybrid zone in New Mexico, and greenhouse choice tests to rigorously evaluate how hybridization in oaks impacts gall wasp diversity, speciation, and insect fitness. Training activities include skill building in field techniques, molecular biology, and bioinformatics in preparation for a career as a federal scientist. Broader impacts will involve creating resources for graduate students and other postdoctoral researchers to find careers in the federal workforce. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.