Ecologically Mediated Hybrid Speciation in Rhagoletis

Hybridization has been recognized as an important mode of speciation in plants, but its relevance to animal systems has been less clear. A new host-associated fruit fly (Rhagoletis) population on an introduced weedy plant is likely a hybrid between two native fly species. This study will combine population genetics, chemical ecology, and theoretical modeling to examine the key elements of hybridization that led to novel behavioral and ecological traits. Populations of the hybrid fly will be compared at different geographic levels to look for a common evolutionary history. The chemical ecology of host choice will define changes between the hybrids and its parents that explain a host shift to a new plant. The theoretical model will tie these elements together to explain how hybridization facilitated a host shift, how the new hybrid taxon has spread throughout the range of its host, and the extent to which this specific example may be more general in biology.<br/><br/>These activities are relevant to how new species, including agricultural pests, may arise in nature. This project will also increase the level of understanding of the impact of invasive species on native fauna. Students will be trained at a variety of levels, from K-12 through outreach activities to university undergraduates, graduates, and postgraduates through research projects.