Hybridization is broadly relevant because it is the basis for much of the diversity around us, including agricultural crops and pests. The existence of successful ancient natural hybrids between species challenges traditional notions in biology that hybrids are ephemeral dead-ends in the evolution of biodiversity. However, detecting ancient hybrids using genetic data is challenging since hybrids have a "mosaic" of genes possessing different underlying histories and traits.
In this project, the investigators will test hypotheses about ancient hybridizations, specifically whether Pleistocene glaciations have enabled hybridization by causing range shifts. The proposed work will be conducted within the genus Heuchera by comparing species richness between hybrid and parental lineages in several parallel cases that have been identified. This project analyzes Coral Bells (Heuchera) from a DNA and morphological perspective to investigate the long-term contribution of hybridization to evolution. The objectives of this study include (1) the discovery of hybrids, (2) examination of relative rates of species formation with parents, and (3) reconstruction of historical geographical ranges. This study contributes to scientific infrastructure through the provision of DNA sequences for comparative studies, data for the inference of evolutionary history, descriptions of new and rare species and varieties, and the creation of museum specimens and identification keys. The project includes training of undergraduates in research methods, the creation of pedagogical exercises for undergraduate classes, and public lectures on hybridization in general and on specific aspects of the project.
