DISSERTATION RESEARCH: Evolutionary Genomics of Hybrid Speciation and Divergence

Indiana University, Bloomington IN

Investigators

Abstract

What evolutionary forces govern the patterns of biodiversity found in nature? This question will be addressed using the sunflower Helianthus deserticola as a study organism. Helianthus deserticola is a hybrid species, the end product of an ancient cross between the two parental species. Studying the origin and divergence of H. deserticola from its parental species provides an opportunity to elucidate the contribution of two major evolutionary factors, hybridization and natural selection, to biodiversity. This project employs genome-level techniques to broadly survey the genetics of the hybrid species and the parental species. It will identify genes that enabled the hybrid species to adapt to an extreme environment, and also reveal how gene expression in the hybrid species differs from the parental species. This work is of broad relevance in both basic and applied biology. Understanding the causes of biodiversity is a challenging question in evolutionary biology. The study organism is watch-listed as a sensitive plant, and will therefore provide important information for conservation biology. Finally, there is strong interest in the preservation of rare sunflowers as a resource for crop breeding, and these species are likely to have a strong economic impact on the US sunflower crop in the future.