DISSERTATION RESEARCH: Evolutionary Genomics of Hybrid Speciation and Divergence

是什么进化力量支配着自然界中生物多样性的模式？这个问题将以向日葵为研究对象来解决。荒漠向日葵是一种杂交物种，是两个亲本物种之间古代杂交的最终产物。研究荒漠蒿与其亲本种的起源和分化，为阐明杂交和自然选择这两个主要进化因素对生物多样性的贡献提供了机会。本项目采用基因组水平技术对杂交种和亲本种的遗传进行广泛的调查。它将确定使杂交物种适应极端环境的基因，并揭示杂交物种的基因表达与亲本物种的差异。这项工作在基础生物学和应用生物学中都具有广泛的相关性。在进化生物学中，理解生物多样性的原因是一个具有挑战性的问题。该研究的生物被列为敏感植物，因此将为保护生物学提供重要信息。最后，人们对保护稀有向日葵作为作物育种资源有浓厚的兴趣，这些物种未来可能对美国向日葵作物产生强烈的经济影响。

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.