Dissertation Research: Testing Phylogeographic Hypotheses of Holocene Plant Migration and Endemism in the Solidago simplex Species Complex

古生态学证据表明，更新世的冰川作用导致了北美植被的大规模变化，但个别植物物种如何应对这些重复的冰川作用周期仍然在很大程度上未被研究。 该项目将研究北美广泛分布的一枝黄花物种复合体对最近一次冰川作用的反应。 叶绿体DNA序列数据的分析将用于1）描述和评估整个范围内的遗传多样性的结构。2）验证了长期存在的假设，即一些广泛分布的物种在北美西部避难所的冰川作用下幸存下来，并在全新世期间迁移到大陆东部的冰川地区。这项研究将是第一个研究整个北美地区草本植物物种的地理分布模式和冰川历史的分子地理学研究之一。 这项工作产生的信息将为我们提供更精确的理解：1）植物物种如何应对历史气候变化; 2）更新世冰川周期如何影响种群分化和物种形成。 这些信息可以提供有价值的见解，以了解现存物种如何应对未来的气候变化，因此可以显着帮助当前的栖息地和物种保护工作。

Paleoecological evidence indicates that Pleistocene glaciations caused broad scale changes in vegetation across North America, but how individual plant species responded to these repeated cycles of glaciation remains largely unstudied. This project will examine how the widespread, North American, Solidago simplex species complex responded to the most recent period of glaciation. Analyses of chloroplast DNA sequence data will be used to 1) describe and assess the structuring of genetic diversity across the range of S. simplex in North America and 2) test the long-standing hypothesis that some widespread species survived glaciation in western North American refugia and migrated to eastern, glaciated regions of the continent more recently during the Holocene.This study will be one of the first molecular phylogeographic studies to examine the biogeographic patterns and glacial history of an herbaceous plant species across the entirety of its North American range. The information generated by this work will provide us with more refined understandings of 1) how plant species responded to historical climate change and 2) how Pleistocene glacial cycles affected population differentiation and speciation. This information can provide valuable insight into how extant species may respond to future climate change and can therefore significantly aid current habitat and species conservation efforts.