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冰川导致了北美植被的大范围变化，但单个植物物种如何对这些反复的冰川循环做出反应仍未得到研究。该项目将研究分布广泛的北美单Solidago simplex物种复合体如何对最近的冰期做出反应。叶绿体DNA序列数据的分析将用于：1)描述和评估北美单一葡萄球菌范围内的遗传多样性结构；2)验证一个长期存在的假设，即一些广泛分布的物种在北美西部的冰河时期幸存下来，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在整个北美范围内研究草本植物物种的生物地理模式和冰川历史的分子系统地理学研究之一。这项工作产生的信息将为我们提供更精细的理解：1)植物物种如何响应历史气候变化；2)更新世冰川循环如何影响种群分化和物种形成。这些信息可以为了解现存物种如何应对未来的气候变化提供有价值的见解，因此可以极大地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.