Dissertation Research: Phylogenetic Systematics and Biogeography of Hawaiian Dryopteris (Dryopteridaceae)

物种边界，进化关系，和历史生物地理学的夏威夷成员的蕨类属（鳞蕨科）将利用DNA序列数据和形态数据进行探索。毛蕨属是一个世界性属，由大约250种组成。在夏威夷群岛有九到十六种特有种和一种非特有种。过去的形态学研究所划定的物种界限是不清楚的。本研究将使用分子和形态学来客观地解决物种划分的问题。尽管对物种数量存在混淆，但在夏威夷观察到的物种多样性似乎是夏威夷群岛多次成功殖民事件的结果。本研究旨在确定夏威夷毛蕨的种类数量，物种间的进化关系，以及夏威夷毛蕨的生物地理起源。虽然已经对夏威夷的开花植物进行了一些系统发育和生物地理学研究，但迄今为止，还没有发表过关于夏威夷任何蕨类植物群的系统发育研究。蕨类植物约占夏威夷本土维管植物种类的1/5，蕨类植物系统发育信息的缺乏是我们对夏威夷植物区系进化认识的一大空白。此外，拟议的研究对于研究岛屿的进化具有至关重要的意义，特别是在夏威夷群岛上，因为我们将阐明一组特有物种的系统发育和生物地理历史，这些物种可能代表了群岛的多个独立殖民地。我们的研究结果将有助于阐明可能对岛屿生物多样性有重大贡献的生物地理过程。

Species boundaries, evolutionary relationships, and the historical biogeography of Hawaiian members of the fern genus Dryopteris (Dryopteridaceae) will be explored using both DNA sequence data and morphological data. Dryopteris is a cosmopolitan genus comprised of approximately 250 species. Nine to 16 endemic species and one non-endemic species of Dryopteris occur in the Hawaiian Islands. Species boundaries, as delimited by past morphological studies, are unclear. This research will use both molecules and morphology to address objectively the issue of species delimitations. Although confusion about numbers of species exist, it appears that the species diversity observed in Hawaii was a result of multiple, successful colonization events to the Hawaiian Islands. This study aims to determine the number of Dryopteris species present in Hawaii, the evolutionary relationships among those species, and biogeographical origins of Hawaiian Dryopteris. Although several phylogenetic and biogeographical studies have been performed for flowering plants in Hawaii, to date there are no published phylogenies for any pteridophyte group occurring in Hawaii. Pteridophytes make up about 1/5 of the native vascular plant species in Hawaii and this lack of phylogenetic information about pteridophytes represents a large gap in our understanding of the evolution of the Hawaiian flora. Additionally, the proposed research is of critical importance to the study of evolution on islands in general, and on the Hawaiian Islands in particular, because we will elucidate the phylogenetic and biogeographical history of a group of endemic species that probably represents multiple independent colonizations of the archipelago. Our results will help elucidate biogeographical processes that may contribute significantly to the biological diversity of islands.