Dissertation Research: Phylogeny,Floral Evolution, and Patterns of Homoplasy in Pedicularis (Scrophulariaceae)

在哈佛大学的Michael Donoghue博士的指导下，研究生Richard Ree正在研究马先蒿属（玄参科的苔藓）的系统发育关系和形态特征的进化模式，马先蒿属是北方半球的开花植物谱系，在中国中南部和邻近地区的山区经历了非凡的多样化。本属的许多种的简化分类学分类（约。500描述的物种总数），导致了不同的重点花的特点与营养特征的分类学家在他们的物种之间的相似性大多是直观的评估。该项目的主要目的是测试的假设，马先蒿属的分类之间的主要差异反映了营养与花的特征的进化变化的差异率。从核和叶绿体DNA序列的分子数据，补充形态学数据，将被用来构建一个系统发育（系谱）框架的样本CA。该属估计有270种亚洲物种中的90种。性格变化的模式和速率，然后将探讨使用的方法推断祖先的国家和评估异质性的速度在整个血统。该项目是第一次努力应用现代，明确的系统发育方法的研究和解释的花和营养的多样性在马先蒿属，它将提供一个框架，扩展分析其他物种的属和相关玄参科。此外，这项研究的目标是东喜马拉雅生物多样性“热点”中物种最丰富的地区之一，因此将深入了解使这个偏远地区成为北方温带最多样化的地区的过程。

9972612Donoghue and Ree Graduate student Richard Ree, under the direction of Dr. Michael Donoghue at Harvard University, is studying the phylogenetic relationships and patterns of evolution in morphological characters in the genus Pedicularis (louseworts, of family Scrophulariaceae), a northern hemisphere lineage of flowering plants that has undergone extraordinary diversification in the mountains of south-central China and neighboring regions. Conflicting taxonomic classifications of the numerous species in this genus (ca.. 500 described species in total) have resulted from differing emphases on floral features versus vegetative characters by taxonomists in their mostly intuitive assessments of similarity between species. The primary aim of the project is to test the hypothesis that major differences among classifications of Pedicularis reflect differential rates of evolutionary change in vegetative versus flower characters. Molecular data from nuclear and chloroplast DNA sequences, supplemented with morphological data, will be used to construct a phylogenetic (genealogical) framework for a sample of ca. 90 of the estimated 270 Asiatic species of the genus. Patterns and rates of character change will then be explored using methods of inferring ancestral states and assessing heterogeneity in rates across lineages. The project is the first effort to apply modern, explicit phylogenetic methods to the study and interpretation of floral and vegetative diversity in the genus Pedicularis, and it will provide a framework for extended analyses on other species in the genus and in related Scrophulariaceae. Furthermore, the research targets one of the most species-rich regions in the eastern Himalayan biodiversity "hotspot" and hence will provide insights into the processes that have made this remote region the most diverse in the northern temperate zone.