DISSERTATION RESEARCH: Phylogenetic Systematics, Diversification, and Character Evolution in Hydrophyllaceae

9623683 Donoghue研究生Diane Ferguson在哈佛大学Michael Donoghue的指导下，正在研究水族科植物，重点是推断系统发育关系的新分子证据。水生植物是一类多样性的草本植物和灌木，在进化意义上已经辐射到北美西部，特别是加利福尼亚州，那里有17个属和大约130个物种中的13个。鉴于水生植物的大多数属在分布上都是局部的，但在这个范围内是可变的和物种丰富的，它们为深入研究系统发育、物种多样性和特征进化提供了机会。该项目的目标包括：(1)利用从叶绿体基因ndhF的DNA序列中测量的突变差异，推断该科内和相关类群中具有代表性的类群的系统发育(系谱)；(2)评估该科传统分类中所使用的形态特征的变异性和可靠性；以及(3)在该系统发育框架内开始分析特征进化(方向和程度)、生物地理学和多样化比率的变化。该植物科包括草本植物和木本植物，具有一系列的花卉和水果特征，主要集中在北美西部。对这一组的系统发育分析将确定草本和木本物种之间的关系，测试转变是单独发生还是多次发生，以及其他营养或生殖特征是否与这些生长型转变相关，以及推测物种在热带和温带范围之间的迁徙。来自DNA测序的新分子数据将为这些系统发育评估提供强有力的证据。***

9623683 Donoghue Graduate student Diane Ferguson, with direction from adviser Michael Donoghue at Harvard University, is studying the plant family Hydrophyllaceae, with emphasis on new molecular evidence for inferring phylogenetic relationships. Hydrophyllaceae are a diverse group of herbs and shrubs that have radiated in an evolutionary sense in western North America, especially California where 13 of the 17 genera and ca. 130 species occur. Given that most genera of Hydrophyllaceae are localized in distribution yet are variable and species-rich within this range, they present an opportunity for intensive study of phylogeny, species diversification, and character evolution. The goals of the project include: (1) to infer the phylogeny (genealogy) of representative taxa within the family and among related groups by using mutational differences measured from DNA sequences of the chloroplast gene ndhF; (2) to assess the variability and reliability of morphological characters used in traditional classifications of this family; and (3) to begin analyses of character evolution (direction and degree), biogeography, and shifts in diversification rates within this phylogenetic framework. %%% The plant family Hydrophyllaceae includes herbaceous and woody members, with an array of floral and fruit characteristics, mostly concentrated in western North America. Phylogenetic analyses of this group will determine relationships between herbaceous and woody species, test whether transitions have occurred singly or many times, and whether other vegetative or reproductive features correlate with these growth-form transitions and with presumed species migrations between tropical and temperate ranges. New molecular data from DNA sequencing will provide robust evidence for these phylogenetic appraisals. ***