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

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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. ***