UNIVERSITY OF CALIFORNIA, DAVIS

Award Description Title: Collaborative Research: Phylogeny, Diversification, and Evolutionary Trajectories in the Terebinthaceae (Anacardiaceae and Burseraceae) Documenting the patterns and understanding the causes of variation in rates of lineage diversification (speciation minus extinction) is a central objective of evolutionary biology. Diversification rates may be influenced both by the origin of intrinsic traitskey innovations, such as morphological, behavioral, or physiological noveltiesand the incidence of extrinsic eventskey opportunities, such as episodes of biogeographic or climatic change. Accordingly, a comprehensive understanding of the causes of differential diversification requires the ability to explore the impact of a diverse array of both intrinsic and extrinsic factors. Attempts to understand Darwins abominable mysterythe staggering radiation of flowering plants have largely focused on the search for intrinsic correlates of diversification, including a few putative key innovations relating to floral morphology, growth form, and fruit type/dispersal mechanism. The role of extrinsic factors in flowering plant diversification has received less attention; however, an important class of abiotic factors pertains to the impact of biogeography on diversification. The terebinth clade represents a perfect case study for elucidating the factors that have influenced angiosperm radiation. This ecologically and economically important groupcomprising the two sister families Anacardiaceae and Burseraceaeincludes ~1500 species that exhibit exceptional ecological diversity, morphological disparity and complex biogeographic history. Rigorous analysis of the factors that influenced the terebinth radiation requires a densely sampled, wellsupported phylogeny and a detailed study of the morphology and biogeography of the species. These criteria will be achieved by the following three goals. Goal 1: Estimating higher-level phylogenetic relationships within the terebinth clade (years 12). We will sample broadly, targeting existing gaps to produce a robust, dated phylogeny of all major lineages in order to revise the classification of the two families. Brooklyn Botanic Garden will sequence molecular data for Anacardiaceae, conduct Euroschinus fieldwork, and coordinate collaborative research. University of California, Berkeley will sequence molecular data for Burseraceae and conduct Protieae fieldwork. Goal 2: Estimating species-level phylogenies within four terebinth focal clades (years 12). We will target four terebinth lineages for detailed phylogenetic study: Commiphora and Protieae in the Burseraceae, and Euroschinus and Abrahamia-Baronia in the Anacardiaceae. The New York Botanical Garden will collect morphological data and will conduct fieldwork for Protieae and Euroschinus, respectively. George Mason University, will sequence molecular data for Burseraceae and will gather data for the Commiphora evolutionary ecology studies. Goal 3: Exploring the impact of key historical events on diversification of the four focal clades (years 34). We will adopt a rigorous phylogenetic approach to explore the impact of morphological innovation, habitat specialization, and island colonization in the four focal clades. University of California, Davis will perform analyses to estimate phylogenies for the terebinth clade and the focal groups based on the newly sequenced data, and will perform the necessary analyses to investigate patterns of diversification in these focal clades. This project will provide much-needed clarification of relationships (and classification) within this important groups of flowering plants and greatly advance our understanding of the tremendous radiation of flowering plants.

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