9318640 Schwaegerle Understanding the taxonomic relationships, evolution, and biogeographic history of organisms depends upon accurate phylogenetic information, that is, knowledge of the genealogy of the group. Dr. Scott Armbruster of the University of Alaska in collaboration with Dr. Bruce Baldwin of Duke University is reconstructing the phylogeny of Old and New World species of the pantropical plant genus Dalechampia (Euphorbiaceae family) in order to gain insights into the evolution of the group's pollination system and its biogeographic history. Specific objectives include: 1. to collect liquid preserved and herbarium specimens for morphological analysis and for DNA sequencing of chloroplast and nuclear ribosomal genes; 2. to determine the pollination ecology of a sample of Old World taxa, thus complementing knowledge of New World species; 3. to reconstruct the phylogenetic pattern of species divergences using nuclear and chloroplast DNA data and morphology; and 4. to use the phylogeny to trace the biogeographic history of the group and to generate testable hypotheses about change in pollination ecology and floral form. The application of phylogenetic information to evolutionary biology and ecology has generated considerable excitement in recent times. Important features of studying evolution with an estimated phylogeny include the ability to infer long term evolutionary history of characteristics not preserved in the fossil record, such as ecological relationships between plants and animals, and to distinguish adaptive evolution from the effects of phylogenetic constraint and past stochastic events. The Armbruster and Baldwin project will advanc e that agenda.
