Dissertation Research: Biogeography and Phylogeny of Malesherbiaceae

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9623496 Crawford Graduate student Karla Gengler, with direction from adviser Daniel Crawford at Ohio State University, is studying the South American plant family Malesherbiaceae, with an emphasis on obtaining new DNA sequence data from all the species in the family in order to infer phylogenetic relationships. This small family is endemic to the Pacific coastal desert region of South America, and occurs in two areas separated by the Atacama Desert in northern Chile. It will serve as a starting point for the study of biogeography and speciation patterns of aridland plants and animals of this region. The current taxonomic classification is based on morphological characters, most of which have not been evaluated for variability and reliability. Re-evaluation of these and addition of new molecular evidence from nuclear ribosomal gene sequencing will provide data for robust inferences of phylogenetic (genealogical) relationship among the species and with related groups. Field work in Peru will augment collections already made in Chile and those from herbarium holdings. In turn, the phylogeny will provide a necessary background for studies of biogeography (migration routes, centers of origin and of diversification) and of speciation patterns. %%% The Pacific coastal desert of South America contains a variety of arid habitats that are presumed to have developed since the Paleocene as the Andes mountains rose and the cold Humboldt Current formed to the west. Pleistocene glaciations are thought to have further affected plant distributions in this region. In order to establish patterns of plant species movements through time, robust phylogenies of many groups must be established. This project promises one of these, for the small family Malesher`iaceae. ***