DISSERTATION RESEARCH: Evolutionary Trends Within the Polemoniaceae (Ericales)

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The Polemoniaceae, the phlox family, is a textbook example of an adaptive radiation and has long been studied by biologists from diverse fields under the assumption that pollinators have played a key role in the formation of its species. However, this, hypothesis remains untested. This research explores evolution in the phlox family, a group of plants with most species found in the United States to test this this hypotheses from ecological and genetic perspectives. This research will benefit science and society by developing identification keys which will allow the public, especially members of native plant organizations, to identify and therefore have a deeper appreciation for the biological diversity of phlox. These data will also allow conservationists to make informed, cost-effective decisions as they seek to preserve endangered and threatened species at both the State and Federal level, especially in California, Nevada, Minnesota, and Wisconsin.Polemonium has been the subject of multiple molecular phylogenetic studies yet the relationships among its species remain undetermined. Species boundaries between species are also unclear, perhaps as a result of reticulate evolution. This project will generate a near species-level phylogeny of the Polemoniaceae and will also use morphometric techniques to generate trait data. This study will be the first to sample all species and utilize multiple nuclear loci to determine species relationships. These data will test the hypothesis that floral form has been selected for by pollinators and the morphometric data will determine the evolution of leaf form. Collection data from natural history museums will be used to investigate the biogeographic history of Polemonium. The use of comparative phylogenetic methods with these data sets provides a unique opportunity to reconstruct the ancestral character states at various time periods during phlox evolution. Polemonium occidentale ssp. lacustre is endangered in both states in which it occurs, but is not yet Federally listed as endangered. Next-generation sequencing approaches will be used to determine its taxonomic status and population structure to inform conservation of this rare taxon.