Endara, Lorena , Whitten, W. Mark , Williams, Norris .
The preliminary phylogeny of Scaphosepalum (Orchidaceae) suggests speciation patterns strongly influenced by the Andes.
The neotropical orchid genus Scaphosepalum (Pleurothallidinae) encompasses 49 species and reaches its diversity peak in the montane forests of the northern Andes. Scaphospealum is an ideal system to explore speciation patterns and the effects of the Andes as a dispersal barrier since it is common to find several narrow endemic species living in sympatry. The objective of this research project is to reconstruct a phylogeny using molecular and morphological characters, and use it as a phylogenetic framework to evaluate if the current distribution of the species is the result of sympatric speciation or allopatric speciation followed by secondary contact. The phylogeny of Scaphosepalum was obtained from the amplification and sequencing of the nuclear regions ITS, pgiC, xdh and the plastid regions trnL-F, matK, and ycf1. The congruence of the data sets corresponding to different gene regions was evaluated previously been combined. The single and combined data sets were analyzed under Maximum Parsimony, Maximum Likelihood, and Bayesian approaches and all obtained similar results. The results of the molecular phylogeny suggest a prevalence of allopatric speciation in the system and a strong geographic structure that reaffirms the importance of the Andes as a dispersal barrier since two almost identical clades were recovered by all the approaches: a mainly Central American-Northwestern Ecuador clade and Eastern Andes-Guyana Shield clade. The morphological dataset is currently been generated using 366 herbarium specimens and preliminary morphological information coincides with the molecular phylogeny reconstruction. Funding: American Orchid Society, San Diego County Orchid Society, International Association of Plant Taxonomists, National Science Foundation, American Society of Plant Taxonomists.
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1 - University of Florida, Department of Botany / Florida Museum of Natural History, Dickinson - FLMNH, Gainesville, FL, 32611, USA
2 - University Of Florida, Florida Museum Of Natural History, PO BOX 117800, Gainesville, FL, 32611-7800, USA
Presentation Type: Poster:Posters for Sections
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM