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Phylogenetics, evolution and systematics of Holodonata with special focus on wing structure evolution: Morphological, molecular and fossil evidence

Posted on:2009-12-05Degree:Ph.DType:Dissertation
University:University of FloridaCandidate:Bybee, Seth MFull Text:PDF
GTID:1440390002993393Subject:Biology
Abstract/Summary:
A brief review of phylogenetic methods and theory with a focus on insect phylogenetics is presented. A morphological study of fossil dragonflies was a heavy focus of this work, and gathering information from fossil insects required some novel methods. Methods for fossil insect imaging and databasing are presented. The major focus of this research consists of two major phylogenetic questions focused on dragonfly-like insects. The first is a comprehensive morphological and molecular phylogenetic analysis of dragonfly phylogeny, focused primarily on extant lineages, although fossil lineages were included and analyzed in a simultaneous analysis. The legitimacy of higher-level family groups and the phylogenetic relationships among families were tested. Thirteen families were supported as monophyletic and eight as non-monophyletic, although two were recovered as monophyletic under Bayesian analyses. Epiprocta and Zygoptera were recovered as monophyletic. Epiophlebiidae and the lestid-like damselflies are sister to the Epiprocta and Zygoptera, respectively. Characters associated with wing structure were optimized revealing two wing character complexes: the pterostigma–nodal brace complex and the costal wing base & costal–ScP junction complex. In turn, these two complexes appear to be associated; the pterostigma–nodal brace complex allowing for further modification of the wing characters comprised within the costal wing base & costal–ScP junction complex leading the modern odonate wing.;The second project also included extant dragonflies but focused heavily on their fossil record (26 extant and 60 fossil Holodonata taxa) and included 352 morphological characters and DNA (~6kb). The orders of Holodonata were found to be monophyletic and all major suborders of Odonata were also found to be monophyletic. The topologies where similar for both morphological data and combined morphological and molecular data: (Protodonata (Protanisoptera (Triadophlebioptera (Protozygoptera (Zygoptera + Tarsophlebioptera + Epiprocta))))). Zygoptera and Epiprocta were found to be nonmonophyletic and the subordinal status of Tarsophlebioptera is placed in question. Wing forms appear to move from a strongly petiolate wing to a less petiolate or non-petiolate wing among the taxa from each suborder. Characters of the wing venation are found to be extremely homoplasious, but much less so when analyzed together with DNA data.
Keywords/Search Tags:Wing, Morphological, Phylogenetic, Focus, Fossil, Molecular, Holodonata, Found
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