Dissertation/Thesis Abstract

Multi-gene phylogenetics to resolve key areas in the fly tree of life
by Trautwein, Michelle Denee, Ph.D., North Carolina State University, 2009, 137; 3377635
Abstract (Summary)

FLYTREE (an NSF Assembling the Tree of Life project) is a large collaborative project aimed at reconstructing relationships among major lineages of Diptera. Previous morphological and molecular work, along with preliminary analyses of phylogenomic and total evidence data sets from FLYTREE, have provided evidence that while much of the fly tree of life can be confidently resolved, some regions remain challenging to decipher. Flies are a species-rich lineage of insects that originated more than 240 MYA in the Mesozoic. Ancient radiations, particularly if they occurred rapidly, can be difficult to resolve, even with large amounts of data. Phylogenetic inference can be misled by both systematic and stochastic error. The reliance on rigorous data exploration to decipher phylogenetic signal from noise can be crucial to the accurate recovery of evolutionary relationships. This study utilizes multiple nuclear genes and data exploration to address three persistently problematic regions of dipteran evolution. The first chapter evaluates the relationships of the lower brachyceran superfamily Asiloidea, the putative sister-group to Eremoneura (Cyclorrhapha + Empidoidea). CAD + 28S support traditional asiloid clades and recover multiple hypotheses for the sister group to higher flies, primarily due to the indeterminate placement of the family Bombyliidae (bee flies) and the enigmatic genus Hilarimorpha. The genus Apystomyia is strongly supported as sister to Cyclorrhapha. Taxon stability and the effects of additional genes are explored. The second chapter addresses the phylogenetics of the subfamilies of Bombyliidae by analyzing CAD + 28S alone and with morphology. The monophyly of 8 of 15 subfamilies are confirmed along with the polyphyly of Bombyliinae. A hypothesis for the interrelationships of bee fly subfamilies is presented. Topological incongruence and the effect of the removal of conflict-inducing taxa are explored. The third chapter relies on six-nuclear genes to identify the sister-group of Diptera by resolving the phylogeny of Holometabola. Traditional supraordinal groupings are confirmed. Mecoptera+Siphonaptera are sister to Diptera. Strepsiptera, previously hypothesized as the closest relative of Diptera, is confidently placed as the sister-group to Coleoptera. A thorough exploration to rule out the effects of long-branch attraction is presented.

Indexing (document details)
Advisor: Wiegmann, Brian, Deitz, Lewis
Commitee:
School: North Carolina State University
School Location: United States -- North Carolina
Source: DAI-B 70/10, Dissertation Abstracts International
Source Type: DISSERTATION
Subjects: Organismal biology, Systematic
Keywords: Diptera, Holometabola, Strepsiptera
Publication Number: 3377635
ISBN: 9781109440485
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