Molecular Phylogenetics of the Superfamily Curculionoidea (Insecta: Coleoptera)

Gillett, C. P. D. T. (2014) Molecular Phylogenetics of the Superfamily Curculionoidea (Insecta: Coleoptera). Doctoral thesis, University of East Anglia.

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This thesis examines higher-level evolutionary history within the superfamily Curculionoidea, the most speciose family-level taxon, which includes beetles commonly known as weevils. This is achieved using a phylogenetic approach incorporating the largest datamatrix yet employed for weevil molecular systematics, and includes an investigation into the prospect of obtaining short phylogenetically informative amplicons from archival museum specimens. Newly obtained DNA sequence data is analysed from a variety of mitochondrial and nuclear loci, including 92 mitogenomes assembled through the approach of next-generation sequencing of pooled genomic DNA. The resulting trees are used to test previous morphological- and molecular-based hypotheses of weevil relationships and classification schemes.
Mitogenomic-derived trees reveal topologies that are highly congruent with previous molecular studies, but that conflict with some morphological hypotheses. Strong nodal support strengthens inferences into the relationships amongst most weevil families and suggests that the largest family, the Curculionidae, is monophyletic, if the subfamily Platypodinae is excluded. Division of the Curculionidae into two large clades is well supported and the wood-boring habit adopted by three subfamilies is shown to have arisen multiple times, contradicting most morphological analyses.
Addition of several nuclear loci to the mitogenomic data is found to provide little additional value, in terms of improving nodal bootstrap support. A suggestion is made that future efforts to enhance understanding of relationships should focus on improving taxon sampling. Statistical tests of an augmented dataset, derived from public database sequences for single mitochondrial genes, wherein multiple tribes and subfamilies within the broad-nosed weevils are constrained as monophyletic, indicate that three entimine tribes, as currently defined, are each not consistent with the hypothesis for their monophyly.
Incongruences between molecular data and classical morphological taxonomy are suggestive that the current weevil classification system is misleading if used to interpret species richness, geographic distributions or ecological traits within currently recognised lineages.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Biological Sciences
Depositing User: Megan Ruddock
Date Deposited: 15 May 2018 14:27
Last Modified: 15 May 2018 14:27


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