PhD Thesis: Chapter 4

Avian Louse Phylogeny (Phthiraptera: Ischnocera): A cladistic study based on morphology

VINCENT S. SMITH

Division of Environmental and Evolutionary Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom.

Corresponding Author: Vince Smith
e-mail:v.smith@nhm.ac.uk

Current Status: Published in Zoological Journal of the Linnean Society

Abstract

The louse suborder Ischnocera (Phthiraptera) contains 3,060 currently described species from over 150 genera. These lice are permanent obligatory ectoparasites of a diverse selection of birds and mammals with a worldwide distribution. They have, historically, played a major role in the development of our ideas on coevolution, and species hosted by mammals have been used extensively as model organisms for the study of cospeciation. In contrast, avian taxa comprising 90% of ischnoceran species have been neglected due to a lack of data on their wider systematics. A comparative study based on the adult and instar morphology of avian lice yielded 138 characters from 56 species (51 genera), all of which are illustrated or discussed here for the first time. A further five outgroup taxa were examined from the mammalian ischnoceran family Trichodectidae. Phylogenetic analyses of these data produced three most parsimonious cladograms, the strict consensus of which is highly resolved and broadly consistent with previous classifications. Morphological character variation is extensive, and nymphal character traits are useful in identifying instances of convergent evolution in adult morphology. The role of ontogeny in the development of the major character complexes of the head and abdomen is discussed, and its implications for further work on the phylogeny of avian Ischnocera is considered. Comparison with host taxonomy reveals a series of complex host-parasite associations which do not support a hypothesis of strict one to one cospeciation. However, extrapolation of these associations is compromised by the low sample size. The role of niche specialisation to explain the presence of multiple unrelated lineages on the same host taxon is considered.

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(PDF 2.72MB) Smith, V. S. (2001). Avian Louse Phylogeny (Phthiraptera: Ischnocera): A cladistic study based on morphology. Zoological Journal of the Linnean Society.

NEXUS File and Images

The full data matrix includes detailed notes and observations on the character states and taxon attributes, many of which are supplementary to those given in the paper. This can be viewed in HTML format from here, or in downloadable NEXUS format. Because the size of this file is very large (particularly with character state and taxon images) four options in NEXUS format are available:

Simple Matrix

(No char. state labels, observations or images)

Full Dataset

(Complete data set without images )

Full Dataset

(Includes images in separate zipped files)

Full Dataset

(Inc. images compiled as part of the NEXUS File)

Ideal for simple analyses

For NDE or MacClade users

Best option for PC users running NDE

For Apple Mac (MacClade) users only

This data set is best viewed with NEXUS Data Editor (NDE), a PC program writtain by Rod Page. This fully impliments the NEXUS format and allows character names, states, notes, comments and images to be easily viewed and edited. MacClade users will be able to view character and taxon images. However, due to a limitation in the way MacClade displays text, only the first 32 characters of each field can be viewed.