Phylogenetic analysis of partial sequences of Elongation Factor 1alpha identifies major groups of lice (Insecta: Phthiraptera)

Publication Type:Journal Article
Year of Publication:2001
Authors:R. H. Cruickshank, Johnson, K. P., Smith, V. Stuart, Adams, R. J., Clayton, D. H., Page, R. D. M.
Journal:Molecular Phylogenetics and Evolution
Pagination:202 - 215
Date Published:2001
Keywords:Ischnocera, leaf stability analysis, lice, molecular systematics, niche specialization, Phthiraptera, Phylogeny

As a first attempt to use molecular data to resolve the relationships between the four suborders of lice and within the suborder Ischnocera, we sequenced a 347-bp fragment of the elongation factor 1 gene of 127 lice (Insecta: Phthiraptera) as well as outgroup taxa from the order Psocoptera. A number of well-supported monophyletic groups were found but the relationships among many of these groups could not be resolved. While it is probable that multiple substitutions at high divergences and ancient radiation over a short period of time have contributed to the problem, we attribute most of this lack of resolution to the high ratio of taxa to characters. Nevertheless, the sequence data unequivocally support a number of important relationships that are at variance with the conclusions of morphological taxonomy. These include the sister group relationship of Chelopistes and Oxylipeurus, two lice occupying different ecological niches on the same host, which have previously been assigned to different families. These results provide evidence in support of the hypothesis that lice have speciated in situ on the host in response to niche specialization and that this has given rise to convergent morphologies in the lice of different host groups which share similar ecological niches. We discuss our attempts to overcome the limitations of this large data set, including the use of leaf stability analysis, a new method for analyzing the stability of taxa in a phylogenetic tree, and examine a number of hypotheses of relationships based on both traditional taxonomy and host associations.

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Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith