The wrens (Aves: Troglodytidae) are a group of primarily New World insectivorous birds, the monophyly of which has long been recognized, but whose intergeneric relationships are essentially unknown. In order to test the monophyly of the group, and to attempt to resolve relationships among genera within it, sequences from the mitochondrial cytochrome b gene and the fourth intron of the nuclear β-fibrinogen gene were obtained from nearly all genera of wrens, from their relatives as suggested by traditional taxonomy and DNA-DNA hybridization analyses, and from additional passerines. Maximum likelihood analysis of the two data sets yielded maximal congruence between independently derived estimates of relationship, outperforming a variety of weighted parsimony methods. Hierarchical likelihood ratio tests indicated that the two gene regions differed significantly in every estimated parameter of sequence evolution, and combined analysis of the two data sets was accomplished using a heterogeneous-model Bayesian approach. Independent and simultaneous analyses of both data sets supported monophyly of the wrens (excluding one recently added member, the monotypic genus Donacobius) and a sister-group relationship between wrens and the gnatcatchers (Polioptila). Additionally, strong support was found for paraphyly of the genus Thryothorus, and for a sister-group relationship between the genera Cistothorus and Troglodytes. Analyses of these data failed to resolve basal relationships within wrens, possibly due to ambiguity in rooting with a distant, species-poor outgroup. Analysis of the combined data for wrens alone yielded results which were largely congruent with relationships inferred using the complete data set, with the benefit of stronger support for relationships within the group. However, alternative routings of this ingroup tree were weakly supported by nucleotide substitution data. Insertion-deletion events suggest that the genus Salpinctes may be sister to all other wrens.
Bibliographical noteFunding Information:
This work was supported by grants from the Hinds Fund, University of Chicago; the F.M. Chapman Memorial Fund, American Museum of Natural History; and the American Ornithologists’ Union (Blake Award). For their generosity in providing samples, I thank Leo Joseph (ANSP), Fred Sheldon (LSUMNS), Carla Cicero (MVZ), Jon Fjeldsa (MZUC), and Adolfo Navarro Sigüenza (MZAH); and for sharing unpublished data I thank Shannon Hackett and Amy Driskell. I thank Fredrik Ronquist (Uppsala) and Birali Runesha (UMN Supercomputing Institute) for troubleshooting compilation of MrBayes v3.0. Various versions of the manuscript benefited from the comments of Allan Baker, Barry Chernoff, Shannon Hackett, Sharon Jansa, François Lutzoni, the American Museum’s Ornithology Discussion Group, and an anonymous referee.
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