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Abstract

BackgroundThe typical antbirds (Thamnophilidae) form a monophyletic and diverse family of suboscine passerines that inhabit neotropical forests. However, the phylogenetic relationships within this assemblage are poorly understood. Herein, we present a hypothesis of the generic relationships of this group based on Bayesian inference analyses of two nuclear introns and the mitochondrial cytochrome b gene. The level of phylogenetic congruence between the individual genes has been investigated utilizing Bayes factors. We also explore how changes in the substitution models affected the observed incongruence between partitions of our data set.ResultsThe phylogenetic analysis supports both novel relationships, as well as traditional groupings. Among the more interesting novel relationship suggested is that the Terenura antwrens, the wing-banded antbird (Myrmornis torquata), the spot-winged antshrike (Pygiptila stellaris) and the russet antshrike (Thamnistes anabatinus) are sisters to all other typical antbirds. The remaining genera fall into two major clades. The first includes antshrikes, antvireos and the Herpsilochmus antwrens, while the second clade consists of most antwren genera, the Myrmeciza antbirds, the "professional" ant-following antbirds, and allied species. Our results also support previously suggested polyphyly of Myrmotherula antwrens and Myrmeciza antbirds. The tests of phylogenetic incongruence, using Bayes factors, clearly suggests that allowing the gene partitions to have separate topology parameters clearly increased the model likelihood. However, changing a component of the nucleotide substitution model had much higher impact on the model likelihood.ConclusionsThe phylogenetic results are in broad agreement with traditional classification of the typical antbirds, but some relationships are unexpected based on external morphology. In these cases their true affinities may have been obscured by convergent evolution and morphological adaptations to new habitats or food sources, and genera like Myrmeciza antbirds and the Myrmotherula antwrens obviously need taxonomic revisions. Although, Bayes factors seem promising for evaluating the relative contribution of components to an evolutionary model, the results suggests that even if strong evidence for a model allowing separate topology parameters is found, this might not mean strong evidence for separate gene phylogenies, as long as vital components of the substitution model are still missing.

Increased knowledge of Francisella genus diversity highlights the benefits of optimised DNA-based assays

“…To determine whether the observed topological differences could have occurred by chance, our comparison approach can be combined with a statistical test, such as the SH test applied here or an alternative test, e.g. [44,45]. …”

A multi‐locus phylogeny ofEuryops(Asteraceae, Senecioneae) augments support for the "Cape to Cairo" hypothesis of floral migrations in Africa

“…As an alternative, the use of Bayes Factors within a Bayesian framework has been recently proposed to test for congruence between partitions (Irestedt & al., 2004;Nylander & al., 2004). The Bayesian approach of phylogenetic inference provides, through the calculation of Bayes Factors (hereafter BF), a convenient way for comparing how well two models describe the processes generating a dataset X (Kass & Raftery, 1995).…”

Analysis of multiple chromosomal rearrangements in the genome of Willisornis vidua using BAC-FISH and chromosome painting on a supposed conserved karyotype

“…The Thamnophilidae family (typical antbirds), are a widespread radiation of insectivorous Passeriformes birds. They are a monophyletic and diverse group [ 4 ] of species and 45 genera with many occurring in upland forests of the Neotropics [ 5 , 6 ]. In Brazil there are 195 species of Thamnophilidae birds [ 7 ], although it is likely that this is an underestimation of true diversity, particularly in the Amazon region, since the Brazilian avifauna is still being sampled [ 8 ].…”