[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

More evidence for Eufalconimorphae and Psittacopasserae


the following paper has recently been published on MBE's advance access
(abstract is at the end of this post):

Ning Wang, Edward L. Braun and Rebecca T. Kimball (in press): Testing
hypotheses about the sister group of the Passeriformes using an independent 30
locus dataset. Mol Biol Evol. doi: 10.1093/molbev/msr230

Although the taxon sampling is a bit patchy (e.g., no representatives of
Acciptriformes and Strigiformes) and the methodology is not completely
independent from previous sequence analyses (such as Ericson et al. 2006,
Hackett et al. 2008), it's nice to see that there is now more sequence-based
support emerging that is congruent with the retroposon evidence for
Eufalconimorphae and Psittacopasserae. :-)

Best regards,

- Ericson, P. G. P. et al. Diversification of Neoaves: integration of
molecular sequence data and fossils. Biol. Lett. 2, 543–547 (2006).
- Hackett, S. J. et al. A phylogenomic study of birds reveals their
evolutionary history. Science 320, 1763–1768 (2008).


Abstract Wang et al.:

"Although many phylogenetic studies have focused on developing hypotheses
about relationships, advances in data collection and computation have
increased the feasibility of collecting large independent datasets to
rigorously test controversial hypotheses or carefully assess artifacts that
may be misleading. One such relationship in need of independent evaluation is
the position of Passeriformes (perching birds) in avian phylogeny. This order
comprises more than half of all extant birds and it includes one of the most
important avian model systems (the zebra finch). Recent large-scale studies
using morphology, mitochondrial and nuclear sequence data have generated very
different hypotheses about the sister group of Passeriformes, and all conflict
with an older hypothesis generated using DNA-DNA hybridization. We used novel
data from 30 nuclear loci, primarily introns, for 28 taxa to evaluate five
major a priori hypotheses regarding the phylogenetic position of
Passeriformes. Although previous studies have suggested that nuclear introns
are ideal for the resolution of ancient avian relationships, introns have also
been criticized because of the potential for alignment ambiguities and the
loss of signal due to saturation. To examine these issues we generated
multiple alignments using several alignment programs, varying alignment
parameters, and using guide trees that reflected the different a priori
hypotheses. Although different alignments and analyses yielded slightly
different results, our analyses excluded all but one of the five a priori
hypotheses. In many cases, the passerines were sister to the Psittaciformes
(parrots), and taxa were members of a larger clade that includes Falconidae
(falcons) and Cariamidae (seriemas). However, the position of Coliiformes
(mousebirds) was highly unstable in our analyses of 30 loci and this
represented the primary source of incongruence among analyses. Mousebirds were
united with passerines or parrots in some analyses, suggesting an additional
hypothesis that needs to be considered in future studies. There was no clear
evidence that base compositional convergence, saturation or long-branch
attraction affected our conclusions. These results provide independent
evidence excluding four major hypotheses about the position of passerines,
allowing the extensive studies on this group to be placed in a more rigorous
evolutionary framework."