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Metaves and Coronaves

Houde recently sent me a pdf of an interesting paper-

Fain and Houde, 2004. Parallel radiations in the primary clades of birds.
Evolution. 58(11), p. 2558-2573.

It contains a phylogenetic analysis of intron 7 of the beta-fibrinogen gene,
which is said to have low rates of mutation which are less variant across
sites, and more homogeneous substitutions among character states.  There are
also numerous insertions and deletions, which the authors find useful.  The
50% bootstrap maximum parsimony consensus tree (from 262 mpt's) is-

   |  |--Anseriformes
   |  |  |--screamers
   |  |  `--+--magpie goose
   |  |     `--+--whistling ducks
   |  |        `--ducks
   |  `--Galliformes
   |     |--currasows
   |     `--+--pheasants
   |        `--megapodes
      |  |--hoatzin
      |  `--+--sandgrouse
      |     |--doves
      |     |--frogmouths
      |     |--nighthawks
      |     |--owlet nightjars
      |     |--+--swifts
      |     |  `--hummingbirds
      |     |--mesites
      |     |--+--kagu
      |     |  `--sunbittern
      |     |--grebes
      |     `--flamingos
         |  |  `--finfoots
         |  `--+--trumpeters
         |     `--+--limpkin
         |        `--cranes
         |--new world vultures
         |  `--+--cormorants
         |     |--anhingas
         |     `--boobies
         |  `--storm petrels
         |--thick knees
         |  `--+--plovers
         |     `--+--stilts
         |        `--oystercatchers
         |  |  `--+--+--plains wanderer
         |  |     |  `--seedsnipe
         |  |     `--+--painted snipe
         |  |        `--jacanas
         |  `--+--buttonquail
         |     `--+--coursers
         |        `--+--jaegers
         |           `--+--auks
         |              |--gulls
         |              `--skimmers
         |--+--secretary bird
         |  `--+--osprey
         |     `--hawks
         |  `--barn owls
         |  `--trogons
         |  |--jacamars
         |  |--rollers
         |  |--+--kingfishers
         |  |  `--motmots
         |  `--+--+--toucans
         |     |  `--barbets
         |     `--+--honeyguides
         |        `--+--wryneck
         |           `--woodpeckers
         |--+--new world flycatchers
         |  `--cotingas
            `--+--old world flycatchers

No, neither Metaves nor Coronaves are defined.

"MP and ML bootstrap values support the monophyly of Metaves at 73% and 58%
and Coronaves at 58% and 62% when analyzed using only nucleotide characters.
MP and NJ bootstrap values are 85% and 82% for Metaves and 60% and 52% for
Coronaves when indel characters are included in the analysis. Bayesian
posterior probabilities are 95% for Metaves (99% excluding hoatzin) and 83%
for Coronaves using only nucleotide characters. A likelihood-ratio test
shows that the branches to Metaves and Coronaves are significantly different
from zero at the P , 0.001 level."
"... Metaves and Coronaves are recovered as strictly monophyletic by
analysis of alternative alignments
produced using ClustalX at a variety of gap and extension penalties, and by
"Metaves and Coronaves are recovered as monophyletic even under alignment
parameters that give obviously unreasonable alignments."

"Metaves and Coronaves are broadly distinguished by four indels: a five-base
deletion in Coronaves, a 15-base deletion in Coronaves plus Syrrhaptes (one
of two genera of sandgrouse, both studied), a 21-base deletion in Coronaves
plus ostrich or insertion in Metaves plus Galloanserae, and a fourbase
deletion in Metaves plus bustards (for list of all vernacular and Latin
family names see Fig. 2). Less than perfect
consistency of these indels demonstrate that they are not evolving in a
perfectly correlated fashion."

"ML analysis excluding these regions of the alignment (nucleotide data
subset 3, see Methods) still recover
Metaves and Coronaves as monophyletic, although with reduced bootstrap
support, 71% and 39%, respectively. In other words, the neoavian dichotomy
is obtained even when these regions of homology to the metavian- and
coronavian- specific indels are completely removed from the dataset."

One point the authors make is that metavians and coronavians have converged
to a remarkable degree.  This is illustrated convincingly by their
comparative photos in figures 4 and 5.  I never realized how similar monias
and thrashers were, or sandgrouse and seedsnipe.

Pdf's are available by asking me offlist.

Mickey Mortimer
Undergraduate, Earth and Space Sciences
University of Washington
The Theropod Database - http://students.washington.edu/eoraptor/Home.html