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RE: Several New Papers



Eike's original has not made it to the list, so I haven't deleted anything 
below.

> > or, better yet, Mayr's discovery of (*Juncitarsus* +
> > (flamingos + grebes)) being cases in point --,
>
> Yes, this one I find intriguing. What is certain that
> many works on these have been less than satisfactory
> at closer look. The fin-propelled diver ecotype
> enforces very similar morphological adaptations
> apparently.
> That flamingos have evolved the "anseriform" bill in
> parallel, so much is fairly certain. The entire
> morphotype seems fairly ancient, think Presbyornis,
> "Graculavidae", Laornis etc.

What do you mean? AFAIK no skulls are known for any "graculavid" or *Laornis*.

> Parasite studies are,
> huh, well - what does one, with the benefit of
> hindsight, expect from fowl which hang out with geese
> (and pelicans...)
>
> I am more reserved about "Odontanseres". Tytthostonyx,
> well, sooner or later I'll check out the description
> to see what this critter was (except 1 bone or so),
> might be a candidate even. For now, I am undecided
> whether the selective forces would be sufficient to
> enforce osteological homoplasy in large pelagic birds
> (though I tend to a cautious "yes").

That's the point. Ducks are not "large pelagic birds". Many pelecaniforms are, 
and that's where the false-toothed birds used to be put.

> > Anyway, I expect plenty of morphological surprises.
> > There is, after all, not a single morphological
> > phylogenetic analysis of Neornithes of a size that
> > can be taken even remotely seriously. The one in
> > preparation by Livezey & Zusi will be the first.
> >
> > > I wonder why Poe & Chubb's "Birds in a Bush"
> > > (Evolution 58:404) is missing from the references.
> > > Have I missed something? Was it ripped to pieces?
> >
> > Could you remind me what that was about?
>
> "All recent studies of bird phylogeny have produced
> poorly resolved relationships among the orders of
> Neoaves, the lineage that includes most modern birds.
> This ââbushââ result suggests the possibility of an
> explosive and potentially unresolvable evolutionary
> radiation. However, simultaneous radiations of multiple
> lineages are thought to be rare or nonexistent in nature
> and difficult to corroborate empirically because lack of
> phylogenetic resolution can also be caused by analytical
> artifacts. Here we examine the predictions of the explosive
> radiation hypothesis for five independent genetic datasets
> for Neoaves. We propose a methodology for testing for
> polytomies of evolutionary lineages, perform likelihood-ratio
> tests to compare trees with zero-length branches to more
> resolved trees, compare topologies between independent gene
> trees, and propose a power test for the SOWH test. The evidence
> of (1) extremely short (in some cases zero-length) branches for
> interordinal relationships across independent gene trees and
> (2) topological incongruence among gene trees suggests that the
> bird tree includes essentially simultaneous radiation of
> multiple lineages. This result explains why a robust
> phylogeny of birds has not been produced despite much
> effort on the part of avian systematists."

An interesting and entirely possible idea, but at present no more than that. 
There has been "much effort on the part of avian" phylogeneticists, but by far 
not enough, considering the sheer size of the problem.

Be careful with branch lengths. Those depend to a surprising degree on the 
_method_. I have run parsimony and likelihood analyses of the same large 
molecular dataset (to be resubmitted very soon); the topologies are almost 
identical, but the most likely tree has suspiciously short internal branches 
close to the root, while those of the most parsimonious tree are about half as 
long as the terminal branches throughout and make the tree look entirely 
believable.
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