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RE: Several New Papers



--- Michael Mortimer <mickey_mortimer111@msn.com>
schrieb:

> But the 'caprimulgiformes paraphyletic to flamingos'
> arrangement wasn't even 
> supported by bootstrap values of over 50%.  No
> molecular worker would take 
> such a result seriously, and if you thought it was
> something Fain and Houde 
> advocated, you're surely mistaken.

No, I wouldn't say that. (Still, if that counts, this
http://www.bioone.org/perlserv/?request=get-abstract&doi=10.1650%2F0010-5422(2002)104%5B0725%3ASAHBOW%5D2.0.CO%3B2
should probably never have been published as it was...
and I have seen far too many of these. If node support
is bad, that's that. But one could just let it rest
there and not try to fit the evidence to the
inference.) 

>  So you can't use
> very poorly supported 
> ingroup nodes of Metaves to argue against the
> reality of Metaves itself, 
> which had an 85% bootstrap (not bad, but not great)
> in Fain and Houde's 
> analysis.

Tempting but insufficient for me, because it is full
of weakly-supported and otherwise spurious nodes and
as a whole is not supported well by other than
molecular data:

"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 four-base
deletion in Metaves plus bustards"
(from Fain & Houde)

4 characters, each one of which is *known* to occur as
homoplasy, and as such could have switched state once
or (unlikely) repeatedly since the Cenomanian,
approximately (as delimited by Galloanserae and
Syrrhaptes). Hm.

In any case, the goatsucker-flamingo clade was a bait,
not an argument.

> >This being science after all, I'll just put it like
> >this: give me a good solid attempt to *falsify* the
> >Metaves-Coronaves dichotomy, and if that *fails*,
> I'll
> >think about it.
> 
> Wasn't that what Ericson et al.'s analysis was?

I'd rather call it a good review/meta-analysis. They
didn't set out to refute anything, but rather to
assemble that what was lying around and see where they
arrived at. Which is also entirely valid.
Biogeographical data, the incompleteness of the fossil
record nonwithstanding, should be moe used to put
hypotheses to the test methinks.

(Is there a good paleogeographical atlas on the Web? I
don't really want to have to make my own.)

> other taxa too.  But they basically ignore
> Cretaceous neornithine fossils, 
> and by only using Eocene fossils as calibration,
> force a result where the 
> main neoavian 'orders' diverge after the K-T
> boundary.

Yes, but this is obviously due to the fact that the
record of Mesozoic Neornithes that can be assigned to
any lineage (other than Galloanseres) with reasonable
certainty is slim. They could have made an explanatory
drawing though, indicating the uncertainty caused by
"stuff" like Tytthostonyx, but in a pinch I prefer it
this way rather than to mess up the analysis by
assigning the unassignable.

I expect ATM that eventually, the Coronaves-Metaves
concept as proposed will fail, with "Metaves" as it
presently stands turning out to be paraphyletic "waifs
and strays" and perhaps one or two minor clades, but
that the 4 major neornithine lineages will hold.

I also expect that *phylogenetically* even in the
"higher landbirds" the basal divergences will
eventually be placed in the Mesozoic.


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?

Regards,

Eike




        
                
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