Re: New paper on Neoaves

[Michael Mortimer <mickey_mortimer111@msn.com>]

Tim Williams wrote-

> > Or maybe Amphioxus isn't a chordate.
>
> That's a tough sell.  Notochord, pharyngeal slits, myotomes...?

And echinoderms are crazy things that could have reversed characters.  Lots 
of mammalian groups which molecular evidence reject were also supported by 
good-looking lists of synapomorphies.  But I do favor molecular over 
morphological, so I may be biased.

> > Also the phenotypic results of the nucleotide changes are often difficult 
> > to determine.
>
> I know you're addressing David's point, but I would take this opportunity 
> to mention that I don't think that this is important for molecular-based 
> phylogenetic analyses.  What I think is essential is a better understanding 
> of the genes and proteins themselves before we become too carried away with 
> molecular-based analyses.  So many phylogenetic analyses pin their hopes on 
> protein-coding genes (including their introns) without understanding why or 
> how the changes at the level of DNA or protein actually occurred.  The 
> amount of homoplasy caused by biochemical constraints may be vastly 
> underestimated.

I think we're basically talking about the same thing.  I just think doing 
this will take a LOT of time.

> Oh dear, I'm veering way OT.  Back to avian theropods.... the thing is, I'm 
> deeply suspicious of this Metaves-Coronaves split, and the constituent taxa 
> within each.  Some signal is undoubtedly 'real' - particularly the more 
> recent divergences.  But I hope the study of Ericson &c (and similar 
> studies) doesn't prompt people to start erecting a host of new 
> molecule-based clade names, such as happened with mammals.

Well, do you find that many of the new mammal clade names to be useless?  I 
mean, ignoring mammalogists' need to rename clades if a member is included 
or excluded (Eulipotyphla, Euarchonta, etc.).  But Laurasiatheria, 
Afrotheria and such seem quite useful to me.  I figure even Scrotifera and 
Pegasoferae will be useful once paleontology catches up and actually tries 
to figure out how so many fossil taxa fit in.  Quite angering it's taking so 
long.  Does NOBODY care how xenungulates fit in?

Mickey Mortimer