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RE: Avian origins: new analysis confirms ancient beginnings



> Mesozoic neornithine relationships.  For a future
> proper analysis of Mesozoic neornithines, you have
> the right idea as far as plugging them into Livezey
> and Hope's matrix.  That's really outside my area of
> expertise though, and Mayr's comments about the
> matrix are discouraging.

True, but I thought more of piggybacking their
character data (as far as it can be checked) onto the
draft consensus phylogenies, to glean info on how to
interpret Hope's data in the light of 5 more years of
insight.
Just take the plain L/Z character data of a terminal
clade as per the draft consensus phylogeny (NOT the
L/Z phylogeny) and compare it with the data for their
sister lineage(s) to get the presumed state changes,
repeat with the higher-level clade, etc. The result
should allow reasonably robust inference about at
least some character states in the basalmost taxa of
the tubenose-et-al clade. These can be compared with
the character states of candidate taxa in Hope (2002).

It would still be advisable to go a bit further than
the clade in question. If characters turn out to
change state very frequently, namely outside the clade
in question also, and especially if ecomorphological
constraints are not readily apparent, one will
immediately known that inference of the ancestral
state *in* the clade in question is unreliable. To go
beyond this, one would probably need a dedicated
analysis. But this is just a quick-and-dirty way to
pick out promising candidates for thorough study.


Eike


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