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Re: Livezey and Zusi's big bird morph analysis [...]

But the case for convergence confounding analyses has
been made, time and again, for exactly this clade. It
is THE showcase example where parsimony is likely to
run into a wall*, and has been since more than a
decade (in fact, try doi:10.1007/BF01908745). This
cannot be dismissed out of hand. Basically they
reiterate a cold case; this is not good.

Wait a minute. How else than by cladistic analysis can we _recognize_ convergence?

* Especially in such large-scale analyses, where the
data set cannot be sufficiently fine-grained because
it could then not be applied to many other taxa.

That doesn't really matter. With clever coding inapplicable characters can often be avoided, and the rest is just treated as missing data.

A morphological analysis of foot-propelled divers that
is good (IMHO) would run into problems as soon as it
comes to outgroup selection, because the character set
would include a load of F-PD apomorphies.

It is not possible to do a morphological cladistic analysis _of foot-propelled divers_. Such an analysis must be done of Neoaves or Neognathae as a whole. Fossils included (Palaelodidae, *Juncitarsus*...!).

However, correlated characters must be avoided. (Correlated characters are really one character that is given more weight than the others.)