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Re: avian nomenclature

> The trouble is that (with few exceptions) we lack fossils
> from at or near the critical branching points in neornithean
> evolution, corresponding to when different 'orders' first
> appeared.  A similar problem occurs with
> placentals.  I'm certain we know more about the
> relationships of non-avian theropod taxa than we do about
> the relationships of modern bird orders (Neornithes).

It's not that bad, actually. Apart from the "uncertainty region" - which 
according to what fossils pop up when is the 5 Ma or so just after the K-Pg 
boundary; go figure! - between "higher waterbirds" and "near passerines", a 
very large amount of diversity is placed quite firmly.

The second Mayr et al paper for example was mainly taxonomic cleanup work. 
Everyone who cared knew where it was heading; the morph and mol data fits 
together very nicely here. but it needed to be published. 

And that's why it seems to be so confusing: even if following the literature of 
the last 5 years or so will yield a pretty good idea of what's going on, 
without the fossil data being formally reevaluated in the light of the 
molecular data, and vice versa, and all that being integrated with biodiversity 
it's not solid enough.

We're even making good way out of the ratite tangle! The "Falconiformes" and 
"Gruiformes" are perhaps the two really large problems that remain, because the 
latter and at leats part of the former are at the junction between "higher 
waterbirds" and "higher landbirds", and the effect on the cladistic structure 
is of course severe (are "higher landbirds" a clade? are "higher waterbirds" 
*without* "higher landbirds" a clade?). 

The rest is mainly questions like "what is the exact nature of the relationship 
between Hoatzin versus cuckoos and turacos versus pigeons and sandgrouse, and 
how far are these from passerines?"

But given that passerines make up 60% of all living bird species, and that the 
phylogeny of 95% of all passerine species is essentially known (or we can at 
least make a well-founded guess that is very unlikely to be wrong - plumage is 
helpful ;-) ), it's really well resolved, compared to other taxa of such age 
and diversity.

And that is very good, because given the popularity of songbirds, knowledge of 
their phylogeny is *really* helpful in convincing people that Darwin was right. 
For almost any phenomenon in the field of evolutionary biology, among the 
Passeri(formes) an example is to be found.t



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