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Re: Greg Paul is right (again); or "Archie's not a birdy"



On Wed, Aug 3, 2011 at 4:34 AM, David Marjanovic
<david.marjanovic@gmx.at> wrote:
>
> ...and open the way for unjustified inferences in the other direction, where
> plesiomorphies are extrapolated too close to the crown.

Curious to see some examples of this in the literature.

The crown-stem distinction is not meant to limit apomorphies to the
crown. Rather, it identifies a clade where we are certain of the
presence of an apomorphy (except in cases of secondary loss) and a
paraphyletic grade where we are less certain. (I know you know this,
of course.)

> Is it really a good idea to maximize cross-disciplinary understanding at the
> expense of intradisciplinary understanding by making unneeded breaks with
> history? I'm all for bloody revolutions, but I don't like it when they're
> bloodier than necessary.

I don't think this one is really that bloody, when you consider there
is far more neontological literature on Aves than paleontological.
I'll grant that it's bloodier than, say, Mammalia (where traditional
paleontological usage was already close to the crown), which in turn
is bloodier than the huge numbers of crown clades where the stem group
is completely unknown (i.e., the majority of crown clades).

Again, though, what makes "Aves" so exceptional? So far the best
argument I've seen is its homonymy with a vernacular word in certain
languages. I don't find that argument terribly compelling, either,
since the vernacular word is also primarily neontological in usage.

2011/8/3 David Černý <david.cerny1@gmail.com>:
> But what if it is a vernacular name (like "birds") that is prone to
> unjustified inferences? The examples presented by Gauthier and de
> Queiroz (2001) all involved the term "birds", not _Aves_. You cannot
> get rid of unjustified infereces unless you convince all biologists
> that _Ichthyornis_ is not a "bird". Moving it out of _Aves_ is not
> enough.

Could I convince biologists to avoid the term "bird" and use an
appropriate alternative (avian, ornithuran, avialan, avipinnan, etc.)
in technical discussions? (Or at least clarify what they mean by
"bird"?)

-- 
T. Michael Keesey
http://tmkeesey.net/