Re: Apomorphy-based definitions

["David Marjanovic" <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Jaime A. Headden" <qilongia@yahoo.com>
To: <dinosaur@usc.edu>
Cc: <david.marjanovic@gmx.at>; <mike@tecc.co.uk>
Sent: Thursday, August 23, 2001 7:50 PM
Subject: Re: Apomorphy-based definitions


> Hoping that Mike allowed this discussion to be posted to the list ...

...yes, the PhyloCode mailing list :-)

> David Marjanovic (david.marjanovic@gmx.at) wrote to Mike Taylor
(mike@tecc.co.uk)
> [and the PhyloCode mailing list (phylocode@ouvaxa.cats.ohiou.edu):
>
> <Suppose you'd be [naïve] enough do define birds as possessing feathers.
8-) Then the definition
> would read "the first species that possessed feathers synapomorphic with
those of *Passer*, and
> all its descendants" and be abbreviated as (Feathers in *Passer*).>
>
>   This definition would be a very bad idea. For one thing, the feathers of
*Passer* are suddenly
> the defining feature for feathers as a phylogenetic tool; ratite feathers
are different, foir the
> bulk of their morphology, and it is conceivable that Ratitae would be
excluded from this
> definition.

Completely true; I have used this example because I have read it somewhere
(probably Sereno's rationale in Neues Jahrbuch) and for a moment thought it
was in the PhyloCode (wrong).