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



On 2 August 2011 13:58, Thomas R. Holtz, Jr. <tholtz@umd.edu> wrote:
>> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu]
>> On Behalf Of Matthew Martyniuk
>> Sent: Tuesday, August 02, 2011 8:22 AM
>> To: dinosaur@usc.edu
>> Subject: Re: Greg Paul is right (again); or "Archie's not a birdy"
>>
>> To be fair, this again depends on how you define Aves. The
>> oldest phylogenetic definition published for Aves is an
>> apomorphy-based on anchored on the presence of feathers
>> (Charig, 1985). In this usage (which is just as valid as any
>> other pre-PhyloCode), feathers are not only a fundamental
>> avian attribute, they are the *defining* attribute of Aves.
>>
>> (How you define 'feather' is another story).
>>
>> Matt
>
> I find it highly unlikely that Charig defined ANYTHING phylogenetically! What 
> is his actual statement? I suspect it something more
> along the line of "Aves is defined by the presence of feathers"; if so, that 
> is simply traditional pre-cladistic gradistic
> classification. On the other hand, a statement along the lines of "Aves is 
> that entire branch of the tree of life descended from the
> first feathered animal", that is a fairer claim to a phylogenetic defintion.

Surprisingly enough, what Charig (1985:26) actually wrote was "Let us
define a class Aves as the clade that is demarcated from its
antecedents by the appearance of the evolutionary novelty ‘feathers’"
(quoted from Senter 2005:4).

So, yeah, an explicit clade definition.  Albeit not a very good one.

-- Mike.