Re: FEATHERED THEROPODS

[smithjb@sas.upenn.edu (Joshua Smith)]

Tetanurae@aol.com wrote:
> 
> Back to the subject.  Parsimony dictates that since the sister taxon to
> dromaeosaurids (birds) were feathered, and an outgroup (Sinosauroptryx) had
> hairlike structures that were hollow like feather shafts, then dromaeosaurids
> should have had some sort either hairy covering, or feathers.

        Dromaeosaurids _should_ have had some sort of hairy or feathered 
covering if parsimony dictiates

IF and only IF parsimony (a condition which we all run around 
applying liberally which is a hypothesis in and of itself which DOES NOT 
NECESSARILLY HAVE to operate in all (or indeed any, as it IS a 
hypothesis) cases) 

that since the sister taxon to dromaeosaurids (birds)

(the HYPOTHESIZED sister taxon--you said yourself in this same post that it is
not possible to prove a hypothesis, only bash away at its competition)

were feathered, an outgroup (Sinosauropteryx)

arbitrary outgroup which was SELECTED by the individual running the 
analysis, not always or necessarilly by scientific methods.

had hairlike structures that were hollowed like feather shafts.


> Additionally, the most recent (and only) analysis with Protarchaeopteryx
> showed that it fell in an unresolved trichotemy with dromaeosaurs and birds,
> which means that 2 of the three possible places for Protarchaeopteryx to
> actually show up, shows that the common ancestor of dromaeosaurus and
> Protarchaeopteryx had real gosh darned feathers.
> 
        based on THE SUITE OF CHARACTERS USED IN THIS ANALYSIS.  Change 
the characters (which are subjectively selected), and you could very well 
change the possible positions.


        There are a lot of ifs in these statements (and these analyses).  
These are tests of hypotheses, not statements of tested theories.  
Everyone seems to be arguing this stuff with the same zeal they would of a 
pet theory that they received a Nobel Prize from, and with the same lack of 
objectivity.  This is the same situation that I would call the Ruben et 
al. clan on--they are so set on making THEIR point that they don't care 
if it is reality anymore.

        Relax, people.  The answer is all that is important in all of this 
bird/dinosaur crap.  Who cares which one it is?  


-- 
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Josh Smith
University of Pennsylvania
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