Re: FEATHERED THEROPODS

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

Jeff Poling wrote:

> At 03:28 PM 9/27/98 -0400, Joshua Smith wrote:
> >were feathered, an outgroup (Sinosauropteryx)
> >
> >arbitrary outgroup which was SELECTED by the individual running the 
> >analysis, not always or necessarilly by scientific methods.
> 
>    Uh, no.  Choosing _Sinosauropteryx_ is NOT arbitrary.  There are only two
> (ignoring _Caudipteryx_ and _Protarchaeopteryx_) groups you can pick (birds
> and _Sinosauropteryx_) if you are using phylogeny and parsimony to gain
> insight into the possibility of integument in other related groups using
> known data.
> 
        Right.  Stupid of me.  Point in your court, Jeff.  That was more 
of a generalized rant on outgroup selection because of the tendancy for 
them to often TO be selected, effectively, at random.  Dodson delivered 
that one during a graduate seminar in '95 and it has always bugged me, to 
the point where I probably rant about it more than is deserved.  Hmmm...I 
wonder if that can be used as support of my original point on visceral 
reactions decreasing objectivity...

        Although, let me be a jerk and beat the horse a little bit and 
point out that you are using phylogeny and parsimony to gain insight into 
the possibility of integument in other groups that are HYPOTHESIZED 
relatives.  Just because our cladograms say something is related, doesn't 
mean it is.  In support of this, I refer you to the theropod mud-slinging
match (oh, I mean "symposium") in Pittsburg in 1995.

        I think the horse it pretty much dead now...

-- 
__________________________
Josh Smith
University of Pennsylvania
Department of Earth and Environmental Science
471 Hayden Hall
240 South 33rd Street
Philadelphia, PA  19104-6316
(215) 898-5630 (Office)
(215) 898-0964 (FAX)
smithjb@sas.upenn.edu