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Re: Arbitrary science further ...

In a message dated 6/8/99 7:29:10 PM Eastern Daylight Time, 
Z966341@wpo.cso.niu.edu writes:

<< We all have opinions, biases, etc., and total objectivity is impossible, 
but this is what we shoot for, to practice science as best as is humanly 
possible.  >>

However, regardless of  the people doing the work, I'd suggest that 
paleontology can be considered arbitrary in two areas.  The first, as we've 
discussed,  is in naming.  As you know, I wish that brontosaur was still in 
scientific use and that dinosaurs and birds (?) had escaped classification 
under reptiles.  The rules are consistent and openly applied, but the outcome 
could have been different without being in contradiction of fact.

The other area is shown in Mr. Headden's posting about Caenagnathus:

<< Okay, by 1972 we've got a happy little bunch of theropods (or birds, 
considering Joel Cracraft's past take on Caena). 
Currie and Russell (1988) synonymized Macro with Chiro on the basis on a new 
skeleton; no more Macro.
Paul (1988) synonymized Chiro and Elmi on the basis of the tarsometatarsi; 
relatively sound, seconded (in a sense) by Currie (1989)
 -->. Currie (1989) synonymized "O." elegans with Elmi based on the 
similarity of the tarsometatarsi compared to Chiro (more later); no more 
"O.", now E. elegans.
Sues (1997) synonymized Caena and Chiro, long suspected but improvable until 
then; no more Caena.
This made all Caena's species Chiro's...
Sues took E. elegans elegans and made it a species of Chiro, arguing that he 
percieved no great distinction between the two species,
and promptly, on basis of size, synonymized C. sternbergi and E. elegans; the 
latter, by facter of being named first, became the valid name.
Currie (1989) placed E. elegans with Elmi on basis of distinct fused distal 
tarsals forming a cap over the metatarsus, and by possessing a posteromedial 
(E. rarus is larger, more robust, and has a posterior ridge on the distal 
tarsals, rather like *Avimimus* and parvicursorids (see Osmolska, 1971)).
Relative slenderness in elegans as compared to rarus and [Chiro] pergracilis 
argues for some distinction from either as a species, but closer to rarus 
than to pergracilis, despite that it's N.American, not Asian.
Such stratigraphic separation is not sufficient (given LK transitional 
Berring bridges) for combining N.Amer. species into a genus.
C. sternbergi jaws are different from C. pergracilis in that they have a 
shorter, wider
articular face, and relatively deeper and wider surangular (e.g. more 
"robust") coupled with smaller size and similar degree of fusion between the 
elements. Refered jaw _may_ or _may not_ belong to the species, but 
Cracraft's reasons to naming a new
species seem to me to be valid (based on proportions).
So, therefore, I'm more inclined to believe the following to be closer 
phylogenetically... >>

This is a bravura display of erudition and judgement!
Consider the bases for decision.  Only the first mentioned is based on new 
data (a new skeleton).  The rest are based on tarsometatarsi ('relatively 
sound'), no perceived distinction between species, size, 'distinct fused 
distal tarsals forming a cap over the metatarsus, and... a posteromedial 
"tongue"', relative slenderness, NOT stratigraphic separation, jaws with 'a 
shorter, wider articular face, and relatively deeper and wider surangular 
(e.g. more "robust") coupled with smaller size and similar degree of fusion 
between the elements', and proportions. 
This list includes items of detailed anatomy and gross observations.  Is it 
possible that another paleontologist could look at this list and find other 
compelling reasons for a different set of relationships among the fossils?  
That is, has judgement, as opposed to universal rules, been applied?  From 
this distance, it appears that some of the distinctions do appear arbitrary, 
though based on great knowledge and skill.

Some time ago I read that physicians in emergency rooms now have available to 
them a computer program which is able to develop a prognosis for patients 
which is at least as good as the one developed by the doctors themselves.  
Apparently it is possible to develop invariable rules which have predictive 
value.  In the absence of prediction as a test, is it possible to reduce to 
indifference the amount of judgement inherent in identifying relationships 
among animals?
As we have discussed, there are established principles, such as parsimony, 
which allow choice among the various alternatives.  Aren't there close calls 
in at least some situations?  How do you weight a factor like geography, as 
in the discussion above where one animal was closer to animals a continent 
away than to its neighbors?
To me, paleontology, like chess, has an element of art to it no matter what 
the computers do.  This art, or arbitrariness, is part of my interest.