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Re: cladobabble--here we go again



Hope you all had a nice weekend.  During that time, Tom Holtz wrote 
(11/14/97; 1:58p):

(referring to clade definitions)

>. . . I find that my students can handle current definitions very
>well.  (And, for the most part, my students are non-science majors).

My comment had been intended to apply to multisyllabic clade definitions, 
in response to another posting by Jonathon Woolf.  This may not have been 
clear in the chain of discussion.

Yes, a phylogenetic Dinosauria is easy to understand, and my students can 
handle it very well.

And yes, I agree there will always be a clade Maniraptora.

As another postor (poster?) commented, this is indeed a philosophical 
issue that may not be appropriate for this forum.  I have also ranted 
before that the definitions we use for clades, while they do have 
content, seem to have certain aspects common to tautologies.  I think 
there's something wrong with the folowing statement, which is a 
paraphrasing of what Tom said in response to my attempt at denying 
Maniraptora:  "The clade Maniraptora exists, no matter what it is."  My 
background in the branch of philosophy that treats such questions is 
limited, so I can't quite put my finger on the problem.  It is probably 
based on a broader issue that this specific definition only symptomizes, 
perhaps the question of defining "clade" in general, as opposed to 
identifying the content of a clade (the latter does not seem to be a 
definitional problem, in spite of the words we use; in other words, what 
does it really mean to "define" Maniraptora, if it exists no matter what 
it is).

I do not retreat from my opinion that it would have been better to define 
clades consistently, and that it would be best if they were 
understandable to a large number of people.  Maybe that simple statement 
would have sufficed from the beginnning in last week's rant, but it 
wouldn't have had much impact.  Contrary to one posting, I do not think 
those opinions are ill-advised; people like to know what we scientists 
are doing--our future might depend on it.

Nobody has to jump in with additional responses--as anyone can probably 
see, this all seems a bit marginal to our purpose here.

Then Jonathon Wagner commented (in "Teaching the straight 
dope"--11/15/97; 10:44a) that he can teach non-science students how to 
read cladograms.  So can I, and I do.  I didn't say I don't teach that.  
Tom referred to the problem of seeing what words say as opposed to what 
we think they say.


As Jonathon said:  "And now, back to dinosaurs..."


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Norman R. King                                       tel:  (812) 464-1794
Department of Geosciences                            fax:  (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712                      e-mail:  nking.ucs@smtp.usi.edu