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Re: More reptile stuff



Chris Campbell (12/18/98; 1:00a) has brilliantly distilled into words one 
aspect of what is wrong with phylogenetic taxonomy.  There are other 
things wrong with it, and I have been biting my tongue since Tom Holtz 
mentioned with a sneer how these questions come up every 6-9 months or so 
(see below).  I haven't the time now to re-enter the fray, except to note 
that it wouldn't keep coming up if there weren't some problems with it.

I will do some snipping to show what I think is a fine summary of the 
situation, and then I got to go.


>[snip] "reptile" has lots of different meanings, creates confusion
in folks who aren't taxonomists, and carries with it heavy implications
in terms of biology and behavior.  It's not the same as, say, "diapsida" 
since diapsid refers to one thing and one thing only -- holes in the
skull.  "Reptile" refers to poor thermoregulation, sluggish behavior, 
scales, egg-laying, particular forms of locomotion, goofy reproductive 
patterns (by mammalian standards, of course, which don't count for much), 

and a half-assed (though admittedly effective) circulatory system.  
Perhaps two of these apply to birds; at least one does not apply to 
turtles, and another doesn't apply to crocs.  Now, I know you don't 
include these things in your definition, and that's fine, but that's 
what the definition means to a lot of people.  You're redefining the 
word, which is fine for cladists, but who's gonna catch up the rest of
the world?<

[snip]

>What it means depends on who you ask.  The cladists have one 
version, while the rest of the world has another, and they don't 
quite gel.<

This snippet comes from an earlier posting by Chris:  >>Yes, 
lumping lepidosaurs and archosaurs and testudines together is a 
valid clade, but what's the point? I'm just not very clear on what 
this really tells us about the groups involved.<<

And, quoting Tom, who was repsonding to the above:  >What is it you 
want it tell us?  No, really, I am intrigued by this question.  You
(and you are not the only one this list: the same questions rise up 
every six to nine months, it seems) seem to be expecting something 
from taxonomy other than labelling particular branches of the tree 
of life.<

Now, going back to the Chris' most recent posting:  >I want it to 
tell us something readily observable about the animals in question.  
Mammal tells me an animal bears and nurses live young and that it 
has hair of some sort.  Fish tells me an animal is an aquatic
vertebrate with a two-chambered heart and gills.  Bird tells me an
animal is covered with feathers, has forelimbs modified into wings, 
lays eggs, and has exceptional respiratory and circulatory systems.  
Arachnid tells me an animal has eight limbs and a body divided into a
cephalothorax and an abdomen.  Reptile, particularly the cladistic
definition, tells me nothing whatsoever about the animal in question. 
It doesn't tell me what it looks like, how it acts, how it's covered,
how it reproduces, how it moves, how good it is with circulation or
temperature regulation, or anything beyond skeletal characteristics.  
I don't expect a definition to tell me all of the above, but I expect
*something* to go on, particularly if it's a definition in common use
not only in the biological sciences but in the world at large.  If
you're talking sauropsids or pelycosaurs fine, go to town with 
skeletal characteristics.  I really think, though, that we should have 
more to go on with a term which sees as much use as "reptilia".<



Well said!

I once asserted that even a child can see that a bird is not a dinosaur, 
and boy did that rile some people up.  Well, I submit that even a child 
can also see that a turtle is a reptile.

It may be true that you could take a child who had been raised by wolves 
and teach him/her from the ground up that birds are dinosaurs, etc. etc. 
and it would be no problem.  But it IS a problem to take words like 
"reptile" and "dinosaur" and try to give them new meanings in your own 
little (VERY LITTLE!) world of phylogenetic taxonomy, then keep hammering 
away at the rest of the world filled with many fully competent people, 
berating them for not being able to catch on to the way things REALLY 
are.

I'm afraid the way things really are may be in the eye of the beholder, 
and just keep up with this assault on common sense to make sure these 
respective beholders always remain separate.

Pant, pant pant!

Happy holidays.


*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
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




*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
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