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various & sundry



Trying to play catch up with things:

Chris Campbell, writing in response to me:
>> Even here on campus, the College of Agriculture has a Department of Animal
>> and Avian Sciences.  You can check out the U Maryland website if you want to
>> verify that.  (And, no, even when folks from Zoology and I complained, they
>> don't want to change it).
>
>Well, how many ornithologists work in said department?  If a good chunk
>of the department is into birds there's your answer right there.  It
>isn't necessarily ignorance so much as the self-importance of bird
>people.  :-)

Actually, it is an Agro School department, a recent fusion of the old Dept.
of Animal Science and the Dept. of Poultry Science.  Not much in the way of
zoologists (exclusive of ornithologists) or ornithologists in either old
department or the new one.  It is mostly nutritionists, animal husbandry
researchers, etc.

Needless to say, neither the old Dept. of Animal Science or the new Dept. of
Animal & Avian Sciences devotes much time or energy to crustacean
systematics, salamander life histories, or bat echolocation.  (The
Departments of Biology and of Entomology, in the School of Life Sciences,
however, is a different story).

Christian Kammerer's suggestion of using "reptilian" to refer to "a member
of the clade Reptilia" isn't bad, but I'm afraid that the same arguments
against the cultural baggage associated with "reptile" apply equally well to
"reptilian".  Furthermore, the idea that we should exclude nonavian
dinosaurs from "reptiles" (sensu Kammerer) because they were warm-blooded
is, unfortunately, still premature.  Despite a quarter century of research
by some very, very smart people, there is no consensus yet as to the thermal
physiology of nonavian dinos.  In fact, Horner has gone as far to say (at
recent conferences) that maybe they reason we haven't answered the question
"Were dinosaurs warm- or cold-blooded?" is because that is the WRONG
question!  (The question he, and most others, would prefer is "What sort of
thermal physiology did dinosaurs have?").


Many people working on dinosaur physiology suspect that there may have been
more than one different types of thermal physiologies among the dinosaurs,
and that only some of the dinosaurs had avian-style tachymetabolic
homeothermic endothermy.

Mickey Rowe added much details and corrections to my comments about
vertebrate eyes (which I was hoping he would!!).  Interesting stuff about
marsupials (hey, anyone out there want to look into marsupial eyes...) (and
see the koalas staring back)?  UV-sensitivity in Reptilia?  I like it.

(And, of course, Mickey points out the semantic problems with terms like
"color spectrum", mixing perception and physics.  Consider my hand slapped.)

And, finally, to Norm King's assertion that "any child knows that turtles
are reptiles".  This is wholly a case of education, and could (and can) be
corrected by new education.  The idea of grouping non-warm-blooded scaly
terrestrial egg-layers is not a "natural" one: no culture outside of Western
science in the post-Linneaus era ever did this.  (At least none I have heard
of).  This is unlike birds, for example, a group which almost every culture
recognizes (although some threw bats in there, too).

The idea that turtles, lizards, snakes, and crocodiles form a group of some
sort is not something that kids automatically know; it is something they are
taught.  Teaching the paraphyletic sense had its purpose, but it is time to
move on.  As Darwin suggested back in the 1850s evolutionary history and
common ancestry should be the key concept in classification.  It has now
reached that status within the science.  It is our duty and responsibility
as scientists and science educators to help bring this concept to youngsters
and other interested parties out there.

Now to get a glass of wet water and get back to grading dino exams...

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:tholtz@geol.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661