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Re: non-avian "reptiles"
Taxonomical categories must be based on relationship and not morphology. If
a father is blond and has a blond son and a brunet son, he's not "closer" to
his blond son. So, I think taxonomical cathegories must be like
----- Original Message -----
From: Jaime A. Headden <email@example.com>
Sent: Wednesday, August 02, 2000 5:42 PM
Subject: Re: non-avian "reptiles"
> Ken Kinman wrote:
> <It is certainly desirable to maintain "well-known"
> classifications if they are correct, but that is not
> one of my main priorities.>
> You had previously argued for maintaining some
> historic perspective in classification (Reptilia;
> distinction of Aves); why not extend this perspective
> to all groups? I can answer this in one way for at
> least some groups. Whatever the assumed relationship
> of two fossil taxa, there will always be an upsetting
> perspective, at some point in scientific time.
> It would be interesting why you say it is not your
> priority to maintain well-known classifications, since
> certainly Linnean taxonomy is so widely known it has
> been taught in some grade schools, pick up a bio text
> for High [Secondary] School or College in the States,
> read the Brittanica or Americana, so, and they follow
> this. Go international, and in at least German,
> Spanish, English, Portiguese, Italian, and
> French-speaking countries, they'll teach the same
> thing. So quoting "well-known" would be a misuse of
> data; and really, it evinces your personal perspective
> of a generality (this is not a qualification of your
> position, the term itself is a generality no matter
> who or how you use it).
> <For me the best classifications have what might be
> called "heuristic value", and the cladistic
> maximization of predictivity is only part of that.
> Pure cladifications eventually suffer from some
> combination of complexity, instability, confusion,
> lack of utility, and certainly no way to reflect>
> anagenetic information (divergence).>
> Pfff. Neither does Linnean. There is only a "I think
> this feature meight be more telling as to phylogeny
> and diversity than that" (as if a keeled sternum has
> more phylogenetic information than a single-headed
> quadrate) and this is not scientific. Cladistic
> analysis uses computer algorhythyms to find best-fit
> scenarios; the human elements is left to only the pick
> and choose with characters, and this is testable by
> repeating or changing the characters. If you think
> they ran the character wrong, or shouldn't've used it
> for whatever intrinsic value you place on the feature,
> weighted or not, run it yourself, your way, and
> compare results. Or, in other words, don't knock it
> 'til you try it.
> <Cladists are fond of quoting Darwin wanting to base
> classification on phylogeny, but he also advocated
> reflecting divergence in classifications as well.>
> Science is about the science, not the people who did
> it. Unless there is an abject partialism in the
> statements or experiments, you should leave whose
> quote is being used over whose else's, or which of
> one's quotes is being preferred over another. Simply,
> sometimes, a person can be wrong, and in one phrase,
> be right (or apt) and wrong (off the mark).
> <A mammal order will never equal an insect order, and
> there is no reason that they need to be.>
> You just unarbitrarily weighted consideration of two
> branches of life. Mammals and insects are two
> different groups, and in most aspects of their
> biology, insects have far more anatomical diversity
> than mammals, with less hard-tissue effects on their
> anatomy, being so small, they can diversify the shapes
> of their chiton exoskeleton far more variedly than
> flesh or hair does, etc....
> <And I certainly would never removed Chiroptera from
> Mammalia just because they fly. They can't match birds
> in any measure of diversity that I am aware of, much
> less geological range.>
> Pardon? What features do you use to quantify avian
> diversity from other reptiles? Or for that matter,
> compare to chiropterans, and you will find much the
> same features concerning flight. Don't want to use
> flight as the scale, but integument? Compare to
> diversity of scale form and structure within Selachii
> (anatomically similar to teeth) or just a single
> "order" of "fish" like Perciformes.
> <Although I am an eclectist, I have found a way to
> nest groups without all the disadvantages of strict
> I would disagree with your use of "nest" since
> Linnean taxonomy as you have presented obviates
> nesting (nodes, inclusions obviating exclusions),
> where taking birds from within dinosaurs (or turtles
> from within previous analyses of reptiles* and
> diapsids*) is the exact opposite.
> <Unfortunately when you try to explain this to either
> traditional eclecticists or traditional cladists, both
> sides think I'm "caving in" too much to the other
> I would also disagree with splitting scientists into
> traditional anythings. This is unscientific, and
> individuals can alter (and should, given new evidence
> obviating a position) their positions quite easily.
> Here on the list, the movement from non-saurischian
> therizinosauroids to coelurosaurian therizinosauroids
> happened quite dramatically (you can peruse the
> archives for the extensive discussions on this
> matter), but still there were several participants who
> stated that presented evidence was too strong for them
> to negate the position.
> * vernacular
> I would like to ask you if you could quantify (aside
> from generalizing "diversity") the reasons you have
> presented as existing for removing Aves from
> Dinosauria, and also not even recognizing Dinosauria
> as a clade.
> Jaime "James" A. Headden
> Dinosaurs are horrible, terrible creatures! Even the
> fluffy ones, the snuggle-up-at-night-with ones. You think
> they're fun and sweet, but watch out for that stray tail
> spike! Down, gaston, down, boy! No, not on top of Momma!
> Do You Yahoo!?
> Kick off your party with Yahoo! Invites.