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Re: Non-serpentine lacertids (was RE:WHAT'S GOING ON?)

At 08:32 AM 03/07/2000 -0400, ELurio@aol.com wrote:
The fact is that except for "glass snakes," the tuatara and the three
monotremes, all the distaff forms of vertabrate life fit perfectly within the
"linnean" system.

What does this mean? The Linnaean system certainly encompasses these three taxa, as the Family Anguidae within the Order Lacertilia, The Order Rhynchocephalia within the Class Reptilia, and the Order Monotremata within the Class Mammalia, respectively.

This says little about the relative merits of the Linnaean system. However, at one remove, any biological classification system is arbitrary because it seeks to impose categorization onto a continuum, and any taxonomic category breaks down at its borders (even if these are temporal borders). At the lowest level, for example, if you say that species A gives rise to species B what you really mean is that some individuals of that species - possibly a single breeding pair - did so, while other individual lineages within that species did not. Does that mean that the ancestral pair belongs in a different taxonomic category (with its decendants) than, say, its siblings or cousins?

Therefore in my view a lot of this discussion turns on what a classification is for. Is it meant to be a verbal repersentation of a phylogenetic tree? A tool for sorting out museum collections or ecosytem occupants? A guide for the general public?

For example, I think it is highly unlikely that the general public will, anytime soon, abandon the use of the word "reptile", and attempts to convince it to do otherwise may be met with scornful claims that scientists have no connection with the real world. Even among knowledgeable amateurs like experienced birders, traditional linnaean levels like "Family" are useful mnemonics that they are unlikely to drop without a struggle (listen to birders complain every time a species name gets changed!).

However, that doesn't mean that within the scientific community a better system cannot be developed - but even there, use of an unfamiliar system can cause unecessary confusion, especially if the paper using it is not dealing with matters of classificationin the first place. Also, scientific disciplines within zoology, when they divide along taxonomic linse, do so in line with the "old" system - thus herpetologists and ornithologists are not likely to reorganize their disciplines even though they are clearly "paraphyletic" (unless all you dinosaur researchers would care to start referring to yourselves as ornithologists?)

The trick, then, it seems to me, is to be clear, when you use one system or another, of (a) your purpose and (b) your audience, and, where necessary, to explain what system you are using and why. I am facing this myself - I am writing a popular book on turtles, with a chapter on turtle evolution, and have the job of explaining the controversy over turtle origins to an audience that has probably never heard the term "parareptile" or even "anapsid", and wouldn't know a pareiasaur if they fell over one. At some point I will have to (briefly!) explain what the term "reptile" means, if anything, these days, and I am still trying to figure out just how to do it without giving my readers a serious case of cramp.
Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2 mailto:ornstn@home.com