Paraphyly, Aves, man, etc.
tdib at OCEANCONSERVANCY.ORG
Tue Jan 29 12:31:47 CST 2002
From: Ken Kinman
Man is a member of genus Homo, which is in Order
Primates, Class Mammalia, Phylum Chordata, Kingdom Metazoa. You can call me
a mammal or a metazoan, but *please* don't call me a Sarcopterygian
(although I do have sarcopterygian ancestors). I am typing this message
with hands, not fleshy-fins.
This is precisely the point I was asking you about. Lets hone in on this
rather than just repeating the old arguments. My specific questions are as
follows: WHY do you consider us to be in the same class as rats, but birds
not in the same class as lizards? WHY are we chordates, but not
sarcopterygians? Yes I know that your hands don't exactly resemble the
fleshy fins of coelacanths, but then again your spinal column doesnt exactly
resemble a hagfish's notochord either, does it? Not do a snake's limbs
resemble a frog's, but I bet you consider them tetrapods, don't you? And
what about cephalopods and cetaceans (to mention a couple of examples that
should be accessable to all of our readers - there are of course thousands
of such examples)? In short, what are your principles for making such
By the way, I was rather taken aback by the suggestion that I'm just
"winging it" with no "principles" in my methodology. The Library of
Congress has two copies of The Kinman System (my 1994 book), and plenty of
universities have it too (so interlibrary loan is always an option as well).
As a US taxpayer, I am greatly relieved to learn that the Library of
Congress is stocked only with books that rigorously adhere to explicit
scientific principles. I didn't realize that.
I hope that you realize that I was not trying to be gratuitously insulting -
I think it is a crucial question. You present your eclectic classification
as scientific, and yet I cannot for the life of me find any consistent
principle by which you make your crucial classification decisions. What are
they? Lacking a convincing answer, I can only conclude that you are making
completely personal decisions, on a case by case basis, according to your
own private sense of how things should be arranged. This is not science.
I was rather disappointed that Thomas seems to be slipping back
into the argument (with Zdenek Skala) that paraphyletic groups are not
"real". The human decisions involved in establishing boundaries are just as
arbitrary whether you are an eclecticist or a strict cladist.
I am not "slipping back". I have never left that position. I profoundly
disagree with your assertion that simply because we are human beings, and
thus must necessarily make human judgements, that therefore all human
judgements are equally arbitrary. Perhaps it is an "arbitrary" decision to
decide to classify according to phylogeny, as opposed to by color, or
alphabetically, or eclectically. That is an issue for a higher level of
epistomology. The issue here involves the standards that one adopts after
one has made this higher level decision. If one decides to classify by
phylogeny, there are explicit principles and standards that one must follow
- essentially to recognize as taxa those groupings that emerge from an
empirical analysis of the character evidence. End of story. It is very much
like being an empirical scientist in any other field. Are all possible
models of the solar system equally arbirtrary? Or can we claim that a
scientist who accepts the restraint of only putting forth the model that
best reflects empircial data is being non-arbitrary? In short, do you
believe that science is in any sense different from mere opinion-mongoring?
You have made a higher level decision to classify by some other set of
criterea than simply the phylogenetic relationships of taxa. And I ask you
once again - what are the specific principles that you use? What are the
rules that you can share with us, so that if I had the same set of character
data, and was armed with your rules, I could reach the same conclusions, the
same classification as you do? Does repeatability mean anything to you? I
propose that it does not. I propose that it would be impossible for anyone
to arrive at the same classification as you do, unless thay actually became
To anticipate an irrelevant response: When cladists disagree on a
classification, it is NOT because they disagree on the methodology of
classification - which is the issue we are discussing. My questions relate
to the step from having character codings in hand, to the production of a
classification. I am not talking about the prior issue of how we go about
coding characters. That is an issue that transcends the cladist-eclecticist
dispute about classification.
If States truly "evolved" (from east to west), Colorado would have to be
cladistically a sub-state of Kansas, and Kansas would in turn be only a
sub-state of Missouri.
Yeah, so what? It sounds silly because it is a silly example. States did not
truly evolve as taxa do.
... And finally, this argument about eclecticism being "non-transparent"
doesn't hold water any more either. My classifications are eclectic and
they are quite explicit and transparent.
Not until you answer the questions at the beginning of this post can you
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