Paraphyly is real (+ "strict cladist" defined)
kinman at HOTMAIL.COM
Tue Jan 15 15:04:50 CST 2002
I understand your concerns. What *really* happens and what can be
somewhat "objectively" discovered scientifically are almost always two
different things. Even at the population level of living species,
discerning the "reality" of what is happening can be extremely difficult,
and above species level it becomes virtually impossible to achieve any
degree of real "certainty" (which will always elude us).
That is why cladistic conventions are so useful, and scientists must
indeed force logical discovery operations on nature (such as cladistic
analysis)---that comes with the territory. We can only approximate the
reality through inference, so conventions will always be necessary.
HOWEVER, whether we must limit ourselves to strict cladistic conventions is
the real issue, and I have yet to be convinced that Hennigian arbitrariness
is superior to Mayrian arbitrariness. And any strict cladist who has
convinced himself that he can solve the problem of arbitrariness is deluding
himself. We can only minimize such problems as best we can, and the rest of
us are really sick of strict cladists "lording it over" the rest of us on
the issues like naturalness and artificiality.
In any case, I must disagree with Byron's application of Plato's
"barbarians vs. Greeks" analogy. Substitute the amniote clade (Amniota) for
Greeks. The privative group "non-amniotes" (an informal name, like
barbarians) can indeed be easily subdivided --- for instance, we can
separate and delimit the traditional Class Amphibia, which originates at one
synapomorphy (tetrapody or stegocephaly) and ends where the synapomorphy of
amniotic eggs appears. Amphibia is the mother taxon of the amniota clade
(daughter). In delimiting Amphibia by the presence of tetrapody (or
stegocephaly, if you wish) and the absence of the amniotic egg, you are
utilizing the information of plesiomorphic absence.
Strict cladists' suspicion of plesiomorphy strikes me as being just as
limiting as their intolerance of paraphyly (so I would say to Tom
DiBenedetto that I think he is more trapped by his concepts than I am). The
unfortunate result is that they too often dwell on a few "proposed"
synapomorphies, name a formal group on that basis, and when their hypothesis
is overturned by better "synapomorphies", someone proposes another new name,
ad naseum. Nomenclatural litter proliferates like never before.
A recent example. Even the proposer of the dinosaur clade
Arctometatarsalia had to admit (just a few years later) that it was based on
a convergent character (and he is extremely intelligent and one of the best
when it comes to cladistic analysis). Unfortunately, due to cladistic
definition, this formal name continues to be applied to only one particular
group of "arctometatarsalians". However bad they are, such names hang
around forever in some form. Let's hope noone cladistically defines
"Vermes", because we could never get rid of it. PhyloCode will make this
process precise and bureaucratic, but we will still have a lot of precise
bickering and confusion, and "precise" clutter that never goes away (like
plastic in a landfill). If the really good cladists are producing such
clutter, think of the mountains of trash that the bad ones are going to
Too many formal names, and that is why I advocate coding many
relationships rather than attaching a formal Latin name. And strict
cladists inappropriately recycle some names in the worst possible way,
namely by stealing names of paraphyletic taxa and cladistically redefining
them to suit their tastes (Reptilia, Amphibia, Bacteria, just to name a few
of the worst cases).
So although Richard Pyle and I agree on most things, I can't agree that
the two "sandboxes" are a good idea, since they keep raiding our sandbox for
names, and then have the gall to justify it by saying we are so
simple-minded that we don't understand arbitrariness and artificiality. The
fighting will never end, although it may get increasing precise and
legalistic. I still say that a single optimal cladisto-eclectic system is
the only way to minimize arbitrariness, instability, and confusion. I still
trust Mayr and Ashlock more than I trust Hennig (even though I have
incorporated some of the ideas of the latter).
------ Ken Kinman
P.S. By Tom DiBenedetto's definition, I cannot be a cladist, even though I
am a strong advocate of cladistic analysis, and my classifications are
heavily cladified. Fine, you can steal the definition of "cladist" as well.
But I am still going to call you strict cladists, I will continue to stand
up to the continued "catch-22" bullying, and if you want to call me a
"whiner" for resisting, so be it. I still think you are more "trapped by
your concepts" than we are.
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