"Fuzziness" (Continuity and classification)

John Grehan jrg13 at PSU.EDU
Thu Jul 26 08:23:59 CDT 2001


always given high priority, but I discovered that with a balanced approach

The very concept of 'balanced' seems to convey decisions that are
arbitrary. Anytime a 'balanced' approach is introduced into science it is
of a political rather than scientific nature. In earlier days
panbiogeographers, for example, were dismissed by the orthodox because they
were not presenting a 'balanced' approach to biogeography. Similarly Gould
has made similar sorts of appeals in support of his Darwinism ('pluralism'
I think he cited).

The Kinman
System uses coding that is primarily cladistic (main clades are numbered,
subclades are lettered), but to insist that all classification be strictly
cladistic is nonsensical, impractical, and besides it is fundamentally at
odds with the paraphyletic nature of speciation.

I think I agree with some of this with respect to a cladogram being a
representation of specific relationships that may not encompass the
entirety of an actual phylogenetic process (a biological cladogram does not
include information about space for example). Whether that renders a
cladogram entirely nonsensical or impractical I will suspend my judgement
for the present.

American cladists swung
the pendulum too far the other way (i.e., overly reactionary) and have
become too dogmatic and rigid.

It seems to me that 'they' are no more dogmatic or rigid than any other
persuasion. However, dogmatism and rigidity may be seen to be good
qualities in science. If one does not have sufficient confidence in one's
perspective why bother. No doubt I am dogmatic and rigid in sticking with
panbiogeography against the 'better' judgement of the majority.

And as for a child being distinct from its parents, let's not take the
concept of "a species as an individual" too far. The edges (bounds) of
species are much more "fuzzy" or diffuse than the bounds of a human or other
organism. And the birth of a species is not the same thing as the birth or
an organism.

I was not saying that species and an organism were the same, just that each
could be referred to an event.

We know that mother mammal and child will separate at the
umbilical cord, whereas speciation is much more unpredictable and tenuous a
process (in both space and time).

Is the 'separation' of mother and child really defined by the break at the
umbilical cord? That's just one physical event of many in the
differentiation process. Perhaps one could argue that the umbilical cord is
an artifact of a separation that has already taken place. Perhaps the
separation of individuality (whatever that may be) is just as fuzzy as for
species.

Cutting up a continuous series of fuzzy overlapping "species" will
always be arbitrary,

In one sense perhaps, but in another these 'arbitrary' species have
distributions that can be analyzed and generate empirically testable (and
tested) predictions about earth history. This would mean that an arbitrary
construction resulted in non-arbitrary knowledge.

With more information (morphological and genetic) and more fossil
intermediates, the fuzziness is slowly starting to show the fundamental
weakness of purely cladistic classifications, and even shows how difficult
it is to do cladistic "analysis" correctly

The problematic nature of relationships is not confined to cladistics. Its
true of any approach.

cladist----just not a strict cladist. And predictive value is important to
me, but I'm not going to let that one factor completely override the
importance of other factors necessary for what I consider "good"
classifications.

If the criteria for "good" classifications resides only within one's
personal preference there is nothing to debate.

John Grehan




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