[Taxacom] Mona Lisa Smile
pierre.deleporte at univ-rennes1.fr
Thu Jul 27 09:21:33 CDT 2006
Richard's interpretation of my post is correct, hence Thomas Lammers first
answer was effectively right beside the (my) point.
Talking of the "meaning" or "usefulness" of a classification (hence, I
think, of its "degree of optimality") without specifying a context of
relevance is nonsensical - (and must lead to endless, hopeless, desparating
Tom's specification below gives some partial clues for a real, constructive
discussion: he seems to need a phylogenetic classification - but I must
notice that he doesn't states why: the nature of the desired classification
is rather explicit, but a clear statement of the context of relevance for
such a phylogenetic classification is missing. Once conceived and
established, what are we supposed to do with such a classification?
Answering this question would allow everyone to make up his mind about the
optimality of the proposed system: a tool for which use? Unless Tom would
share the still repanded illusion of a self-evident "natural"
classification obviously standing out there, just waiting to be checked and
written down (as suggested by Richard, and already discussed on this list).
But Christopher Rogers recently explained that he had no use of "ivory
tower" evolutionary considerations for his environmental "bioassessment
When Richard states that a classification is not a hypothesis, I would
specify that I see classifications as contextually relevant conveniences,
while they may refer to some hypotheses about some biological properties of
organisms (e.g. not alphabetic order, however useful such kind of
classification may be for some uses). As a logical consequence: if
different properties are considered, different classifications ensue (more
in Biosystema 24 "Philosophie de la systematique" / French Systematics
Society - SFS).
I can conceive a phylogeny as a hypothesis (i.e. a tentative historical
explanation in terms of a sketch of the macroevolution of a lineage as
Fitzhugh would put it), and consider a corresponding phylogenetic
classification as a convenience for some evolutionary biologists (naming
only monophyletic taxa may be convenient for communicating about
phylogenetics and macroevolution some way, pace Ken).
The same way I can conceive putative "ecological indicator species" (e.g.
for pollution...) as hypotheses (here again, we may scientifically improve
on them), and consider a corresponding ecological-environmentalist
classification of such indicator species as a convenience for bioassessment
industry (naming only groups of similarly meaningful and efficient
indicators may be convenient for communicating about bioassessment).
Christopher clearly stated that phylogenetic considerations are of little
use, if any, for his industry: we must listen very seriously to that point.
Obviously Christopher has quite little need of Tom's phylogenetic
classification, for he explicitly prefers a "Linnean" one, whatever this
may mean. Hence the point that Tom's phylogenetic classification would be
true or not is quite irrelevant for the initial choice of a classificatory
logic of some sort - to the difference of his phylogeny being true or not,
for people interested in phylogenetics and possibly using a convenient
phylogenetic classification for related purposes.
(In the text above one can of course change Tom for Ken, or an australian
native tribe, or my fishmonger, and corresponding classificatory logics or
Not to develop at length on Barry Roth question to Ken : "what criteria for
Looks like the criteria should be like those presently preventing anybody
on earth to know where monophyletic birds begin, while allowing Ken to know
fairly well where paraphyletic dinosaurs stop.
Just a timid suggestion: what about "hatred of things getting worse while
favoring usefulness and stability for everyone, based on the general
philosophy of well balanced middlegrounds"?
Unless I missed - at the very least - something about context of relevance...
Friendly teasing, from tropicalizing France
(planning to plant banana trees here in my Brittany garden)
A 07:32 27/07/2006 -0500, vous avez écrit :
>----- Original Message -----
>From: Richard Pyle <deepreef at bishopmuseum.org>
> > I don't think that was Pierre's point. I think he was
> > saying that there are many "correct" (optimal?) classifications,
> > depending on the axis around which you want to arrange your
> > classification (phylogenetic vs. ecological vs. phenetic,
> > etc.)
>Fair enough. I agree with that.
> >>The "Classification Is A Hypothesis" approach you advocate (to which I
> do not personally subscribe), seems to
>imply that there is some sort of singular "natural" classification "out
>there", against which these classification
>hypotheses can be "tested".<<
>There is. It's called "the actual historical facts of the group's
>evolution." These populations we see today ARE derived from pre-existing
>populations through modification over time. I think we all can agree to
>that. I believe that the more closely our classification reflects that
>underlying "truth," the better it is. We can argue about whether
>cladistics is the best method for inferring this historical truth, or HOW
>our classification should reflect it (e.g., is paraphyly okay?), but I
>cannot imagine anyone thinking it would be a BAD think if our
>classifications reflected evolutionary history.
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