[Taxacom] (no subject)

Fri Apr 3 09:21:48 CDT 2009

Three very important points in favor of strict cladistics which hardly
seem to have been touched in the discussion: firstly, if you do not use
this criterion, what is your agreed-on criterion for recognizing groups?
Similarity lies in the eye of the beholder. It seems you end up with
arguments from authority, where every expert can say that genus A should
or should not belong to family B, and then they can shout "does" and "does
not" at each other for years like in kindergarten. Monophyly, on the other
hand, is a clear, testable criterion. The testability then leads to the
second point. It makes systematics a hypothesis-testing endeavor, i.e.,
real, hard science, and thus takes it above the purely descriptive level.
Thirdly, what is a system (or scientific knowledge in general) meant to
be? An as accurate model of nature as possible. And it just so happens
that in higher taxa what we observe is a bifurcating tree of life, and
this is best described with a strictly cladistic system.

(Where "strict cladists" really go to far IMO is when they try to apply
monophyly to the recognition of systems that are, by their very
definition, not bifurcating but reticulating, such as species. I have even
once seen a presentation where a master's student, apparently brainwashed
by cladomania, was apologetic for recognizing paraphyletic SUBspecies...)

On the other hand, there are hardly any convincing arguments for
paraphyletic higher-level taxa. It all seems to boil down to "I (or the
end-user) like the names and system I'm used to better". But science is
not about what you find comfortable, it is about building the model that
best describes what goes on/happened in nature. And if the current model
is suboptimal, yes, then sciences is anti-(taxonomic) stability, that is
how it should be!

And finally as a personal note, I as a botanist have yet to see a case
where the recircumscription did not immediately make imminent and
intuitive sense. When I first saw Epacridaceae in an Australian field
guide, I instantly asked "so why is this not in Ericaceae? They look the
same." When I was in first year and we had beginner's plant determination
courses, everybody had a hard time recognizing the family affiliation of
newly introduced Scrophs. No wonder: you did not need to know cladistics
to recognize them as a poorly conceived wastebasket (=paraphyletic)
family. The recircumscription makes much more sense. Same thing with
Caprifoliaceae.  Same thing with Tricolpates, by the way. The delimitation
of Verbenaceae and Lamiaceae was obviously silly, now there is a solid
basis for it. Liliaceae s.l. was a weird mishmash. The list goes on and
on. It makes it much easier to recognize these groups in their new
circumscription and to communicate to others why they are circumscribed in
this way, and the system already includes important evolutionary
information in the form of the apomorphies at every important node.

Alexander N. Schmidt-Lebuhn
http://www.minthostachys.com

> Richard,
> what you (and other people) see as a "problem" (phylogenetic
> classification) is viewed as a "solution" by others, including me. So,
> your "fixes" (return to a traditional, non-phylogenetic classification)
> will become our "problems", which then we will try to "fix". It all
> depends on your viewpoint. Even among "traditional" taxonomists there
> are competing classifications for certain groups (and the same is true
> for phylogenetic taxonomists).
>
> It is going to be like this probably for the rest of our lifetimes and
> even beyond. That is why I don't think there will ever be a single,
> universally accepted classification. And this discussion will go on and
> on until everyone realizes this point. Which is unlikely, I know.
>
> -----------------------------
> Mario A. Blanco
> Department of Biology
> University of Florida
> 227 Bartram Hall
> Gainesville, FL 32611-8526
> -----------------------------
>
> -------- Original Message --------
> Subject:     Re: [Taxacom] (no subject)
> Date:     Thu, 2 Apr 2009 10:20:04 -0500
> From:     Richard Zander <Richard.Zander at mobot.org>
> To:     Jim Croft <jim.croft at gmail.com>, <Don.Colless at csiro.au>
> CC:     taxacom at mailman.nhm.ku.edu
>
> Well, there's a problem with the dichotomy, Jim. There are three
> classifications, a traditional one based on morphology (expressed
> traits, anyway), a phylogenetic one based on a combination of morphology
> and phylogeny, and the phylocode.
>
> The trouble is that the phylogenetic one is gradually being changed more
> and more into a purely sister-group classification and the phylogenetic
> one is replacing the morphological one rapidly. "Them" is now "us."
>
> To fix this requires an evaluation of phylogenetic classification (e.g.
> APGII), and if the phylogenetic classification does not truly represent
> what we feel is the best way to present an evolutionarily based
> classification, then to publish an alternative in the field of one's
> expertise. Otherwise there will be a true dichotomy, a complely
> phylogenetic (holophyletic) classification and the phylocode. If we want
> anything else, we must do the work and present it in the marketplace of
> ideas with a thorogoing justification.
>
> _______________________
> Richard H. Zander
> Missouri Botanical Garden
> PO Box 299
> St. Louis, MO 63166 U.S.A.
> richard.zander at mobot.org
> ________________________________
>
> From: taxacom-bounces at mailman.nhm.ku.edu on behalf of Jim Croft
> Sent: Wed 4/1/2009 11:59 PM
> To: Don.Colless at csiro.au
> Cc: taxacom at mailman.nhm.ku.edu
> Subject: Re: [Taxacom] (no subject)
>
>
> But we do...  one is used by 'us'... and the other is used by 'them'...
>
> jim
>
>
>
>
>
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