generic oversplitting (heart of the problem)

Robin Leech releech at TELUSPLANET.NET
Wed Jul 18 20:40:21 CDT 2001


We put labels on organisms and clusters of organisms because it seems to be
an innate human trait to be able to, and to want to, name and label things.
Reflect on Ernst Mayr's findings about the New Guinea natives and their
knowledge of and names for the birds - if I recall correctly, they had names
for 143 of the 144 species he identified.
The New Guinea natives did not eat or use each of the identified species,
but they could name them.
As for communication, the communication improves after we have a name for an
organism or cluster or organisms.  Without a name, we can describe organisms
so that others understand what organisms we are talking about, but it takes
time.  A name is a shortcut.
Robin Leech
----- Original Message -----
From: "Richard Pyle" <deepreef at BISHOPMUSEUM.ORG>
To: <TAXACOM at USOBI.ORG>
Sent: Wednesday, July 18, 2001 3:06 PM
Subject: Re: generic oversplitting (heart of the problem)


> > Should the scientific classification
> > be aligned with our conclusions regarding how lineages have diverged, or
> > should our classification be only partly reflective of that pattern,
> > modified by other criterea as well. That has always been the real issue
> > between cladists and "darwinians". Paraphyly is a deriviative
> > issue in this dispute. Paraphyletic groups are an absurdity in the first
> > perspective, and they are probably a necessary feature of the second. It
> is a
> > distraction to argue about them when the real issue is even more
> fundamental.
>
> This nails the basic issue, in my opinion.  The question I have always
asked
> when I've participated in this sort of discussion is: "Why, exactly, are
we
> putting labels on clusters of organisms?"  Obviously, it is to allow us to
> communicate with each other -- but the question is targeted at
specifically
> what it is we want to communicate.  When the Linnaean system was invented,
> the intent was to reflect similarity in form.  Even early taxonomists
> recognized the importance of subtle detail over gross design, when they
> lumped bats with mammals, rather than with birds; but it was still a
> classification based on form. Somewhere along the way, the concept of
> biodiversification through evolution took hold in biological circles,
> providing a mechanism to serve as a foundation for the existing
hierarchical
> nomenclatural system.  I am not aware of any published article, or
revision
> in the IC_N Codes, that states, "Henceforth, the hierarchical nomenclature
> shall reflect the inferred phylogeny, without regard to form or
> function." -- but evidently a large segment of the taxonomic community has
> shifted over to accept that premise.  Free thinkers that they are, not all
> taxonomists made this shift at the same time, setting up the current
> debates.
>
> The primary opposition to the "nomenclature must strictly reflect
phylogeny"
> perspective comes from the early days cladistic application, when
> overconfidence in comparatively weak inferences of true phylogeny led to
> unprecedented instability of names.  As our ability to resolve the most
> fundamental subtlety of critter/weed design (DNA) has improved, along with
> improved methods for interpreting such data, so too has improved the
> integrity of our inferred phylogenies, and thus the confidence that
altering
> nomenclature to reflect such phylogeny is (presumably) less likely to lead
> to nomenclatural instability. This ability of ours continues to improve
> rapidly. I can envision a day some decades hence when the vast majority of
> Life's diversity has been documented (rather than the current vast
minority
> of documented species), and when technology will allow the entire genome
of
> an organism to be sequenced in seconds, and subjected to powerful and
> well-tested computer algorithms that will place the organism in
phylogenetic
> context with enormous certainty.
>
> But even when that day has come to pass, we may still not have answered
the
> question posed at the start of this message. Even when we can point with
> high confidence to the correct phylogeny of a group of organisms, does
that
> mean that we will no longer wish to reflect in the nomenclature a
> particularly divergent (in form) clade nested within a larger clade of
> otherwise more or less homogeneous forms? Will it always be in the best
> interest of communication amongst biologists (and lay-folk alike) that the
> nomenclatural hierarchy strictly reflect the evolutionary phylogeny,
without
> any bias whatsoever towards the reflection of function, form, or role in
the
> larger ecological environment?  Perhaps -- but I submit that we (as a
> community) are not yet in a position to confidently make that prediction.
>
> I presented my own position for a solution on Taxacom last October, when
> there was a lengthy discussion about Phylocode.  I don't think it's in
> anyone's best interest (especially my own) to re-hash that discussion now,
> so I refer the reader to the Taxacom archives.  However, I will summarize
in
> that I support Phylocode as a "language" that is much better designed to
> reflect phylogeny in nomenclature than the Linnaean system is, considering
> that the Linnaean system was never intended to strictly reflect
phylogenies.
> As someone who will not likely incorporate Phylocode into my own research,
I
> would like to see stability restored to the Linnaean system for those of
us
> who like to use it in a manner consistent with how it has been mostly used
> for the past two and a half centuries. Eventually, as technology improves
to
> allow more and more reliable phylogenetic reconstruction with greater and
> greater confidence, and with less and less commitment of time and effort,
> the Phylocode nomenclature will expand and stabilize. Sure, there is the
> risk of confusion of maintaining two separate nomenclatural systems, but
> there already is confusion enough in that (at least) two separate camps
are
> trying to use a single system for what amounts to two separate purposes. I
> also think that the transition from one system to the other will be less
> painful if it is gradual, rather than abrupt. Moreover, the confusion of
two
> separate systems can be mitigated by including some sort of marker or flag
> as an integral part of Phylocode names. It can also be mitigated if
> Phylocode postpones efforts to encompass species (and ideally genera as
> well), until the system has been "test-driven" for a least a few years --
> but I realize that is a touchy subject in the Phylocode camp.
>
> Finally, while I applaud Ken Kinman's efforts to help us "all just get
> along" by developing a compromise system, I remain skeptical that such a
> system won't end up frustrating both sides, more than serving the needs of
> both.  It all comes back to the basic question that Tom DiBenedetto
outlined
> as quoted above. As long as we don't all share a common vision for the
> purpose of biological nomenclatural classification, we'll have a difficult
> time sharing a common system.
>
> Aloha,
> Rich
>
> Richard L. Pyle
> Ichthyology, Bishop Museum
> 1525 Bernice St., Honolulu, HI 96817
> Ph: (808)848-4115, Fax: (808)847-8252
> email: deepreef at bishopmuseum.org
> http://www.bishopmuseum.org/bishop/HBS/pylerichard.html
> "The views expressed are the author's, and not necessarily those of Bishop
> Museum."




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