[Taxacom] Tuataras are REAL (the relativity of reality)
Ken Kinman
kinman at hotmail.com
Mon Jun 4 09:40:07 CDT 2007
Pierre,
I like your tentative exercise. But no matter how carefully we state
our positions or goals, the problem will always remain that most species
(species-level clades) have not totally cut their reproductive ties to their
closest relatives (especially mother species or sister species with which
they once formed a single species).
Extensive extinction eliminates close relatives, cutting those
reproductive ties and making that species more obviously "real" due to its
relative isolation. Another good example that was pointed out to me is the
Wollemi pine, and there are many others. Just to be clear, I am not saying
that they are real because they are obvious, but that they are obvious
because they are real.
All the not-so-obvious examples (where such isolation is not so complete)
will always cause some level of dispute, whether they are subspecies, full
species, or something in between (e.g., Mayr's use of semi-species for some
birds). In part this is due to the contingencies of future events which we
cannot predict. But I have sometimes wondered if increased use of the
semi-species designation would lead to more agreement or to more
controversy. I guess it depends on the nature of the organisms involved,
how much information we have (birds are relatively well-known), and the
personalities of the researchers involved. In any case, no matter how messy
and fuzzy (and ever-changing) the case is, I still view species-level clades
as real, and what is arbitrary are the communicatory boundaries and labels
we humans attach to various groupings so that we can increase our collective
knowledge of them. Cycles of splitting and lumping of species and
subspecies continues, but there is a whole more consensus today than there
was 100 years ago.
-----Ken
**********************************
>From: pierre deleporte <pierre.deleporte at univ-rennes1.fr>
>To: taxacom at mailman.nhm.ku.edu
>Subject: Re: [Taxacom] Tuataras are REAL (the relativity of reality)
>Date: Mon, 04 Jun 2007 11:45:34 +0200
>
>
>some agreement with Kirk seems possible to me:
>
>I have no problem with a clade (possibly qualified of "species-level" by
>any means) being considered as a historical explanation for a set of
>organisms,
>then what I consider a class (the corresponding "species") is the set of
>individuals sharing the property "being attributed to this clade" = fitting
>this explanation (= considered as being descendant from the exclusive
>common ancestor of this species-level clade)
>
>the common property shared by the clade as historical explanation and the
>corresponding class of historically explained individuals is that both are
>concepts, not self-consistent material "individuals", which was my point
>
>otherwise Ken is talking of "obvious gaps" allowing easy common agreement
>among scientists as for delineation of clades, ands he is using "real" as
>"obvious", still another matter
>
>and Richard (Aloah!) is somewhat using "real" as "true" in his reply to Ken
>
>it's all semantics OK, but the elementary caution of "defining our terms"
>is crucial for avoiding endless misconceived debates, which is occasionally
>reproachable to taxonomists
>
>the question turns to be, not "what IS a species", but "what do we mean by
>this word", and hopefully agreeing on a common vocabulary
>
>as a tentative exercise : "this species-level clade is the concept of
>historical explanation for the class of 'species-member' individuals
>according to that species-delineating criterion, and I hope this clade is
>true, i.e. fitting the real history"
>
>Pierre
>
>A 09:12 02/06/2007 -0700, Kirk Fitzhugh wrote:
>
> >Clades are neither
> >individuals nor classes. A clade simply summarizes the past
> >reproductive events that indicate the origins and fixation of derived
> >characters, and events of population splitting. Clades as such are
> >simply explanatory constructs that enable us to make sense of why
> >some tuataras have certain traits in contrast to what are observed of
> >other lizards.
> >
> >Kirk
> >~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >J. Kirk Fitzhugh, Ph.D.
> >Curator of Polychaetes
> >Invertebrate Zoology Section
> >Research & Collections Branch
> >Los Angeles County Museum of Natural History
> >900 Exposition Blvd
> >Los Angeles CA 90007
> >
> >Phone: 213-763-3233
> >FAX: 213-746-2999
> >e-mail: kfitzhug at nhm.org
> >http://www.nhm.org/research/annelida/staff.html
> >http://www.nhm.org/research/annelida/index.html
> >~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> >
> >-----Original Message-----
> >From: taxacom-bounces at mailman.nhm.ku.edu on behalf of Ken Kinman
> >Sent: Fri 6/1/2007 8:09 PM
> >To: taxacom at mailman.nhm.ku.edu
> >Subject: [Taxacom] Tuataras are REAL (the relativity of reality)
> >
> >Dear All,
> > These endless arguments about whether species are real (or not)
>seem
> >largely to be semantic exercises which largely rest upon on which
>particular
> >species one is talking about. The fuzzier they are, the more likely they
> >are to be branded a class of objects rather than a real entity.
> >
> > The tuatara is an excellent example. Admittedly, we could
>probably
> >argue endlessly about whether there are actually one or two species of
> >extant tuataras. HOWEVER, tuataras are so distinctive that I cannot see
>how
> >anyone can argue against the reality that they constitute a REAL clade of
> >organisms which share descent from a common ancestral population of
>tuataras
> >(whether it is one or two distinct species just distracts from the
>reality
> >of the clade). Such a clade seems to me to be BOTH a class AND an
> >individual. It's like having your cake and eating it too, but some seem
> >intent on denying that we can have our cake and eat it too, even in such
> >clear-cut cases.
> >
> > Why can't it be both, rather than only one or the other? It is
>only
> >in a minority of cases that we can do this, so why not celebrate them
>rather
> >than insist that it has to ALWAYS be only one or the other just because
>many
> >cases are not so clear-cut? In a Universe full of continuua, it seems
>such
> >a waste of time arguing over a term like "reality", when it is such a
> >relative term and dependent on a given context and perspective.
> > ----Ken Kinman
> >
> >_________________________________________________________________
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> >
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>Pierre Deleporte
>CNRS UMR 6552 - Station Biologique de Paimpont
>F-35380 Paimpont FRANCE
>Téléphone : 02 99 61 81 63
>Télécopie : 02 99 61 81 88
>
>
>
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