[Taxacom] Tuataras are REAL (the relativity of reality)

[pierre deleporte]

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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Pierre Deleporte
CNRS UMR 6552 - Station Biologique de Paimpont
F-35380 Paimpont   FRANCE
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