Message 2004-10-0022: Re: Panstems

Sat, 11 Sep 2004 15:32:03 -0700 (PDT)

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Date: Sat, 11 Sep 2004 15:32:03 -0700 (PDT)
From: [unknown]
To: Kevin de Queiroz <Dequeiroz.Kevin@NMNH.SI.EDU>,
Subject: Re: Panstems

Kevin de Queiroz (Dequeiroz.Kevin@NMNH.SI.EDU) wrote:

<The problem with using standard affixes for ALL of the different cla=
of names is that this practice would result in the disruption of
continuity for many, many names.>

  I cannot see how this is possible. If you can offer an example of a
real-world case where this would disrupot any form of nomenclatural
continuity, I would like to see it to graps this reasoning.
<In the case of total clades, one could argue that most names that ha=
been associated with these clades have also been associated with othe=

  By historical "nesting," usually due to Linnaean taxonomy and ranks=
Perhaps by "preserving" such continuity, one gives credence to the va=
of ranks?

<Thus, the names could be defined as referring to the other clades, a=
the Pan- names could be used for the total clades, without eliminatin=
g any
widely known names.>

  I thought the premise of any new name was that it would NOT elimina=
any widely known names?
<For example, the name Synapsida could be associated with the clade
stemming from the species in which the synapsid apomorphy originated,=
PanMammalia could used for the total group (which includes Synapsida)=
Mammalia (used for the crown). Thus, both preexisting names (Synapsid=
a and
Mammalia) are retained.>

  I still don't se ehow their existence was jeopardized. But on part =
this, at which point is it constructive to even suggest a clade that =
in about 95% of the clades named, a 1:1 ratioi of panstem to crown? W=
UTILITY is there in naming two clades with identical content? Isn't t=
EXCESSIVE taxonomy? Perhaps the recommendation should be that a pan-s=
should only be coined when there is NOT a 1:1 congruence between crow=
n and
pan-stem, leaving the panstem recognized but unnamed, as excessive an=
effectively useless, nomenclature....

<However, if ALL of the different types of clades are given names wit=
standard affixes (e.g., PanMammalia, ApoSynapsida, ApoMammalia,
AcroMammalia), then many preexisting names (e.g., Synapsida, Mammalia=
won't be used for any clades, let alone for the clades to which they =
traditionally referred.  This disrupts stability/continuity and thus =
against one of the fundamental principles of the PhyloCode.>

  You colleague Jacques Gauthier, along with Joyce et al., have alrea=
suggested an alternative ... suppress the non-panstem [which only enf=
the knowledge that the clades would come in conflict as synonyms by m=
than say, Lissamphibia and Amphibia would].

  As for naming this particular clade, this only seems reasonable in =
no one has as yet been applying nomenclature to these types of clades
(save one name, Pancrustacea), so adding affixes seems like a fun ide=
a in
automatically recognizing it. But this is counter-intuitive, especial=
ly in
light of forcing Pan- to be applied only to a pan-stem, would then ca=
use a
disruptive effect in the historical record, i.e., forcing a redefinit=
and useage of Panarthropoda; indeed, it seems to be wanting to do thi=
only because it's a _now_, _new_ thing, and to go back and do it with
other clades would be "disruptive," so do it with the new fad, panste=

  Why not just name the "total clade content" by another name? Or def=
those words closest to that in meaning and usage as pan-stems? We don=
use signifiers for crowns, stems, and nodes, leaving that to the
definition form as used, and seem to have little problem with it. Yet=
want to do the REVERSE for another type of clade, for no other reason=
to add a communicative, "intuitive" marker to looking at names (somet=
Linn=E9 thought of quite a long time ago). This, it would seem to me,=
be more disruptive than not naming panstems, just recognizing them by
definition -- just like all other clades.


Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to mak=
ing leaps in the face of adversity, that a simple skip is so hard to =
do.  We should all learn to walk soft, walk small, see the world arou=
nd us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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