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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>, phylocode@ouvaxa.cats.ohiou.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= sses 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. =20 <In the case of total clades, one could argue that most names that ha= ve been associated with these clades have also been associated with othe= r clades.> By historical "nesting," usually due to Linnaean taxonomy and ranks= . Perhaps by "preserving" such continuity, one gives credence to the va= lue of ranks? <Thus, the names could be defined as referring to the other clades, a= nd 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= te any widely known names? =20 <For example, the name Synapsida could be associated with the clade stemming from the species in which the synapsid apomorphy originated,= and PanMammalia could used for the total group (which includes Synapsida)= of 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 = of this, at which point is it constructive to even suggest a clade that = has, in about 95% of the clades named, a 1:1 ratioi of panstem to crown? W= hat UTILITY is there in naming two clades with identical content? Isn't t= his EXCESSIVE taxonomy? Perhaps the recommendation should be that a pan-s= tem 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= d effectively useless, nomenclature.... <However, if ALL of the different types of clades are given names wit= h 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 = have traditionally referred. This disrupts stability/continuity and thus = goes against one of the fundamental principles of the PhyloCode.> You colleague Jacques Gauthier, along with Joyce et al., have alrea= dy suggested an alternative ... suppress the non-panstem [which only enf= orces the knowledge that the clades would come in conflict as synonyms by m= ore than say, Lissamphibia and Amphibia would]. As for naming this particular clade, this only seems reasonable in = that 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= ion and useage of Panarthropoda; indeed, it seems to be wanting to do thi= s 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= ms. Why not just name the "total clade content" by another name? Or def= ine those words closest to that in meaning and usage as pan-stems? We don= 't use signifiers for crowns, stems, and nodes, leaving that to the definition form as used, and seem to have little problem with it. Yet= we want to do the REVERSE for another type of clade, for no other reason= than to add a communicative, "intuitive" marker to looking at names (somet= hing Linn=E9 thought of quite a long time ago). This, it would seem to me,= would be more disruptive than not naming panstems, just recognizing them by definition -- just like all other clades. Cheers, =3D=3D=3D=3D=3D 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) =09=09 _______________________________ Do you Yahoo!? Shop for Back-to-School deals on Yahoo! Shopping. http://shopping.yahoo.com/backtoschool