[Tcs-lc] concepts of Higher taxa

[Martin Pullan]

While on the whole I think we are all in agreement - namely
 
1) The creation of new taxa cannot change existing higher taxon concepts
2) Because of the way nomenclature is implemented it is not and should not be possible to identify the concept of  higher rank that the author was placing the new taxon in.
 
I think there are two terms that we cold coin here that may be useful
1) Nomenclatural placement
2) Conceptual placement
 
We the describe the publication of a new taxon - eg a species as being in a genus this will be precise in its nomenclatural placement but at best vague in terms of its conceptual placement. Rich's suggestion is that the nominal concept is a good way of handling the conceptual vagueness of higher taxa, I unfortunatley have to disagree. As far as I can see the "nominal concept" only  muddies the distinction between nomenclature and classification which is one of the things we are trying to avoid. To my mind the use of the nominal concept in this way runs the risk of overemphasising its importance by potentially giving the impression of it being a coherent whole when in reality it would be just an ad-hoc collection of entities that have no formal placement in a higher ranking concept. Why not accept the fact that when a new taxon is published the associaton of the new concept with a name of  higher rank is just that - a relationship to a name not a concept. We can then represent this relationship in the schema by a "link" to a name and not a concept (nominal or otherwise). Now that it is agreed that names will be represented in the schema as "top level" objects this should be quite possible to do. What is more because all the type infomation should be held in instances of name objects and not concept objects the default association between a member taxon and the type of the higher name with which it is associated will be maintained, but with the advantage that the type information need not be repeated for each and every concept that is to be represented. Although such a change will make the schema slightly less elegant conceptually it will be much cleaner.
 
>This sounds better to me, but I'm not clear of what you mean by "revision".
>Does that basically mean that concepts are created only when all senior and
>junior synonyms of all child taxa are explicitly addressed within the same
>publication?

This is where the binomial naming scheme trips me up again and I have to mix concepts and nomenclature -sorry - 
So the answer to your question is Yes - it is a question of intent - in effect the placement of a new taxon in a higher "thing" (nomenclatural placement)  requires the new taxon to be "identified" within the context of an existing higher taxon concept although the concept is not usually specified when the name is published. Therefore, although the addition of the new taxon to a higher taxon effectively creates a new higher taxon concept, it was not the intention of the author of the new taxon to do so nor is it clear what the circumscription of the modified higher taxon should be. It is therefore better to leave the new taxon without any association with any existsing higher concept.
Only when a publication clearly states that its contents represent the results of a re-eaxmination of the entirety of an existing concept, or a geographically restricted subset of such a concept should we recognise, for the purposes of TCS, the creation of a modified concept. At the time that such a revision is undertaken all "free floating" concepts associated with the name of the higher taxon (eg. species concepts that are only linked to the name of the genus being revised) should be taken into consideratoin and be either explicitly included or excluded from the new version of the higher taxon concept.
 
I think that makes sense ;-)
 
 
BTW I can't remember but does the current TCS have a means of flagging the geographical scope of a classification? eg. for representing a classification presented in a flora.
 
Martin
-----Original Message----- 
From: tcs-lc-bounces at ecoinformatics.org on behalf of Richard Pyle 
Sent: Fri 01/04/2005 09:19 
To: tcs-lc at ecoinformatics.org 
Cc: 
Subject: Re: [Tcs-lc] concepts of Higher taxa




	> Actually the mixing of taxonomy and nomeclature was deliberate
	> although I now regret having removed a sentence regarding my
	> concerns over suggesting that the higher taxon concept and not
	> just the name of higher taxon should be cited when publishing a
	> new member taxon. Primarily this is because such a change would
	> indeed further erode the supposed distinction between nomenclature
	> and classification embodied in the codes.
	
	I see now that we are in agreement on this point as well!
	
	> However we have to face the fact that the binomial naming
	> in itself creates this confusion.
	
	Indeed!  That's why I tend to favor the Zoological perspective that the
	"name" is the terminal part only, and the binomial/trinomial parts are
	simply there to indicate classification, and to disambiguate
	terminal-epithet homonyms. To me, "Aus bus Smith" and "Xus bus (Smith)
	Jones" should be treated as the same "name", with the recognition that Smith
	and Jones each placed the species within a different nomenclatural
	classification.  No difference, in my mind, from "Aus Smith, placed in the
	family Aiidae by Smith" vs. "Aus Smith, placed in the family Xiidae by
	Jones".  It sort of boils down to what role we perceive the "binomal" nature
	of Linnean names to be.
	
	> If we wish to remove the confusion created by binomial names then
	> IMHO we have to make the change to the codes and accept the erosion
	> of the separation between nomenclature and classification.
	
	Or...we convince the botanists to adopt the zoological perspective of a
	"name".
	
	> By requiring the author to identify the higher taxon concept they
	> are expanding when publishing a new member we would then be
	> forcing them to perform "the specific act of inclusion" and a new
	> concept of the higher taxon would be automatically created.
	
	I would rather that the new species be "included in" the Nominal-type
	TaxonConcept instance for the name; or, perhaps, the creation of a new
	TaxonConcept instance of the genus AccordingTo the new-species author, which
	minimally includes the type specimen of the new species and the type
	specimen of the type species of the genus name -- and may map congruevtly or
	otherwise to previous concept defintions of the same genus name, as
	determined by third parties via RelationshipAssertions.
	
	> This, however, would be a version of the higher taxon concept sec.
	> the author of the new member taxon and not sec. the author of the
	> original higher taxon concept.
	
	Exactly!!!
	
	> 1) Higher taxon concepts are developed in a strict linear sequence
	> and any new member taxa always extends the newest higher taxon
	> concept in the sequence.
	
	I do not favor this view.
	
	> 2) Higher taxon concepts are developed in a non-linear sequence with
	> branches created whenever a new revision (as opposed to just adding
	> a new member taxon in isolation) of the higher taxon is undertaken.
	> Once such a branch in the sequence is created each arm of the "tree"
	> develops in its own independent linear sequence and new members can
	> be independently added to any branch.
	
	This sounds better to me, but I'm not clear of what you mean by "revision".
	Does that basically mean that concepts are created only when all senior and
	junior synonyms of all child taxa are explicitly addressed within the same
	publication?
	
	Aloha,
	Rich
	
	
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