[Tcs-lc] concepts of Higher taxa

[Martin Pullan]

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. However we have to face the fact that the binomial naming system
in itself creates this confusion. The binomial naming system and the
various codes governing them were invented prior to the development of
explicitly concept oriented taxonomy and before the idea of multiple
legitimate taxon concepts all bearing the same name had been concieved.
 
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. 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. 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. As far as I can
see if we don't adopt this approach the whole thing becomes
unmanageable.
 
I am starting to wonder if the disagreement is centered around the
sequencing of concept development. I think there are two possible points
of view :
 
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.
 
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. 
 
As you may have guessed I think the latter model is a truer reflection
of reality and as such I do not think that it can be assumed that the
addition of a new member to a higher taxon expands all simiiar higher
taxon concepts.
 
Martin
 
 

Dr. Martin Pullan

The Royal Botanic Garden Edinburgh

Web site: http://www.rbge.org.uk

Phone: (+44) 0131 248 2908

Fax: (+44) 0131 248 2901

 

	-----Original Message-----
	From: tcs-lc-bounces at ecoinformatics.org
[mailto:tcs-lc-bounces at ecoinformatics.org] On Behalf Of Paul Kirk
	Sent: 31 March 2005 11:49
	To: tcs-lc at ecoinformatics.org
	Subject: Re: [Tcs-lc] concepts of Higher taxa
	
	
	It's difficult to dissect the paragraph below because it's a
fair mix of nomenclature and taxonomy but here are a few comments. The
first sentence here is what prompted my question (perhaps off list) last
week which was how do nomenclators decide which parent (genus) a species
belongs to when generic homonym are involved; the protologue of the
species may contain this information but I suspect that it has not
always been captured. So, there may be multiple concepts for two reasons
- nomenclature and taxonomy. The Code cannot be changed to require the
latter be defined for this is taxonomy and outside the Code, and it may
not be necessary to change it for the former reason as there are no
nomenclatural consequences, IMO, of this uncertainty. I think the
'specific act of inclusion' referred to is answered in the previous
sentence - use of the binomial system - for the act of publishing a
binomial must either change the existing generic concept or, if we all
accept that concepts when published (do we have an unambiguous
definition of the word published? - not lifted from the Code I hope!)
immutable, create a new one.
	 
	Paul
	 
	-----------------------------
	To my understanding at the moment it is not necessary to
identify the specific concept of the genus one is using when publishing
a new species. Therefore when there exist mulitple concepts of a genus
it is not possible to determine which genus concept is being expanded by
the publication of the new species. This could be a case for requesting
a change in the codes such that the specific concept being used must be
identified when publishing a new name. However, as it stands at the
moment, the publication of a species within a genus is a purely
nomenclatural exercise required to satisfy the demands of the binomial
naming system and has no influence whatsoever on any existing concepts
of the genus. In order for a new species to be incorporated into a
generic concept a specific act of inclusion must be performed at which
point a new generic concept is created. 
	 
	Martin

	Dr. Martin Pullan

	The Royal Botanic Garden Edinburgh

	Web site: http://www.rbge.org.uk

	Phone: (+44) 0131 248 2908

	Fax: (+44) 0131 248 2901

	 

		-----Original Message-----
		From: tcs-lc-bounces at ecoinformatics.org
[mailto:tcs-lc-bounces at ecoinformatics.org] On Behalf Of Paul Kirk
		Sent: 31 March 2005 07:32
		To: tcs-lc at ecoinformatics.org
		Subject: Re: [Tcs-lc] concepts of Higher taxa
		
		
		I disagree; publication of a new species always changes
the circumscription of the genus! Since at least one components which
define the genus when the new species is described (the new species)
have changed
		 
		Consider these hypothetical examples:
		 
		Genus Aus Smith SEC. [everyone up to now] has species
with flowers that are red or yellow; a new species by Jones has blue
flowers thus genus Aus Smith SEC. Jones has a new circumscription.
		 
		Genus Aus Smith SEC. [everyone up to now] has sequence
data represented by GenBank acc. numbers 1234, 1238, 1239 ...; a new
species by Jones have sequence data represented by GenBank acc number
2375 thus genus Aus Smith SEC. Jones has a new circumscription.
		 
		I am not sure how anyone can say the cicumscription of
the genus has not changed, unless we are using different definitions
(concepts) of the words we use to communicate - often a problem as we
all know too well ;-)
		 
		pAUL
		 
		> 2) I also believe that it is erroneous to consider
that the pubication 
		> of new species constitutes an expansion of of the
existing concepts of 
		> the higher taxon to which they are stated to belong. 

		In my view, it may or may not.  Whether or not the
publication of a new species within a genus expands the genus concept in
which it was placed (relative, e.g., to the concept intended by the
original creation of the genus name) depends on subjective judgement. In
most cases, I suspect that it does not (should not) alter the genus
circumscription.

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