Message 2000-10-0001: Benton's paper

Tue, 03 Oct 2000 11:40:03 +0100

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Date: Tue, 03 Oct 2000 11:40:03 +0100
From: Michel Laurin <>
Subject: Benton's paper

Hi all,

	I have read Benton's manuscript, and I must say that I am not
impressed.  It is a collection of misconceptions about phylogenetic
taxonomy, and it is based on a confusion on practical problems that
have arisen out of the use of phylogenetic definitions.  Many of these
problems should be fixed by the Phylocode (that is one of its main
purposes, as I understand it), and Benton fails to understand or accept
that.  I will explain my point of view below, but let me first state
that I think that this paper is so poorly argued that it would not
deserve a reply, except to prevent the possibility that the absence of
a reply from us might be interpreted as a lack of argument against
Benton's paper, or an implicit acceptation of the problems that he
raised.  Thus, I think that we should reply, only to clarify our

	First, Benton emphasizes repeatedly that classifications are only
convenient human constructs.  This was partly (if not largely) true of
linnean classifications, but this is not true of phylogenetic taxonomy
(to the extent that it describes historical entities).  Thus, Benton
inappropriately uses his position that classifications only need to be
convenient and stable, and that they don't need to be natural, to
criticize a set of taxonomic principles that are designed to make
taxonomy both stable and natural.

	Second, I think that Benton misleads the readers in suggesting that
Linnean taxonomy has led to stability.  The casea of Mammalia and
Anthracosauria both show this.  Rowe & Gauthier (1992) provided a
review of all the meanings that have been given to the name Mammalia,
that ranges from Synapsida to Theria.  It was even amusing to see how
some authors had used two or three different concepts of the name
Mammalia.  The case of Anthracosauria is less well known, but I have
discussed it recently (Laurin, 1998).  This taxon has also had a very
confusing history.  These are only two examples, but we could find
hundreds, I think, so I strongly disagree with  Benton's position

	Benton argues that two cladograms demand different nomenclatures (in
section "(2) Explicit, universal and stable?").  This depends on how
one defines nomenclature.  In any case, the definitions need not
change, although the composition of a taxon will change to reflect the
new phylogeny.  This is unavoidable if one accepts only monophyletic
taxa, even in the Linnean taxonomy, and Benton does not seem to
appreciate this.  This could be explained in more detail, but I think
that you all understand, so I won't.

	Benton then makes the point that various clades have been given
various names, and that the same name has been defined in at least two
ways, using the case of the names Aves, Neornithes, and other theropod
taxa.  Here, he is right, and I have already argued (Laurin, 1998) that
the lack of adherence of the proponents of the principles of synonymy
and priority by the very people that have proposed it would deter other
people from accepting and using these principles.  Unfortunately, in
addition to the problems that Benton cites, de Queiroz and Gauthier
have proposed two different definitions of Amphibia, and have defined
synonymous names for both of these clades (Temnospondyli and
Lissamphibia).  I must even admit that I have been guilty of similar
faults, but in my case, this concerns my early work when I was not
aware of the publications by deQeuiroz and Gauthier (1990, 1992, 1994)
that proposed these principles of synonymy and priority.  In my latest
papers, I have been very careful about respecting synonymy and
priority, and I believe that with the Phylocode, most of us will adopt
this position.  Therefore, I believe that Benton is wrong when he
argues that the Phylocode won't solve this problem. =20

	Benton is also misled when he tries to explain that phylogenetic
uncertainties will lead to multiple potential meanings of a definition.
 He justifies this claim by stating that if high-level taxa like
Neornithes or Eumaniraptora are used as specifiers, and if one of these
taxa were later found to be paraphyletic, or if its phylogeny were
altered.  This whole argument is wrong because the Phylocode will
require that specimens, species or synapomorphies be used as specifiers
(Chapter IV, article 11.1).  Thus, Neornithes or Eumaniraptora could
never be used as specifiers.  Apparently, Benton did not read all of
the Phylocode before writing his paper.

	These are my main comments.  More could be said, of course, but that's
enough for now. I just hope that you will receive this message because
the last one that I sent about Nathan Wilson's question did not
generate any comments from you (I don't know whether you received it or




de Queiroz, K. and Gauthier, J. 1990. Phylogeny as a central principle
in taxonomy: Phylogenetic definitions of taxon names.
<italic>Systematic Zoology</italic> 39 (4): 307-322.

de Queiroz, K. and Gauthier, J. 1992. Phylogenetic taxonomy.
<italic>Annual Review of Ecology and Systematics</italic> 23 449-480.

de Queiroz, K. and Gauthier, J. 1994. Toward a phylogenetic system of
biological nomenclature. <italic>Trends in Ecology and
Evolution</italic> 9 (1): 27-31.

Laurin, M. 1998. The importance of global parsimony and historical bias
in understanding tetrapod evolution.  Part I-systematics, middle ear
evolution, and jaw suspension. <italic>Annales des Sciences Naturelles,
Zoologie, Paris, 13e S=E9rie</italic> 19 (1): 1-42.

Rowe, T. and Gauthier, J. 1992. Ancestry, paleontology, and definition
of the name Mammalia. <italic>Systematic Biology</italic> 41 (3):


	Michel Laurin

	Equipe 'Formations squelettiques'

	CNRS - UMR 8570

	Case 7077

	Universit=E9 Paris 7 - Denis Diderot

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