Nomenclature vs. Systems of Classification

Sun Mar 19 08:28:00 CST 1995

The question was asked, what changes can be made in the future that might
address some of the probems discussed recently on TAXACOM. Firstly, I think it
is important to differentiate between what is identification, nomenclature
and classification, and the way each is addressed especially in practice.

Identification is the mere recognition that something exists and that the
object in question is distinguishable by some means from other objects. The
process of identification is a result of our human ability to discriminate
between objects in ways unique to our species.

Nomenclature is the mere application of some symbol to denote an identified
object; its purpose is to provide a means of communicating an impression of
an object to another.

Classification is much more complex. Object can be identified and named
without classifying them; yet, as humans, almost immediately upon being
introduced to an object, even without a name, it is classified. Furthermore,
there are levels of sophistication relative to our human-based means of
classifying objects, with the nomenclature used expressing one or more levels:
"This thing is a plant." "This thing is a green plant." This thing is a green,
vascular plant." This thing is a green, vascular plant with petals." This is a
flowering plants." This is a daisy." "An English daisy." "Bellis perennis."

Each expression conveys a level of sophistication about a classification
scheme; each assumes a level of sophistication on the part of both the
person making the statement and the one receiving the statement. Just listen
to people talk about any object. The degree to which an object is identified
and named will be reflected in the level of sophistication in the way the
object is classified.

When it comes to biology, the objects themselves tend to be grouped before
one even begins to name or classify, but not always. As humans we tend to
identify and name other humans on an individual bases. Yet, when we are
unable to identify particularly individuals, we shift both our nomenclature
and our classification to a higher level. Yet, once again, depending upon
the circumstances, the nomenclature shifts to reflect our impression of the
level of sophistication of the receiver to comprehend what we are trying to
convey. "That's Robert Jones." "He's a taxonomist." "He's a zoologist."
"He's a biologist." "He's a scientist."

When it comes to other biological objects, we tend to group even more. While I
might name all of my horses, except for a limited few the term "horses" is
much more informative than "Araby" or "Starr" or some other specific name.
Aside from pets (in a broad sense), as already noted by others in this
discussion, we do not, as humans, individually name all of the members of a
group. Here we revert back to a more general nomenclature which reflects a
higher order of classification. For example, biologists use a system of
classification by which other living objects are classified into species,
genera, families, orders, etc. Each taxon for a particular kind has a name;
each name conveys a concept that becomes both more general and less exclusive
as one proceeds through the levels of hierarchy. Given my particular level of
ignorance, if someone mentioned to me a particular species name for an ant it
would be meaningless (except, perhaps what the scientific name might mean).
Even a generic name would like not convey any particular image. But ant, ah
now I have at least a general concept.

In the TAXACOM discussions so far, I fear that some have not always maintained
a clear distinction between nomenclature and classification.

Some have called for a single name, number or code that would identify a
species. The purpose of this suggestion, as I understand it, is to allow the
maximum amount of classification possible without biasing the information by
putting, a priori, some modification that reflects a relationship. Inasmuch as
the rank "genus" denotes a group which in all likelihood has no biological
significance in nature, why associate any species with any other species
except through its own particular ancestory?

This I suggest is a worthy goal but one that I fear is not attainable. I keep
asking my students to please discover the secret to Mr. Peabody's Wayback
Machine, but alas no one has yet come forth. And consider this. Even if we
knew the history of each and every species that has ever existed on this
planet do any of you think for a single moment that each species will not be
arranged into broader and broader groups? Of course they will.

Neither code prevents anyone from placing all living creatures in a single
genus and thereby establishing in effect a single name for each without
biasing the information by grouping them. What the codes prohibit is the use
of numbers or codes unless those numbers or codes are treated as Latin. This
is not difficult to overcome. In short, the codes do not prevent anyone from
doing what they want to do when it comes to establishing a means of
communicating about new, as yet to be described species.

True, both codes today restrict the wholesale changing of all names. But even
this is not all that difficult. Let's put all biological things in the genus
Magnolia. This is a Linnaean name and predates essentially all zoological
names at the genus rank. Now, in 1753 Linnaeus used the specific epithet
"virginiana" numerous times, including Magnolia virginiana. The codes say one
must use, in this case, "virginiana", but all other species that currently
bear this epithet would have to have another name. As one would be readily use
up existing Latin names following the rules of priority, soon the vast
majority of Latin names would be exhausted and one could turn to a more
formulated set of randomly generated letters and/or numbers all Latinized!
Remember, into the genus Magnolia we are placing several million species.

In short, the codes are not preventing anyone from establishing a rather
different way of classifying or naming biological entities.

Now, when it comes to identification, codes do not come into play but systems
of classification frequently do. Here is the key. As long as the rule of the
game is that each unique kind must have its own unique name (which after all
is the only way we can have sound, scientific communication; e.g., avoiding
common or vulgar names) then all of the kinds must be identifiable. Codes do
not constrain identification, failures in systems of classification do. I do
not see how, given the dynamics of the Code, anyone is constrained in
establishing a system of classification. The codes do not affect methods of
identifications at all.

Allow me to turn to the current International Code of Botanical Nomenclature
and provide some suggestions that might address some of the concerns raised on

The present Code allows conservation of names at the ranks of family, genus
and species. The Code also allows the rejection of any name regardless of
rank. One suggestion is to allow conservation at all ranks where priority is
a factor (family and below).

I have been asked by the International Association for Plant Taxonomists to
review, between 1994 and 1999, suprageneric names for extant vascular plants.
The task is a substantial undertaking, and one, I fear, that will result in
the killing of the messenger. In working with family names in association with
the late Ru Hoogland, we discovered numerous names of families validly
published long before what is given in App. IIB of the Code. We pointed these
out to the botanical community, and there is now a statement in the Code which
acknowledges the fact that some of the bibliographic references should be
corrected, but this is not to be done at this time. A second suggestion is to
allow conservation of both name and bibliographic information.

I raise these two points in order to give the following example: Most workers
in systematics know the subfam. Maloideae, a taxon within Rosaceae. This name
was proposed in 1964 because the previously used name, Pomaceae or Pomeae or
Pomoideae, according to the Code, was illegitimate. However, no one did the
necessary homework to discover that in 1835 G.T. Burnett proposed Pyroideae.
As some workers reduce the genus Malus to Pyrus, I can assure you that the two
names have for all practical purposes the same circumscription. Thus, the
earliest name for the maloid roses is Pyroideae. Except for a handful of
people currently, no one is aware of this.

Conservation would allow Maloideae to remain in current use if conservation
were extended to other ranks. Rejection of Pyroideae in this instance is not a
valid suggestion, because while I might be of the opinion that Malus and Pyrus
belong to the same subfamily, someone else might not concur. Rejection would
therefore restrict the taxonomic freedom of another were it exercised in this

The concept of NCU (names in current use) was adopted by the Zoological
community but rejected by the botanical community. One reason for the failure
was the assumed lack of scholarship in the proposed lists. Having worked on
that for vascular plant family names for more than four years, I reject this
excuse. However, I did not then, and do not now, appreciate the fact that NCU
provisions allowed invalid names to be valid, and earlier, valid places of
publication to be ignored. A final suggestion: Let us approve the concept of
NCU and then provide a mechanism for submissions and for evaluation and
approval of each list. But, in submitting any list for consideration, the
researcher must do the scholarly research to resolve the nomenclature. This
will do due justice to those numerous workers who have been ignored or
forgotten who have made significant contribution -- an objection by many --
and it will stablize nomenclature to a signicant degree -- the desire of many.

NCU provisions do not inhibit the rights of others to modify the taxonomy of a
taxon. New taxonomic knowledge will always alter nomenclature. What I would
like to see ended is old nomenclature altering established nomenclature
especially after an effort has been made to resolve the matter as thoroughly
as possible.

Frankly, when it all boils down to a few modifications, simply allowing
conservation at all ranks where priority is in effect would resolve much of
the nomenclatural instability that we have, and if that were coupled with
the simultaneous conservation of the place of publication, the problem of
finding an earlier valid place of publication of a name would be resolved.
But to those out there who are not in systematics, nothing will prevent, nor
should prevent, new knowledge about the taxonomy of a taxon from altering
its established nomenclature.

Jim Reveal (MARY)

More information about the Taxacom mailing list