Numbers for critter names

Richard Pyle deepreef at BISHOPMUSEUM.ORG
Thu Oct 11 08:59:45 CDT 2001

Ron Gatrelle wrote:

> Number 4481 is Phyciodes tharos and 4482 Phyciodes batesii.  Today we know
> that one of the synonyms he listed under tharos (cocyta) is
> actually a full
> species. It can not be given the number 4482 as that number is already
> taken.  Thus it has no whole number and can have no whole number in a
> sequence that would indicate its relativity to tharos or batesii.
>  The next
> available number is 11234.  It can be given 4481.1 but then why not 4482.1
> if the number is to relay something of relationship?  Would not 4481 and
> 4481.1 and 4482 go against logic and form?  Why should some species be
> listed as whole numbers and others by decimal points?  Hodges simply gave
> the numbers as a list sequence for the list given.  If he had intended it
> as a "system" then each genus should have been assigned a unique number
> with X number of zeros to allow for plenty of additions.  As I
> said, I find
> his numbers pointless.

Perhaps the reason you find them pointless is that you want them to convey
some sort of meaning, or contain some sort of information. However, if I'm
not mistaken, Doug's point about assigning numbers to taxa was about the
issue of uniqueness and constancy.  The two problems with using binomials
(or even monomial names of rank higher than species) as unique identifiers
for taxon names are that: 1) Names are not constant, due to generic
reassignment, alterations of species epithets for gender matching, etc.; and
2) Names are not universally unique, due to homonymy and potential dual
usage at different ranks, and between botanical and zoological codes.

We humans can usually discern the meaning of any given taxon name in spite
of these two problems, because we can interpret the context (which may be
subtle at times).  A computer (a tool that taxonomists use with increasing
frequency, and one which holds great promise for more efficient
identification and documentation of species and specimens) would need a LOT
of AI-type programming to be able to discern the context as well as a human
can, so for the most part, computers are better-off with a unique and
constant "handle" (identifier, or "Primary Key") for each taxon name.

One approach is to use complex primary keys; that is, the combination of
Taxon Name plus Authorship plus year plus page number etc., taken together,
for the most part constitute a unique identifier for a particular name.  As
a database programmer, however, I can testify to the technical difficulties
in taking this approach.

Another approach is to erect a "Surrogate Key", usually an integer, to
assign to each Taxon Name.  These numbers neither change, nor are
duplicated. The trick to using these numbers effectively is to rob them of
*ANY* meaning whatsoever. If Hodges numbers were assigned in a particular
sequence for the purpose of conveying information (e.g. establishing a sort
order of species), then it would not represent an effective Surrogate Key.
If, on the other hand, the numbers just happen to be in some sort of
sequence because that's the order they were initially assigned, then the
case of Phyciodes cocyta is a no-brainer -- it gets the number 11234 and
that's the end of it.

I don't know Hodges' intent in assigning these numbers, but I have learned
from my own database experience that assigning Primary Key numbers in
sequence (even with no intent of conveying meaning) leads to the problem of
users *assuming* there is some sort of meaning to the sequence. Largely for
this reason, I now exclusively assign random numbers to each new entry, so
that nobody has any illusions about extracting information from the numbers

This is all very basic stuff for anyone who has built a robust database
system involving taxonomic nomenclature.  Most database systems hide the
surrogate key number, so the user never even knows that it exists. In my
opinion, that's the way it should be. The numbers should not be printed in
catalogs, or used commonly in the literature. No human should ever have to
write one down or type it into a computer, because an incredibly trivial
transposition or other error in the number could lead to an incredibly major
point of confusion for taxonomists ("What was a water buffalo doing 200 feet
down on a coral reef?"). Also, as Ron pointed out in a later post, numbers
are not as easy for humans to work with and learn and memorize as names are.
Computers, on the other hand, LOVE numbers.  They rarely make such
transposition errors, so they have no difficulty managing such numbers. Many
(most?) existing databases of taxon names already have such numbers, and use
them very effectively (i.e., without the user ever knowing that it exists).

The problem is that each database system assigns its own set of numbers to
every taxon name.  Bill Eschmeyer's Catalog of fish names uses one number
for each species name. FishBase uses another.  Species 2000 probably uses
another, Specify probably uses another, ITIS probably uses yet another, my
own database system uses yet another still....and so on.  The problem, of
course, comes when trying to link these databases to each other.  In many
cases, we can create "synonymies" of the different numbering systems.  While
marginally more effective than maintaining synonymies of the names
themselves, this approach is still cumbersome, and needs to be mapped and
maintained by someone as each individual database systems grow.  Another
approach is to link different sets to each other using the aforementioned
complex key (Name, Author, Year, Page, etc.).  This is not an effective way
to do it either for many reasons, for example one database records the
author as "Smith & Jones", and another records it as "Smith and Jones", and
yet another may record it as "Smith, Jones", or "Smith et Jones".....

The value of an "established", "centralized" numbering system is that all of
the databases could use the same number. This makes the task of linking
different systems ENORMOUSLY easier.  Attempts have been made in the past to
create such numbering systems, but most (all?) seem to have failed for
various reasons (lack of adoption, falling into the trap of trying to convey
information within the number, narrowly restricted taxonomic scope, etc.).

In this electronic age, the field of taxonomy could benefit tremendously by
the establishment of "registration numbers" for taxon names. So far, the
taxonomic community as a whole seems to have rejected the idea.  And so we
continue to stumble on, wrestling with the same old problems....


P.S. Ron later wrote:

> IF I did a check list I
> would assign a base number for each genus etc.  In a computer file, all
> world genera known and unknown would have to have a base number asigned or
> available. 10000 = genus A, 10001 genus species, 10001.1 genus species
> subspecies. Permanency by uniformity  -- which was what Doug was actually
> dirrecting us to -- not numbers for the sake of numbers.

This is where we seem to disagree.  In my opinion, a computer's unique
"handle" on a taxon name should convey zero meaning. If you want to erect
some kind of sorting system, do that independently of the primary key. I
think that a large part of the reason that many previous efforts to
establish "universal" numbers for taxa is that they tried to convey meaning
within the numbers themselves (as you outline above).  If you want to use
this sort of system in a phylogenetic sorting field, then great (I use an
analagous system for my sorting field). But keep the unique and constant
identifiers arbitrary.

Richard L. Pyle
Ichthyology, Bishop Museum
1525 Bernice St., Honolulu, HI 96817
Ph: (808)848-4115, Fax: (808)847-8252
email: deepreef at
"The views expressed are the author's, and not necessarily those of Bishop

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