More on the 5-year Rule, ICZN

Robin Leech robinl at NAIT.AB.CA
Wed Jan 24 06:22:08 CST 1996

A few more comments to invoke comments.
Robin Leech

---------- Forwarded message ----------
Date: Thu, 24 Aug 1995 23:57:53 -0600 (MDT)
From: Robin Leech <robinl at>
To: pkt at
Cc: George Ball <gball at>
Subject: More on the 5-year Rule

Hi Philip Tubbs,

Would you believe that I could not find a copy of the Tokyo Code (1994)
of the ICBN in Edmonton.  Ordered one from the N.Am. distributors, and it
came Monday.  I do not publish botanical taxonomic papers, but I do use
the ICBN in my vascular plant taxonomy classes in order to show the
students a few points, but mainly the common threads with the ICZN on
name stability, junior and senior synonymy, types, etc.

I have often wondered why there could not be an International Code of
Biological Nomenclature.  There are a few things in the ICBN that I would
like to see in the ICZN, and vice versa.

But to my point for today.

One of the greatest strengths of the Code is the Principle of Priority of
published names.  Note how carefully, cautiously and rarely - relative to
the number of names produced - that we apply for petitions for
conservation, or for stability.  It is perhaps for this one feature alone
that the Code of 1961, and its predecessors, were initiated.  Consider
the arbitrary starting date of 1758, and how Clerk's 1757 Svenska
Spindlar was redesignated to be 1758 and that names in it are valid over
and above those in Linnaeus' Systema Naturae.

The 5-year rule serves the lazy souls who do not want to do the work
required for a careful literature review, and who are unprepared to
accept the consequences of their laziness or inefficiency, i.e., to see
their names, or the ones they have chosen, sunk as junior synonyms of
previously published names.

The Principle of Priority is an arbitrary rule that is applied
non-arbitrarily.  If we do not stick with this Rule, I believe that chaos
will be the result.

A few examples at the species level will serve as examples.

A few years ago, it was realized that the name CERVUS CANADENSIS (our
wapiti) is a junior synonym of CERVUS ELAPHUS (your red deer), and that
MUSTELA RIXOSA (our least weasel) is a junior synonym of (I think)
MUSTELA NIVALIS.  At any rate, these syonymies were published and
accepted, even by older, well-established mammalogists and the public.

The wapiti is a high-profile species with a huge scientific and public
name following.  Yet, when the synonymy was published, the world did not
stop, and now we have a system of names that is based on the Principles
of Priority.  Everyone has accepted it because it is recognized as fair.

I know the examples mentioned below are outside the scope of the ICZN,
but I mention them to show what happens when nationalism or region or
influence affects what name is used.  Consider that in arachnology we
have two names for the harvestmen or daddy-long-legs: PHALANGIDA and
OPILIONES.  For the wind scorpions, we have SOLPUGIDA and SOLIFUGAE, and
for the spiders we have ARANEIDA and ARANEAE, and for entomology and the
webspinner insects we have EMBIOPTERA and EMBIIDINA, and for mayflies

As I mentioned above, use of a particular name is partly national, partly
regional, and partly who is doing the most publishing (i.e., influence) on
the group at the moment.  For some reason, we taxonomists are willing to
accept this sort of non-priority system at this level.

Robin Leech

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