Rare species

[Thomas G. Lammers]

At 08:42 AM 07-30-97 -0400, Eric or Pat Metzler wrote:

>Vulnerable, as defined here with rates of decline, is also the
>equivalent of "threatened" which is a legal definition, not to be
>bandied about when one is talking about infrequently encountered species
>rather than species which need governmental protection.  In my opinion,
>the definition at this WWW page further confuses the issue by combining
>two completely different situations - (1) the decline of species with
>(2) frequency - in a single definition.  This situation illustrates my
>frustration that "rare" can easily be translated to "threatened," thus
>eliciting protection when none is needed.
>
>Until a better definition is provided, the word "rare" is unfriendly.

It seems to me that the observed problems with the definition of Terms of
Endangerment (pardon the pun) is part of a larger problem faced by all
biologists (perhaps by all scientists).  That is, because we examine
phenomena more closely than the average person, we feel the need to define
the terms that relate to these phenomena more precisely than the average
person.  However,in seeking greater precision, our vocabularly is frequently
constrained to terms already in current use in whatever language is spoken
where we live.  Thus, we find ourselves having to usurp or co-opt terms that
long have been defined  by ordinary speakers of the language in a very
general or slack fashion, giving them much more precise (tight) definitions.

When I teach botany, I see  the confusion this causes for students.  For
them, almost any axial component of the plant body is "stem" or "stalk"  --
they think me odd for insisting that they discriminate stem from petiole,
peduncle, rachis, pedicel, and phyllode, and odder yet when I tell them that
corms and rhizomes are also stem, and not "root" as they would define it.
Similarly, carpels with the pericarp dry at maturity (particularly
one-seeded ones like achenes and caryopses), do not comply with their
definition of "fruit", though the enlarged receptacle of the strawberry
does.  They have a hard time grasping why the capitate inflorescence of a
daisy or sunflower is not "a flower".

So it is with terms like "rare", "threatened", and "endangered".  The
proverbial Man in the Street knows damn-good-and-well what those mean:
"rare" -- something you don't see very often;  "threatened" -- something in
trouble ; "endangered" -- something in danger.

Our problem is that,  as biologists,  we know there are many reasons WHY a
thing can be rare, many reasons WHY a thing can be "in trouble" or "in
danger", and we want our terms to reflect these differences.  A plant that
you don't see very often because historically it's only ever grown in one
place is a very different thing from a plant that has been wiped out from
999 of the 1000 places it once grew.

I've commented before that we often don't clearly differentiate PRODUCT and
PROCESS in biology.  This seems another such case.  "Being rare" or "being
endangered" is a PRODUCT of some process or processes at work in the
environment.  Those dealing with conservation issues know that it is
essential to understand these processes, and naturally desire to incorporate
this information into their terminology.   Short of coining entirely new
words with no precedent in the language, the only solution is to strive
towards standardized definitions that represent a concensus of thought  on
the topic.




Thomas G. Lammers

Classification, Nomenclature, Phylogeny and Biogeography
of the Campanulaceae, s. lat.

Department of Botany
Field Museum of Natural History
Roosevelt Road at Lake Shore Drive
Chicago, Illinois 60605-2496 USA

e-mail:     lammers at fmppr.fmnh.org
voice mail: 312-922-9410 ext. 317

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"Science is not a sacred cow.  Science is a horse.
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