Species as "Hypotheses"

Ron at Ron at
Mon Jul 12 14:27:28 CDT 2004


----- Original Message -----
From: Paul van Rijckevorsel
Subject: Re: Species as "Hypotheses"


> Guy Redeuilh Wrote:
> > This concept applies to a taxon better than a species only.

From: Richard Pyle <deepreef at BISHOPMUSEUM.ORG>
> To maintain consistency with the point of my original question, I would
have to qualify this as "ranked taxon".

+ + +
Seems to me that a taxon is ranked, by default. A taxon is a taxonomic
grouping, the result of the application of taxonomy. It is the core business
of taxonomy to make hierarchical classifications, and the units of the
taxonomic process are ranked. This may be the big difference between
taxonomy and systematics?

**********

The ICZN glossary has two interesting and useful catagorical definitions of
taxon.

A  "zoological taxon" is:  "A natural taxon of animals (which may, or may
not, have had a name applied to it)."

A "taxonomic taxon" is:  "A taxon (e.g. family, genus, species) including
whatever nominal taxa and individuals a zoologist at any time considers it
to contain in his or her endeavour to define the _boundaries_ of a
zoological taxon (q.v.).  A taxonomic taxon is denoted by the valid name
determined from the available names of its included nominal taxa."
(Emphasis mine.)

So, for the zoologists here, Richard's term "ranked taxon" would be accurate
as he applies this to the humanly defined taxa (our species inquiry).   By
the two ICZN definitions of "taxon", a taxon is not ranked by default -
unless it is  a taxonomic taxon.  So some hair splitting of terms is
warranted.   Which brings us full circle into the original question.

A zoological taxon is simply an observed type of living animal, then, once
we as humans propose its _boundaries_ and create a taxonomic taxon have we
proposed a hypothesis or a definition?  That is, a definition (= delimited
by recognizable boundaries) of the zoological taxon?   To me, it is as
Richard stated, "...definitions that are followed or ignored based on
subjective preference by other taxonomists?"   I don't see species as a
hypotheses.   I see their systematic evolutionary relationships as
hypotheses - but not their states as species, genera or families.   This is
because the taxonomic taxon names we create are applied to snap shots taken
from specific spatial and temporal locations - past or present.

We _collectively rank_ our taxonomic taxa in a hierarchy, which indicates
their hypothetical evolutionary past.   But with each ranked entity itself
we (should) have a taxon that is an observable product of the process, a
definable reality know not by hypothesis or theory but observable factual
_boundaries_.  Thus, this is why species are merely argued about and can not
be put into some pragmatic, standardized, falsifiable formula.   Systematics
is a quest/debate for/about origins and relationships - taxonomy is about
subjectively perceived reality at a fixed point in time and space.  The
reason we talk of "missing links" is because they are missing - thus the
hypothesis.  Nothing is missing in an observable population of a zoological
taxon - just let it sting or bit or flog or eat you if you question its
factual reality.   Species are about tangible boundaries not hypotheses.
Disagreement on which boundaries are "valid" or which to utilize does not a
hypothesis make - it makes an opinion based position.   Of course,
scientists always like to think of their opinions as analytical conclusions
(by scientific means and methods) and not what they often are - mere
personal bias.

Ron Gatrelle.




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