[Taxacom] Binomial Nomenclature - was: "cataloguing hypotheses & not real things"

Richard Pyle deepreef at bishopmuseum.org
Thu Sep 5 12:38:26 CDT 2013


I've never understood this whole "species are hypotheses" thing.  I
certainly get how a clade is a hypothesis, and I suppose that if you think
of a species as a clade then you could frame the hypothesis along the lines
of "all individual members of this species share a more recent common
ancestor with each other than they do with any other species".  However,
because we do not, in practice, enumerate every individual within a species,
I don't really see how this works.  The real-world practice seems to be that
identifications/determinations of organisms are the hypotheses; as in: "this
individual I have in front of me shares a more recent common ancestor with
the type specimen of this named species, than it does with the type specimen
of any other available name with higher nomenclatural priority".  But that's
not a "species as hypothesis"; that's a "determination as hypothesis".

How would you frame the hypotheses for a species?  Given two type specimens
for two available names, where the phylogenetic affinity is not in dispute,
but where lumpers see a single species with a synonym, and splitters see two
distinct species -- what, exactly, is the basis of the hypothesis that
allows you to objectively determine if there is one species, or two?
Traditionally, such a hypothesis could be framed thusly:

"Any given organism that shares a more recent common ancestor with the type
specimen of Species 'A' than with species 'B'; can reproduce with any given
organism that shares a more recent common ancestor with the type specimen of
Species 'B' than with species 'A', and produce fertile offspring [in

However, this traditional view (BSC) tends to break down in terms of how
lines between species are drawn these days.  Perhaps someone could state the
hypothesis represented by a species in other species concept paradigms?

Ashley wrote:

> Yes I do understand these things and the practical issues involved.
> names are not just names -- they represent someone's hypothesis (good or
> bad). Hypotheses do not disappear just because names become synonyms --
> this is bad empirical science! The problem is that species hypotheses
> be verified or falsified because species are mental constructs (extremely
> helpful mental constructs) and not real objects. 

I agree with the second part of this ("mental constructs"), but the text
above seems to me to be self-contradictory.  My understanding of a
"hypothesis" is consistent with what I found on Wikipedia:

"A hypothesis (plural hypotheses) is a proposed explanation for a
phenomenon. For a hypothesis to be a scientific hypothesis, the scientific
method requires that one can test it."

I assume we're talking about scientific hypotheses here.  In an earlier
post, you had referenced Popper's World 2 (the world of mental objects) --
which I think is appropriate in the context of what we refer to as species.
However, Popper was also of the school that a hypothesis must be
falsifiable. Even the more liberal interpretation of hypothesis that
accommodates verifiability is not met per your statements above (and I
agree!). If, as we seem to agree, species hypotheses can neither be verified
nor falsified, then whose notion of a hypothesis do they represent?

> Have you ever taken an
> entire species (every individual) into the laboratory and objectified it?
> Species hypotheses are abstractions very often from limited data.
> Taxonomists do their best under the circumstances. If you want certainty,
> which these lists demand, then become a dictator -- as they seem to live
in a
> very certain world! 

While we seem to be in full agreement on the notion of species as
non-objective entities (certainly in practice, and, perhaps, conceptually as
well); I'm not sure we have a mutual understanding of what "these lists"
(i.e., the digital world catalogues about which this thread was begun) are
intended for.  I know many of the people who develop "these lists", and not
a single one of them regards them  as demanding of certainty.  They are not
intended to be *the* answer, forever and for all.  They are intended as a
consensus view to serve the needs of the VAST majority of consumers of
biological information -- who simply want to know which, of several
alternative views (e.g., lumpers v. splitters) to follow in naming the
entities they wish to refer to.  These global catalogues are NOT static --
they evolve as the community perception evolves, and as more information
becomes available.  They are in no way dictatorial. Rather, they are a
convenience -- they represent a *service* for positing a snapshot of the
biodiversity landscape in time.  Their value is in their relative stability
among a sea of competing views (i.e., "noise").

In short, there certainly are folks who wallow in the notion of "species are
objective entities in nature, independent of human perception"; but the
people who compile global catalogs of species with assertions about
classifications and synonymies are generally not among them.

> However, we must not confuse
> hypotheses/ideas/tradition/analyses or superstition with the truth
> (whatever that is).

This seems to me to be a bit of a straw-man: I think most people on this
list do not confuse what we do in taxonomy with "truth".  I think the issue
is more about confusing/conflating objective entities with subjective
definitions. Do we discover species?  Or, do we define them?  The part I
find a bit ironic is that subscribers to the former (i.e., that species are
objective entities in nature that we must discover) are the ones who tend to
view "species as hypotheses". The latter camp (which you and I both appear
to be solidly within) are the ones who tend not to frame species as


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