Real species

Richard Pyle deepreef at BISHOPMUSEUM.ORG
Fri Apr 16 18:53:43 CDT 2004


> Thus, subspecies are the most real
> organic groups in nature - not species and surely not genera.

I would rephrase that as "...subspecies are the most real taxonomic group
formally recognized by the International Commission for Zoological
Nomenclature..."

In the botany world, you can go with Form, or maybe Cultivar.

In the broader view of biology, you can tunnel down to populations, kin
groups, etc., etc.

So...I agree with your basic point that the further you get from an
individual organism, the less "real" a collective set becomes (the word
"real" here refering to some intrinsic property that transcends mere human
definition). But drawing a line at subspecies as "real" and the higher ranks
is every bit as arbitrary as the notion that I've seen some suggest, that
species are "real", while genera and higher ranks are not.

> I define a subspecies as:  Any regional population of a species that has
> evolved into a unique reproductively stable component of that species.
> Unfortunately re this thread,  I use the word species.  So forget that
> word - it is a detractor in this case.

...you also use the words "regional", "unique", and "stable" -- all of which
point to an "artificial" construct.

> I see several issues not the least of which is if one is looking for past
> phylogenetic connectivity or present - even future - evolutional states.
> Perhaps this is an intrinsic problem of systematics vs. taxonomy.
>   Taxonomy
> being more focused on what is now in hand - reality - this is an
> X.   While
> the systematic concern is ancestry - linkage - boundaries.  ?????

And later...

> In my subspeciation
> paradigm, the "of" is unimportant - almost a non factor - a
> necissary evil -
> that is where all the subjectivity lies.   It doesn't matter much
> to me what
> "species" someone may or may not connect the subspecies to - with - of.

O.K., so you're not concerned with evolutionary affinities -- just defined
collections of critters/weeds.  That's fine, but it doesn't allow you to
escape having to deal with boundaries. We taxonomists (not just what you
describe as systematists) also have to deal with boundaries on a very
regular basis.  To wit, "Is this set of organisms consistently distinct from
this other set of organisms enough that the interests of communication among
biologists is best served by the designation of different textual labels
applied to each set?"  This is the question I ask myself whenever I
contemplate naming a new species.  I long ago abandoned any notion of trying
to "discover" whether the two sets of organisms "are", or "are not",
different species.

> The central matter is that the regional entity is _unique_ (in and of
> itself).  Unique how?  That is up to the  researcher to find out.  Life is
> unique in many varying ways.   It is that uniqueness that is
> tangible (real /fact) and the basis for recognition.

Yes, but every individual organism is "unique", and my family tree is
"unique" with respect to your family tree.  I see a virtual continuum from
an individual, out through subspecies, and into species, genera, families,
etc.  There seems nothing more "real" to me about drawing the line at some
arbitrary rank of "subspecies", rather than at "species" (or "genus", etc.).

Having said all of that, I do believe there is likely to be an observable
inflection point in a lineage split -- some point where gene flow drops from
something on the scale of flow within a typical population of organisms, to
something on the scale of rare hybridization events or the "background
radiation" of lateral gene flow.  There is a continuum between those two
points, but I imagine that when we step back and look at the larger picture,
we'll see a demonstrable "dip" in the otherwise smooth continuum.  Almost
like punctuated equilibrium (but not really). Those borderline cases we see
around us are cases that happen to be on the "dip" at this point in
evolutionary history.  Most organisms (e.g., humans, chimps, and orangs)
will have passed the "dip" some time ago. Reading through the rest of your
email, I think I mean the same thing here as you do with "plateaus" and
"steps" between them.  Except there is really only one step -- that between
large-scale gene flow and near-zero gene flow.  Once gene-flow steps to near
zero, I imagine it usually stays that way (plants & corals notwithstanding).

> And is not everything in an "in-between state"?

No, I don't think so (unless I'm wrong about comparing your "steps" to my
"dips").

> I contend that before any
> species reached that "rank /state" it was a sister (subspecies ) with a
> conger first
  ^^^^^^

Really?  You mean that all living things are somehow derived from eels? ;-)

(fish-nerd joke)

Aloha,
Rich

=======================================================
Richard L. Pyle, PhD
Ichthyology, Bishop Museum
1525 Bernice St., Honolulu, HI 96817
Ph: (808)848-4115, Fax: (808)847-8252
email: deepreef at bishopmuseum.org
http://www.bishopmuseum.org/bishop/HBS/pylerichard.html




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