Real species
Richard Pyle
deepreef at BISHOPMUSEUM.ORG
Fri Apr 16 21:35:55 CDT 2004
Hi Ron,
We seem to agree on most of the core philosophy here. Couple minor
quibbles:
> Stable is simply if they "do" the same thing over and over
> (let's say a particular migratory path, or a specific diet).
On evolutionary time scales, I'd say we do not yet have any meaningful data
in this regard. What appears to us as "stable", might be something that
varies widely over cycles of centuries (tick o' the clock, evolutionarily).
> > Richard: O.K., so you're not concerned with evolutionary affinities --
just defined
> > collections of critters/weeds.
>
> ******
> Ron: I would say naturally occurring populations, not collections.
Reading "collections"
> as museum specimens. I see collection determinations to any rank as
inherently flawed.
Sorry -- I should have used the word "sets" (as in, "more than one"),
instead of "collections". (As someone who has worked in a Museum collection
for the past 18 years, you'd think I would have been more careful about my
choice of words!). I was specifically trying to avoid the word
"populations", as it is every bit as loaded/ambiguous as "species" or
"subspecies".
> Ron: I especially like that last statement. To me, I'd be just as
> content to do away with ranks all together and simply work to discover
> organic SETS - unique population entities.
Hey, that sounds like a *perfect* solution! Let's get some other biologists
to join forces with us. We can draft a new set of rules for objectively
applying names to groups of organisms, such that we can reduce the level of
ambiguity of what scope of organisms the names are inteded to represent!
All we need to do is come up with a catchy name. Hmmm....I know! Let's call
it "Phylocode"!
;-)
(Sorry -- couldn't resist....)
> My opposition to PhyloCode is that I see it as myopic and exclusionary to
other
> points of view.
I disagree...but we've been down that path before, and we needn't revisit
it. And as someone who would never use the Phylocode (like you, I am much
more interested in documenting and cataloging the diverse forms of extant
critters, than I am in making guesses about their evolutionary affinities --
Viva alpha taxonomy!)
> I see the traditional Linnaean taxonomy as a system in and through
> which all the diverse "specialized" groups can find expression.
...as well as grounds for passionate arguments flawed by non-mutual
understandings of nomenclatural purpose....but on balance, I'd say the plus
outweighs the minus.
> I see subspecies utilization as a communication option for those who want
to note
> node 123xyz - but they would't think that was cool. Old school and a step
backwards.
Like you, I'd also like to see subspecies used on a more regular basis.
Jack Randall and I plan to write an opinion piece outlining our perspective
of the nomenclatural function of trinomials (somewhat in response to an
earlier published opinion piece on this topic for fishes). In a nutshell,
we think the subspecies designator should be used for those borderline cases
about which we've been discussing, where it's not clear whether two
populations are destined to remain reproductively isolated from each other
into perpetuity, or might converge again sometime in the future. This
doesn't remove any of the subjectivity or "artificial" components of the
nomenclatural process, but it seems to us to be a practical (and logical)
application for trinomials. Referring back to my earlier description of
white zones (clearly heterospecific -- essentially zero gene flow on
evolutionary time scales), black zones (clearly conspecific -- essentially
unobstructed gene flow on evolutionary time scales), and grey zones ("fuzzy"
transitional cases in-between), the subspecific designators would be used
for the cases in the grey.
Essentially, this would be taxonomic nomenclature by consensus. If
virtually everyone agrees that two populations are conspecific, then we'll
use one species epithet. If everyone agrees two populations are distinct,
we'll use two species epithets -- one for each. In cases where there is
contemporary disagreement on whether two populations should be regarded as
distinct species, we'll use one species epithet and two subspecific
epithets. Lo & behold, "A species is what a community of taxonomists say it
is."
> "If what I know met what I don't know, what I know would be highly
embarrassed."
I like that!!!
Aloha,
Rich
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