rankless nomenclature

[Richard Pyle]

Doug Yanega wrote:
> This is a view which, in all fairness, I think maybe only a vertebrate
> systematist could ever envision (and maybe rightly so, from that
> perspective) as possible in our lifetimes. However, I submit that the odds
> of us ever having anything approaching a complete and stable species-level
> phylogeny of even a significant *fraction* of the Arthropoda are roughly
> equivalent to the odds we will learn how to build vacation homes inside
> black holes in other galaxies. Heck, we haven't even put *names* on an
> estimated 80-99% of the extant arthropods, let alone worked out
> species-level phylogenies, and H. sapiens will probably be extinct before
> we get anywhere close to finishing the task (especially at the rate we're
> losing alpha systematists). If we're missing that many species from the
> hierarchy, how much faith do you put in our higher-level taxon
> circumscriptions? Heck, I don't even think we have a stable idea of what
> the circumscription of the Phylum Arthropoda is to *begin* with.

Perhaps, but if we really want to solve these issues in biology, I think we
need to look beyond our "lifetimes".  If you look back at arguments among
biologists of a hundred years ago, they often seem myopic in scope, and
lacking in imagination for what the future may hold.  Who knows - maybe the
documentation of all species on earth within, say, a quarter century is more
than just a pipe dream.  Compare the difference in DNA sequencing technology
and related bioinformatics before the start of the HGP, and now.  Maybe 25
years from now obtaining a complete genome of an organism will be as simple
as dropping a tissue sample in a portable "Mr. Genome" machine and pressing
a big blue button.  Maybe computer technology and information databases will
be sophisticated enough that absolute phylogenies based on complete genomes
of organisms can be generated with a few mouse clicks, and with a high
degree of reliability and stability.  Pipe dreams?  Maybe....but maybe not.

My point is that the use of the Linnaean classification scheme as a tool for
documenting and communicating interpretations of phylogenies is cumbersome
at best.  By all accounts, PhyloCode might be the better tool for this
endeavor, leaving Linnaean taxonomy to represent intuitive human
perceptions. But just because the PhyloCode system isn't easy or meaningful
to apply to certain groups of organisms, doesn't mean it's not useful to
others, and therefore doesn't mean it shouldn't be developed.  At the same
time, just because the Linnaean system is not an ideal tool for
communicating phylogenetic hypotheses, doesn't mean it's a useless archaic
system that should be abandoned altogether. Each has it's value, and I
believe each will persist.

>         If the stability (and superiority) of the PhyloCode
> system is based
> on the assumption of stable underlying phylogenies, then it is a
> pipe dream
> to expect it to be superior to the Linnaean system for the majority of
> extant taxa, for centuries to come - unless we experience about a
> thousand-fold increase in the number of systematists. Richard, if you KNEW
> that 95% or so of the world's fish species had yet to be discovered and
> described, would you be ready to switch to the PhyloCode
> tomorrow, or would
> you consider it hopelessly premature?

Who said anything about "switching"?  My fundamental point was that the two
systems need not be mutually exclusive. Why can't both be valid and active
endeavors, each with different purposes?  PhyloCode (as I understand it) is
a "superior" system for communication among people who are interested in
elucidating phylogenies.  But the Linnaean taxonomy remains a "superior"
system of communication among biologists with other interests, especially
for groups that are largely incomplete and are a long way from enjoying a
stable phylogenetic interpretation.  The problem is that we're trying to
force-fit a single system to accomodate multiple purposes (hence my
question, "Why are we putting names on taxon groups?").  Why can't
Lepidopterists engage in PhyloCode "numenclature", while researchers
interested in other less completely known insect groups focus more on
Linnaean nomenclature?  Maybe the phylogenies of Lepidoptera can apprach
stability in our lifetimes, and thus Linnaean nomenclature can be compared
and "finalized", diverging from the numenclature only where it makes
intuitive sense to do so.

Again, my overall point is that these are two different tools that are
optimal for two different endeavors.  The mistake, I think, is the mentality
that we must choose one or the other, or that there can be only one
classification system, or that the two classification systems must somehow
be in perpetual "competition" with one another?  Why can't they compliment
and support each other? I think that anyone who believes that a PhyloCode
approach will completely replace the Linnaean system anytime in the
foreseeable future is just plain naive. The same naivity, I think, is
exhibited by those who feel that a PhyloCode approach has no use in biology.

> Maybe the underlying problem is that
> PhyloCode proponents are trying to devise one set of idealized rules for
> everything, when the reality is that what may be marginally practical for
> one small set of taxa (vertebrates) may never be practical for anything
> else. As Utopian visions go, the PhyloCode is fine, but it's not something
> *I* will ever be able to use, so don't expect me to adopt it. I'd sooner
> become fluent in Esperanto.

O.K., so don't adopt it - that's fine.  In my view it would be just as
inappropriate for practitioners of phylogenetic studies of well-known groups
to criticize your decision to focus on classical taxonomy of a poorly-known
group, as it would be inappropriate for you to make the reverse criticism of
their efforts.  Why can't we accept that the two systems are both useful
tools for different purposes in different contexts?

Aloha,
Rich

Richard L. Pyle
Ichthyology, Bishop Museum
1525 Bernice St., Honolulu, HI 96817
Ph: (808)848-4115, Fax: (808)847-8252
email: deepreef at bishopmuseum.org