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Date: Mon, 12 Feb 2001 11:16:24 -0500
From: Gerry Moore <gerrymoore40@hotmail.com>
To: PhyloCode@ouvaxa.cats.ohiou.edu
Subject: Codes
Through some glitch my last message was incomplete. I try again below. Thanks to those who pointed this out to me. I. Co-opting existing codes In contrast to P. Cantino’s "two systems operating in parallel approach", D. Hillis recently wrote that he viewed the PhyloCode as an "upgrade" ("version 2") of the of the old system ("version 1") and one that should "co-opt" the existing system. Such a view is quite different than that put forward in the Preface of the PhyloCode. Also, Hillis noted that most of the resistance he had seen to the PhyloCode was from people who objected to the creation of a competing parallel system. This is different from the perspective I took away from the Nomenclatural Section at the 1999 International Botanical Congress (note: the symposia on phylogenetic nomenclature was not part of the Section). Phylogenetic nomenclature was discussed in an official capacity because a proposal was put before the Section to consider permitting the valid publication of "unranked" taxon names (it was defeated by a simple show of hands)and there was also much watercooler discussion of the topic during breaks. My take on those discussions was that most felt that it was fine for advocates of phylogenetic nomenclature to construct a different system so long as it did not co-opt or take over the existing system. Creating two systems parallel would allow people to use both systems and see for themselves which one worked better for their particular needs. Back in October 2000 a lengthy phylo nom thread developed on TAXACOM. Many of the comments were strongly critical of phylo nom. Phil C. performed the Herculean task of responding to almost all of the posts. He basically made the "parallel" argument, and it had a remarkably assuasive effect on that thread. Some who were strongly opposed even conceded that they might actually test drive phylogenetic nomenclature. I suspect that had he characterized the PhyloCode as the version 2 that would co-opt the version 1 (the exisitng codes) his comments would have generated much more heat than calm. II. Under the PhyloCode we can do everything that we do with the existing codes If this were the case then it would certainly make sense to regard the PhyloCode as the "version 2" of the existing system. However, I disagree with this assessment. Under phylogenetic nomenclature a name is formally attached to a clade. Barring intervention by a committee, it remains attached to that clade regardless of how the content of the clade changes with changes in ideas about phylogeny. Under traditional nomenclature names are not formally attached to clades. I regard this difference between the two systems as so fundamental that it is inappropriate to characterize one as simply a newer version of the other. Thus I do not agree with Hillis’s assessment that "the PhyloCode can be designed so that it does everything the old codes do…" . The two systems may use many of the same names but the names are defined in very different ways. The task before the systematic community now is to decide which one is better. I believe that there is not enough evidence yet to make a clear judgment here. It is simply not enough to develop a phylogenetic nomenclature for a group of organisms. We must allow these new nomenclatures to age to see how they handle changes in phylogenetic concepts. Having both systems in use parallel would allow us to study each system in the face of changing phylogenetic concepts. Hillis was critical of the existing system, noting that it required "diagnoses of taxa rather than phylogenetic definitions, and the diagnoses don't even have to be correct." However under the PhyloCode one can define taxon names under a phylogenetic hyopthesis that is also later proven incorrect. It is important to study what happens to the applications of these names in these cases (e.fg., how much content change occurs, how much need for formal conservation is there). III. The Species problem In his recent posts Hillis has stressed that the PhyloCode should incorporate rules for species before any official status is accorded to the code. Under such a set of rules what would the status of names be that were created under the existing system? Would species names also require formal conversion from the traditional system into the phylogenetic system? Who would be responsible for handling the issues relating to conservation and rejection of species names? Would the standing committees that deal with these matters under the existing system be "co-opted" by new committees under the PhyloCode? Cheers, Gerry Moore _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com