[Previous by date - Fwd: Species and genus names [was: RE: Genus names]]
[Next by date - Re: Addendum 4: Conversion of generic epithets]
[Previous by subject - RE: apomorphy-based names]
[Next by subject - RE: conflict between monophyletic taxonomy and rank-based classification]
Date: Wed, 07 Feb 2001 16:47:45 -0600 (CST)
From: "Jonathan R. Wagner" <znc14@TTACS.TTU.EDU>
To: "Moore, Gerry" <gerrymoore@bbg.org>
Cc: PhyloCode@ouvaxa.cats.ohiou.edu, Dequeiroz.Kevin@NMNH.SI.EDU
Subject: RE: apomorphy-based names
At 02:34 PM 2/6/01 -0500, you wrote: > I believe the intent (Jonathan W. or Kevin deQ. please correct me if am >wrong) of this draft recommendation is to deal with former suprafamilial >names developed in the traditional system in which the name is not based on >a type genus (e.g., Magnoliaceae based on the type genus Magnolia) but >rather is based on a character (e.g., Monocotyledonae). Exactly! It seemed consistant, in that if we insist that type taxa be internal specifiers, we should at least ask for definitions that explicitly specify an apomorphy for clade named for that apomorphy. Ask, not insist, in this case. >However, the way >Recommendation 11.8C is written it would suggest that _all_ names "derived >from apomorphy names be given apomorphy-based defintions". Please see my response to Dr. De Quieroz (sorry, this is something of bad form, but I have been trying very hard to catch up on a bundle of e-mail, so I handled the short messages first). >Thus it seems to >cover former generic names that are derived from an apomorphy name. As I have recently posted, I think we need to be very careful with these... >In these cases, >doesn't Recommendation 11.8C indicate that the apomorphy definition is to be >given preference over stem- and node-based definitions? No. It would recommend to the namer that they be used. Am I just misinterpreting the meaning of the term "recommendation?" On another hand, I was not even considering genus names, as I was under the mistaken impression these were off limits until we decided what to do with species (since some of the Cantino et al. options preclude the use of at least some genus names as clade names). > D. Hillis's example using the genus name Gastrotheca shows how there can >be translation and derivation determination difficulties. Should the name be >literally translated as "stomach pouch" and thus not having to do with the >pouch on the back or can it be more loosely translated so as to be derived >from the character involving the pouch on the backs of the females? Again, the systematist might invoke good judgement, and the fact that Recommendation 11.8C is just that, a recommendation, and use a node- or stem-based definition, or a different apomorphy-based definition (despite Recommendation 11.8E. Must/should we spell out "but you don't have to," at the end of each of these recommendations. Or put the universal catch-all about failure to do so not being grounds for rejection of a name? > Also regarding new names let's say someone has identified a clade and >provided it with a stem- or node-based definition. Recommendation 11.8C >seems to frown on one then coming up with a new name for this clade that is >derived from an apomorphy name. OK, please forgive what may seem like pedantry, but what you wrote is not clicking with me: A clade is a clade, there is no defining a clade... you define a name. If I find a clade in my analysis, and "provide it with a definition," I must also be providing it with a name. A new name, then, must perforce involve a new definition, because if it had the same definition, it would sink in objective synonymy. Althought the Code doesn't "frown" on this, it is pretty much pointless. With a new definition, the two names are NEVER objectively equivalent, uness the definitions are equivalent (as above). If they describe the same clade in your phylogeny, your new name would be sunk in synonymy (so why are you naming it?). Long story short, I'm afraid I don't see your point. If you are implying that the 11.8C "frowns" on using an apomorphy-based name for a node- or stem-based definition, this is exactly what it does. I hardly think the scorn of a mere Recommendation will keep systematists from doing this, however. >Thus, one has less freedom in how to develop >a name for a clade when following Rec. 11.8C. and using stem- and node-based >definitions. Not really, because you can ignore it if you feel it is necessary, on a case-by-case basis. The examples included were meant to show different situations, and give a feel for the type of issues involved. I don't think most serious practitioners want to see an apomorphy-based Tetrapoda or Mammalia, but some less important, less well known clades, which are very strongly indicated by a very pronounced apomorphy (like Ankylopollexia) might warrent the application of such a definition. This is a recommendation intended to make the namers or converters of such taxa think twice before automatically applying a node- or stem-based definition. Dr. De Quieroz take note: Many converters seem to tend towards the latter option (above), looking at recent cladograms and opting for a defintion which encompasses the CONTENT of the traditional group. This is especially evident in Paul Sereno's recent definitions based on his ornithischian phylogeny, and is indicative of one approach to the use of PN (as a tree descriptor, rather than a nomenclature for biological entities). >It probably poses less problems when converting >suprafamilial names that are based on apomorphy names and that have well >established apomorphy-based concepts. Then perhaps these are the cases which it will serve best. Indeed, these are the cases for which it was intended. Which is why it was proposed as a recommendation, not a rule. Again, I hope this does not seem curt. I am trying to give Dr. Moore's thoughts their due, while managing a tight schedule. Dr. Moore, no offense is meant in any way. Wagner -------------------------------------------------------------------------------- Jonathan R. Wagner, Dept. of Geosciences, TTU, Lubbock, TX 79409-1053 "Why do I sense we've picked up another pathetic lifeform?" - Obi-Wan Kenobi