[CPN] PLEASE VOTE on CBM-related proposals

[Cantino, Philip]

I have not had time to think carefully about David's comments.  At this point, proposals 1, 3, 4, 5, 6, 8, 9, and 10 have been approved by the majority of the CPN, and proposal 7 (deletion of Rec. 11.4B) was rejected in an earlier vote.  However, we may want to reconsider proposal 9 in light of the issues David has raised.  I will respond to David's comments in a few days after I have time to think about them more. 

Item 2 (revision of Art. 21) and the glossary definition of "taxon" still remain to be considered after we revisit proposal 9, and Kevin and I have materials ready to send you on both of these remaining items.  

Phil


On Nov 6, 2012, at 4:33 PM, David Marjanovic wrote:

> I am really sorry that I wasn't able to reply earlier. It turns out that 
> items 9 and 10 require more discussion than we've had over them -- and 
> now almost everybody has already voted. Here is my ballot:
> 
> 1) approve
> 3) approve
> 4) approve (I actually prefer "taxonomic rank" over "categorical rank" 
> because I think the former has a little less potential for confusion, 
> but that potential is low anyway)
> 5) approve
> 6) approve
> 8) approve (see 4; and I'm actually unhappy with "scientific name", 
> seeing as nomenclature isn't science, but I don't have a better idea!)
> 9) I disagree with the justification and, somewhat independently, with 
> the proposal. The apparent contradiction in the current wording of Note 
> 11.1.1, pointed out in the justification, actually allows for naming 
> clades that overlap with species rather than containing them entirely. 
> Under at least some species concepts, this has no problem happening. The 
> potential example that comes to mind are the famous teleost fishes from 
> somewhere in Central America (I forgot all details) that have a 
> phylogenetic tree as follows, where each letter stands for the 
> population of one river (or river system or something):
> 
> --+--A
>   `--+--B
>      `--+--C
>         `--+--D
>            `--E
> 
> (In case your e-mail reader removes the leading spaces, this is a Hennig 
> comb.)
> 
> Now, A and E can interbreed, making them the same species under one of 
> the Biological Species Concepts. B, C and D, however, cannot interbreed 
> either with each other or with A or E! Under the BSC in question, we are 
> thus dealing with a triply paraphyletic species.
> 
> Now suppose somebody wants to name the clade (CDE), and suppose it is 
> not known that A and E can interbreed, so that everybody agrees that E 
> is a distinct species. Further suppose that this species is used as a 
> specifier in the definition. What happens when it is discovered that A 
> and E can interbreed?
> 
> Under the current wording of Note 11.1.1, nothing happens; the type of E 
> remains the implicit specifier even if the name of A has priority over 
> that of E, so that the definition continues to apply to (CDE).
> 
> Under the proposed wording, A becomes part of the specifier. If the 
> definition is node-based or apomorphy-based, it suddenly applies to 
> (ABCDE) instead of (CDE). If it is branch-based with B or C as an 
> external specifier, it self-destructs -- it ceases to apply to any 
> clade, and the name is lost (for the time being).
> 
> ...But all this is only true for people who happen to accept this 
> particular species concept. To people who use, say, any Phylogenetic 
> Species Concept, the whole synonymization of A and E never happened in 
> the first place. Consequently, _different people will use the same name 
> for different clades even though they agree on the phylogeny_. To 
> prevent _exactly this_ from ever happening is the first and foremost 
> purpose of the PhyloCode. We cannot make the application of definitions 
> dependent on species concepts. The only way I can see of preventing this 
> is to use only specimens as specifiers, explicitly or implicitly.
> 
> The use of implicit specifiers, and here we get back to the apparent 
> contradiction, looks silly at first (though see below!), but I think 
> it's the best option in some (OK, a few) cases -- those where the type 
> specimen isn't actually what people have in mind when they use the 
> species name that's attached to it, so that eventually the responsible 
> commission of the rank-based code in question steps in and declares a 
> neotype. The example that comes to mind is the dinosaur *Coelophysis 
> bauri*. The original type series (syntypes, IIRC), found and described 
> in the mid-late 19th century, are a few isolated incomplete bones; *C. 
> bauri* became extremely well known to scientists and the general public 
> when a large number of complete skeletons were found at another site and 
> stratigraphic level in the early-mid 20th century. Those skeletons, in 
> particular the famous plate with AMNH 7223 and 7224, is what people have 
> been de facto using as the type when comparing specimens from elsewhere 
> to *C. bauri*. A few years ago it turned out that the original types are 
> only diagnostic to Coelophysidae or Coelophysoidea or something. 
> Normally, *C. bauri* would have become a nomen dubium, and a new name 
> would have had to be created for the complete skeletons, massively 
> disrupting continuity of usage. Instead, following a petition, the ICZN 
> made AMNH 7224 the neotype, and everyone is happy. In such cases, the 
> implicit specifier designated by a species name should shift, too.
> 
> The same holds for species names that lack types at present: the 
> implicit specifiers that they designate should be whatever their 
> _future_ type specimens will be.
> 
> The justification continues: "Some PhyloCode users who believe the 
> species is nothing more than a Linnaean rank may not like this change, 
> but it shouldn't matter to them because they don't intend to use species 
> as specifiers anyway.  They have the option of explicitly using type 
> specimens rather than species as specifiers, in which case the specimen 
> is truly the specifier (see proposed change #10 below)." But that's not 
> true. Whether species or specimens are the specifiers of a particular 
> definition would, under the proposed wording, depend on the definition, 
> not on the user! Under the current wording, all specifiers are 
> (implicitly or explicitly) specimens.
> 
> Implicit specifiers are not new to the PhyloCode. It expressedly allows 
> branch-modified and apomorphy-modified node-based definitions; their 
> specifiers are all members, known or unknown, of another clade that is 
> described by another definition.
> 
> 10) I would approve if "explicitly" were inserted near the beginning: 
> "When a type specimen is explicitly used as a specifier," that should be 
> taken as meaning that the authors really want that specimen to be a 
> specifier, future neotypes be damned. -- As explained above, I disagree 
> with the justification; but that's not actually relevant.
> 
> If my line of argumentation is accepted, it might be a good idea to 
> write a Note about implicit vs. explicit specifiers to make sure authors 
> will understand that both options exist and that the choice is theirs.
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