[CPN] proposed revisions of Note 9.3.1

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Dear CPN members,

Kevin and I discussed the specific suggestions made by David (copied below).

1) Rather than replacing "synapomorphy" with "autapomorphy" in the wording of apomorphy-based definition, as David proposed, we think that it should be replaced with "apomorphy", and that the same change be made in the wording of the apomorphy-modified crown clade definition.  Although David is right that an apomorphy of a clade is an autapomorphy when viewed in relation to other clades (the outgroups), it is a synapomorphy of the members of the clade being named, which is why we used the term synapomorphy.  However, given that it can be viewed either way, the term "apomorphy" is clearer.

2) We agree with David's suggestion that "and" be changed to "or" in the definition of a total clade in Art. 2.2.

I am attaching a new version of the proposed changes that incorporates these new modifications.

David, thank you for your careful reading of the proposal.

Does anyone else have any comments?  Tomorrow is the day I said I would call for a vote if there was no active discussion.

Phil





On Apr 25, 2013, at 5:35 PM, David Marjanovic wrote:
> ================== 
>  
> Concrete points about the current proposal: 
>  
> I am particularly happy about the replacement of "most/least inclusive" by "largest/smallest". The former are unambigous, but sound abstract enough that -- for a long time -- they managed to confuse me anyway. 
>  
> In the proposal to change the definition of "apomorphy-based clade", replace "synapomorphy" by "autapomorphy" (twice). Hennig liked inventing terminology, and he wanted to express every possible concept in a single word made from Greek components; therefore _one_ clade has autapomorphies (auto- = "self") while _two_ sister-groups (or more in case of a hard polytomy) have synapomorphies (syn- = "together"); the synapomorphies of two sister-groups are automatically autapomorphies of the smallest clade they form together, which makes the terms redundant in many cases, but still, there they are, and one clade can't have _syn_apomorphies together with just itself. -- The use of "apomorphy" in that section is correct; that term just means "derived character state" without saying derived relative to what. 
>  
> By using "and" in strategic places, the proposal to change the last point of Article 2.2 implies that total clades must contain entire species (even if they contain other organisms in addition). In turn, this implies that there cannot be clades within a species. This is correct under Hennig's species concept, but not under whatever concepts the ancestor worshippers think they use. Simply use "or" like in the proposal to change the preceding point (the one about crown clades). 
>  
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