[Taxacom] Morphological characters was New lizard species

[Doug Yanega]

Jason Mate wrote:

>Dear Fred, your argument assumes that only morphological differences 
>can define species; alas there are numerous examples that prove this 
>argument fallacious. Off the top of my head, the A. gambiae complex. 
>I cannot defend nor criticize the paper that spurred the whole 
>argument in the first place since I don´t have access to a copy but 
>even assuming that it is truly "rubbish", one example doesn´t set a 
>rule. In the end molecular data will become part of the tool-kit of 
>taxonomists. That doesn´t mean that I endorse Phylocode. However 
>their strengths lie precisely in the Code´s weaknesses and this 
>thread is a good example that maybe some changes might be necessary 
>to accomodate the shifting reality "out there". Since we have 
>several commisioners following this thread they could suggest 
>something?

I'm not sure that there is anything needed here in the way of 
suggestions, as this is a false dichotomy. Let me illustrate my point:

Consider the following possible diagnoses:

(1) Taxon X is diagnosable by its possession of "AT" in the 16th & 
17th codon positions of the "eyeless" gene, where all known congeners 
possess "CC" or "CG" at these positions.

(2) Taxon X is genetically different from taxon Y.

Example #1, while purely molecular in nature, is a perfectly 
code-compliant diagnosis, and - other things being equal - would 
suffice to make a taxon name available. Example #2 is NOT a 
code-compliant diagnosis, and is precisely analogous to the present 
example. Significantly, example #2 is not unavailable because it is 
based on molecular data, but because it does not state in words what 
the "diagnostic molecules" actually ARE. Stephen seems to be of the 
belief that the present case is simply a matter of how ones defines a 
"character", and it is not *just* about that. The Code Article in 
question reads "accompanied by a description or definition that 
STATES in words..." - and I emphasize the word "states" here because 
that is where the primary failure here lies. The purportedly 
diagnostic characters HAVE NOT BEEN STATED in the description.

Note that neither example lives or dies on the basis of the perceived 
validity of the taxonomy, which is purely subjective; this is 
strictly a matter of whether the description complies with the 
nomenclatural rules, and example #2 fails the test for exactly the 
same reason the lizard descriptions fail. Other diagnoses which would 
fail would be things like:

(3) Taxon X is diagnosable by being all individuals below node Y in 
our cladogram.

(4) Taxon X is diagnosable by its being the sister to taxon Y in our analysis.

(5) Taxon X is diagnosable by being called "purumbe" by the local 
villagers, while taxon Y is referred to as "sasambe".

(6) Taxon X is diagnosable by virtue of my liking this species, while 
I dislike its congeners.

A dedicated pedant might insist that these are "attributes of 
organisms" and therefore "characters", but they are not. A position 
on a cladogram is NOT a character, nor is the name given to an 
organism, nor one's opinions about an organism. They are all purely 
subjective.

Sincerely,
-- 

Doug Yanega        Dept. of Entomology         Entomology Research Museum
Univ. of California, Riverside, CA 92521-0314        skype: dyanega
phone: (951) 827-4315 (standard disclaimer: opinions are mine, not UCR's)
              http://cache.ucr.edu/~heraty/yanega.html
   "There are some enterprises in which a careful disorderliness
         is the true method" - Herman Melville, Moby Dick, Chap. 82