[Taxacom] taxonomic resistance? (was Re: Phylocode vs Linnean)

[Stephen Thorpe]

the basic problem here is the absurd notion that binomials have to reflect 
phylogeny, when we want/need the binomials to be stable and known, but the 
phylogeny can be highly unstable and at least in part unknowable! 


... cake and eat it too ...

Stephen



________________________________
From: Kim van der Linde <kim at kimvdlinde.com>
To: Karl Magnacca <kmagnacca at wesleyan.edu>
Cc: taxacom at mailman.nhm.ku.edu
Sent: Sun, 17 April, 2011 2:42:57 PM
Subject: Re: [Taxacom] taxonomic resistance? (was Re: Phylocode vs Linnean)



On 4/16/2011 4:42 PM, Karl Magnacca wrote:
> I don't really think that 1) providing diagnosable characters for
> the proposed genera, such that they can be separated with a
> dichotomous key, 2) being clear about exactly which species go into
> which new genus, and 3) resolving the status of ~100 species that
> aren't currently placed to species group and would be left without
> generic assignment, are either arbitrary or a particularly high
> threshold.  It's kind of basic, actually.  Anybody here disagree?

Well, lets see.

1) Drosophila is now defined as not anything else. There is no single 
characteristic that can be used in a dichotomous keys. This will be a 
lot better for the split genera.

2) That is crystal clear for the new genera.

3) This is one of those absurd demands, as genera are split all the time 
without demanding this. But more important, it is absurd to claim that 
those species won't have a generic name after a split, as they already 
do have a generic name, namely Drosophila. Unless they are actively 
moved to another genus, they will remain within Drosophila until their 
status is resolved. Furthermore, many of those species might never be 
resolved for various reasons, such as missing type species with obscure 
and ambiguous descriptions, etc., and holding any revision hostage 
because of this demand is something I never have seen except in the 
demands for the revision of the genus Drosophila.

>> Anyway, for the time being, phylocode is what rules the genus
>> Drosophila sensu lato.
>
> This is just an absurd statement.  Athough it does make a sort of
> sense, in that a few people have proposed generic names for "clades"
> that are dissociated from the species binomials (PhyloCode Art. 21),
> and are completely ignored in actual usage.

Well, you are right, it is not to the letter of phylocode, but the 
central idea that clades are defined by concept and not content, this 
holds, because the de facto definition of Drosophila is as follows:

Drosophila refers to the crown clade originating from the most recent 
common ancestor of Drosophila (originally Musca) funebris (Fabricius, 
1787) and Drosophila melanogaster Meigen, 1830. This definition is 
node-based and designates a crown clade.  Abbreviated definition: 
Drosophila = < Drosophila (originally Musca) funebris (Fabricius, 1787) 
& Drosophila melanogaster Meigen, 1830.

Call it what you want to call it, it does not change that the de facto 
used clade called Drosophila includes ten plus other genera that are 
primarily positioned within the various subgenera. Anyway, call the mess 
what you want.

Kim

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