Re: seeking clarification on the cladism debate (RE: hidden "cladistic" ranks)

["Ken Kinman" <kinman@hotmail.com>]

    If I understand David's question correctly (about "setting points" 
along a phylogeny), this is precisely what I do in my classifications.  I do 
try to minimize the use of paraphyletic groups, cutting the Tree of Life at 
only certain strategic "points" which are very biological significant (and 
which often have long histories in the biological literature, thus promoting 
some degree of continuity and relative stability when possible).
     At such a "re-setting" point, a divergent and rapidly evolving taxon 
is bumped up a rank (sometimes even more than one rank).  In my dinosaur 
classification, Family Dromaeosauridae is presently coded as sister group to 
Class Aves (the latter having thus been "promoted" by two ranks).  This 
two-rank jump is shown by two separate {{Aves}} markers:  (1) one at family 
level (coded as sister group to Dromaeosauridae) within the classification 
of Order Saurischiformes; and (2) one at order level (within Class Reptilia) 
just after Saurischiformes, coded to show that Class Aves has been 
paraphyletically removed from Order Saurischiformes (and thus has a sister 
group within it), and therefore from Class Reptilia as well.
    This kind of cross-referencing system thus renders paraphyletic groups 
informationally "complete", by adding a marker for the "exgroup" which has 
been promoted to higher rank.  Since "markered" taxa are no longer 
incomplete in informationally terms, I call them semi-paraphyletic (or 
sometimes call them "semi-holophyletic" to try and make it more palatable to 
strict cladists).
     Thus unlike traditional "eclectic" classifications, paraphyletic 
groups are clearly marked as such, and sister group information is retained. 
 And it does this without the adverse "side-effects" of purely cladistic 
classifications (e.g., multiplicity of names, hierarchical instability, lack 
of anagenetic information, and decreases in utility).  In many ways, we can 
have our cake and eat it too (i.e. get the best of both cladistic and 
traditional approaches), and avoid many of the drawbacks of both.  The 
Kinman System is therefore more synergistic than a mere compromise (and it 
certainly is not like being half pregnant, which is something I hear all too 
often).
      I therefore completely disagree with Mike's statement that nesting a 
higher ranked taxon in one of lower rank renders such ranks meaningless.  On 
the contrary, it is a more efficient and stable way of reflecting the 
punctuated-equilibrium irregularities of evolutionary history, particularly 
those which are magnified by mass extinctions.  No classification can truly 
be devoid of subjectivity, but we can certainly try to minimize such 
subjectivity.  Instead of eliminating subjectivity, "strictly" cladistic 
classifications unfortunately just substitute new forms of subjectivity for 
the old (and it comes at a very high price-----as the side-effects mentioned 
above attest).
         ----------Ken Kinman
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David Elliott wrote:
> > Has the idea of setting points along phylogenies where the ranks are 
> "reset" been discussed?

Mike Keesey responded:
> That would undermine the entire concept of an absolute rank. A taxon with a 
> lower level rank (e.g. Ordo Saurischia) should never include a taxon with a 
> higher level rank (e.g. Classis Aves). If it can, then the ranks are 
> rendered even more meaningless than before.
>
> Furthermore, picking these points would be an entirely subjective practice, 
> without any scientific principle to back it up.

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