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cladistic wrap-up, please!



I continue to be surprised where discussions I inspire end up.  I need a 
final comment on this one in my own defense, if you don't mind, Mickey or 
Chris.  If anyone out there needs the final word, go for it, but, with 
this, I'm done.

[ As I've been saying, this is a dinosaur list, not a cladistics list,
  so if you feel compelled to respond at least try to mention
  dinosaurs a few times as Norm did.  To put that another way, let's
  try to stay reasonably on topic. -- MR ]

Wagner wrote:

>>You see, I haven't been completely assassinated yet--

>If I had wanted to assassinate you, you wouldn't be e-mailing now... :)

Please, don't flatter yourself.  :->

And:

>Once the determination of phylogeny is made, morphological distance
>adds no useful information about the phylogeny.

This is clearly true, but I'm not looking for more information about the 
phylogeny.  This point reflects the philosophical disagreement I referred 
to: what SHOULD we be doing in taxonomy?

I am introducing a term for the problem I perceive.  I will call it 
"cladistic hyper-reductionism."  You heard it here first, folks!  

Is phylogeny the only value?  It is, by definition, if we are doing 
phylogenetic taxonomy.  I just disagree that this should be the only 
consideration.  Ecology molds organisms, too; ecology is real, and it can 
make real groups.  Does that mean that we need horizontal groupings in 
place of clades?  I think not.

But it clarifies nothing to say that birds are dinosaurs.  Any child can 
see that birds are not dinosaurs.  Likewise, any child can see that 
whales are not condylarths, although they are members of the same clade.  
We have always discussed evolutionary lineages, and the dinosaur-bird 
connection has been discussed since the late 1800's.  In this sense, 
phylogenetic taxonomy has added nothing.  But making birds into 
dinosaurs--that's a new way of thinking about things that has its own 
shortcomings.  Cladistics clarifies the obscure (phylogeny).  Yet it 
attempts to obscure what is obvious even to a child (morphological 
distance).  Hence, children are not likely to be impressed by cladists 
who are "cladistic hyper-reductionists."

>However, it [morphological distance] does not point to clear groupings,
>nor does it show us what "physically exists in the world", and I eagerly 
>anticipate teh inevitable clarification of your point.

It depends on what kind of groupings you are after.  

Moreover, while I can show anybody a dinosaur or a bird, you cannot show 
anybody a clade.  I rest my case.  Well, I would, if I didn't need a few 
more rebuttal comments.

>Yes, but *groupings* of animals and plants based on diagnostic
>definitions and paraphyly are *not* real entities.

I have never said that animals and plants should be grouped solely on the 
basis of diagnostic definitions.

>NK, please re-read my last couple points, I don't want
>to clutter the list yet again. . . [snip] . .Please reread my
>posts.  If you still do not understand why a phylogenetic taxon is 
>real, see Gauthier and DeQuieroz 1990.

I am not having trouble understanding your statements or the bases of 
cladistics.

>>Even though the ancestor-descendant chain is complete,
>>there was a major discontinuity in the history of life at that
>>transition.

>Bufallo chips!  The "History of Life" as you call it is not a real
>thing.

Now there is a statement I don't understand.  The history of life is just 
as real as human history.  If the history of life isn't real, why do we 
need clades?

>No one is "defining away" a major event.  We grace that event with
>the creation of a new taxon just like traditional taxonomy.  What we 
>do not do is redefine the ancestral group because of that event. 
>Phylogenetic taxonomy covers the novelty of birds in an objective and
>even-handed way, by recongizing a new taxon.

No argument here!

>The phylogenetic taxonomicist does not re-arrange ranks (which are
>purely subjective, and have no basis in phylogney, and no 
>quantifyable, discernable basis in objective reality), nor does he 
>redefine the more inclusive clade, or remove the less inclusive from 
>the more inclusive. . .

I wouldn't want a phylogenetic taxonomist to do anything he or she 
doesn't want to do in phylogenetic taxonomy. 

>The phylogenetic relationship of birds and other dinosaurs is much 
>better represented by this system.

I never said it isn't.

>An objective system, like the cladistics, or rock classification
>(well, OK, it approaches this...), which is based on an objective 
>reality. . . 

Maybe we just need better definitions here--like, what is objective 
reality?  Is something that can be seen, measured, handled, etc. (e.g., 
morphology) objective reality, or is a conceptual organizing principle 
(e.g., common descent) objective reality? 

>In short, it is the Beverly Hills principle.

I don't know what this is.

As a final comment, were I to do a taxonomic study of any group (which I 
wouldn't, but for the sake of argument) I cannot imagine a scenario by 
which I would not use cladistics.  I have stated on several occasions 
here that I think cladistics is the greatest thing since sex.


*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Norman R. King                                       tel:  (812) 464-1794
Department of Geosciences                            fax:  (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712                      e-mail:  nking.ucs@smtp.usi.edu