Paraphyly and names
SKÁLA Zdenek
skala at INCOMA.CZ
Wed Jan 30 10:48:59 CST 2002
Tom:
>Interesting that you cut out the phrase after "because", and substituted a
>later phrase that represents a consequence of the reason rather than the
>reason itself. Are you making an effort to make it sound circular? Why not
>simply consider the statement as written? If you wish to cut something, cut
>out the phrase after "- and thus"
With a pleasure. In earlier postings you have written:
Tom (28 Jan 2002):
(in response to Zdenek):
>>I would ask you once again for the meaning of the words like
>>"natural", "useful", "real" etc. Apparently you still have in mind the
>>clades - information that supports them is then "natural, useful and real"
>>isn't it?
Tom:
>Yes. I use "natural" and "real" somewhat synonomously ...
Then I am reading your statement:
>My statement is that monophyletic taxa are best becaue they are based on
>synapomorphy, and synapomorphies are the preferred basis for classification
>because they represent character states considered at their true historical
>level of generality
...that the "true historical level of generality" means to support clades. In that case your statement indeed is circular, since the "...monophyletic taxa (=clades in your own definition) are best because based on synapomorphy (=clade supporting character in your own definition)". If I am wrong, explain kindly what do you mean by the "true historical level of generality" instead.
Tom:
>Secondly, all apomorphies _are_ to be used so that we _do_ end up with as
>many taxa as clades, That is the whole point. A recognized clade is a taxon
>- that is why we call it cladistics.
>Are we all clear on this now?
Completely. You simply prefer to have 2^n-1 taxa (given n=number of species). I would only like to recall that taxonomy was (and still is, by some at least) originally intended to reduce biological diversity in a way that can be both informative and practical. To go from n entities to 2^n-1 entities can be hardly called reduction IMO. If this is really the way cladistics will proceed (which I personally doubt), I suspect that there is no room to use cladistics as a *systematics*. This is not speaking about its power in phylogeny reconstruction but phylogeny reconstruction alone can well live without taxa.
Best.
Zdenek
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