The nature of cladistics [...]

[pierre deleporte]

A 08:17 22/11/2004 -0500, Richard jensen wrote:
>pierre deleporte wrote:
>
> > No evolutionary systematicians, no phylogenies.
>
>I see this as the same kind of philosophical question as "If a tree falls in
>the forest, and no one is there to hear it, does it make any noise."
>
>IF one accepts the tenets of evolutionary theory, then phylogenies exist
>whether or not there are systematists to ponder the mysteries of the 
>proccesses
>that gave rise to them.  I would modify Pierre's statement this way "No
>evolutionary systematists, no phylogenetic hypotheses."

I could agree, provided that when you state "phylogenies exist" you mean 
"history did likely occur this way", which is perhaps a less ambiguous 
formulation. Now, your reformulation seems OK: by definition, hypotheses 
don't exist as material things, but as constructs, however scientifically 
relevant.

Effectively I don't mean at all that the successive generations didn't 
exist or that we can't reconstruct a sketch of the past history. I mean 
that the notion of a phylogeny, or a clade, is consistent in a scientist's 
brain, while individuals and populations have (and had) a proper material 
coherence out there, to the difference of clades.

We can debate of the material reality of an individual or a social group 
out there (real systems); but we better debate of the scientific 
plausibility of historical reconstructions, and of the relevance of this or 
that classification (be it phylogenetic) in a given context of use by human 
people (scientists, gardners, fishmongers, medecine-men...).

Pierre


Pierre Deleporte
CNRS UMR 6552 - Station Biologique de Paimpont
F-35380 Paimpont   FRANCE
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