[Taxacom] Phylogenetic classification? (and a masterpiece by Knox)

[Kirk Fitzhugh]

Cladistics is a process of inferring phylogenetic hypotheses, not assessing them. The latter lies in the realm of hypothesis testing, which is wholly separate from the activity of inferring hypotheses and rarely ever correctly performed (testing, that is) when it comes to phylogenetic hypotheses. As such, any desire for stability is a useless dream. Stability is a hallmark of the track record of testing. To wit, to invoke the notion of truth is contingent on two things: knowing what theory of truth (of which there are about six) you're applying and presenting the confirming test evidence that is the basis for asserting such (always ephemeral) truth.

I'm always amused by the defenses and critiques of 'cladistics.' Most of them are founded on misunderstandings of how science actually operates.

Kirk

-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu on behalf of Stephen Thorpe
Sent: Sun 7/26/2009 8:38 PM
To: lammers at uwosh.edu
Cc: taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] Phylogenetic classification? (and a masterpiece by Knox)
 
There is nothing intrinsically wrong with phylogenetic (cladistc)  
classification - it is just that although it solves some problems, it  
creates others (cake and eat it syndrome!) It solves the problem of  
instability due to subjectivity, but instead creates instability due  
to incompleteness of data. I guess the HOPE is that one day, data will  
be complete, so it is temporary instability (that's the theory,  
anyway!) Furthermore, the really BIG evil of phylogenetics is that it  
has become a bandwagon which has taken over and pushed taxonomy to the  
sidelines, outcompeting it for funding (new toy syndrome!) Someone of  
note in the taxonomic world recently told me that he turned his back  
on phylogenetics for the reason that 90+% of all the species that have  
ever lived are extinct and unlikely to be found as fossils (or if  
found as fossils, then unlikely to be informative enough to be  
useful). With so much missing information, data will never be even  
remotely complete. Also, my worry, though I'm not really up on the  
relevant details, is that I haven't seen a proof that cladistic  
methodology is even likely to uncover the evolutionary truth.  
Objectivity alone doesn't imply truth: let's all follow an algorithm  
so that the outputs depend only on the inputs and not on who is doing  
it. Great, we all get the same answer - but, er, is it the truth????

S