NT & modern cladistics

Don.Colless at CSIRO.AU Don.Colless at CSIRO.AU
Mon Apr 21 14:43:01 CDT 2003

Chris Thompson has it dead right; and despite rumours to the contrary, I
have never opposed the reconstruction of phylogenies - only the hubris
that often attends the process. And the insistence that classification
should be based on a one-to-one mapping on the hierarchy displayed in
some phylogeny.  

After years wondering just how one could really accept any one such
reconstruction, I now believe that a process like Hennig's (as described
by Chris) is about right. As in all science we have to base conclusions
(which are always hypotheses and to some degree tentative) on a set of
"basic facts". And that set can only be chosen by a process that is
largely informed by judicious, well-trained intuition. Our current
problem is, that we don't yet (or no longer) have a "college" of wise
men to judge those intuitions.

There is a current fashion to refer to phylogenies as "hypotheses"
(simpliciter), without any reference to the (even qualitative)
credibility that must attach to an hypothesis if it is to be of any use.
This is nonsense, and evading the basic responsibility.

I should, I suppose, admit to being a dipterist, once an amiable
correspondent with Willi Hennig, and a good friend of Lars Brundin.

      Don Colless       
      CSIRO Div of Entomology,
      GPO Box 2600, Canberra, ACT, 2601,
      Tel: 02-62464270,
      Email: don.colless at csiro.au
      Tuz li munz est miens envirun


> -----Original Message-----
> From: christian thompson [mailto:cthompson at SEL.BARC.USDA.GOV] 
> Sent: Thursday, 17 April 2003 12:35 AM
> Subject: NT & modern cladistics
> Dick, Don, et alia, are right when they say, to quote Dick:
> "Despite wishes to the contrary, modern cladistics is
> an outgrowth of NT."
> Everyone one should know that Steve Farris started off in the 
> NT group and only later switch over the emerging American 
> Museum school of "cladisitcs," etc.  And thus was born 
> "phenetic cladistics."
> What has really been lost today is what Willi Hennig was 
> really all about. As working dipterist, I can tell you what 
> Hennig really did was produce "Argumentation Schemes," not 
> cladograms, etc. There was nothing about "modern cladistics" 
> where you take the "total evidence," following parsimony, run 
> everything thru a computer and produce the best answer, which 
> for insects and their allies as published in Nature last year 
> showed that Hennig's flies where the sister-group to 
> barnacles! [Darwin's group!]
> Hennig studied diverse "character systems," such as wing 
> venation, immature stages, male genitalia, etc., and look at 
> a broad range of exemplars, including fossils, as well as 
> looking at distribution
> (geographic) patterns. From all these sources of information 
> he developed his hypotheses, basing them on character 
> evidence as he saw it. Yes, selective character evidence. If 
> some molecular sequences put Drosophila with the barnacles, 
> he would have ignored them.
> Fortunately Willi Hennig died young and, thus, unlike Ernst 
> Mayr, did not have to suffer to see his Science and Name corrupted.
> Oh, well ...
> F. Christian Thompson
> Systematic Entomology Lab., USDA
> c/o Smithsonian Institution
> MRC-0169 NHB
> PO Box 37012
> Washington, DC 20013-7012
> (202) 382-1800 voice
> (202) 786-9422 FAX
> cthompso at sel.barc.usda.gov e-mail
> www.diptera.org  web site

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