[Taxacom] paraphylophobia again

[Michael Heads]

Dear colleagues,
 
A recent paper was titled "Cymbonotus (Compositae):  an endemic Australian genus embedded in a southern African clade', and yet the area phylogeny given was (Africa (Africa (Africa (Africa + Australia )))). The Australian group isn't nested in an African group, it's nested in an African and Australian one. It seems that even cladists are using paraphyletic groups now!  I suppose the authors argued this way because they wanted to downplay the significance of the Australian locality and give the impression that the Australian genus dispersed secondarily from a center of origin in  Africa . But this is not necessary based on the phylogeny. The pattern could just as easily be due to vicariance of a widespread Africa-Australia group, with the splits developing in Africa . In a similar way, the ancestor of fishes and tetrapods isn't simply fishes, it's something like (fishes + tetrapods)/2, which may have been quite a different group.  
 
Michael Heads

Wellington , New Zealand .

Wellington, New Zealand.

My papers on biogeography are at: http://tiny.cc/RiUE0

--- On Wed, 7/22/09, Richard Zander <Richard.Zander at mobot.org> wrote:


From: Richard Zander <Richard.Zander at mobot.org>
Subject: Re: [Taxacom] paraphylophobia again
To: "Curtis Clark" <jcclark-lists at earthlink.net>, taxacom at mailman.nhm.ku.edu
Date: Wednesday, July 22, 2009, 2:44 AM


Well, we all have premises, which we as typical humans defend might and
main. On the other hand, I like Dewey's (the pragmatitist) observation
that the greatest advance for human thought is the notion of
intellectual pursuit of process (as scientific theories), which ideally
has taken the place of pursuing absolutes (Truth, Beauty, Goodness,
whatever). 

Thus, premises I suppose can be minimized by redefining absolutes as
"what you do." My point is that classification by holophyly is a
premise, a criterion, a maxim. It is a way to deal with patterns in
nature. The problem is that naming a node as a taxon at the same
taxonomic level as one of the sister lineages connected to it
immediately makes the next lower lineage paraphyletic. Thus, nodes
cannot be assigned a taxon at the same level as any one of their pair of
lineages. If nodes cannot be named, then there is no real modeling or
explanation of macroevolution in phylogenetic classification. Thus,
speciation (and generation of higher taxa) is not demonstrated in
phylogenetic classification, and, more importantly, is ignored in the
"evolutionary analysis" on which the classification is based. That
analysis is powerful but limited in interpretation by strict
phylogenetic monophyly.

The premise of systematics should not be strict phylogenetic monophyly,
but instead evolutionary monophyly, which allows paraphyly to represent
a "good taxon" that generates evolutionarily another good taxon through
macroevolution. This latter premise does not contain the fatal flaw of
ignoring some evidence of evolution (ancestor-descendant relationships)
and focusing only on other evidence (sister-group relationships).

*****************************
Richard H. Zander 
Voice: 314-577-0276
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299 USA
richard.zander at mobot.org
Web sites: http://www.mobot.org/plantscience/resbot/
and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
Non-post deliveries to:
Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, MO 63110
*****************************


-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Curtis Clark
Sent: Monday, July 20, 2009 11:58 PM
To: taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] paraphylophobia again

On 2009-07-20 07:09, Richard Zander wrote:
> ...a taint of common sense...

I've been tainted with common sense for a long time, but I never get any

credit for it from those who disagree with my basic premises.

-- 
Curtis Clark                  http://www.csupomona.edu/~jcclark/
Director, I&IT Web Development                   +1 909 979 6371
University Web Coordinator, Cal Poly Pomona

_______________________________________________

Taxacom Mailing List
Taxacom at mailman.nhm.ku.edu
http://mailman.nhm.ku.edu/mailman/listinfo/taxacom

The Taxacom archive going back to 1992 may be searched with either of
these methods:

(1) http://taxacom.markmail.org

Or (2) a Google search specified as:
site:mailman.nhm.ku.edu/pipermail/taxacom  your search terms here

_______________________________________________

Taxacom Mailing List
Taxacom at mailman.nhm.ku.edu
http://mailman.nhm.ku.edu/mailman/listinfo/taxacom

The Taxacom archive going back to 1992 may be searched with either of these methods:

(1) http://taxacom.markmail.org

Or (2) a Google search specified as:  site:mailman.nhm.ku.edu/pipermail/taxacom  your search terms here