Fwd: Re: [TAXACOM] Inadequacy of cladistics

John Grehan jgrehan at SCIENCEBUFF.ORG
Fri Jan 23 14:36:37 CST 2004


>Date: Fri, 23 Jan 2004 14:36:22 -0500
>To: "Thomas G. Lammers" <lammers at VAXA.CIS.UWOSH.EDU>
>From: John Grehan <jgrehan at sciencebuff.org>
>Subject: Re: [TAXACOM] Inadequacy of cladistics
>
>Thomas Lammers wrote:
>
>>Evolution is NOT perpetually dichotomous.  In plants at least, there is a
>>great deal of reticulation.  Paraphyly is real; a parental population does
>>not speciate when it gives rise to a daughter species.  Etc.
>
>I would be interested to know how this may invalidate cladistics in that
>the cladistic method does not require evolution to be perpetually
>dichotomous. Dichotomies are just the greatest amount of resolution
>possible in making statements about character relationships. I am also not
>aware that I have to take a position on speciation or not of a 'parental
>population' simply from a cladistic application. The argument could go
>either way no matter what the systematic method.
>
>>Since the early years of the 20th century, we have learned a great deal
>>about the complex array of diverse biological phenomena by which species
>>come into existence.  With cladistics, we have chucked all that out the
>>window and chosen to represent it by a gross oversimplification of the
>>process.  Those pretty stick figures are utterly detached from the complex
>>reality they purport to represent.
>
>It would seem to me that all systematic renditions are just as 'detached'
>as gross oversimplification and as a biogeographer I could say even more
>so in that systematics is usually form systematics (i.e. homologies are
>biological homologies rather than spatiotemporal homologies). And then all
>phylogenetic arrangements are just metaphorical representations of
>'reality' (itself another metaphor).
>
>>Cladograms may be objective, testable, and repeatable, but if the procedure
>>by which they are created IGNORES underlying biological reality, they are
>>(pardon the horribly mixed metaphor) a house of cards with feet of clay,
>>built on sand.
>
>I would agree with that as I would with any systematic method. Personally
>I regard all systematic methods as providing phylogeny for characters
>rather than taxa (and thus biogeography is really character geography).
>
>John Grehan
>
>
>Dr. John Grehan
>Director of Science and Collections
>Buffalo Museum of Science
>1020 Humboldt Parkway
>Buffalo, New York 14211-1293
>Voice 716-896-5200 x372
>Fax 716-897-6723
>jgrehan at sciencebuff.org
>http://www.sciencebuff.org/biogeography/Panbiogeography/Panbiogeography-Gate.htm
>http://www.sciencebuff.org/HepialidaeGate.htm

Dr. John Grehan
Director of Science and Collections
Buffalo Museum of Science
1020 Humboldt Parkway
Buffalo, New York 14211-1293
Voice 716-896-5200 x372
Fax 716-897-6723
jgrehan at sciencebuff.org
http://www.sciencebuff.org/biogeography/Panbiogeography/Panbiogeography-Gate.htm
http://www.sciencebuff.org/HepialidaeGate.htm




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