Richard.Zander at mobot.org
Thu Dec 30 14:42:33 CST 2010
Okay, Ken. When you say x gives rise to y, then y to z, you are indeed advancing a theory of macroevolution, and you have no problem (other than whether you are right or not). This in nested parentheses may be ((a)b)c, which has no sister groups.
There may be sister-group nested parentheses for any ancestor-descendant group, like ((polarbear, brownbear1) brownbear2) ... which is the sister group relationships after cluster analysis. This is data. Evolution is not data, it is a theory. I expect you would say that one brown bear molecular line gave rise to the polar bear. This is a good evolutionary theory, and we can look for additional data to support it or find some data to falsify it. If you ALSO say the polar bear is sister to one brown bear molecular lineage, that is okay as far as it goes but it is only data.
If you want classification to be based on evolution, you should explicitly state an ancestor-descendant relationship (if you have the data to infer one, and you do with these bears) and discuss the data (the paraphyletic sister group nesting) secondarily. Using only "paraphyly" or "semi-holophyly" continues to refer to the modern practice of basing classification on unanalyzed data, not theory, which results, often, in nonsense and cripples biodiversity study.
Joe Fatch goes in the slammer when you focus on the process of evolution, and walks if you make "semi-holophyly" your primary focus, which implicitly rejects analysis of process.
Thus, I counsel NO use of the jargon of phylogenetics when discussing the use of evolution of taxa as a basis for classification. If you only have a cluster of a bunch of species, then you should classify then as an evolutionarily poorly understood group.
If anyone has a scientific theory-based alternative to my suggestions above, I'd like to hear it.
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Richard H. Zander
Missouri Botanical Garden, PO Box 299, St. Louis, MO 63166-0299 USA
Web sites: http://www.mobot.org/plantscience/resbot/ and http://www.mobot.org/plantscience/bfna/bfnamenu.htm
Modern Evolutionary Systematics Web site: http://www.mobot.org/plantscience/resbot/21EvSy.htm
From: taxacom-bounces at mailman.nhm.ku.edu [mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Kenneth Kinman
Sent: Wednesday, December 29, 2010 7:29 PM
To: taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] Phylocriminetics
I'm really trying to get past the semantics and understand exactly what you want me to do, other than stop using the "term" paraphyletic (which I agreed to do by using the more precise term
"semi-holophyletic" more consistently).
As for "sister-group triples", although extant exemplars would result in a cladogram like (Amphibia (Reptilia, Aves)), I classify them as an ancestor-descendant series: Class Amphibia giving rise to Class Reptilia, and Class Reptilia giving rise to Class Aves. I really don't see how I am letting "Joe Fatch walk"
(which makes me sound like I am as bad as strict cladists). That's why I often say "mother group" (ancestor) and its exgroup (descendant).
Class Amphibia and Class Reptilia are based on symplesiomorphies, so would it be better to call them "symplesiophyletic" taxa? I think "semi-holophyletic" sounds better (since I include exgroup markers in these taxa), and it doesn't carry the baggage that paraphyly and symplesiomorphy have been saddled with.
So my question is simple. If "paraphyletic" is an unnatural and unscientific term, what is (are) the natural and scientific term(s) that I should use for describing groups like Class
Amphibia or Class Reptilia?
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