[Taxacom] Usefulness vs convenience (Protista)
Richard.Zander at mobot.org
Tue Dec 21 13:23:58 CST 2010
Okay, Ken: By mish-mash I meant that, because nobody involved in the present discussion is a pure ideologue, we mix phylogeny-speak with evolution-speak. In one sentence one of us may say "((ab)c)" and in the next "b is a peripatric puppy". It is totally true that phylogenetic clustering is valuable information, but the apple vs orange occurs when the interpretation of the cluster nesting ENDS in classification versus when the interpretation of a theory from the cluster (when one is available, which it often is) ends in classification. We use the highly supported cluster pattern when it is important to emphasize the high support, rocket science, and sneak in theory when no phylogeneticist higher on the social scale is looking.
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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: Monday, December 20, 2010 9:35 PM
To: taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] Usefulness vs convenience (Protista)
You seem to be saying that my classifications (like the one for Kingdom Protista) are like a "mish-mash of apples and oranges", and if so, could you clarify what you mean by mish-mash? Using words more precise than mish-mash, how would you characterize such eclectic classifications. Unnatural? or Natural (but arbitrary)?, or some other combination of adjectives?
As for a paraphyletic group being merely a synchronic (present-day) view, and I'm not sure I would totally agree with that, I don't think this is that big of a problem (especially for higher ranked paraphyletic taxa). The 5 generally-recognized Kingdoms of life were well-established and fairly well-diversified by the beginning of the Carboniferous, so if I were living then instead of now, I would have still recognized a paraphyletic Kingdom Protista with three exgroup Kingdoms. The youngest Kingdom (Metaphyta) would have been less diverse than today (since angiosperms hadn't evolved), but it would have still been diverse enough to merit 3 phyla (Bryophyta, Pteridophyta, and Spermatophyta), and the fourth Phylum Magnoliophyta (angiosperms) would have been rather diverse by the Cretaceous.
And Classes Mammalia and Aves were already fairly diverse by the end of the Cretaceous, so a paraphyletic Reptilia was already justifiable by that point. Of course, much of the diversity of Mammalia and Aves at that time has not yet been found in the fossil record, and much of that diversity was wiped out by the end-Cretaceous extinction, with the surviving taxa reradiating into new taxa in the Paleocene and Eocene. Aves is younger than Mammalia, but still had a lot of enantiornithean-type diversity in the Cretaceous (which then went extinct, and replaced by a radiation of the neornithine survivors in Paleocene and Eocene).
So I don't think one is being merely synchronic (present-day view only) if the exgroups to Kingdom Protista were diverse by the beginning of the Carboniferous and the exgroups to Class Reptilia were diverse by the Cretaceous. Or perhaps I am misinterpreting what you meant that paraphyletic taxa are synchronic (present-day only)?
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