[Taxacom] Dark taxa: GenBank in a post-taxonomic world

[Richard Zander]

That raises another point: one may have back mutations but when dealing with evolution, Dollo's Law has some cogency. I recently found Gould, S. J. 1970. Dollo on Dollo's Law: Irreversibility and the status of evolutionary Laws. J. History of Biology 3: 189-212. in a set of discarded issues of this journal. 

Gould discusses a point others have made here that Dollo's Law originally claimed that complex structures could not be re-evolved, which Gould says, and I agree, is a valid statement. Short of the idea that in an infinite universe or multiverse all things must re-occur exactly (a hellish idea), then one cannot use infinite sequence data to study evolution. (Is this metaphysics?)

 
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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



-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu [mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Curtis Clark
Sent: Wednesday, April 13, 2011 11:42 AM
To: taxacom at mailman.nhm.ku.edu
Subject: Re: [Taxacom] Dark taxa: GenBank in a post-taxonomic world

Your point about whether the set is finite or infinite is an interesting one. For it to be infinite, the rate of occurrence of novel changes (as contrasted to back-mutations to characterized states) must exceed the rate of sequencing. The latter is increasing almost exponentially, so I would expect that the curves will eventually intersect, and the set is finite. Whether that makes any difference in the near term is another matter.

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Curtis Clark
Cal Poly Pomona