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>Mickey Rowe (rowe@lepomis.psych.upenn.edu) writes: >> >>... >> >>Although I'm no fan of taxonomic ranks, I think "fundamentally flawed" >>is a bit harsh. It's important to take liberal doses of salt with all >>conclusions based upon such an "artificial" analysis, but aside from >>using other taxonomic ranks (as is being done), I don't see how else >>to approach the subject about which Benton wrote. If your imagination >>is fertile enough to provide alternative strategies, I'd love to see >>them! > >Clades, rather than "families" (or members of any other formal rank of >canonical systematics), should be the unit of analysis. > >A very good start would be to sort the "families" of conventional taxonomy >into those taxa that are founded on the basis of "magnitude-of-difference" >criteria (recognizable by statements with the general form, "Taxon <a> is >_so different_ from Taxon <b> that I regard it as a <name of category>) from >those that are based on the presence of evolutionary novelties. (A third >category -- the largest? -- might be "we don't know why we call it a family, >but everybody else does....") This ignores perhaps the most common type of fossil family - those based on presence of some evolutionary novelties combined with absence of others - i.e. rigorously definable paraphyletic groups. For a database such as Benton's this type of taxon is probably essential as it is for most purposes of communication when dealing with fossils (to put it another way fish may not form a clade but that is no reason not to examine their biogeography). ----------------------------- Dr. Jeremy R. Young Tel: +44 (0)171 938 8996 Palaeontology Dept. Fax: +44 (0)171 938 9277 The Natural History Museum INTERNET: jy@nhm.ac.uk LONDON, SW7 5BD, UK E-Mail Program used: Eudora
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