[Taxacom] Insects are crustacean descendants vs. "insects ARE crustaceans"

[Kenneth Kinman]

Hi all,
       The present discussion about paraphyly reminds me of strict cladists insisting that "birds ARE dinosaurs", rather than "birds are dinosaur descendants".  I suppose they might think that they are preparing the next generation of young dinosaur lovers to support strict cladists and perhaps even become future strict cladists.

      But not all dinosaur researchers think that this is a good idea.  In his paper Origin of Birds: The Final Solution? (American Zoologist: Vol. 40, No. 4, pp. 504-512), Peter Dodson says: "For example, the word dinosaur was not previously problematic - it was universally understood. Within cladistics it has now been redefined to include birds ... and then a new and cumbersome phrase, non-avian dinosaur, has been substituted. This is not progress; this is semantic obfuscation not enlightened communication."

       I agree that it is semantic obfuscation.  Saying "Birds are dinosaurs" (instead of birds are dinosaur descendants) is  like saying "Tetrapods are sarcopterygian fish" (instead of Tetrapods are descendants of sarcopterygian fish).  Or how about "Insects are crustaceans", rather than "Insects are crustacean descendants."

       In all these cases, you would be trying to force a well-known exgroup taxon back into its mother taxon.  In other words, it is a war against paraphyletic taxa which would become glaringly absurd if applied across the board.  How about "Vertebrates are invertebrates" instead of "Vertebrates are invertebrate descendants"?
                  -----------------Ken Kinman

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