[Taxacom] On genera, splitting and ranking

Frank.Krell at dmns.org Frank.Krell at dmns.org
Sat Jul 13 09:38:53 CDT 2013

"Yes, Hennig once did propose a testable criterion for rank, that is, age of origin. However, everyone, including Hennig himself, rejected that criterion."

Chris, would you remind me where he did so? I just cannot remember that he did, but it is long ago that I read all his theoretical works (in German).

"Age is a wonderful and scientific criterion for rank. If we had such, then we could easily propose that higher Diptera (Cyclorrhapha, a suborder) is the same as birds (Aves, a Class) and far more diverse [Yes, the little creatures with narrow specialization generate more species, than larger more generalized predators, etc.]. But these kinds of scientific questions are not now possible due to the distorted system of classification we have and used."

Isn't it amazing that a clear and useful criterion, probably the only phylogenetically justifiable criterion to define rank meets with so much resistance, rendering comparisons beyond one's small research domain so difficult?
Tradition (Aves is a class, Scarabaeidae is a family) is so much more important for emotionally heavily invested scientists than scientific reasoning.

And, of course, we have many paraphyletic species, but we should not have paraphyletic higher taxa. There is no reason to let the pendulum swing back to pre-hennigian times.


Dr. Frank-T. Krell
Curator of Entomology 
Commissioner, International Commission on Zoological Nomenclature
Chair, ICZN ZooBank Committee
Department of Zoology 
Denver Museum of Nature & Science 
2001 Colorado Boulevard 
Denver, CO 80205-5798 USA 
Frank.Krell at dmns.org 
Phone: (+1) (303) 370-8244 
Fax: (+1) (303) 331-6492 
lab page: http://www.dmns.org/krell-lab
The Denver Museum of Nature & Science aspires to create a community of critical thinkers who understand the lessons of the past and act as responsible stewards of the future.

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