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RE: Cladospeak: Bonnan errata and corrections
> From: email@example.com [mailto:firstname.lastname@example.org]On Behalf Of
> Well, indirectly. Groups are now >defined< in terms of phyletic
> relationships, e.g., common ancestor of x and y plus all its descendants
> (node group) or all organisms more closely related to x than to y (stem
> group). Once a group is defined, the problem is to figure out
> whether a given
> organism is in the group or out of the group, and that's where
> the characters
> come in.
> I support this method of doing taxonomy, although it has not yet
> been taken
> to its logical conclusion in many instances (e.g., accepting Peter Ax's
> definition of stem-group birds as including dinosaurs).
Actually, your example is not necessarily the "logical conclusion". There
would be nothing programmatically incorrect with regards to such a
definition, save for the fact that there already are precedants and
priorities set for the stem-group of birds and everything closer to them
than to crocs; for the name "Aves" and "Avialae" and "Neornithes"; and for
That is to say, the logical conclusion is to give formal phylogenetic
definitions to taxon names; it is not neccessarily to give a stem-based
definition for all well-loved, well-known names.
Thomas R. Holtz, Jr.
Department of Geology Director, Earth, Life & Time Program
University of Maryland College Park Scholars
College Park, MD 20742
Phone: 301-405-4084 Email: email@example.com
Fax (Geol): 301-314-9661 Fax (CPS-ELT): 301-405-0796