names & numbers
dyanega at POP.UCR.EDU
Mon Oct 15 09:59:31 CDT 2001
Richard Pyle wrote:
>To do it right, you only need two separate entities: NAMES, and ASSERTIONS
>(=circumscriptions). Everything you enter into the database is OBJECTIVE -
>no opinions by the data gatherers required. If ITIS or some other agency
>wants to select one particular taxonomy, then they need only designate one
>assertion record for each name record to serve as the "current" or "correct"
>circumscription of that name. From a data concept perspective, it's pretty
>straightforward. The real work is in trudging through all those
>publications to capture all those taxonomic assertions in electronic form.
>Incidentally, you need not restrict it to just "published" references. Any
>identification of a Museum specimen can serve as an assertion, just as any
>unpublished pers. comm. from an expert.
I don't think this claim applies to higher classification, however:
most people have databases designed in a strict "parent:child"
hierarchy. If taxon X belongs to subfamily Y of family Z in one
classification, and to tribe A of subfamily B of family C in another,
you have VERY different parent:child links all leading down to the
same terminal taxon. If anything, this sort of variant supra-generic
classification is probably *more* common (in terms of numbers of
species involved) than disagreement about species and genus placement.
Maybe others here will see a simple workaround to accommodate it, but
I don't - it's an extremely complex thing to do. I think it
necessitates a disassociation of the terminal taxa and the
alternative hierarchies within the data (in other words, taxa are
stored *without* being classified, and the phylogenies are stored as
separate data sets, so you only get the computer to spit out a
classification for a taxon after you choose which phylogeny you wish
to view), OR, you stick with the default, reliance on a single
classification. Right now, *all* the major on-line databases,
including ITIS, choose the latter option; a single, invariant higher
classification. You can't have a child link to two different parents,
so ITIS will presumably *never* be able to designate alternative
classifications above the terminal taxa - unless they radically
change their data structure.
Doug Yanega Dept. of Entomology Entomology Research Museum
Univ. of California - Riverside, Riverside, CA 92521
phone: (909) 787-4315 (standard disclaimer: opinions are mine, not UCR's)
"There are some enterprises in which a careful disorderliness
is the true method" - Herman Melville, Moby Dick, Chap. 82
More information about the Taxacom