[Taxacom] Why stability?

Stephen Thorpe stephen_thorpe at yahoo.co.nz
Wed Apr 29 16:54:34 CDT 2015

There are some potential problems arising from this example. Suppose somebody today wants information about Quercus grisea. We immediately face complication (A): Is there a single uncontroversial concept (today) for Q. grisea. If so, then all is well (so far). If not, then things become more complicated. Competing concepts for the same taxon tend to arise at different times, so one needs to know if the later one uncontroversially replaces earlier ones, or else sits in competition with it. You seem to have assumed the former in your example. Complication (B): Although it certainly helps to know if and how a concept has changed, it may just be a drop in the ocean. Incorrect information about a taxon possibly results far more from misidentified specimens, particularly for taxa that have been mentioned by many authors. Without tracking and checking vouchers (if they exist, and if they are accessible), there is no way to solve this problem. But, if all you
 want is descriptive taxonomic information, then this might not be a problem. But if you want specimen data (or summary data thereof), then this is likely to be a significant problem.


On Thu, 30/4/15, Nico Franz <nico.franz at asu.edu> wrote:

 Subject: Re: [Taxacom] Why stability?
 To: "TAXACOM" <taxacom at mailman.nhm.ku.edu>
 Received: Thursday, 30 April, 2015, 9:26 AM
 Hi Peter:
    I hope I can
 address this. Mind you the general notions have been
 in the TDWG community since at least
 the early 1990s.
    Let's make it somewhat
 concrete (more abstract = easier to keep
    SEINet currently displays two
 circumscriptions that are labeled with the
 name Quercus grisea:
    That would be,
 more granularly identified:
 Taxonomic concept label 1: Quercus grisea sec.
 FNA (1997, Nixon)
 Taxonomic concept label 2:
 Quercus grisea sec. VPAP (1993, Landrum)
    With that kind of identifier
 granularity, we can express the following:
 is_included_in 1993.Quercus_grisea
 1997.Quercus_grisea is_included_in
    The 1993 classification
 recognizes more narrowly circumscribed concepts.
 Two non-congruent theories of what the name
 Quercus grisea refers to are in
 play. Others
 might be added in the future. It might well be that in
 case synonymy can account for the
 different degrees in resolution. In other
 cases it cannot:
    SEINet currently
 returns 1349 records for the search term "Quercus
 arizonica". And 1324 specimens for
 "Quercus grisea". I would guess that
 some of the latter 1324 specimens are also
 validly identifiable to Quercus
 arizona sec.
 VPAP (1993), whereas others are not.
    A query that uses taxonomic
 concept labels just looks like this:
 Show all specimens for Quercus grisea sec. FNA
 (1997, Nixon). => More
 specimens, wider
 or more dense distribution.
 Show all
 specimens for Quercus grisea sec. VPAP (1993, Landrum).
 => Fewer
 specimens, narrower or less
 dense distribution.
    So "Quercus grisea"
 produces two non-identical distributions maps in a
 system that handles concept-level resolution.
 This requires that the
 specimens are
 identified to the concept level in the system.
 Best, Nico
 On Wed, Apr 29, 2015 at 1:20 PM, Peter
 Hovenkamp <phovenkamp at casema.nl>
 > I still
 wonder (and that was the main question in my previous post)
 > anyone will be able to select, for
 any particular query on such a database,
 > the concept that is to be used in the
 query. Do you envisage "concepts of
 > concepts", allowing a querier to
 limit the query to at least a subset of
 concepts? Or what?
 > Peter
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