[ Another topic for comments. Please
keep the Topic number in responses.
]
Topic 3: GUIDs for Taxon Names and Taxon Concepts
Another key area in which TDWG has
recognised the need for globally unique identifiers is in connection with taxon
names and the various concepts associated with them. This issue actually
also intersects with that of identifiers for taxonomic publications.
Definitions
In the following discussion, a
“taxon name” is a scientific name string which simply identifies a
name assigned in the taxonomic literature. In many cases such a name may
have been applied in different ways by the original author and subsequent
taxonomists. Each such application of a taxon name by a taxonomist to a
set of organisms is here referred to as a “taxon concept”. An
understanding of the taxon concept adopted by a researcher is frequently
essential if data are to be interpreted correctly. In its most basic form
a “taxon concept” can be considered to be the use of a given
“taxon name” in a given “taxonomic publication”, in
other words something that could be represented as, “Agenus aspecies Author1 Year1 sec. Author2
Year2”. One possible approach to assigning identifiers
to taxon concepts would therefore be to assign identifiers to taxon names and
to taxonomic publications and to use a combination these identifiers to
identify each taxon concept.
Note that a taxon concept may be defined
at least in part by a set of assertions about the relationship between the
present concept and the concepts adopted by earlier taxonomists. In
addition it is possible for other researchers to make their own assertions
about the relationships between the concepts published by different
taxonomists. Much of the interest and value to be gained from modeling
taxonomy relates to the interpretation of these asserted relationships.
Although the distinction between taxon
names and taxon concepts may seem (over-)subtle, it is important that we should
know whether we are referring simply to a nomenclaturally valid name, quite
independently of any set of organisms to which it may be applied, or to a taxon
concept which somehow applies such a name to such a set of organisms.
Without this distinction, we will be restricted in our ability to develop biodiversity
informatics, although of course there will be many cases in which all we can
say is that a data set refers to some unspecified taxon concept associated with
a given taxon name.
Identifiers
Clearly there are many situations in which
a taxon name can itself be treated as a unique identifier without any apparent
ambiguity about which name is being referenced (e.g. Turdus merula; Poa annua),
but the existence of homonyms prevents this from being generally true.
Even when taxon names include citations of the original publications (e.g. Turdus merula Linnaeus, 1758; Poa annua L.), they can be very difficult
to compare since the form of the citations may vary greatly. Even where
there is no ambiguity about which name is being referenced, such a name does
not by itself serve to identify which associated concept is being referenced.
There are many different systems in place
for associating other identifiers with either taxon names or taxon
concepts. ITIS (http://www.itis.usda.gov/,
http://www.cbif.gc.ca/pls/itisca,
http://siit.conabio.gob.mx/) assigns
Taxonomic Serial Numbers (TSNs) to each name in its system. Other species
databases have their own identifiers for taxon concepts. Recording
schemes often have their own identifiers for taxa (e.g. Bradley and Fletcher
numbers for Lepidoptera in the
Questions
I would like therefore to ask the
following questions of any of you who use scientific names in your databases (either
taxonomic databases recording a list of taxa, or databases recording
information about taxa, specimens, observations, etc.):
As before I am looking for information on
existing practices and any requirements that would need to be accommodated
within any general system of identifiers.
Thanks,
Donald
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Donald Hobern (dhobern@gbif.org)
Programme Officer for Data Access and Database Interoperability
Global Biodiversity Information Facility Secretariat
Universitetsparken 15, DK-2100
Tel: +45-35321483
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