[tdwg-content] New terms need resolution: "Individual"

Richard Pyle deepreef at bishopmuseum.org
Fri Jul 15 15:29:15 CEST 2011

Thanks, Régine.  You wrote:

> taxa" and "population" are set of living organisms. The two can be defined
> implicitly or explicitly

I'm not aware of anyone who has attempted to establish an extensional definition a taxon; but I can imagine both extensional and intensional definitions of populations.


> -----Original Message-----
> From: Régine Vignes Lebbe [mailto:regine.vignes_lebbe at upmc.fr]
> Sent: Friday, July 15, 2011 10:01 AM
> To: Richard Pyle
> Cc: 'Chuck Miller'; 'Gregor Hagedorn'; tdwg-content at lists.tdwg.org
> Subject: Re: [tdwg-content] New terms need resolution: "Individual"
> "explicit inclusion vs. implicit inclusion of members ". I agree it is
> fundamental. We have here the two classical definitions of a "set"
> (mathematical) :
> - extensional definition it means by the explicit list of its elements or
> instances
> - intensional definition it means by properties (implicit inclusion of the
> members having these properties)
> "taxa" and "population" are set of living organisms. The two can be defined
> implicitly or explicitly. The term "class" or "living_set" could be prefered for
> extensional definition (and "living_unit" or living_instance" for the
> members). The term "living_concept" for abstract concept with intensional
> definition.
> Régine
> Le 15/07/2011 08:52, Richard Pyle a écrit :
> > I think the key point is that “taxa” represent a set of individuals implicitly
> (i.e., a taxon definition exists without the need to define or enumerate the
> complete set of individuals contained within it); whereas the class that I think
> we need to add to DwC is one that deals with *explicitly* defined or
> enumerated members.  These sets of explicitly defined or enumerated
> members can be assigned as implicit members of a single taxon (via an
> instance of dwc:identification), but the difference, I think, is in is the explicit
> inclusion vs. implicit inclusion of members. This may seem trivial, but I believe
> it to be fundamental.
> >
> > The problem with “populations” is that they can be defined either way
> (either implicitly or explicitly).  If you think of them from the implicit
> perspective, they seem more like taxa.  If you think of them from the explicit
> perspective, they seem more like an extension of an “Organism” instance.  In
> a way, populations are the exception that proves the rule. Or….the exemplar
> that illustrates the distinction.
> >
> > Aloha,
> > Rich
> >
> >
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> --
> -----------------------------------------
> Régine Vignes Lebbe
> Laboratoire Informatique et Systématique Université Pierre et Marie Curie-
> Paris6 CR2P UMR 7207
> MNHN Département Histoire de la Terre
> Bâtiment de Géologie
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