[tdwg-content] Occurrences, Organisms, and CollectionObjects: a review

Richard Pyle deepreef at bishopmuseum.org
Thu Sep 8 23:31:17 CEST 2011

> a) I think it is not that simple. The combination of fungus and algae is
given its
> own taxonomic name, the lichen name. A lichen taxon always identifies at
> least two organisms.

It may be two "organisms", but its taxonomically homogeneous because it has
one (lichen) taxon name.  I didn't advocate that Organisms be
"phylogenetically homogenous", only "taxonomically homogeneous".  If Lichen
names are intended to represent a taxon, then I still don't see the problem.

> b) I think we very often use the main, dominant organism when recording
> mutualistic symbiosis. Most trees and many other plants die without their
> mycorrhiza. No group of oaks is taxonomically homogeneous - it is always a
> mixture of plant and fungus. We normally just know, but don't record this.
> would like to be able to keep it that way.  You can say definitions don't
> matter, I prefer to explicitly state the flexibility inside the def.

Perhaps, but maybe this is a perfect example of the difference between
"Organism" and "CollectionObject"; the former should be taxonomically
homogeneous, but the latter need not be. 

> That should not mean, that we should not record a symbiosis as two records
> where appropriate, just that there are good reasons not to force people to
> do it, because it would be at the expense of what they really want to
> achieve.

I don't think anyone is forcing anyone to do anything.  If you want to talk
about a fish as it swims through the water (or "sleeps" in a jar of
alcohol), you create a single Organism instance for it, even though there
are many symbionts physically attached to it.  If/when you need to recognize
these symbionts as individual things with their own properties (e.g.,
taxonomic identifications), you then create the necessary Organism instances
to which those properties are applied.


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