Perhaps it's better to take one step back further, and enumerate a variety
of
example instances of biological entities that we all agree should be in
the
class, and a contrary enumeration of example biological entities that we
all
agree should not be in the class. If you include less obvious and possibly controversial ones in these lists, it may help to narrow down what the differentiating criteria really are. And while this exercise may sound
trivial, it
hasn't been done yet as far as I'm aware, and from a number of the posts
in
this thread I sense that there is actually not consensus on which side of
the
divider the border-cases go. And you can't hope for consensus on the label (or the definition) if there isn't first consensus on how we want the
instances
classified.
I agree with Hilmar on this approach.
Just to throw in an example, I might argue that at least some organelles should actually be among the biological entities included in the class.
Some
organelles have their own genome and evolutionary history, and were once independent organisms. If we accept this, then we might say that
biological
entities to be included have a genome or a pool of genomes with a (shared
in
the case of a pool) evolutionary history, and those to be excluded do not. This would exclude vacuoles from the class, but include plastids, viruses, cows, and buffalo herds.
This *might* be close to what my own vision of how to establish the criteria for things to include within this class. But following Himar's suggestion, I will try to list some things that I think may be useful to represent as instances of this class.
I'll start with the entities that most of us probably agree with:
- A single whole-organism specimen curated and preserved at a Museum - A single whole organism (whale, wolf, buffalo, tree, insect, etc.) documented in nature - A single, cohesive colonial organism (e.g., coral head), either preserved in a Museum, or documented in nature
Now some well-enumerated aggregates:
- A single "lot" of multiple whole-organism specimens of the same taxon curated and preserved at a Museum - A well-defined and enumerated set of whole organisms (pod of whales, pack of wolves, etc.) documented in nature
Now some non-enumerated, but still reasonably definable aggregates:
- A colony of ants (or termites, or bees, etc.) in nature - A living culture of bacteria - A flock of birds in nature
Now some parts of a single whole organism:
- A preserved herbarium specimen - A preserved skeleton of a mammal - A preserved skin of a mammal - A preserved head of a fish - A tissue sample extracted from a whale in nature
The preceding set requires some elaboration. For example, a herbarium specimen is usually a clipping or other small part of a larger whole plant. Often multiple clippings from the same individual plant are taken and preserved as separate herbarium specimens. Should there only be one instance of this class representing the whole plant? Or should there be multiple distinct instances of this class, one for each herbarium specimen? If the former, would the herbarium specimens represent instances of the "Evidence" class, linked to the one instance of this class (whole plant)? If the latter, should there be a separate instance of this class to represent the whole plant, and then each of the instances of herbarium specimens be linked via a "derivedFrom" relationship to the whole-plant instance?
Similarly, suppose the mammal skeleton and skin in the above list are from the same individual mammal. Would there be one instance of this class (for the whole organism), and the Skeleton and Skin be treated as instances of the Evidence class? Or, should there be two instances (one for the skin, one for the skeleton)? Or should there be three instances (one for the whole mammal organism, one for the preserved skin derived from it, and one for the preserved skeleton derived from it)?
Take the example of the whale. Suppose there is a pod of 7 whales that is well-defined, cohesive, tagged, and studied in nature. Would there be one instance of this class for the pod, and then 7 additional instances (one for each individual whale) that are linked as "memberOf" the pod instance? What to do with the tissue sample? Is it an instance of the Evidence Class? Is it another instance of this class, "derivedFrom" the instance of this class representing the specific whale from which the sample was taken?
Now some border-line and controversial cases:
- A non-enumerated but otherwise well-defined population of a single species in nature. [How do we distinguish this from a well-defined taxonomic unit?] - A single rock in a Museum collection that has multiple fossils (representing multiple phyla of animals) embedded in it - A single rock preserved in alcohol containing multiple invertebrate specimens from different phyla
I'm sure we can come up with other examples. I do not have web access (only email), so I was unable to look at Peter DeVries' links to examples of what he felt belonged in this class. Pete -- maybe you can summarize them in text form?
I would like to believe that all instances of Occurrence can be rooted into one instance of this proposed new class. So, maybe it would be useful to think about all the different ways that an Occurrence is currently represented in actual instances, and see if we can scope this new class to be the generalized "basis of record" for all Occurrences.
Aloha, Rich
P.S. I have BCC'd the BiSciCol list on this email, because of it's strong relevance to that project.