Hi Nico,
I just HAVE to answer this one thing... (the rest seems
either not too important and/or we're largely in agreement).
[...]
Thanks for that.
I read all of it, understand most of it (I think), and, to the extent that I understand it, I also tend to agree. I do want to clarify that my use of the word "objective" in earlier posts was in no way intended to suggest that I believe taxa exist as objectively-defined entities in nature; but rather that, given an implied taxon concept circumscription (regardless of it's correlation with some "natural" entity in nature), to what extent is it an objective (rather than subjective) exercize to place a given individal within, or outside of, that circumscription.
In other words, I'm very much in this camp:
If, on the other hand, taxonomists thought of their
products merely as a matter of quasi-reliable and convenient vocabularies that somehow reflect something about the human-external world but could well be very different and still serve their purpose ("arbitrary constructs" - though it's never that arbitrary once you start down a given path and test for reliability) - then just the same that should be accommodated within a taxon concept approach.
But I gather that's beside the point.
So then, the reason why mentions of PhyloCode-like
definitions of clades vis-a-vis concept taxonomy tend to give me light allergies, is because phylogenetic taxonomy actually does on occasion make fairly strong claims about what nature is like, and how good taxonomic practice should reflect this ("use definition type X, not Y").
Yes...you and I have had several discussions about Phylocode in the past...usually in the company of some alcohol-containing beverage or another....
:-)
I really didn't intend to open that can of worms; but leaving Phylocode out of it, I still maintain that it is legitimate to define a circumscribed set of organisms as "all descendants of the most recent common ancestor of of 'X' and 'Y'"; keeping in mind all the caveats that go into the words "decendants" and "common ancestor". Certainly, thois is not the only legitimate way to define a circumscribed set of organisms, and I would argue that it's probably not the "best" one either (depending on the metric of "best").
In that sense, I regard concept taxonomy as a full-fledged alternative and competitor to PhyloCode-like taxonomy. Both, I think, try to improve upon the semantics of Linnaean taxonomy and ultimately help users.
I take a more general approach to the notion of Taxon Concept. To me, any circumscribed set of organisms (living, dead, and yet-to-be-born) purported to represent "a taxon", is a taxon concept -- regardless of what methods or metricies are used to define the boundaries of the circumscription. Linnaeus, having preceeded Darwin by a century, was a Creationist; yet some of his taxon concepts seem to have persisted over 250 years (e.g., Homo sapiens -- at least at the species level).
The issue is not at all whether we got the concepts "right", i.e. whether they closely map to natural taxa. Instead, the goal is to properly archive the sequence of views (so that ontological reasoning may come into play).
Agreed!
I think taxonomic publications are real (enough), and I
think occurrences of intersubjective human understanding and misunderstanding are real (enough). That's what concept taxonomy should concentrate on representing. The rest is up to the producers and users.
If I understand you correctly, I agree here as well.
Aloha, Rich