[Taxacom] Why stability? - Revisited

[Jim Croft]

We are obviously in furious agreement. :)

It wasn't the 'flag in the sand' that caught my attention, but the 'around
which a taxon is defined' bit.  It is usually the other way - a taxon is
defined and a type is selected, either from existing, or newly designated
if none exists.

But we do seem to have a slight difference in approach, and it may be
simply semantic. "a very small percentage of taxa are unambiguously
circumscribed based on their type alone" - I don't circumscribe taxa based
on types as such. For the purposes of taxonomy, the type is just another
specimen, even if it is the only specimen. When the taxa are sorted, then
the type becomes important. I like to draw very clear distinctions between
the acts of taxonomy and nomenclature, and between the type specimen as a
specimen and the type specimen as a type. ;)

jim

On Tue, May 5, 2015 at 6:58 AM, Weakley, Alan <weakley at bio.unc.edu> wrote:

>  I agree completely with what you say, Jim, and was making the same point
> you ae making – so, am not sure what you are objecting to in my “flag in
> the sand” analogy.  The flag might be over on one extreme edge of the
> “taxonspace” (as implied by Paul).  A type anchors a name but does not
> circumscribe it (except in the narrowest possible sense of the type itself).
>
>
>
> In very poorly understood groups (with a high taxon:systematist ratio) the
> types stand large as outposts in the bleak unwatered and minimally
> taxonomist-turbed desert.  This seems to be what Stephen was describing in
> his universe.  As systematics proceeds, the types are still critical to
> anchor the application of names, but the emphasis shifts to the boundaries
> between the various flags (types), and which flags are taken over by others
> and become synonyms of what is regarded as a “good” taxon (not to sound too
> militaristic).  In the vascular flora of the Southeastern United States,
> 7200 taxa currently recognized, a very small percentage of taxa are
> unambiguously circumscribed based on their type alone.  Put another way,
> the great majority of taxa can only be unambiguously circumscribed by
> something beyond the name (as typified) because there are sensu stricto or
> sense lato interpretations “in play”.  If I write “Andropogon virginicus
> Linnaeus 1753” on a specimen (or a record in a database) without sec or
> sensu, no one tell whether I mean it in the narrowest sense, or variously
> including 1, 3, 7, or 12 other taxa recognized in “lumpier” taxonomic
> schemes currently or in recent decades followed by other credible taxonomic
> experts.
>
>
>
> *From:* Jim Croft [mailto:jim.croft at gmail.com]
> *Sent:* Monday, May 04, 2015 4:36 PM
> *To:* Weakley, Alan
> *Cc:* TAXACOM; Paul van Rijckevorsel
>
> *Subject:* Re: [Taxacom] Why stability? - Revisited
>
>
>
> This is not strictly true. The purpose of the type is to anchor the name,
> as Paul describes. It is not to centre, circumscribe or in any way define
> the taxon. That is a separate process that may end up including one or more
> types, and hence one or more names. At least with plants. People may think
> they are defining a taxon by selecting the 'best' possible type to
> represent their concept, and it is probably a wise thing to do, but this is
> not what is happening according to the Code. They are simply anchoring the
> name.
>
> Jim
>
> On 05/05/2015 5:20 AM, "Weakley, Alan" <weakley at bio.unc.edu> wrote:
>
> The type is a flag in space around which the circumscription of a taxon
> (its concept) is defined -- usually in relation to other, "competing" taxa.
>
> -----Original Message-----
> From: Taxacom [mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of
> Paul van Rijckevorsel
> Sent: Monday, May 04, 2015 7:57 AM
> To: TAXACOM
> Subject: Re: [Taxacom] Why stability? - Revisited
>
> I was a little uneasy why Stephen Thorpe's attitude that taxa are defined
> by types is so alien to me.
>
> But it is very straightforward: from the very first the 'botanical' Code
> has laid down that nomenclatural types are not necessarily the most typical
> or representative element of a taxon (that is, holding only the type, it is
> not possible to predict with any degree of confidence what the taxon
> exactly looks
> like: the type is only the type) .
>
> For plants there does exist a situation where the whole unit is determined
> by a reference specimen, namely in the ICNCP (Cultivated-plant-Code),
> resulting in names of the type Hydrangea macrophylla 'La France'.
>
> The ICNCP deals with a field of considerable complexity (and which does
> benefit from regulation), but taxonomy is not involved.
>
> Paul
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