[Taxacom] Read... and believe...

Sat Sep 5 22:47:59 CDT 2009

>*All* species have an associated taxon concept.  At the very least it is the type specimen which bears the name
Actually, there very often isn't a determinate type specimen until after a species is revised (and a lectotype or neotype designated), but we still routinely identify unrevised species
Most of the best known (animal) species date from Linnaeus 1758, and I really don't think type specimens have anything much to do with the routine identification of these, Homo sapiens being an interesting case!
What is true is that everybody who identifies any specimen does so SOMEHOW, with reference to SOMETHING, but whatever it is - call it "taxon concept", or whatever you like - it very often isn't something that you can codify or even express in words. 
To take Richard's example of Centropyge, if John Smith identifies a specimen as C. fisheri in 2003, without any elaboration, the "taxon concept" is just "Centropyge fisheri det. J. Smith 2003", and in order to "flesh it out" completely, you might have to spell out the entire history of cases whereby the name 'C. fisheri' caused certain neurological connections to be formed in John Smith's brain, which lead to his identifications in 2003! Maybe, for example, he once or twice or whatever saw a labelled specimen on a shelf in a Museum somewhere which confirmed his suspicions of what the name might refer to. Maybe he has forgotten this, but the neurological connections in his brain which lead to identification remain intact!
An interesting analogy is provided by the example of chicken sexing! Apparently, there is nothing that you can express in words to distinguish the sexes of very young chickens. Nevertheless, you can apparently train a person to distinguish them with near perfect reliability if you reinforce them when they get it right, and punish them when they get it wrong. They start off by guessing, but a neurological network is formed through positive feedback. They can't tell you how they do it - they just do it!

Stephen
________________________________________
From: Jim Croft [jim.croft at gmail.com]
Sent: Sunday, 6 September 2009 6:49 a.m.
To: Stephen Thorpe
Cc: Tony.Rees at csiro.au; fwelter at gwdg.de; TAXACOM at mailman.nhm.ku.edu
Subject: Re: [Taxacom] Read... and believe...

*All* species have an associated taxon concept.  At the very least it
is the type specimen which bears the name.  Unless the taxon is know
from a single specimen, a concept would include the pile (sorry, I
live in a plant world) of specimens that a taxonomist(s) might claim
are the 'same' as the type. There might be several alternative piles
depending on the point of view of the taxonomist(s).

As an aside, a taxonomist might decide to formalize the distinction
between their concept pile and another's concept pile.  To to this
they take out the specimens they do not think belong.  These specimens
will go into an existing pile of another existing named species
concept pile, or they will have to erect and name an new taxon concept
pile to hold them.

*Every* act of identification involves an assertion about a concept.
'Based on ..., I think this specimen belongs in this pile'.  Even is
you do not use a key or a comparative reference specimen, you have in
you mind some conceptual reference you are comparing the specimen
with.  The problem is, because you do not tell us, we have no idea
what that reference is.  And because you do not tell us we make a
guess at what it might be, fill in the gaps and assume that what we
hear from you is what you were thinking.

You are quite wrong about the child cat/dog identification analogy.
The child sees a 4-legged tailed furry thing - without thinking it
compares the atrtributes it sees with its collection of mental
concepts of various 4-legged tailed furry thing  providing the beast
is not a chihuahua it will probably get an unambiguous hit.  The
process happens fast and does not involve ticking of characters in
sequence, but is does involve a rapid comparison of a thing with a
concept followed by a decision to include the thing as part of the
concept, or not.

jim

On Sat, Sep 5, 2009 at 6:19 PM, Stephen Thorpe<s.thorpe at auckland.ac.nz> wrote:
> Tony,
> Actually, I think the problem is that taxa, especially species, very often have no "taxon concepts" at all associated with them, and at any rate such concepts aren't often involved in the process of identification! At least I don't identify insects by checking that they have every character (and no other) attributed to them in a description (original or redescription), nor do I often use keys if I can avoid them! Identifications typically just don't work like that in practice. Actually, we are conflating two quite different aspects to identification:
> (1) recognising the same taxon twice; and
> (2) putting a name to it [=identification sensu stricto]
> Neither of these things need involve a "taxon concept" of a specifiable determinate kind! Both of these things are HUGE topics!
> Reflect a little on how you identify common domestic pets. A 4 year old can probably tell a cat from a dog easily enough. I think that they, and I, identify things by seeing the morphological gaps and learning (from one or a complex mixture of sources) which name applies on either side of the gap. Whatever is going on certainly doesn't involve lists of characters defining what a cat or dog is!
> Cheers,
> Stephen
>
> ________________________________________
> From: taxacom-bounces at mailman.nhm.ku.edu [taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Tony.Rees at csiro.au [Tony.Rees at csiro.au]
> Sent: Saturday, 5 September 2009 6:32 p.m.
> To: jim.croft at gmail.com; fwelter at gwdg.de
> Cc: TAXACOM at mailman.nhm.ku.edu
> Subject: Re: [Taxacom] Read... and believe...
>
> Hi Jim, all,
>
> Well I think it might be good to look at this issue from a couple of other angles. First, how many taxa have a variety of "taxon concepts" as oppose to just one (proabably a minority); second, without a reference specimen (or taxonomic grade photo or drawing) for restrospective checking, all reported observations are unguaranteed in terms of accuracy (of both ID, colletion locality, date-time, and possibly more); the question is then, when does this matter. Which is probably some permutation of (a) are there other species close enough to be liable to be confused with the one reported, and (b) how crucial is the observation (e.g. a range extension or something else of potential novel interest). If it is the latter, then probably corroborative evidence such as a new visit are required; at least the report would then be a prompt that closer re-inspection may be useful. The bird atlas folk have this down to a fine art; reports of easly-to-identify species in expected aeas are gen
>  erally accepted, hard-to-identify ones or range / seasonal extensions require expert confirmation before they are added to the atlas. Not too hard, I would say... In any case, isolated outliers / vagrants are of little weight until confirmed with additional data, or if they cannot be confirmed, may always be suspect. We live in an imperfect world; how much perfection is required? (Answer depends on your particular requirement, no doubt).
>
> - Tony
>
> ________________________________________
> From: taxacom-bounces at mailman.nhm.ku.edu [taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of Jim Croft [jim.croft at gmail.com]
> Sent: Saturday, 5 September 2009 4:12 PM
> To: fwelter at gwdg.de
> Cc: TAXACOM at mailman.nhm.ku.edu
> Subject: Re: [Taxacom] Read... and believe...
>
> Thanks Francisco - you have perfectly described the problem we are
> dealing with.  The way we do business at the moment, we have no way of
> knowing what was going on in a taxonomists mind when they applied a
> name to a specimen.   While not entirely meaningless, this makes it
> very difficult to compare and link the identification assertions of
> one taxonomist with another, or, the same taxonomist identifying
> specimens at different times.
>
> Most taxonomists (unfortunately, not all :) taxonomist don't just make
> it up as they go when it comes to identification.  They carry around a
> mind map based on their knowledge of the prevailing literature, use an
> identification tool that is based on some preferred selection of the
> prevailing literature, or use an existing comparative collection in
> some preferred arrangement based on a preferred selection of the
> prevailing literature.   If we know which of these was in their mind
> when they make the identification we can circunscribe teh concept with
> a bit more precision.
>
> The moment you place your name on an identification you have made a
> decision that the specimen fits within a particular taxon concept, one
> of the many with the same name that are floating around in you mind to
> chose from.  Our problem is that, based on the information provided,
> we do not know which one you chose and we are left to make an informed
> guess on which would have been the most likely, given what we might
> know or assume of your experience or preference.  It could be argued
> that this is our problem, not yours, but with communication, if there
> is a problem, it is a problem for both sides.
>
> Unless we can somehow document and map available concepts used in
> identification assertions, any coupling we might make between
> asserytions can only be loose.  It is an interesting challenge for us.
>
> Concepts do not have to be published.  They can, and often are,
> described over a cup of coffee or a beer.  These one's we are just
> going to have to leave alone for a while... :)
>
> jim
>
> On Sat, Sep 5, 2009 at 3:59 PM, Francisco
> Welter-Schultes<fwelter at gwdg.de> wrote:
>> Rich,
>> When I identify a specimen, I tend to use various sources and build
>> up my mind myself, I don't "follow" one single other source. I
>> also would expect other scientists to do the same. A scientist must
>> be able to have an independent opinion, as the result of having
>> studied various sources. I could not apply this "sec." concept
>> (taxonomic concept proposed by N. Franz, Roger Hyam and others) for
>> my field (malacology). If I identify specimens from museum
>> collections, I add my name and a date.
>>
>>> (or if it's a new circumscription, then they should at
>>> least make a note of "sensu me, not yet published").
>> In European malacology we have the case of the genus Oxychilus
>> (Gastropoda), which was very well defined by Riedel 1998, based on
>> a lot of scientific work, and which was distorted (several
>> arbitrarily selected subgenera were elevated to genera) in a simple
>> uncommented Central European checklist by Falkner et al. 2001. I am
>> asking myself if you would call this a published concept (that
>> deserves a "sec." authorship). Maybe yes. But the other (not
>> Central European) species were of course not listed. So a name of a S
>> European species is "implicitely" sec. Falkner et al. 2001? In
>> real life people take the current generic name of S European
>> species from www.faunaeur.org, they don't ask where the data were
>> based on.
>>
>> Francisco
>>
>>
>> University of Goettingen, Germany
>> www.animalbase.org
>>
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>
>
>
> --
> _________________
> Jim Croft ~ jim.croft at gmail.com ~ +61-2-62509499 ~
> http://www.google.com/profiles/jim.croft
> ... in pursuit of the meaning of leaf ...
> ... 'All is leaf' ('Alles ist Blatt') - Goethe
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--
_________________
Jim Croft ~ jim.croft at gmail.com ~ +61-2-62509499 ~
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... in pursuit of the meaning of leaf ...
... 'All is leaf' ('Alles ist Blatt') - Goethe