[Taxacom] Biodiversity questions: Classifications

[Fred Schueler]

On 10/3/2013 11:20 AM, John Grehan wrote:
> Trouble is that there is no standard objective method for assigning age
> since all age estimates are minimal. Some have made some esoteric
> mathematical arguments for having confidence in a particular age or
> range, but its still an argument. Some groups may have some level of
> "consensus" or majority opinion, but its still just an opinion. As yet
> there is no unambiguous criterion for determining precise age.

* sure - it's an hypothesis. As Bunge says "we know that all our 
constructions are defective, hence corrigible." Ages associated with a 
name both give the general user an idea of at least roughly how old a 
group is thought to be, and would challenge specialists to improve the 
resolution of their estimates.

We now have enough published ages of groups that we can guess in the 
ages of descendent groups, and challenge paleontology, biogeography, and 
genetic comparisons to improve the accuracy of these guesses. We've been 
guessing about distributions on the basis of collected specimens for 
centuries, and this is the same procedure extended from spatial to 
temporal estimates.

fred.
=================================================
> On Fri, Oct 4, 2013 at 3:59 AM, Fred Schueler <bckcdb at istar.ca
> <mailto:bckcdb at istar.ca>> wrote:
>
>     On 10/3/2013 6:59 AM, Chris Thompson wrote:
>      > There is NO scientific information to be derived from higher
>     classifications
>      > as there are NO scientific principles / standards underlying our
>     current
>      > classifications.
>      >
>      > Willi Hennig years ago tried to suggest a standard (age of
>     origin) on which
>      > to base rank within a classification. BUT he was ignored by all.
>
>     * others who have made the suggestion independently have also been
>     ignored. If an age is associated with each category, then the use of the
>     category for a monophyletic group becomes a falsifiable hypothesis, and
>     rescues the notion of category from the stigma of Aristotelian
>     arbitrariness.
>
>     I wonder, if this isn't to be done in an immediate convulsion, if the
>     proposed age of the group could be appended, along with the author's
>     name - e.g. class Mammalia (L; early Permian) - until consensus emerges
>     on the ages of categories in each higher taxon, perhaps grading into a
>     system where age alone is the categorical marker.
>
>     fred.
>     ------------------------------------------------------------
>                Frederick W. Schueler & Aleta Karstad
>     Bishops Mills Natural History Centre - http://pinicola.ca/bmnhc.htm
>     Mudpuppy Night in Oxford Mills - http://pinicola.ca/mudpup1.htm
>     Daily Paintings - http://karstaddailypaintings.blogspot.com/
>                RR#2 Bishops Mills, Ontario, Canada K0G 1T0
>         on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W
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-- 
------------------------------------------------------------
          Frederick W. Schueler & Aleta Karstad
Bishops Mills Natural History Centre - http://pinicola.ca/bmnhc.htm
Mudpuppy Night in Oxford Mills - http://pinicola.ca/mudpup1.htm
Daily Paintings - http://karstaddailypaintings.blogspot.com/
          RR#2 Bishops Mills, Ontario, Canada K0G 1T0
   on the Smiths Falls Limestone Plain 44* 52'N 75* 42'W
    (613)258-3107 <bckcdb at istar.ca> http://pinicola.ca/
------------------------------------------------------------