I have been keeping out of this debate in the hope that others might join,
but Peter Milburn has asked some questions and raised some points that need
addressing.
(1) Apologies to you, Pete Milburn, for any offence I may have caused you
in my first posting. Nevertheless my comments were general and not aimed at
you. Below I have addressed some of the arguments that you have presented.
Please do not take offence that I disagree with some. In the end we have
common goals.
(2) the accusations from Pete Milburn that I have <continued my damnation
of all those involved> in albatross taxonomy and conservation and made <the
Antarctic Division, Environment Australia, some of the worlds leading
Albatross Biologists etc> the targets of my abuse seem a bit ridiculous. I
have merely made critiques of the <interim albatross taxonomy> and the
science behind it. I have not criticised people, only processes, proposals
and publications. Can we please dispense with emotive character
assassinations and concentrate on the issues?
(3) Pete Milburn wrote:
>>My intention was to state that in my understanding at an International
Meeting of Albatross Biologists it was agreed that an interim PSC-based
taxonomy should be adopted on the basis of preliminary results which
yielded identical terminal taxa to those established using the BSC. This
was to form the basis for further studies including those pertaining to
conservation issues. >>
The above paragraph does not make much sense to me. Firstly, there were no
preliminary results. No data, no results. Here say, rumours and promises
for the future are not results. Secondly, <PSC-based taxonomy> [sic] does
not use different taxonomic data to the BSC. The species concepts are
theoretical frameworks for interpreting data. Robertson & Nunn (1989 p. 14)
said that <Reassuringly, traditional taxonomic and novel molecular
phylogenetic methods are largely supportive of each other>. This has
nothing what so ever to do with species concepts. Further more, neither
molecular data nor morphological data on albatross taxa will provide any
insight as to which species concept is most appropriate.
(4) Pete Milburn and others have stated or implied that the <interim
taxonomy> is a better system for conservation of albatrosses. PM wrote >>It
is thus perfectly clear that I support 'taxonomy for conservation
convenience'.>> Peter Menkhorst has shown that taxonomy makes little
difference to legislative protection in Australia. Clearly the crux of
albatross conservation is to stop fishers from killing them, and fishers
kill albatrosses independently of taxonomy. If there were a taxonomy that
helped the plight of albatrosses I would support it. I suspect that it is
the one that best reflects their phylogeny. Would anyone care to elaborate
as to how the <interim taxonomy> is better suited for conservation of
albatrosses than the <existing taxonomy> is? But please don't repeat
arguments that have already been refuted.
(5) Pete Milburn wrote
>So far in this discussion no-one has challanged the interim taxonomy with
>any contradictory data. While the published primary data in its support is
>meagre it still outweighs that which refutes it.
Apologies if some of this seems like repetition.
(a). Robertson & Nunn did not refute the existing taxonomic treatment that
they proposed to replace, except to say that they would adopt a more
appropriate species concept, ie. the PSC. They did not explain why the PSC
might be more appropriate. It would therefore seem to me that the onus
rests on the proponents of the <interim taxonomy> to refute the existing
taxonomy.
(b) The <interim taxonomy> is an untested hypothesis. It was proposed on
the basis of no data. It has not been tested. The general approach in
science is to not accept new hypotheses to replace existing ones until they
have been tested. Science is conservative by definition.
(c) Robertson & Nunn re-assessed existing data, claimed to have new data
(that they couldn't tell us about), re-affirmed the existing conclusions
that were based on the existing data, and shoved it all into a different
conceptual framework. The difference between the <interim taxonomy> and the
<existing taxonomy> lies not in the data but in the species concept used to
interpret the data.
so
(d) Proponents of the PSC have not yet managed to establish that the PSC is
more suitable than the BSC by refutation of the arguments that support the
BSC. The debate is alive, but not over. Data on the evolutionary divergence
of albatrosses is irrelevant to this question.
(e) There is much more to the PSC than has been discussed in this debate so
far. PSC species are defined as terminal taxa of monophyletic assemblages.
Terminal taxa are diagnosable populations, i.e. populations that can be
diagnosed by (molecular, morphological, vocal, behavioural or whatever)
characters that define them as separate from other populations. However, in
practice PSC species are no easier to diagnose by this definition than are
BSC species. It remains an arbitrary decision as to what is the appropriate
level of distinction within a complete cline of evolutionary divergence
shown by the worlds biota. The PSC just moves the goal posts toward the
terminal end of taxonomic divergence.
(f) The PSC was proposed as a model that would allow more rigorous
scientific analysis of quantitative data sets to assess phylogenetic
lineages. To erect a taxonomy based on the PSC it is necessary to construct
a phylogeny that allows discrimination of cladogenic and anogenic changes
(ie changes that cause dichotomies in phylogenies and changes that occur
within monophyletic lineages). This is very difficult to do, but Robertson
& Nunn (1989) did not even attempt to do so. It is ironic that Robertson &
Nunn is an example of the non-quantitative, arbitrary decision making
taxonomy that moved Cracraft et al to devise the PSC. In fact, I think R&N
may have harmed the cause of the PSC by undermining its stance of
objectivity.
(g) Under the PSC hybrids are polyphyletic at the species level and cannot
be classified as belonging to any species. Hybrids miss the boat. Thus
under the <interim taxonomy> hybrid albatrosses are not classified below
the level of genus. So maybe there are not many hybrid albatrosses but
there are a lot of hybrid organisms in the world.
(h) The interim taxonomy treats albatrosses in a taxonomic framework that
is inconsistent with the treatment of other groups of birds. It is either
saying: (1) albatrosses deserve different treatment; or (2) all other
families of birds are treated incorrectly in checklists such as Christidis
& Boles or Schodde & Mason; or (3) we don't need consistency in taxonomic
treatments of birds. Some clarity as to which stance is taken and and some
data to support it would be helpful. But its not the place of R&N's paper
on albatrossess to address this issue.
(6) Pete Milburn wrote
<<For species with dispersal over huge ranges and those with widely
separated small (vulnerable) breeding populations it seems that
international consensus has some merit.>> And <<I think that it is useful
to use international convention in cases where a species normal
distribution overlaps many national boundaries.
I once again refute the notion that there is international consensus in
support of the interim taxonomy. There is no international convention of
taxonomic treatment of albatrosses. However, there was a few years ago?
(7) PM wrote
>> It happens that the PSC-based taxonomy was adopted as the
internationally agreed basis for legislation. My point about the state of
crisis addressed the urgent need to facillitate IMMEDIATE INTERNATIONAL
AGREEMENT rather than complicate things by arguing about nomenclature for
years and years in the way we are doing now. I agree with Peter Menkhorst
that the outcome in Australian legislation would be neutral>>.
Just who adopted the <interim taxonomy> as the internationally agreed basis
for legislation and on what authority? Can you support this claim? Surely
an internationally agreed basis for legislation would be a first for this
planet? Did scientists adopt it at the albatross conference as the basis
for legislation? If so, what arguments did they present to governments to
support its adoption?
My main point all along is that there seems to be little wisdom in adopting
a taxonomy with NO SUPPORTING DATA, no matter who it is adopted by.
If you don't want to argue for years about nomenclature of albatrosses then
you should not promote changes to scientific theory that are not
substantiated by facts.
I can only conclude that my position remains unchanged, that the <interim
taxonomy> of albatrosses has little to offer as a taxonomic classification
scheme or a conservation tool but has caused tremendous confusion and
uncertainty. perhaps it has increased the focus on terminal taxa which is
an excellent thing, but then perhaps terminal taxa of have always enjoyed
a bit more focus in albatrosses than they have in many other familes.
David James
PO BOX 5225
Townsville Mail Centre,
Qld 4810, Australia
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