fossil flies in Antarctica

[John Grehan]

I've since had the opportunity to read the Nature article. Christian's
comments on the positive evidence is certainly warranted. The article
itself which is basically a traditional biogeographic approach
incorporating geohistorical narratives to provide historical context. Thus,
the presumption of 'Gondwnana' comes not from biogeographic analysis, but
the acceptance of a particular geohistorical narrative for a particular
time period.

I'm lost as to what the biogeographic 'ointment' is intended to represent.
Some additional clarity would also have come from mentioning why there was
a 'long-held belief that the continent was never inhabited by these
insects' in the first place.

On the more positive side, the article presents artifactual evidence
supporting a formerly diverse Antarctic biota that is also predictable from
the position of the continent within the trans-oceanic tracks of many groups.

John Grehan

At 09:31 AM 5/9/2003 -0400, christian thompson wrote:
>Yes, do read the Nature article.
>
>Willi Hennig once suggested on the basis of zoogeographic analysis that
>higher flies where not part of the earlier Gondwana fauna, etc.
>
>Upon finding POSITIVE evidence that higher flies did exist on the
>Antarctic landmass, we merely suggested that there are two
>possibilities: 1) higher flies may be older and may have been part of
>the earlier (Mesozoic) Gondwana fauna (that is, Hennig was wrong) or 2)
>they colonized Antarctica more recently.
>
>So, we concluded that "dipterists need to re-examine the taxonomy of
>southern cylcyorrphaphan fly taxa to see whether any trans-Antarctic
>relationships among the more derived clades have been overlooked."
>
>Yes, Nature likes fancy/catchy titles. But at least Nature accepted
>something about little things, not just big fossil bird / dinos for
>once!
>
>Cheers
>
>F. Christian Thompson
>Systematic Entomology Lab., USDA
>c/o Smithsonian Institution
>MRC-0169 NHB
>PO Box 37012
>Washington, DC 20013-7012
>(202) 382-1800 voice
>(202) 786-9422 FAX
>cthompso at sel.barc.usda.gov e-mail
>www.diptera.org  web site
>
> >>> John Grehan <jgrehan at SCIENCEBUFF.ORG> 05/09/03 08:43AM >>>
>Without yet seeing the article, I would concur with Ken that, in
>general
>principle, there would be nothing to suggest that the apparent absence
>of
>the taxon in Antarctica represents a historical reality. For the ghost
>moths (Hepialidae), for example, there are no fossil or living taxa in
>Antarctica, yet one cannot say they were never there. Similarly, they
>are
>absent from Madagascar, the Caribbean, much of West Africa, and the
>lowlands of the southeastern United States but this does not mean they
>were
>never there.
>
>There is a common technique in the biogeographic and evolutionary
>literature (and this may not apply to the Thompson article) to
>proclaim
>that a new find (modern or fossil) as changing what was 'previously
>thought' about the age or distribution of that taxon to make the
>discovery
>more significant and noteworthy. One does see this kind of rhetoric
>quite
>often in Nature and Science, but it is widespread in other journals as
>well. It will be interesting to see what the empirical issue is in
>Thompson's article.
>
>John Grehan
>
>At 01:55 AM 5/9/2003 +0000, Ken Kinman wrote:
> >Dear All,
> >      I see that Christian Thompson is co-author of a short piece in
>the
> >latest issue of Nature.  I don't have a subscription, so could only
>read the
> >first paragraph.  However, it contained a statement that I found
>puzzling:
> >that there had been a longheld belief that flies of the clade
>Cyclorrhapha
> >had never inhabited Antarctica.
> >     What was the basis of that belief?  If the fossil record of
> >Cyclorrhapha goes back into the Mesozoic, why wouldn't some members of
>that
> >clade have lived in Antarctica in the late Mesozoic and Early
>Tertiary?
> >Just curious.
> >      ---- Thanks,
> >                Ken
> >
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>Dr. John Grehan
>Director of Science and Collections
>Buffalo Museum of Science
>1020 Humboldt Parkway
>Buffalo, New York 14211-1293
>Voice 716-896-5200 x372
>Fax 716-897-6723
>jgrehan at sciencebuff.org
>http://www.sciencebuff.org/biogeography/Panbiogeography/Panbiogeography-Gate.htm
>
>http://www.sciencebuff.org/HepialidaeGate.htm

Dr. John Grehan
Director of Science and Collections
Buffalo Museum of Science
1020 Humboldt Parkway
Buffalo, New York 14211-1293
Voice 716-896-5200 x372
Fax 716-897-6723
jgrehan at sciencebuff.org
http://www.sciencebuff.org/biogeography/Panbiogeography/Panbiogeography-Gate.htm
http://www.sciencebuff.org/HepialidaeGate.htm