Antarctica and biogeography

John Grehan jgrehan at TPBMAIL.NET
Mon Apr 5 06:36:05 CDT 2004

At 09:29 PM 4/4/04 -0500, Ken Kinman wrote:
>      I didn't say to include Antarctica in the tracks.  I just said to
> put it on the map when a taxon may have lived there.  I don't see you
> ever omitting Japan, Greenland, Australia, or any other islands (some
> quite tiny), even when there is no hint that the taxon ever lived on
> them.  So I can see no justification for leaving off the entire continent
> of Antarctica (especially when a taxon has a track in the southern
> hemisphere).

It seems I misunderstood Ken's characterization. His statement that
Antarctica being left off the map when it is not involved with a locality
record is correct. This is probably more a function of the map orientation
which would require the outline of Antarctic across the base of the entire
map. I would find this somewhat cumbersome. However, it is a matter of
personal choice rather than that of the panbiogeographic method. When polar
views are presented Antarctica is most definitely included (which Ken
should know), and there is nothing stopping any panbiogeographer or other
biogeographer such as ken putting Antarctica in. It should be further
pointed out that non-panbiogeographic maps often leave Antarctica out so
Ken's disagreement also lies with biogeographers in general. As for me, I
do not see any deficiency in leaving Antarctica out in non-polar views. It
does not change the track and it does not change the interpretation so
there is nothing 'misleading' (A Pacific track is still a Pacific track,
for example).

John Grehan

>A track across the southern Pacific (from South America to Australia or
>New Zealand) will often be misleading if you don't show the proximity of
>Antarctica.  It's omission of potential information and I therefore don't
>like it at all.  It also seems to indicate presumptions about the age of
>some taxa or just how long ago suitable habitat may have existed in
>Antarctica (and in combination such presumptions could be doubly
>wrong).  It just seems to detract from the potential usefulness of
>panbiogeography to do this.
>                   ----- Ken Kinman
>Date:   Sat, 3 Apr 2004 22:01:07 +1200
>From:   John Grehan <jgrehan at TPBMAIL.NET>
>At 09:54 PM 4/2/04 -0600, Ken Kinman wrote:
> >  In much the same way, it does not sit well with me when he fails to
> include Antarctica on his pangeographic maps for groups that probably
> occurred there before Antarctica froze over.  That they no longer occur
> there does not justify completely leaving Antarctica off such maps.  Such
> approaches just feel to me like wearing blinders and thus hamper useful
> speculation where it is needed.
>Panbiogeography deals with empirical rather than imagined data. Thus,
>Antarctica, like any other location, is not included in a track when there
>it is not part of the distribution records for a group. Thus, a track
>linking locations in the North Island of New Zealand, Hawaii, and Costa
>Rica for example, obviously represents the current distribution for a
>group which may have also present in western North America, western South
>America, Australia, Japan, China, and Antarctica. In fact one might
>predict that these locations are more likely for the ancestral
>distribution than India or Africa. However, at this point including any of
>these localities of absence would not be any more informative for the
>track of the currently known distribution records.
>John Grehan

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