Antarctica and biogeography

[Ken Kinman]

John,
     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).  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
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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