biogeographic homology

[Fred Rickson]

I have followed the biogeographic discussion with some interest because I
am wrestling with a plant distributional problem that seems to involve
Africa, India, and Sri Lanka.  I also read the "teeth chattering" books by
L. Croizat when they were first published.  I had a problem with the
"correctness" of panbiogeography then, and I still do now.  My problem
involves the drawing of tracks as solid lines.  The distributions are not
continuous, they are dots on a map in the same sense as any taxa
distribution notation.  The lines connecting terminal taxa on a cladogram
are not indicative of direct evolutionary connections, just help in
arranging the final organisms into one suggestion of monophyletic groups.
Likewise, tracks just outline where one finds organisms, not how they
are/were connected, and supposing anything more is mostly guessing without
corroborating data.

Fred Rickson