Reading Croizat

[John Grehan]

For the sake of geneal discussion for those interested in such matters,
I felt some further comment might be pertinant regarding the current
relevance of Croizat's writings given subsequent developments. Since
it is true that there have been new developments in the panbiogeographic
method, and new comparisons considering issues or processes (e.g.
geological) that were not around in Croizat's time, one might not have to look
to Croizat on these aspects. However, Croizat remains the only source of
a global panbiogeographic perspective since he mapped and analysed
a large number of taxa in a global context.

As Brown and Lomolino liked
to point out, there are technical errors and some of the systematics
might not have been all that good, but the fact remains that no one has
refuted the validity of the great majority of examples in terms of their
biogeographic homology.

If one takes, for example, the biogeography of the southern beeches
(Nothofagus),
no matter how much cladistic manipulations (and there are a few) have resorted
the interrelations among the member species, the genus remains recognized,
and the known geographic distribution still conforms to the Pacific pattern
identified by Croizat in 1952.

Regardless whether one might regard oneself as a vicariance cladist,
dispersalist, panbiogeographer, or some amorphous mix, Croizat's
original writings remain  perhaps the only comprehensive source for
addressing such basic questions as; How does the group I study conform or
differ from biogeographic patterns in general? Vicariance theorists (with the
possible exception of Morrone and colleagues) have tried to relegate Croizat
to a historical curiousity, while biogeographers such as Brundin saw
 vicariance biogeography as a backward step from panbiogeography.

Since Croizat studied the biogeography of many taxa, current taxonomists
may find the groups they study have been analysed panbiogeographically.
I would seem a basic requiruement of good science for
current researchers to consider that possibility. In the past, biogeographers
such as Abele and Mayr were able to make virtue out of not reading Croizat.
No longer perhaps.

John Grehan