Panbiogeography of the Americas

Thomas Schlemmermeyer termites at USP.BR
Sat Oct 2 19:36:05 CDT 1999


Sorry, if something in this thread escaped my notice. But to what work does the
reference "Heads (1983)" refer to?

>included. Further, Heads (1983) commented on the parallel track structure
>of marine shorefishes and terrestrial organisms in the Pacific.

> Because of the Coriolis force and because
>continental margins create obstacles around which fluids and the
>organisms in
>>>them must flow, they seldom travel in straigh lines of minimum distance.
>I don't understand how this relates to the track method which is about
>spatial relationships, not about dispersal routes (although one might apply
>the method to such consderations).

Yet, if I do recall correctly, Croizat himself used the term "dispersal",
though in an unusual sense, in connection with his method. How can spatial
relations be otherwise explained, if not through dispersal?
A very nice croizatian phrase, I recall, makes use of the spanish verb
"despachar". Croizat wonders how organisms were "dispatched" to the places one
finds them now.

If one assumes, like Croizat, dispersal (or dispatch) through vicariance, the
dispersal routes should follow the movement and direction of tectonic plates?

Are we to enter here a similar debate like in phylogenetics, where some people
always make their shortest trees independent of any process, while others
insist on formulating a process theory before constructing a tree?

And has this debate epistemiologically and so on not already been decided in
favour of the first group mentioned (in cladistics)?

Or in other words, is the understanding of the track as shortest line between
two points the direct translation of cladistics into panbiogeography, while
Stuart Poss' idea would have roughly something to do with those that prefer to
figure out a process before starting a model....

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