Job, Post-doctoral fellowship in molecular systematics

John Grehan jgrehan at SCIENCEBUFF.ORG
Fri Jul 8 15:17:07 CDT 2005

Gary Rosenburg wrote:

> Jamaica has more than 500 endemic species of land snails yet is
thought to
> have been emergent for only about 15 million years, during which time
> has never been in contact with another land mass. 
> of the phylogeny of various clades should therefore help with
> reconstructing the biogeographic history of Jamaica. 

When I read the above I wondered "thought by who" and how would this
thought impact the biogeographic reconstruction. The implication seems
to be that history is derived from geology rather than biogeography.
After all, I don't think Croizat looked at Jamaica that way. Perhaps the
geohistory is wrong. After all, it is only a theory. If the geohistory
is accepted in the biogeography analysis I wonder whether the
'biogeography' will be anything more than a conforming narrative. 

I will stick my neck out and predict the usual molecular clock approach
that will declare in favor of dispersal conforming to the geohistory if
the dates are much later than the geohistorical origin (even though the
earlier events are actually not refuted by later clock estimates). If
the dates are earlier, will the biogeographers have the will to contest
the geohistory? It will be interesting to see.

John Grehan

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