Disease and dinosaur extinction

[Mike Heithaus <SMH5067@ocvaxa.cc.oberlin.edu>]

I seem to recall that somone wanted evidence that disease may not cause huge
extinctions on the order of wiping out the dinosaurs.  Here is one:
The Great American Interchange.  When the land bridge between North and South
America formed, two faunas that were not in contact for millions of years
came into direct contact.  There certainly would have been disease exchange,
probably at levels close to those that may have occured during dinosaur
interchanges.  The result of this interchange was extinction of some species,
but nowhere near all mammals involved in the interchange.  Also, these
extinctions were definately not soely due to disease either.  Surely, some
species were driven to extinction by superior competitors or predators.
        
                        Mike Heithaus
                        SMH5067@ocvaxa.cc.oberlin.edu