"Wolfgang" wrote in message
...

snip
Or, for that matter, why rely on mutation at all when any number of
well-understood (and, in various similar situations, well-documented)
environmental factors could easily account for the sudden problematic
burgeoning of a particular heretofore benign organism?

Wolfgang

I'm well aware of many of the theories that have been put forth - mutation
in place, increased UV light inhibiting the grazing invertebrates that
normally keep it in check, some unknown pollutant either stimulating it or
harming organisms that would normally keep it in check, global warming,
etc.- but I hadn't heard the one I came up with, and its is about as
plausible as the others and equally difficult to prove or disprove. The
difference is that its mine! 8).

Bob Weinberger