Re: extinctions

[JohnE37179@aol.com]

There are many potential weak links in any chain of life. Modification
of a link may lend evolutionary presure. the elimination of a link
probably leads to extinction.  My favorite among the "weak links" is
the production of chlorophyl. If a K/T boundary impact could through
enough debris into the atmosphere to block sufficient incoming light
for a sufficent time to substantially reduce the porduction of
chlorophyl the impact at all levels of the food chain and across phyla
boundaries would be substantial.  The disaster may have been at the
level of plant production and it all could lead from there. This would
affect marine and terrestrial envioronments alike.

Just a thought.

John Ellingson
Madison, WI

The glacier has started to melt.