Re: extinction

[Stan Friesen <swf@tdat.ElSegundoCA.NCR.COM>]

From: Tom Waters; Earth Magazine <72350.1764@compuserve.com>
 > American chestnut is close to extinction because of a disease. If
 the tree
 > species survives it will be because of human efforts to control the
 disease.

Not necessarily so.

If the disease is like Ditch Elm, and requires some time to
infect and kill a newly sprouted tree, then the Chestnut could
respond the same way that the American Elm is responding to
Dutch Elm - by becoming a small understory tree through earlier
reproduction.

 > So I'd say diseases can cause extinctions.
 >
However, this is true.

The question is whether they can cause *mass* extinctions,
where several hundred to several thousand species all become
extinct.

swf@elsegundoca.ncr.com         sarima@netcom.com

The peace of God be with you.