Sean Houtman wrote:

There isn't any real evolutionary
pressure for a tree to be pretty in the fall, it is just something
that some of them do.


There are two major hypotheses to explain colorful fall leaves. One is
that red anthocyanins act as a sunscreen and act as antioxidants. The
other is that colorful leaves repel insects.


The Warm Hues of Fall Foliage Competing theories try to explain the
season's spectacular show of color, but most come up short:
http://www.sciam.com/article.cfm?art...75809EC5880105

A Puzzle for the Autumnal Equinox:
http://www.corante.com/loom/archives/015786.html

Why Leaves Turn Color in the Fall:
http://www.the-scientist.com/yr2001/...p8_011210.html



David R. Hershey