Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!umd5!purdue!i.cc.purdue.edu!j.cc.purdue.edu!pur-ee!uiucdcs!uiucdcsm!wsmith
From: wsmith@uiucdcsm.cs.uiuc.edu
Newsgroups: sci.bio
Subject: Ancient History
Message-ID: <20800001@uiucdcsm>
Date: 7 Apr 88 22:48:00 GMT
Lines: 15
Nf-ID: #N:uiucdcsm:20800001:000:675
Nf-From: uiucdcsm.cs.uiuc.edu!wsmith    Apr  7 16:48:00 1988


In tropical regions, many plants have evolved to be unable to tolerate freezing
weather.  In temperate regions, some trees not only tolerate freezing weather,
but require it in their reproductive cycles.

This leads to a chicken and egg question:  When plants first evolved, were
they able to tolerate freezing weather?  My guess is that they were not
able to because it was difficult enough to get enough energy for reproduction.
Did tropical plants lose the ability to live in cold regions or did
the tropical plants evolve and develop the ability to do such living?   
When did this transition (in either way) occur?

Bill Smith
pur-ee!uiucdcs!wsmith
wsmith@a.cs.uiuc.edu