wsmith@uiucdcsm.cs.uiuc.edu (04/08/88)
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