Evolution of Plants from the Paleozoic to the Present

 

Jon Cawley and Mary Schaeffer

Tested Studies in Laboratory Teaching, 2003, Volume 24

Abstract

In an effort to present well-understood mechanisms of adaptation and selection in a simple format, we have developed an introductory laboratory script based on adaptive history and change in the plant kingdom. The exercise is designed as a “tree-walk through time,” using trees and plants available on campus to illustrate adaptive traits of different plant groups developed during different points in geologic history. Beginning with discussions of the ancient spore-bearing plants and the gymnosperms, the fieldtrip continues through a total of 15 representative plants and their botanical stories, including: ferns, cycads, pine, ginkgo, hemlock, dawn redwood, magnolia, tulip tree, oak, elm, maple, apple, birch, bamboo, and orchids. Each of these is discussed in its evolutionary, morphologic, environmental and/or geologic context. The evolutionary pressures of hemlock wooley adelgid and Dutch Elm Disease are also discussed. This laboratory script has been used with excellent success in General (non-majors) Biology at both Virginia Tech and at Roanoke College.

Keywords:  adaptation, natural selection, disease

Louisiana State University (2002)