In this activity (Page 30 of PDF), learners investigate the evolution of wheat by conducting sedimentation tests on different flours. The evolution of wheat from wild grasses demonstrates the dramatic effect of both natural and directed evolution on the structure of a crop plant and the chemical makeup of the product harvested from it. These activities illustrate the changes to both the structure and the chemistry of the wheat plant. Note: Sedimentation test can also be done using SDS detergent and lactic acid instead of soap and vinegar.