I'm Looking Over a White-Striped Clover
A Natural Selection Case
Author(s)
Abstract
This case is an exploration of the process of natural selection using white clover (Trifolium repens) as an example. In general, two forms of white clover can be found around the world in various habitats. One type is able to produce cyanide in its leaves, while the other is not. This variation within the clover species, along with the fact that cyanide production is paired with the production of a white stripe on the leaf, is used to teach the process of evolution through natural selection. Students use the scientific method to explore these concepts. As an introduction to evolutionary concepts in biology, the case would be appropriate for both high school and college biology courses.
Objectives
- Understand the process of natural selection and the importance of environment-specific adaptations.
- Acquire an understanding of the concepts of variation, natural selection, fitness, selection pressure, evolution, and adaptation.
- Using these concepts, describe the frequency of the two types of white clover.
- Be able to predict the distribution of cyanogenic clover in given microhabitats.
- Gain experience with the scientific method and be able to propose hypotheses and justifications to explain the frequency of the two types of white clover.
- Design experiments to test hypotheses and describe data that would support these hypotheses.
- Understand and synthesize information from figures and tables.
Keywords
Natural selection; variation; adaptation; evolution; white clover; trifolium repens; cyanide; cyanogenesis; experimental designTopical Areas
Scientific methodEducational Level
High school, Undergraduate lower divisionFormat
PDFType / Methods
InterruptedLanguage
EnglishSubject Headings
Biology (General) | Evolutionary Biology | Botany / Plant Science |
Date Posted
11/28/06Teaching Notes
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Answer Key
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Comments
Beth Adler
badler@ortn.edu
Science
Oak Ridge High Shcool
Oak Ridge, TN
03/28/2011
Wonderful case study. I incorporate an intro to the nitrogen cycle and a review of cellular respiration/metabolic poisons and genetics. The white clover project lab activity from Washington University goes well with the activity as well: http://biology4.wustl.edu/cloverproject/ -----------------------------
Renee Diamond
rdiamond2466@optonline.net
Science
Brick Township High School
Brick, NJ
10/15/2013
Fantastic case study! I teach A.P. Environmental Science and I cover this during my evolution section. It is also gives me an opportunity to review genetics and a little preview of toxicology that I cover later in the course. Wonderful! -----------------------------