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Online Lessons for Teachers: Learning Evolution

LESSON 4: 

How Does Evolution Work?

View LESSON 4 Student Page

Activity One: Breeding Bunnies

Activity Two: Flashy Fish

Activity Two: Teacher Notes

Materials You'll Need:

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Breeding Bunnies: Gene Frequency Data form (pdf)

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Breeding Bunnies: Discussion Questions (pdf)

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50 red beans

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50 white beans

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1 paper bag or deep bowl

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3 dishes or containers

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labels

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pens

Activity 1 Teacher Notes: Breeding Bunnies

This activity can also be used to introduce the Hardy-Weinberg principle of gene frequency equilibrium. Although the Hardy-Weinberg principle is not introduced to the students, the concept is at the heart of the activity. If the students have already studied Hardy-Weinberg, or if you want to use this activity as an introduction, you can use the Hardy-Weinberg equation to explain the results the students obtain. Students need to think about factors that can influence evolution like mutation, emigration, and immigration.
Image of Marilyn Havlik

You may want to watch "Teaching Evolution Case Studies: Marilyn Havlik," which documents a teacher who runs a hands-on Hardy-Weinberg experiment using a kiddie pool to represent the gene pool. Information about her lesson can be found here.

Marilyn Havlik
View in:
QuickTime | RealPlayer

Note: In the following activity we have made several simplifications. We have assumed that rabbits mate once and do not reenter the breeding pool. (Of course, this is not true with real rabbits.) For this reason, the population declines artificially rapidly. The activity helps show the change in frequency of a lethal recessive allele over time, but is not intended to represent exactly what would happen with a population of real rabbits.

Learning Goals

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To show students the impact that genetics can have on the evolution of a population of organisms

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To make students aware of the influence that the environment has on organisms

Procedure

1. 

Divide the class into small groups (preferably four students per group), and distribute the materials. Pass out the Gene Frequency Data form (pdf) and the Discussion Questions (pdf), or ask students to print them from the Student Page.

2. 

Have students follow the instructions on the Student Page. You may want to travel around the room at the beginning of the activity to make sure all the groups understand the instructions.

3. 

At the conclusion of the lab, ask students to answer the Discussion Questions. The answers can be discussed by groups or by the whole class.

4. 

When you discuss question seven, consider the definition of evolution as being the change of gene frequency of a population over time. The natural selection against the furless allele may cause the gene frequencies to change, but random genetic changes due to mutation, migration, and natural disasters may impact the already stressed gene frequencies even more. Also, relate the more general definition of evolution ("descent with modification") with the results observed.

Adapted with permission from a 1994 Woodrow Wilson Biology Institute Laboratory "Evolution and Gene Frequencies: A Game of Survival and Reproductive Success," by Joseph Lapiana.


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