## M & M Lab

Linda Gostinger
1994 Woodrow Wilson Biology Institute

#### Introduction

This laboratory investigation is set up to show how selection occurs in a random population. The concept is that selection affects evolution. The Hardy-Weinberg Principle is in effect. There is a large population, random mating, no mutations, no isolation and no migration taking place. This lab will demonstrate how selection occurs and will analyze shifts in the populations. This shift can be shown by a percent change.

#### Target Age/Ability Group

Middle School and High School/Life Science and Biology

#### Class Time

One class period of 50 minutes

#### Materials

• M & M's óEqual number of each color
• extra M & M's
• Candy cornóone for each M & M
• Pan or box to hold candy

#### Procedure

1. Set up candy with equal numbers of M & M's and candy corn. For example use 50 of each of the six M & M colors and 300 candy corn. Do not tell students what is happening or even what you have in the box.

2. Walk around the room and have each student take two M & M's. Tell the students that the candy corn is poison. They may look into the box to pick the color of their choice. You need to go by very quickly.

3. Count the number of each color of candy taken and tally on the board. Make a chart on the board as shown on the next page.

Number
 FIRST GENERATION SECOND GENERATION Number Number Colors Start Taken Left Start Taken Left Red Orange Yellow Green Tan Brown

Have the remaining colors reproduce. If 29 red are left, then add an additional 29 to equal a total of 58 in the second generation.

Leave the candy corn at the initial 300. This can be eaten at the end of the lab.

1. D. Repeat part C for four more generations. Continue to tally on a chart on the chalk board. As a variation (or use for discussion), start over with 50 of each. After the first draw, tell the students the red ones are poison. Go through the next five generations as done above maintaining the red one as poison.

#### Student Discussion Questions

1. Why did they choose the colors they did?

2. How does this relate to sexual selection?

3. How does it show survival of the fittest?

4. What happened when the same colors were chosen repeatedly?

5. What biases would enter into later choices?

6. What happened when the red ones became poison?

7. How does this activity show the concepts of Hardy-Weinberg concept?

8. How does this lab relate to mimicry?

#### Hardy-Weinberg Equilibrium Introduction

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