Warm-up

The Natural Selection Gizmo allows you to play the role of a bird feeding on peppered moths. The initial population of 40 moths is scattered over 20 tree trunks.

How to play

Click play button and then Click on moths to capture them. Click the Next tree button (or the spacebar on your keyboard) to advance to the next tree.

Procedure

• Check that LIGHT TREES is selected.

• Click Play button and hunt moths for one year.

• After one year is over click on the graph tab at top right to see results of capturing for one year.

• Click on the button that says "Captured Moths"

• Take a picture of the graph. The camera button is in the top right corner of the graph.

• Right click on the picture and "Copy Image"

Click in the free response box below and paste the image using Control + V (PCs) or Command + V (Macs)

If a forest contained mostly light-colored trees, which type of moth would you expect to be most common?

Experiment #1

• Click Play and hunt peppered moths on light tree trunks for five years.

• In each year, try to capture as many moths as you can. Note: You can use the spacebar on your keyboard to quickly advance to the next tree.

• At the end of eachyear, you will need to click "Continue" to go to the next year and then the play button to play hunt again.

• After 5 years, select the GRAPH tab and look at the percentages of each moth type population.

• Click on the button that says "Moth Populations." (Note: The table shows current populations of each moth, not the number of captured moths.)

(Your graph should not look the same as mine. This is just an example and contains only one year of data)

• Take a picture of the graph. The camera button is in the top right corner of the graph.

• Right click on the picture and "Copy Image"�

• Click in the free response box below and paste the image. You can right click and choose paste or use keyboard keys Control + V (PCs) or Command + V (Macs)

Experiment #2

• Click Play and hunt peppered moths on dark tree trunks for five years.

• In each year, try to capture as many moths as you can. Note: You can use the spacebar on your keyboard to quickly advance to the next tree.

• At the end of each year, you will need to click "Continue" to go to the next year and then the play button to play hunt again.

• After 5 years, select the GRAPH tab and look at the percentages of each moth type population.

• Click on the button that says "Moth Populations." (Note: The table shows current populations of each moth, not the number of captured moths.)

(Your graph should not look the same as mine. This is just an example and contains only one year of data)

• Take a picture of the graph. The camera button is in the top right corner of the graph.

• Right click on the picture and "Copy Image"

• Click in the free response box below and paste the image. You can right click and choose paste or use keyboard keys Control + V (PCs) or Command + V (Macs)

How did the changes in the moth populations occur?

Claim: Natural selection is the process by which favorable traits tend to increase in frequency over time.

Evidence: How does this experiment illustrate natural selection?

(use the data that you clollected in the graphs to support your answer)