Instructor’s Copy

Lab Worksheet: I See You

Table 1: Number of Moths Captured on Different Backgrounds

Background / Number of moths Captured
Newspaper moths / Black moths / White moths
Newspaper /

Few captured

/

Many captured

/

Many captured

Black /

Many captured

/

Few captured

/

Many captured

Summary of data:

1. Which color of moth was captured most often with the newspaper background? Black or white

2. Which color moth was captured least often with the newspaper background? Newspaper

3. Which color of moth was favored for survival with the black background? White or newspaper

4. Which color of moth was favored for survival with the black background? Black

QUESTIONS:

5. What is the relationship between the type of background and the type of moth caught?

The moths that did not match their background were caught.

6. Which moth was “fittest” for survival?

The one that was camouflaged was fittest for survival.

7. What would happen if the trees went back to their original color after the industrial revolution

ended?

The salt & pepper (newspaper) moths would have the best chance of survival.

8. Where do these variations in moth color come from?

The variations occur naturally.

9. Using Darwin’s theory of the survival of the fittest, how could you explain the different races

of humans? Coloration gives them a better chance of survival, not from predators or

camouflage, but from skin cancer. Darker races are often found near the equator when

the sun’s rays are more damaging. Light-skinned races are often found in regions where

the sun is not as strong.

10. What changes in the “bird” would give it more of an advantage in catching moths?

Almost any answer that would apply to a predator will work, such as better sight, the

ability to smell the moths, etc.

11. What could eventually happen to the genes of the most poorly adapted moths?

They could die out.

12. How would Darwin explain your results? The moths more adapted for survival

(camouflaged) survived to pass on their genes.

13. How would Lamarck explain your results? Because the tree surface changed colors, the

moths changed colors so that they would match their background.