1. Essential Question #2 Lesson #2
Natural Selection
Essential Question #2
Lesson #2

2. This week, we will…
Simulate the natural selction of a fictional moth population over several generations.
Graph the changes in a peppered moth population during the British industrial revolution.
Interpret and analyze the graph according to what we know about the British industrial revolution.

3. Natural Selection Simulation
How can a population change over time?

4. Natural Selection Simulation Instructions
1.) Trace eight butterflies using the outline on page 24.
2.) Pick a spot around the classroom where you will place your butterfly. It must be placed out in the open. Shade your butterflies IDENTICALLY, and so that they will blend in with the spot you choose.
3.) You will attach ONE of the butterflies to the wall with tape, in the spot it will be the most inconspicuous.
4.) One “bird” will have one minute to “hunt” as many of the moths as possible. If your butterfly is removed, it has died. If it is NOT removed, you may add one more- representing that it was able to live long enough to reproduce.
5.) We will complete 2-3 generations and see how the population has changed.

5. 1st Period

6. 2nd Period

7. 3rd period

8. A Historical Example of Natural Selection
The Peppered Moth
A Historical Example of Natural Selection

9. Create a double-line graph to organize the following data…
Year
# of Light Moths
# of Dark Moths 2
537
112 3
484
198 4
392
210 5
246
281 6
225
337 7
193
412 8
147
503 9 84
550 10 56
599

11. Interpret… Put these steps in order!
A: Many years ago, the trees in the countryside between London and Manchester were covered with light-colored lichens.
B: Many of the light colored moths couldn’t survive long enough to reproduce. Meanwhile, the dark colored moths began to flourish, since they could easily blend in to the soot-covered tree bark.
C: After a few years, the moth population, once predominately light-colored, was almost entirely dark. This phenomenon is called “industrial melanism.”
D: The light colored moths were no longer able to blend in to the tree bark, making it easier for birds to find and eat them.
E: The moths that lived there were also light colored, which allowed them to easily blend in to the lichen covered trees to avoid being eaten by birds.
F: At the start of the Industrial Revolution, coal-burning factories began to emit sulfur dioxide and soot, which killed many of the lichens and turned the bark a dark black color.

12. A E F B D C

13. Analyze…
Explain in your own words what the graph is showing. Include the following vocabulary in your explanation…
Survivors
Offspring
Adaptation
Environment
Natural Selection
Camouflage

14. Summary of the Peppered Moth