Peppered Moth Simulation:

Transcription

1 NAME DATE PERIOD Peppered Moth Simulation: Natural Selection in Black and White

2 Peppered Moths: Natural Selection in Black and White Select Peppered Moth simulation from Mrs. Lamers listing on The Destiny Website BACKGROUND Read the following sections and answer the questions below. The titles correspond to the tag for the circles I. The Life Cycle of the Peppered moth 1. Where are peppered moths commonly found? 2. Who are their natural predators? 3. When are moths most active? Why? 4. Describe the adult peppered Moth s camouflage. Be specific. 5. How do the larvae (caterpillar form) avoid detection? 6. What does the typical peppered moth look like? 7. What is the dark, almost black moth called? 8. What name is given to the peppered moth with a greater number of black spots? 9. Up until 150 years ago, which type of peppered moth was most common? II. Pollution and Peppered moths 10. What is the scientific name of the peppered moth? 11. When did the first recorded sighting of a dark peppered moth take place? 12. How did the peppered moth population in England change by 1900? 13. What was happening at the time which favored the survival of dark colored moths? Explain. How were genetics involved in the color of the moths? 14. What is natural selection? 2

3 Name Date Period Peppered Moth Simulation Objective: Simulate changes in moth population due to pollution and predation, and observe how species can change over time. Introduction: Charles Darwin accumulated a tremendous collection of facts to support the theory of evolution by natural selection. One of his difficulties was the lack of an example of evolution over a short period of time, which could be observed as it was taking place in nature. Although Darwin was unaware of it, remarkable examples of evolution were in the countryside of his native England. One such example is the evolution of the peppered moth Biston betularia. The industrial revolution began in the middle of the eighteenth century. Since then, tons of soot have been deposited on the country side around industrial areas. The soot discolored and generally darkened the surfaces of trees and rocks. In 1848, a dark-colored moth was first recorded. Today, in some areas, 90% or more of the-peppered moths are dark in color. More than 70 species of moths in England have undergone a change from light to dark. Similar observations have been made in other industrial nations, including the United States. III. A Bird s Eye view of Natural selection (circle with bird and moths) Instructions: You will each simulations three times, during this time you will play the part of a blue jay that eats moths. After each trial, record the percentage of dark moths and light moths in the table below ( light colored lichen forest and the dark colored sooty forest ) Peppered Moth Analysis Data Table Forest Percent Light Moths Percent Dark Moths Light Forest: Trial 1 Light Forest: Trial 2 Light Forest: Trial 3 Average population in Light (lichen) forest (ave. of trials 1-3) Dark Forest: Trial 4 Dark Forest: Trial 5 Dark Forest: Trial 6 Average population in Dark (sooty) forest (ave. of trials 4-6) 3

4 Analysis: Average the percent of moths of each color for each forest and record the values in the table. To average the values, find the sum of the Percent of Light colored moths in the Light forest for all three trials. Then divide that sum by 3 (the number of trials). Repeat using the values for dark colored moths in the Light forest, light moths in the dark forest and dark moths in the dark forest. Create two pie charts, one for each forest. Use your data to show the moth populations in each. Be sure to include the percentages. Remember, an entire pie is 100 %. Light forest Dark Forest 15. What did the experiment show about how prey is selected by predators? 16. What moth coloration is the best adaptation for a dark background? How do you know? 17. Explain how the color of moths increases or decreases their chances of survival depending on the environment. 4

5 light colored moths and 500 dark colored moths are released into a polluted forest. After 2 days the moths were recaptured, make a prediction about the amount of each type of moth that would be captured. (Hint: if they are not recaptured, assume that they have been eaten.) Use your prior experiment to help form your prediction. 19. How has the striking change in coloration come about? (Include an explanation of how the dark moth appeared and how the proportion of dark moths changed from % to more than 90% in polluted forests.) 20. How does the simulation model natural selection? 5

6 Problem: Examine the table and construct a graph. Plot the years of the study on the X-axis, and the number of moths captured on the Y axis. You should have 2 lines on your graph - one for light moths, and one for dark moths. Year # of Light Moths Captured # of Dark Moths Captured 21. Explain in your own words what the graph shows. 22. Describe another situation where this type of selection might occur. 6