Rock Pocket Mouse - Biology Assignment

Color Variation in Rock Pocket Mice Purpose: To explain how favorable traits increase in a population over time. Introduction: A typical rock pocket mouse is just about 170 millimeters long from its nose to the end of its tail, shorter than an average pencil. It weighs about as much as a handful of paperclips. Despite their small size, they have had an enormous impact on science. Rock pocket mice live all over the Sonoran Desert in the southwestern United States. There are two varieties: a lightcolored variety and a dark-colored variety. They are also two major colors of substrate, or surface materials, that make up the desert floor. Most of the landscape consists of light-colored sand and rock, but patches of dark volcanic rocks that formed from cooling lava are also found in “islands,” separated by several miles of light-colored substrate. Part 1: Order the Populations 1. With your table, review the 4 snapshots of rock pocket mice populations. Each page shows a snapshot of the color variation at two different locations, A and B, at a particular moment in time. The pages are not in order. 2. Count the number of light- and dark-colored mice at each location at each moment in time. Record the number of each type of mouse in each location in the table below. Location A Location B Slide A Slide B Slide C Slide D Number of Mice with Light Fur 11 10 10 11 Number of Mice with Dark Fur 1 2 2 1 Number of Mice with Light Fur 2 10 6 9 Number of Mice with Dark Fur 10 2 6 3 3. Using this information, what order would you put the slides in to show how the mouse population change over time Oldest (10,000 years ago) Slide a Second Oldest (5,000 years ago) d Third Oldest (2,500 years ago) c Most Recent (1,000 years ago) b 4. Using at least 3 complete sentences, explain how you and your table group decided which page represents the most recent population, and why you put the others in the order that you did. The look the most accurate 1 Part 2: Gather Further Information DIRECTIONS: As you watch the short film The Making of the Fittest: Natural Selection and Adaptation, think about why there were differences between the pictures you just sorted and what information might tell you the order they go in. Answer the questions below. 5. Why are some mice light-colored, while others are dark-colored? The color of where they live and since a ancestor had a mutation 6. Does fur color provide any advantage or disadvantage? advantage 7. What can explain the differences between the pictures you just sorted? 6 mice in the dark pic Part 3: Data Collection and Graphing 8. Using what you learned by watching the video, review your order of the pictures. Change them if you need to. When your entire table agrees, fill out the data table below using the counts you recorded. Location A Location B Oldest (10,000 years ago) Second Oldest (5,000 years ago) Third Oldest (2,500 years ago) Most Recent (1,000 years ago) Slide . a. Slide . d . Slide . c. Number of Mice with Light Fur 11 11 10 10 Number of Mice with Dark Fur 1 1 2 2 Number of Mice with Light Fur 2 9 6 10 Number of Mice with Dark Fur 10 3 6 2 Slide . b . 9. Create a bar graph that shows how mice are distributed at locations A and B over time. Make sure you have: a descriptive title and titles and labels for the x- and y-axes. You can choose to record all of the data for time periods A and B on the same graph, OR split locations A and B to make 2 graphs below. (Hint: The number of bars on your bar graph should be the same as the number of boxes in the table) 2 Part 4: Data Analysis Answer the questions below using complete sentences. 10. Why does the color of a rock pocket mouse influence its overall evolutionary “fitness”? HINT: Remember, evolutionary fitness is an organism’s ability to survive and produce offspring. In evolutionary fitness states that a species that can reproduce the most is the fittest so the darker mice who The color is based of where they live 11. Explain the presence of dark-colored mice at location A. Why didn’t this color become more common in the mouse population in location A? The area was light colored 12. Write a scientific summary that is at least 5 sentences and describes changes in the rock pocket mice in location B. Your summary should include: a. A description of how the population of mice has changed over time. b. An explanation of what might have caused those changes. c. A prediction that describes what the population of mice will look like 100 years from now. Make sure that your prediction is based on the patterns you have observed. Assume the environment does not change over the next 100 years. The mice are having a population increase in their areas because they are getting better suited for them. The areas where there is light colored ground the mice are mostly light colored. The reason for the increase in population in the pocket mice is the volcanic eruption. Made it so the mice with the mutation have a chance at surviving. I think that the population will stay the same and won't increase or decrease with time.The only reason the mice population increased is because of the volcanic area. 13. Evolutionary biologists often remind us: mutation is a random process, but natural selection is not random. How does this statement apply to the rock pocket mouse? 3 They are not mutated for no reason, it is for their best survival 4