How do spines protect ocean stickleback fish

SCIN 130 Lab 3: Stickleback Evolution, Part 1

General Instructions

Be sure to read the general instructions from the Lessons portion of the class prior to completing this packet.

Remember, you are to upload this packet with your quiz for the week!

Background

In this experiment, you will analyze the pelvic structures of stickleback fish collected from two lakes around Cook Inlet, Alaska, to determine whether there are significant differences between the two populations. You will then use your data and information about the lakes to draw conclusions about the possible environmental factors affecting the evolution of pelvis morphology.

Specific Lab Instructions

Name:     

Date:     

Go to: The Virtual Stickleback Evolution Lab

1. Read the entire Introduction

a. How do spines protect ocean stickleback fish?

b. Watch the video about pelvic reduction in freshwater stickleback. The loss of stickleback pelvic spines is similar to the loss of which body parts in some other four-legged vertebrates?

2. Click on Overview, read the material.

a. Click on the interactive stickleback fish. Describe where its spines are located.

b. Watch the video about the stickleback fish armor. Explain how the stickleback armor protects the fish from some predators.

3. Click on Tutorial 1, practice scoring the pelvis of living fish until you feel as if you have mastered it.

4. When you are comfortable with scoring, click on Experiment 1. Be sure to read the background information prior to beginning.

SCIN130 Lab 3: Stickleback Evolution, Part 1

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b. Explain in your own words the overall objective of Experiment 1.

c. Click on the link to the map of Alaska, then click on the blue pin “B” on the larger map. What lake is located between Rabbit Foot Lake and Coyote Lake?      

d. In a population, what happens to organisms that are better adapted to the environment in which they live?

5. Click on Part 1 in Experiment 1. Read the information and watch the video. When you are ready, begin the experiment by clicking on the blue gloves. Then follow the directions on the left panel to perform the staining experiment.

6. When you have finished staining the fish in Part 1, move on to Part 2 of Experiment 1.

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8. Before you score the fish, watch the short video on Bear Paw and Frog Lakes. According to Dr. Bell, what is an important difference between Bear Paw Lake and Frog Lake?

9. What is one advantage of studying larger-sized samples?

10. Complete Part 2 of the lab in the window on the left.

a. Why is it important that the labels included in specimen jars be made of special paper that does not disintegrate in alcohol over time?

b. When you have finished scoring fish from both locations, count each phenotype, then submit your totals.

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d. You are to create a graph from your data. The graph creator in the lab works perfectly fine if you do not want to transfer your data to Excel. Create a graph and insert a screenshot of it here.

e. Examine the pelvic score data you just collected. Does the pelvic phenotype differ between Bear Paw Lake and Frog Lake fish? Explain.

f. Explain why the stickleback fish in Frog Lake are more similar to ocean and sea-run stickleback than they are to the stickleback fish in Bear Paw Lake.

11. Take the quiz at the end.

a. When you are finished, Insert your name in the progress section, take a screenshot from the progress section, and insert it here (tutorial 1, Experiment 1, parts 1, 2 and 3 should all say complete).

Adapted from: Brokaw, A. (2013). Stickleback Evolution Virtual Lab. HHMI Biointeractive Teaching Materials.