Stickleback Evolution Virtual Lab
Designed for Remote Learning Name: _______________
In this lab, you will apply the scientific method to a population of stickleback fish in Alaska. These fish have evolved as they adapted from a marine environment to a freshwater one, with some populations losing their pelvic spines. You will also examine the fossil remains of these fish to see how their traits changed over geologic time. You will learn about why these fish are so interesting to evolutionary biologists, collect data in a laboratory simulation, and then analyze your results.
Video – Making of the Fittest
Start by watching clips of the short film, “Making of the Fittest: Evolution of the Stickleback Fish” at this link: https://www.youtube.com/watch?v=Pv4Ca-f4W9Q&feature=emb_logo
- Watch until 4:05 (when the man on the bike appears).
- Skip ahead and start again at 11:40 (section on fossils).
Video Questions
- How were the freshwater lakes featured in the video, like Bear Paw Lake, formed?
- What is the purpose of dorsal (back) and pelvic spines for stickleback fish in their native, marine environment?
- Why are spines a liability in Bear Paw Lake?
- Why does Mike Bell expect to find stickleback fish fossils in the middle of Nevada?
- What trends over time did Mike Bell observe in the fossil record for stickleback fish with spines versus those without spines? Why does he think those trends occurred?
Experiment 1: Analyze Stickleback Fish from Lakes
Now, armed with some background knowledge, you are going to do a lab simulation where you gather data on stickleback fish from two Alaskan lakes. Start the simulation here:
- Read the Introduction material on the right-hand side before you begin.
- The Overview gives you more information about the anatomy of the stickleback fish.
- Click to enter the lab on the left and start Tutorial 1.
- Hint: Once you begin the tutorial, I find it helpful to use the ventral view to see the spines.
The ventral view of a fish with complete pelvic spines.
- If you succeed in the tutorial, you can proceed to Experiment 1.
- Hint: Once you begin Experiment 1 and click on the blue gloves, click on Skip Part 1: Staining.
- You will collect data for 20 fish from Bear Paw Lake.
- Then, you will collect data for 20 fish from Frog Lake.
- When you are done scoring all 40 fish, you can enter and submit your totals.
- You can make your own bar graph, or select option #2 to have the simulation create a graph for you.
- You can click on the blue button on the lab simulator to Verify Your Data. You will not be graded on your accuracy!
- You do not need to do the Quiz that is built in to the simulation, but it might be fun and informative.
Insert your graph here:
Experiment 1 Questions
Make sure you verify your data first, so you are working from the correct information.
- What makes a stickleback fish a good model organism?
- What would be a good hypothesis for this experiment?
- We know from the video that there are dragonfly larvae in Bear Paw Lake. Do you think there are dragonfly larvae in Frog Lake? Why or why not?
- Which population of stickleback fish are more similar to marine stickleback fish: Bear Paw Lake or Frog Lake?
- In terms of stickleback survival, is there a difference between having reduced or absent spines?
Experiment 2: Analyze Fossil Fish
Now you are going to collect data on fossils of stickleback fish from Nevada to estimate the rate of evolution of change in pelvic structures. This is like what you saw at the end of the “Making of the Fittest” video.
- On the picture of the lab, click on Experiment 2: Analyze Fossil Fish.
Select Experiment 2: Analyze Fossil Fish
- Click on Skip Part 1: Fossil Prep
- Now you can read the Background information on the right.
- Go ahead and start the lab simulation by scoring the fossilized fish.
- Hint: If you need to review how to score a fossil fish, there is a link at the top of the data sheet on the left.
- After you score all of the fish from Layers 2 and 5, enter your data and submit it.
- A data chart with data from Layers 1 through 6 should appear, including your data.
- As in Experiment 1, you can have the simulation create a graph for you.
- You can also verify your data. You are not graded on your accuracy!
Insert your graph here:
Experiment 2 Questions
Make sure you verify your data first, so you are working from the correct information.
- In looking at the line graph of the verified data, in which layers were there more fish with complete spines than reduced/absent?
- Layer 1 is the oldest layer. Fish colonized the lake during the time when Layer 1 formed. The lake did not have any large predatory fish for the time that spans Layers 1 through 6. How does this explain what you observe in subsequent layers?
END OF LAB
