Name________________________________
Per______
Guppy Evolution Lab
The purpose of this activity is to analyze how
guppy populations change over time. The
simulation activity allows you to start with a pool
of guppies and your choice of predators, you will
be able to watch what happens to your guppy
population and how the introduction of predators
can affect the guppy's appearance. The simulation
will help you understand what pressures drive
guppy evolution.
*Activity adapted from PBS - http://www.pbs.org
To open the Guppy Sex Simulator.
1. Open Internet Explorer
2. Go to the website: www.pbs.org
3. Click on Teachers in the top tool bar toward the right. This should take you to
the PBS LearningMedia page.
4. On the PBS LearningMedia page, type guppy into the search box.
5. Click on the link for Sex and the Single Guppy.
6. Click on the link that says Launch to open up the interactive lab.
Or type in the following url:
http://www.pbs.org/wgbh/evolution/sex/guppy/
Introduction:
1. Read the introduction on the screen for Sex and the Single Guppy, then answer the following
question:
If being flashy and colorful attracts predators, why do you think guppies are so colorful?
2. Click on Guppy Gallery (lower right corner—or possibly left corner). View the guppy gallery and
pick the fish you find most interesting and record its information below.
Scientific name: ______________________
Origin: __________________
Average Size: ________________
Describe the coloration of the fish you chose:
3. View the predator gallery by clicking on the Predator tab in the lower right corner. Pick the fish
you find most interesting and record its information below.
Common name: _____________________
Scientific name: _______________________
Origin: ______________________
4. View the guppy’s habitats. What habitat conditions would affect the predator populations?
Next, click Back to Simulation in the lower left corner.
Click “I’m ready to find out” and read about Endler’s discovery.
Endler’s Discovery and Variations of Guppies in Pools:
5. Read and scroll through the box about Endler’s discovery and answer these questions:
Who is John Endler? What did he study and where did he study it?
6. Click on the pools 1, 2, and 3 to investigate the guppy stream. For each of the three stream
areas, describe the guppy coloration:
Pool 1:
Pool 2:
Pool 3:
7. Click on “What causes guppy color variation?” Pick a hypothesis from the list and write it below or
develop your own hypothesis about guppy coloration and write it below. The hypothesis should
answer the questions: Why do guppies in different areas of the stream have difference in coloration?
Click on “To start, choose how you want to set up your simulation pool.”
From the drop down menus, select the guppy color types and predator species and
numbers indicated for each trial listed in the data table below.
Allow each trial to run for 5 generations, then press Stop Simulation and View
Results. Record data in the data table.
Next, click on Run another simulation and conduct the next trial.
Continue this process until you have collected and recorded data for all of the trials.
Guppy Simulation
% of Brightest
Guppies
(5 generations)
% of Bright
Guppies
(5 generations)
% of Drab
% of Drabbest
Guppies
Guppies
(5 generations) (5 generations)
Trial 1
Guppy: Even Mix
Predators: 30 Rivulus
Trial 2
Guppy: Even Mix
Predators: 30 Rivulus, 30
Acara
Trial 3
Guppy: Even Mix
Predators: 30 Rivulus, 30
Acara, 30 Cichlid
Trial 4
Guppy: Mostly Bright
Predators: 30 Rivulus
Trial 5
Guppy: Mostly Drab
Predators: 30 Rivulus, 30
Acara, 30 Cichlid
After all data has been collected and recorded, click on Read Summary and answer
the questions on the following page.
Summary:
8. Describe how predators influence guppy coloration.
9. Was your hypothesis correct, use your data to justify your answer.
10. What does it mean that “male guppies live in a crossfire between their enemies and their wouldbe mates”?
11. Why do you think guppies in different areas of the stream have different coloration?
12. What would happen to mostly drab guppies that were placed in a stream with very few
predators?
13. What would happen to brightly colored guppies that were placed in a stream with many
predators?