Flashy Fish: Guppy Simulation
Name: ________________________
Per. _____________
http://www.pbs.org/wgbh/evolution/sex/guppy/index.html
A. Read the introduction, then click “I’m ready to find out.”
B. Read about Endler’s discovery and explore the 3 pools in the stream.
1. If being flashy attracts predators, why are male guppies so colorful?
2. What do you think is responsible for the variation in color from one generation to the
next?
C. Click “What causes guppy color variation?”
3. Select a hypothesis from the list provided or come up with your own and record it
here.
D. Click “To start, choose how you want to set up your simulation pool.”
E. Input these initial settings - Guppy Color Types: Mostly bright
Predator Species and Numbers: 30 rivulus
4. Run your first simulation for seven generations, then click “Stop Simulation,” and
record your results here:
Number of guppies: ____________
Number of generations: ___________
Number of weeks: ____________
Male color types -
Brightest male guppy: __________%
Bright male guppy:
__________%
Drab male guppy:
__________%
Drabbest male guppy: __________%
5. Was your hypothesis supported by your data? Why? If not, you may want to rewrite
your hypothesis below.
(OVER)
F. Click “View results,” then click “Run Another Simulation,” and input these settings –
Guppy Color Types: Mostly bright
Predator Species and Numbers: 30 rivulus, 30 acara, 30 cichlid
6. Run the second simulation for seven generations and record your new data here:
Number of guppies: _______________
Number of generations: _______________
Number of weeks: _______________
Male color types -
Brightest male guppy: __________%
Bright male guppy:
__________%
Drab male guppy:
__________%
Drabbest male guppy: __________%
7. Was your new hypothesis supported by your data? Why? If not, rewrite your
hypothesis below.
8. Summarize what you learned from your experiments.
9. Why do some guppies tend to be drabber than others?
10. Why do some guppies tend to be more colorful?
11. What role does color play in guppy survival?
12. Explain the push and pull that the environment has on the coloration of guppies in
Endler’s pools.
G. If you have extra time, run additional simulations with varying levels of brightness and
different numbers of predators.