They are colorful to look good for the lady guppies.
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Natural selection
3. Select a hypothesis from the Sex and the Single Guppy Web activity or come up with your own and record it here.
Predators are causing guppy populations to become more drab by preying on the most brightly colored individuals and eliminating them from the gene pool.
4. Next you will set up your experiment as directed in the simulation. Record your initial settings here.
Predator types and numbers: 30 rivulus Initial guppy population: mostly bright
5. Run your initial experiment for at least five generations and record your results here.
Number of guppies: 231
Number of generations: 6
Number of weeks: 102
Male color types: brightest, bright, drab, drabbest
Brightest male guppy: 70%
Bright male guppy: 20%
Drab male guppy: 7%
Drabbest male guppy: 2%
6. Was your hypothesis supported by your data? If so, why? If not, you may want to change your hypothesis and rerun your experiment.
No, my hypothesis was not supported by my data. The guppies multiplied like rabbits and the bright/brightest ones dominated over the others.
7. New hypothesis: Predators are causing guppy populations to become more drab by preying on the most brightly colored individuals and eliminating them from the gene pool.
Record your new data here.
My settings this time were mostly bright, and all 3 predators.
Number of guppies: a lot
Number of generations: 9
Number of weeks: 236
Male color types: brightest, bright, drab, drabbest
Brightest male guppy: 1%
Bright male guppy: 1%
Drab male guppy: 33%
Drabbest male guppy: 65%
8. Was your new hypothesis supported by your data?
If so, why? If not, redo. Yes, my hypothesis was supported by my data. All the bright ones basically died out and the drab ones multiplied like rabbits.
9. Summarize what you learned from your experiments.
I learned that it is better for guppies to blend in than brightly stand out. Even though sex selection seems more important than natural selection, the results say differently. Flashy Fish: Discussion Questions
1. Why do some guppies tend to be drabber than others?
They’re adapting to blend in with their surroundings.
2. Why do some guppies tend to be more colorful?
The bright colors attract females.
3. What role does color play in guppy survival?
The brighter they are, the more they will attract predators. If they are drab, they won’t find a mate very easily, but they have less of a chance to get eaten.
4. Explain the push and pull that the environment has on the coloration of guppies in Endler’s pools.
The brighter they are, the more they will attract predators. If they are drab, they won’t find a mate very easily, but they have less of a chance to get eaten.
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