Name:__________________________________________________
Period:__________
Date:__________________________
Natural Selection in Goldfish
Problem: A predator feeds on a fish population made up of YELLOW fish, which are slow and
easily caught, and MULTICOLOR fish, which are fast and not easily caught.
What effect does natural selection have on these two fish populations?
Write a Hypothesis below for the question asked above. (If..then..because..)
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Materials:
● Yellow Goldfish Crackers
● Colors Goldfish Crackers
● Paper/pencil
● Paper towels or cups for crackers
Procedure:
1. Obtain a mixed population of goldfish from your teacher.
2. You will start the activity using 5 yellow fish and 5 colors fish. This is Generation 1. Record
these numbers on the data table in the Generation 1 row.
3. You are a predator that preys upon these fish. Remember, from the paragraph above that the
YELLOW fish are slow and easily caught. The COLORS fish are fast and not easily caught. Eat 3
YELLOW fish (if you do not have three YELLOW fish, then eat the remainder in COLORS fish.
4. Each surviving COLORS fish produces one new COLORS fish, and each YELLOW fish produces
one new YELLOW fish. Add your new generation to your fish family from the cup of crackers your
teacher provided. Record the new number of fishes in your fish family on your data table in row
Generation 2.
5. Repeat steps 3 and 4 two more times for Generation 3 and Generation 4.
6. Create a line graph to represent your data.
Curriculum
1 of 4
11/15/2021
Data Table
Generation
Number of Surviving
COLORS Fish
Number of Surviving
YELLOW Fish
Number of
Surviving Fish
(Total)
1
2
3
4
Graph-Remember TAILS format
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Curriculum
2 of 4
11/15/2021
Analysis Questions
1. Why did the Yellow population go extinct?
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2. Explain what the phrase “survival of the fittest” means and how does it apply to the Orange fish
population?
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3. Use your knowledge of natural selection to explain what happened to the Color population of fish
over the four generations?
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4. Use your knowledge of natural selection to explain what happened to the Yellow population of fish
over the four generations?
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5. Describe the population trend for the Yellow fish over 10 to 20 generations and give reasons using
the data you have collected.
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Curriculum
3 of 4
11/15/2021
Conclusion
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Curriculum
4 of 4
11/15/2021