Objective: SWBAT describe the changes in gene frequencies in a population by

completing a laboratory investigation.

Warm-Up: 1. Define Natural Selection2. Describe the relationship between gene frequency and natural selection (How does

one affect the other?)

Breeding Bunnies LabProblem: What happens to the frequency of harmful recessive genes during evolution?Background: F—allele for fur (dominant) f—allele for no fur (recessive) Frequency—how often some- thing occurs. Written as a decimal. ff

FF or Ff

Hypothesis:

Procedure:1. Make sure you have 50 black beans and 50

white beans in your bag. These are the alleles for adult rabbits.

2. Label 3 bowls as follows: FF, Ff, ff3. The rabbits reproduce: pick out 2 beans at a

time (these are the babies), record the beans in your data table, and put the beans in the proper cup.

4. Repeat this until every bean is gone from the bag, recording the data each time. This represents the 1st generation.

5. The FF and Ff rabbits survive, and go back in the bag, the ff rabbits die, because they have no fur. Keep the ff rabbits in the ff bowl (do not put them back in the bag).

6. Repeat the procedure for 10 generations, recording the data for the whole experiment.

7. Calculate the frequency of the F allele and the f allele for each generation.

Data Analysis:1. Graph the frequencies of the F and f alleles.2. What happened to the f allele? Did it completely

disappear?3. Explain what would happen to the rabbit

population if the hairless gene was dominant?4. What would happen to the frequency of the f

allele if it was not harmful?5. Did the genes of the rabbit population change

over time? Explain.6. Explain how this activity shows evolution.

Genera-tion

Number of FF Individuals

Number of Ff

Individuals

Number of ff

Individuals

Number of F

Alleles

Number of f

Alleles

Total Number

of Alleles

Gene Frequency

of F

Gene Frequency

of f

1

2

3

4

5

6

7

8

9

10

Generation Number of FF individuals

Number of Ff individuals

Number of ff individuals

Number of F alleles

Number of f alleles

Total number of alleles

Gene frequency of F

Gene frequency of f

1 12 26 12 50 50 100 50% 50%2 18 14 6 50 26 76 66% 34%3 19 12 1 50 14 64 78% 22%4 20 10 1 50 12 62 81% 19%5 21 8 1 50 10 60 83% 17%6 21 8 0 50 8 58 86% 14%7 22 6 1 50 8 58 86% 14%8 22 6 0 50 6 56 89% 11%9 23 4 1 50 6 56 89% 11%10 24 2 1 50 4 54 93% 7%

Mr Reeser’s Results