Lab Report (Write in Blue or Black Ink)
Title: Natural Selection and Allelic Frequency
Problem: How does natural selection affect allelic frequency?
Hypothesis: Answer your problem!
Materials:
Paper bag
Pinto beans (red) GG or Gg
Navy beans (white) gg
Safety:
NO horseplay and NO throwing beans!
ED (Experimental Design):
IV (Independent Variable): genotype picked
DV (Dependent Variable): phenotype
Control: compare to a nonchanging population
Constants: types of beans and bag
Procedures:
1. Place 100 beans in bag (50 red and 50 white) and shake.
2. Randomly pull out two beans and make a line of grey rabbits (GG or Gg) and a line of white rabbits
(gg) until all 50 pairs are removed from the bag.
3. Remove 100% of the white rabbits and 25% of the grey rabbits (do this by counting the number of
grey rabbits and dividing by 4). Remove the number that you calculate for grey rabbits.
4. Then count the remaining red beans and write in the data table for the G allele.
5. Then count the remaining white beans and write in the data table for the g allele.
6. Add the red and white beans together to get the total and write in the data table for totol.
7. Take the number of red beans (G) and divide by the total and multiply by 100 to get the percent of
the G allele and write in the data table.
8. Take the number of white beans (g) and divide by the total and multiply by 100 to get the percent of
the g allele and write in the data table.
9. Then count out the number of red beans to equal the % of G and place back in the bag.
10. Then count out the number of white beans to equal the % of g and place back in the bag.
11. Shake the bag and repeat the procedures of removing pairs.
12. Repeat until you have completed 5 rounds.
Data:
# Red (G allele)
% Red (G allele)
# White (g allele) % White (g allele)
Total
Trial 1
Trial 2
Trial 3
Trail 4
Trial 5
Graph: Graph trial # vs %.
Questions:
1. Did either allele disappear? Why or why not?
2. What does your graph show about allelic frequencies and natural selection?
3. What would happen to the allelic frequencies if the number of eagles declined?
Conclusion: Write a conclusion that tells whether your data supported or did not support your hypothesis. Explain
your findings.
Initial & Date each page that you write on!!