Exercise 1
1. "In nature, populations evolve, and individuals do not." Explain this statement.
2. According to your predictions in Data Table 3, what percent of the population would be expected to exhibit brown fur? White fur? According to the data you recorded in Data Table 4, what average percent of the population did you actually observe with brown fur? White fur?
3. List the assumptions of the Hardy-Weinberg Equilibrium Principle. Describe why the principle was or was not supported by the model population.
4. State the Hardy-Weinberg Equation and describe how the equation was utilized in Exercise 1.
Data Table 1: Preliminary Analysis of the Population
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How many alleles does a diploid organism have?
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How many diploid individuals exist in the population?
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What is the allelic frequency of B (p) in the gene pool?
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What is the allelic frequency of b (q) in the gene pool?
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Data Table 2: Descriptions of Genotype and Phenotype of Individuals
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Description
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Genotype
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Color of Each of 2 Beans
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Phenotype
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Homozygous dominant
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Heterozygous
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Homozygous recessive
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Data Table 3: Expected Genotypic Frequency and Number
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Expected Data
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Genotype
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BB (p2)
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Bb (2pq)
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bb (q2)
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Expected Frequency
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Expected Frequency
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Data Table 4: Sampling with Replacement
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Generation
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Genotypic Number
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Allelic Number
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Genotypic Frequency
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Allelic Frequency
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BB
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Bb
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bb
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B
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b
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p2
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2pq
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q2
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p
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q
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1
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2
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3
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4
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5
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6
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7
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8
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9
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10
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Average
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Exercise 2
1. Of 10 total generations, how many generations had at least one individual with the white phenotype?
2. Was the allele for white fur ever fully eliminated from the gene pool of the population? Explain why you think the allele would or would not eventually be eradicated from the population.
3. Using the graph in Graph 1, describe the trends in the genotypes as generations passed. Did genotype numbers change more drastically in early generations or later generations?
4. At what generation (if any) did you first observe no homozygous recessive individuals?
5. How is it that a generation of foxes that all have brown fur could give birth to some foxes with white fur? Did this occur in your population? If so, list the generations that included brown individuals that gave birth to white individuals.
6. Which assumptions of the Hardy-Weinberg Principle were upheld in Exercise 2, and which were not?
7. Explain how evolution was observed in the model population in Exercise 2. If evolution had not been observed, how might the graph in Graph 1 look?
8. Consider how the gene pool of the population might have changed, if, during the winter months, the third generation had unexpectedly high amounts of snowfall. How would the graph in Graph 1 reflect this change?
Data Table 5: Sampling without Replacement
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Generation
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Starting Allelic Frequency
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Starting Allelic Number
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Genotypic Number
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Final Genotypic Frequency
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Final Allelic Number
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p
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q
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B
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b
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BB
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Bb
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Deaths (bb)
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p2
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2pq
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q2
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B
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b
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1
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2
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3
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4
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5
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6
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7
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8
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9
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10
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Average
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