Calculate the genotype and allele frequencies. What would be the expected genotype frequencies if this population were in genetic equilibrium?

Sourav PanOctober 25, 2024

Answered

Sample Dataset for Demonstration:

1. Calculating Genotype Frequencies

• Genotype Frequency Formula: (Number of individuals with the genotype) / (Total number of individuals)

2. Calculating Allele Frequencies

• Allele Frequency Formula: (Number of copies of the allele) / (Total number of alleles)
  • Total Alleles: 2 * Total Individuals = 2 * 160 = 320 alleles
  • Counting Alleles:
    • A Allele in AA: 80 individuals * 2 = 160 A alleles
    • A Allele in Aa: 60 individuals * 1 = 60 A alleles
    • Total A Alleles: 160 + 60 = 220 A alleles
    • a Allele in aa: 20 individuals * 2 = 40 a alleles
    • a Allele in Aa: 60 individuals * 1 = 60 a alleles
    • Total a Alleles: 40 + 60 = 100 a alleles

3. Expected Genotype Frequencies under Hardy-Weinberg Equilibrium (HWE)

Given p (A allele frequency) = 0.6875 and q (a allele frequency) = 0.3125, the expected genotype frequencies under HWE are calculated as:

• Expected Frequency of AA (p^2): (0.6875)^2 = 0.47265625
• Expected Frequency of Aa (2pq): 2 * 0.6875 * 0.3125 = 0.4296875
• Expected Frequency of aa (q^2): (0.3125)^2 = 0.09765625

Comparison:

• The observed genotype frequencies are somewhat close to the expected frequencies under HWE, suggesting the population might be near equilibrium for this locus. However, to conclusively determine if the population deviates significantly from HWE, statistical tests like Fisher’s exact test (mentioned in your query results) would be necessary.