A sample of 2,000 individuals from a human population was scored for MN blood group. The following frequencies were found: 1,600 MM, 250 MN, and 150 NN. How do these numbers compare to those expected under Hardy-Weinberg equilibrium?

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The observed frequencies of MM (1600/2000 = 0.8), MN (250/2000 = 0.125), and NN (150/2000 = 0.075) do not match the Hardy-Weinberg equilibrium expectations, which would predict genotype frequencies based on allele frequencies. The allele frequency for M can be calculated as (2*1600 + 250)/(2*2000) = 0.825, and for N as (2*150 + 250)/(2*2000) = 0.175. Under Hardy-Weinberg, the expected frequency of MN heterozygotes would be 2pq = 2*(0.825)*(0.175) = 0.2885, which is significantly higher than the observed 0.125, indicating there are fewer MN heterozygotes than expected.

A Sample of 2,000 Individuals from a Human Population Was