Final answer:
The selection coefficient (s) indicates the relative fitness of a genotype, and to calculate them accurately, one would need more data than just the change in genotype frequencies. However, without additional details, one can estimate that genotypes which decrease in frequency have a positive selection coefficient, whereas those increasing in frequency could have a negative or zero coefficient, indicating a relative advantage.
Step-by-step explanation:
The student is asking how to calculate the selection coefficients for different genotypes in a population from one year to the next. The selection coefficient (s) is a measure of the relative fitness of a particular genotype, with 0 indicating neutral selection and values approaching 1 indicating stronger selection against the genotype. Given the frequencies of genotypes AA, Aa, and aa in 2019 and 2020, we need to calculate the selection coefficients for each genotype.
We determine the selection coefficients using the formula:
s = 1 - (w), where w is the relative fitness of the genotype. We can estimate w from the change in frequencies of genotypes from one year to the next. However, without additional data such as population size, survival rates, and reproductive success, it is not possible to provide an exact answer to this question.
To fully answer the student's question, we would need to look at factors affecting genotype frequencies such as selection, genetic drift, migration, mutation, and nonrandom mating. Assuming the absence of these factors except for selection, in principle, you would compare the frequency change of each genotype to calculate w and then s. But without specific data on survival and reproduction, or some baseline for the fitness of genotypes, we can only estimate that the selection coefficients would be positive for decreases in genotype frequency and negative for increases, signaling a relative advantage.