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Understanding genotype frequencies is foundational in studying population genetics and the Hardy-Weinberg equilibrium. These frequencies describe the proportion of the various genotypes within a population. In the context of the given exercise, genotype frequencies pertain to the combinations of alleles for a genetic locus: AA, Aa, and aa.

Using the Hardy-Weinberg principle, we expect the genotype frequencies to be represented by the terms of the binomial expansion of \( (p + q)^2 \) for a population in equilibrium. However, as fitness values are introduced, which represent the reproductive success of each genotype, these frequencies can shift, reflecting natural selection. Through calculations such as the ones in the exercise, students can observe how selective pressures can alter genotype frequencies and thus change genetic structure over generations.

On the other hand, allele frequencies refer to how common an allele is in the population, typically denoted as ‘p’ for the dominant allele and ‘q’ for the recessive allele. These two frequencies must always add up to 1, as they represent all the possible variants of a gene in the population. During the exercise, allele frequencies were recalculated after applying fitness values to account for differential survival and reproduction, demonstrating how allele frequencies can change from one generation to the next due to selection. Thus, the concept of allele frequencies is crucial in understanding the genetic variation within a population and predicting its future genetic composition.

Average fitness of a population—denoted as ‘w’ in genetic equations—is a measure that encompasses the reproductive success of all genotypes weighted by their respective frequencies. This measure, fundamentally entwined with the concept of natural selection, gives insight into the adaptive landscape of a population. In the context of the exercise, calculating the average fitness under different scenarios showed how different survival and reproduction rates among the genotypes influence the overall adaptive capacity of the population. Furthermore, it illuminates how more fit genotypes can increase in frequency over time, thereby driving evolutionary change. The computation of average fitness thus merges genotype frequencies and individual fitness into a composite metric reflecting the evolutionary vitality of the population.