Final answer:
If the frequency of allele A in an unstable equilibrium rises above 0.6, it will typically rise quickly to 1.0 until it becomes fixed in the population.
Step-by-step explanation:
In an unstable equilibrium, if the frequency of a favored allele A, which is currently 0.6, rises above this threshold, the frequency will typically rise quickly to 1.0. This is because once the allele frequency starts to move away from the unstable equilibrium point due to some form of selection, the dynamics of the population genetics tend to magnify this deviation until the allele becomes fixed in the population.
Genetic drift is especially influential in small populations where random fluctuations in allele frequencies can lead to one allele becoming fixed over time, as described in the Hardy-Weinberg model. However, in the context of a stable equilibrium, such as described by the Hardy-Weinberg equilibrium, allele frequencies remain constant unless disturbed by factors such as natural selection, mutation, non-random mating, genetic drift, or gene flow.