Answer:
D- The effect of drift on average fitness is not predictable
Explanation:
Genetic drift is a mechanism causing change in allele frequencies in a population from one generation to another. Genetic drift happens by random sampling and the benefit or harm of the allele is not a factor in deciding which allele stays and which is deviated from.
A beneficial allele may be lost, and a harmful allele fixed into the next generation. Genetic drift affects both small and large populations but its effect is more pronounced in small populations.
Since Genetic drift happens by chance and any allele can be selected, the effect of the drift on the fitness of the population cannot be predicted. If a harmful allele is selected, there will be a negative effect on the fitness. On the other hand, if a beneficial allele is selected, there will be a positive effect on the fitness of the population
