Answer:
Mutations and Genetic Drift
Explanation:
A mutation refers to the random changes in the genome of the organisms. Being a random event, it is not possible to calculate the effect of mutations on the allele frequency of a population.
Genetic drift refers to changes in the allele frequency by chance event alone. Since the occurrence of chance events can not be predicted, the resultant changes in the allele frequency of the population can not be calculated.
