Random unidirectional change in allele frequencies that occurs by chance in all populations and especially in small population is known as a. migration b. natural selection c. genetic drift d. mutation
Option C. Genetic drift is the change in frequency of an existing gene variant in the population due to random chance. Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation. It could also cause initially rare alleles to become much more frequent, and even fixed
