Genetic drift is the change in the allele frequencies in a population that occur randomly. It is an evolutionary process (like natural selection), that is associated with the reduction in genetic diversity by the fixation of rare allelic variants and neutral mutations. In this example, this point mutation is neutral since, according to data, the population is evolving by genetic drift. Moreover, it is also important to note that a mutation that involves one nucleotide is also called Single Nucleotide Polymorphism (SNP).
