Final answer:
Mutation, natural selection, genetic drift, and gene flow can all change allele frequencies in a population, with mutation being the source of new genetic variations. These processes do not necessarily create new alleles (except for mutation) but change the distribution and prevalence of existing alleles within a gene pool, influencing the population's evolution.
Step-by-step explanation:
Mutation, natural selection, genetic drift, and gene flow are all forces of evolution that can change allele frequencies in a population. Mutation is the process through which new genetic variations arise, introducing new alleles into a gene pool, which are then acted upon by natural selection, genetic drift, and gene flow.
Genetic drift refers to the random changes in allele frequencies, usually most significant in small populations, and can lead to alleles becoming fixed or lost. Meanwhile, gene flow involves the movement of alleles between populations and can increase genetic variation by introducing new alleles. Natural selection acts on these changes, favoring alleles that increase reproductive success and therefore their frequency within the gene pool.
It is notable that while mutation can create new alleles, the other processes do not create new alleles but rather change their frequencies within the population. Allele frequencies change due to the effects of these evolutionary forces, depicting how a population is evolving over time. The combined effect of these mechanisms contributes to the genetic diversity and adaptive characteristics of populations.