Final answer:
Genetic drift is a random change in allele frequencies in a population. It can occur through phenomena like the founder effect and the bottleneck effect, resulting in reduced genetic variation. Genetic drift is more pronounced in small and isolated populations.
Step-by-step explanation:
Genetic drift is a phenomenon that occurs when allele frequencies in a population change randomly with no advantage to the population. It is the effect of chance on a population's gene pool. Small and isolated populations are more susceptible to genetic drift, which can lead to significant changes in a population's genome.
One example of genetic drift is the founder effect, which occurs when a small group of individuals migrates away from a larger population and establishes a new population. The new population may have an unrepresentative set of alleles, resulting in reduced genetic variation.
Another example is the bottleneck effect, which occurs when a large portion of the population is killed due to natural events like wildfires or hurricanes. The surviving population may have a different genetic structure compared to the original population.