Which process leads to genetic variations due to chance events in a population?

Genetic drift is a process that leads to genetic variations due to random chance events within a population. Unlike natural selection, which involves the differential survival and reproduction of individuals based on advantageous traits, genetic drift occurs randomly and can significantly impact small populations.

In genetic drift, certain alleles may become more or less common simply due to chance events, like random mating or fluctuations in population sizes. Over time, these random changes can lead to significant shifts in allele frequencies within the population, contributing to genetic diversity. This process highlights how environmental factors and random occurrences can influence the genetic structure of a population independently of selection pressures.

While the bottleneck effect is a specific example of genetic drift occurring when a population is drastically reduced in size, leading to a loss of genetic variation, the more general concept described by the correct answer encompasses these chance events without being limited to a dramatic decrease in population size. Hence, genetic drift is the broader process that accounts for these variations.