Final answer:
Genetic drift is a factor that can cause the allelic frequencies of a gene to shift randomly within a population. It is the effect of chance, where some individuals have more offspring than others, not due to an advantage conferred by a genetically-encoded trait, but simply due to random events.
Step-by-step explanation:
Genetic drift is a factor that can cause the allelic frequencies of a gene to shift randomly within a population. It is the effect of chance, where some individuals have more offspring than others, not due to an advantage conferred by a genetically-encoded trait, but simply due to random events. For example, if one male rabbit happened to be in the right place at the right time when a receptive female walked by, it could lead to an increase in the prevalence of a certain allele in the population.
Another example is the founder effect, which occurs when a small group of individuals separate from a larger population and establish a new population. The allele frequencies in the new population can be different from the original population due to chance events during the separation.