Final answer:
The bottleneck effect and founder effect are both created by random chance. The bottleneck effect occurs when a population suddenly becomes much smaller, and the founder effect occurs when a few individuals start a new population. Both effects can lead to changes in allele frequencies due to chance.
Step-by-step explanation:
The bottleneck effect and founder effect are both created by random chance. The bottleneck effect occurs when a population suddenly becomes much smaller due to a natural disaster or other catastrophic event. The allele frequencies of the survivors may be different from the original population due to chance. On the other hand, the founder effect occurs when a few individuals start a new population. The allele frequencies of the founders may be different from the population they left due to chance mutations.