Final answer:
The bottleneck effect and the founder effect are two examples of genetic drift that can result in the loss of genetic diversity in a population. The bottleneck effect occurs when a large portion of a population is suddenly reduced in size, while the founder effect happens when a small group establishes a new population with limited genetic variation.
Step-by-step explanation:
Human ancestors may have experienced multiple bottleneck events in their evolutionary history. Two examples of such events are the bottleneck effect and the founder effect.
The bottleneck effect occurs when a large portion of a population is suddenly reduced in size, resulting in a significant loss of genetic diversity. This can happen due to natural disasters or other events that selectively eliminate certain individuals.
The founder effect, on the other hand, happens when a small group of individuals migrates to a new area and establishes a new population. The genetic makeup of this founder population may be different from the original population they left, due to the limited genetic variation brought by the founding individuals.