Evolution stuff
Bottleneck

The resulting population has lower genetic variation.
Explanation:
A population bottleneck from the graph shows the sharp reduction in population of cheetah.
This could have been due to natural disasters, genocides or diseases.
The reduction in population caused reduction in variation of gene pool.
The population thus have small genetic variation.
The gene flow can only be increased by immigration or mutation
Bottleneck in cheetah is explained as narrowing of gene pool when large numbers of cheetah dies leaving small population with less genetic variation.