Bottleneck effect

The bottleneck effect occurs when a population's size is drastically reduced, often due to events like disasters or overhunting. This sharp decline means only a small, random group survives, and their genetic traits become more common in future generations. As a result, the gene pool is less diverse, which can limit a population's ability to adapt to new challenges. Once the population recovers, it may have reduced genetic variation compared to the original, similar to how a bottleneck narrows a tube, restricting flow and reducing variety.