Final answer:
The bottleneck effect is a significant reduction in a population's genetic diversity following a disaster that randomly kills a large portion of its members, leading to genetic drift and possibly affecting the population's future adaptability.
Step-by-step explanation:
The bottleneck effect occurs when a significant percentage of a population is suddenly eliminated due to a random event, such as a natural disaster.
This leads to a reduction in genetic diversity, as the genetic makeup of the survivors becomes representative of the entire population.
Consequently, the allele frequencies of the surviving population can be significantly different from those of the pre-disaster population, profoundly affecting the population's genetic structure.
These survivors may carry only a small fraction of the alleles present before the disaster, resulting in genetic drift. The bottleneck effect, alongside the founder effect, is a critical concept in understanding how populations evolve through random changes in gene frequencies.
Notably, the bottleneck effect can lead to the loss of genetic variation, and the potentially beneficial alleles can be lost from the population. Hence, the population's ability to adapt to future environmental changes may be compromised.