What is the bottleneck effect a result of?

The bottleneck effect occurs when a significant reduction in population size results from a catastrophic event, such as a natural disaster, disease outbreak, or human activities. This drastic decrease in the number of individuals within a population reduces genetic diversity because only a small number of individuals contribute to the gene pool of future generations. Consequently, the alleles that survive may not represent the full genetic diversity of the original population, leading to a situation where certain traits may become more pronounced or detrimental. This can have lasting effects on the population's adaptability and survival in the long term, potentially increasing vulnerability to environmental changes. This explanation underscores the importance of population size and genetic variation in the survival and evolution of species.