The Bottleneck Model (BNM) is a widely accepted framework for understanding the impact of population size bottlenecks on genetic diversity (Liu & Felsenstein, 2009). The BNM postulates that genetic diversity is reduced in a population when it undergoes a bottleneck event, such as a natural disaster or human-induced population decline. This reduced genetic diversity can lead to long-term consequences, such as increased susceptibility to disease, reduced reproductive success, and decreased adaptability to changing environmental conditions. Several models have been proposed to explain the effects of bottlenecks on genetic diversity, but the BNM is the most widely accepted and extensively studied (Wang & Whitlock, 2003).
The BNM starts with a simple observation: a population’s genetic diversity is reduced when it undergoes a bottleneck event. A bottleneck event is any event that reduces the population size of a species, such as a natural disaster, a human-induced population decline, or a migration event. When the population size is reduced, the number of individuals contributing to the gene pool is also reduced, leading to a decrease in genetic diversity. This decrease in genetic diversity can have long-term consequences, such as increased susceptibility to disease, reduced reproductive success, and decreased adaptability to changing environmental conditions.
The BNM consists of three basic components: the bottleneck effect, the recovery phase, and the equilibrium phase. During the bottleneck effect, the population size is reduced, leading to a decrease in genetic diversity. During the recovery phase, the population size increases, but the genetic diversity remains reduced. Finally, in the equilibrium phase, the population size stabilizes and the genetic diversity slowly returns to its original level.
The BNM has been widely studied and accepted as a useful framework for understanding the effects of bottlenecks on genetic diversity. The model has been used to explain the effects of natural disasters, human-induced population declines, and population migrations on genetic diversity (Liu & Felsenstein, 2009; Wang & Whitlock, 2003). Additionally, the BNM has been used to study the effects of different management strategies on genetic diversity, such as captive breeding programs and reintroduction of species into the wild (Liu & Felsenstein, 2009).
Overall, the Bottleneck Model is a widely accepted and extensively studied framework for understanding the impact of population size bottlenecks on genetic diversity. The model has been used to explain the effects of natural disasters, human-induced population declines, and population migrations on genetic diversity, as well as the effects of different management strategies on genetic diversity.
References
Liu, L., & Felsenstein, J. (2009). Bottleneck models in population genetics. Nature Education, 2(1), 1-7.
Wang, J., & Whitlock, M. (2003). The effect of population bottlenecks on genetic diversity: a review of the evidence. Molecular Ecology, 12(6), 2449-2460.