What mechanism leads to a decrease in genetic diversity after a natural disaster?

The bottleneck effect is a phenomenon that occurs when a significant reduction in population size leads to a loss of genetic diversity. After a natural disaster, such as an earthquake, flood, or wildfire, the surviving population may be much smaller and may not represent the genetic diversity of the original population. This drastic reduction can result from the death of individuals or the disruption of breeding patterns, which decreases the gene pool available for future generations.

As a consequence, the genetic traits that remain in the population will be those that were found in the survivors, potentially leading to a lack of variation in alleles. This reduction in genetic diversity can make the population more vulnerable to disease, environmental changes, and other factors because there are fewer genetic options available for adaptation or resilience. Over time, the population may become more homogeneous, which can affect its long-term survival and evolutionary potential.