AP BIOLOGY

Detailed explanation-1: -The bottleneck effect is an extreme example of genetic drift that happens when the size of a population is severely reduced. Events like natural disasters (earthquakes, floods, fires) can decimate a population, killing most individuals and leaving behind a small, random assortment of survivors.

Detailed explanation-2: -Bottlenecks cause alleles at low frequency (< 0.1) to become less abundant than alleles in one or more intermediate allele frequency class (e.g., 0.1-0.2). This distortion is transient and likely to be detectable for only a few dozen generations.

Detailed explanation-3: -Causes of Bottlenecking When an event causes a drastic decrease in a population, it can cause a type of genetic drift called a bottleneck effect. This can be caused by a natural disaster, like an earthquake or volcano eruption. Today, it is also often caused by humans due to over-hunting, deforestation, and pollution.

Detailed explanation-4: -An example of a bottleneck Northern elephant seals have reduced genetic variation probably because of a population bottleneck humans inflicted on them in the 1890s. Hunting reduced their population size to as few as 20 individuals at the end of the 19th century.

Detailed explanation-5: -A genetic bottleneck occurs when a population is greatly reduced in size. The bottleneck limits the genetic diversity of. the species because only a small part of the original population survives.