AP BIOLOGY

Detailed explanation-1: -Populations generate genetic variation over time, which can be specifically reduced by selection or stochastically reduced by genetic bottlenecks. After a bottleneck, a limited number of randomly selected individuals create a founding population, resulting in genetic drift.

Detailed explanation-2: -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-3: -The bottleneck effect is a phenomenon in which a population is reduced in size due to natural disasters, habitat loss, or overhunting. A consequence of the bottleneck effect is the loss of variation in a population caused by the reduction of allele frequencies.

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.