An scientific example of bottleneck effect?

Answer 1

(In Biology) The bottleneck effect happens when the size of a population or even an entire species is suddenly reduced, with lasting effects on at least one generation. A population bottleneck may occur after an epidemic, drought, fire, hunting, or other destructive events.

Answer 2

Population bottlenecks occur when a population's size is reduced for at least one generation. Because genetic drift acts more quickly to reduce genetic variation in small populations, undergoing a bottleneck can reduce a population's genetic variation by a lot, even if the bottleneck doesn't last for very many generations. This is illustrated by the bags of marbles shown below, where, in generation 2, an unusually small draw creates a bottleneck.

Answer 3

In biology, a bottleneck is a drastic reduction in population size. It can come about by a natural disaster, like a flood or disease. It can also be the result of a small group leaving a population to found a colony elsewhere. Bottlenecks are important because they greatly reduce not only the population size, but the genetic variation as well. Even if the population eventually recovers in numbers from a bottleneck, it can still bear the effects of it in the form of low genetic diversity. An excellent example of a population that probably went through a bottleneck in the past is the cheetah, whose individuals still show little genetic differences between them as compared to other cat species, such as leopards or lions.

Answer 4

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. Their population has since rebounded to over 30,000-but their genes still carry the marks of this bottleneck: they have much less genetic variation than a population of southern elephant seals that was not so intensely hunted.