Bottleneck

bottlenecks Drastic short-term reductions in population size caused by natural disasters, disease, or predators; can lead to random changes in the population's gene pool.

bottleneck effect Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population. Bowman's capsule ...

Bottleneck: A drastic reduction in the population size followed by an expansion. This often results in altered gene pool as a result of subsequent genetic drift.

bottleneck effect Changes in gene frequency that result when numbers in a population are drastically reduced, and genetic variability is reduced as a result of the population being built up again from relatively few surviving individuals.

A bottleneck in gel-based systems is the manual gel-preparation step, which is both time consuming and a potential source of variability in DNA sequencing.

Well, genetic bottlenecks have to do with the question of how much genetic variability there might be in a population.

In a population bottleneck, where the population suddenly contracts to a small size and then grows again to a large population (believed to have occurred in the history of human evolution), ...

In a population bottleneck, where the population suddenly contracts to a small size, genetic drift can result in sudden and dramatic changes in allele frequency that occur independently of selection.

The result is that the small surviving population is unlikely to be representative of the original population in its genetic makeup - a situation known as the bottleneck effect....

Since hunting ended, the population has rebounded from this population bottleneck to some 100,000 animals today. However, these animals are homozygous at every one of the gene loci that have been examined.

So, in populations that undergo a bottleneck (a severe reduction in numbers), the sample of alleles going to the next generation is a small sample of the population gene pool. Full article ...

See also: Human, Environment, Sequence, Genome, DNA