LIFE SCIENCE

Detailed explanation-1: -What is genetic drift? Genetic drift is change in allele frequencies in a population from generation to generation that occurs due to chance events. To be more exact, genetic drift is change due to “sampling error” in selecting the alleles for the next generation from the gene pool of the current generation.

Detailed explanation-2: -The bottleneck effect occurs when a population’s size is reduced for at least one generation. Undergoing a bottleneck can greatly reduce the genetic variation in a population, leaving it more susceptible to extinction if it is unable to adapt to climactic changes or changes in resource availablility.

Detailed explanation-3: -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-4: -Genetic drift is the change in frequency of an existing gene variant in the population due to random chance. Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation. It could also cause initially rare alleles to become much more frequent, and even fixed.

Detailed explanation-5: -Genetic drift is common after population bottlenecks, which are events that drastically decrease the size of a population. In these cases, genetic drift can result in the loss of rare alleles and decrease the gene pool.