All else being equal, among isolated populations comprising of 10, 100, 500 and 1000 individuals, the impact of random genetic drift is LOWEST in the population with _____________ individuals.
Understanding Genetic Drift's Dependence on Population Size
Genetic drift refers to random fluctuations in allele frequencies within a population due to chance events. The magnitude of these fluctuations is inversely related to the effective population size.
In simpler terms:
- Small populations experience strong genetic drift. Random events can significantly alter allele frequencies because each individual's survival or reproduction has a proportionally larger effect.
- Large populations experience weak genetic drift. Random events have a minimal impact on overall allele frequencies, as the effect of chance on any single individual is diluted across many individuals.
Analyzing the Impact on Given Population Sizes
The question asks where the impact of random genetic drift is lowest among isolated populations of 10, 100, 500, and 1000 individuals.
Following the principle that drift is weakest in the largest populations:
- Population size 10: High impact of drift.
- Population size 100: Moderate impact of drift.
- Population size 500: Lower impact of drift.
- Population size 1000: Lowest impact of drift.
Therefore, the impact of random genetic drift is lowest in the population with 1000 individuals, as it is the largest population among the choices.
Important Questions from Genetic drift
- In a diploid population of N individuals, the probability of fixation of a new neutral mutation (assuming no other mutation occurs) is _________.
- Two isolated populations M and N have population sizes of 100 and 1000 individuals, respectively. The starting allele frequencies p and q are 0.5 in both populations. Assuming no selection, which one of the following is expected after 100 generations?
- A few years ago, a very small population of zebrafish became isolated by a newly built dam. As a result, which statement is most likely to be true about this population of zebrafish now?
- Which two of the following processes can result in a decline in heterozygosity in populations?
I) inbreeding; II) genetic drift; III) mutation; IV) random mating - Which of the following processes typically does NOT contribute to increase in genetic variation?
