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
- Which one of the following statements about genetic drift is accurate?
- 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 In a population of birds on an island, the average beak size reduced over one generation. A researcher estimated the association between beak size and relative fitness, shown in the graph. The estimated slope was –0.05 with a 95% confidence interval of -0.15 to 0.09.
Which one of the following evolutionary processes acting on beak size is the most likely reason for the observed reduction in beak size?
- Two isolated populations X and Y have 100 and 10000 individuals, respectively. Both populations have the same starting allele frequencies of p=0.5 and q=0.5. After 1000 generations of genetic drift, which of the following statements is true about the heterozygosity at this locus in these two populations?
