Question

If genetic drift is not accompanied by natural selection, mutation, or migration, then the frequencies of alleles will "wander" between 0 and 1. Using the accompanying figure, which of the following is an accurate statement?

1) Random sampling error generates fluctuations in allelic frequencies over generations, so all populations—both simulated and real—have been found to follow the same evolutionary trajectory.

2) Genetic drift will have no long-term effect on allelic frequencies if the population numbers more than 40 individuals

3)None of these is an accurate statement.

4) The effects of genetic drift are more immediate, and more pronounced, on small population sizes.

Answer 1

The most accurate statement regarding genetic drift is that it has a more immediate and pronounced impact on smaller population sizes, as each individual's genetic contribution is more significant, leading to greater fluctuations in allele frequencies.

Step-by-step explanation:

If genetic drift is not accompanied by natural selection, mutation, or migration, then the frequencies of alleles will 'wander' between 0 and 1. Among the given options, only one statement is accurate in describing the effects of genetic drift:

4) The effects of genetic drift are more immediate, and more pronounced, on small population sizes.

This is because in smaller populations, each individual carries a larger fraction of the population's gene pool, making the impact of random events that prevent an individual from reproducing more significant. Fluctuations in allelic frequencies over generations due to random sampling errors (genetic drift) can lead to significant changes in allele frequencies and may even result in the fixation or loss of alleles. Larger populations are more buffered against these random changes because the genetic contributions of any single individual are less significant.