What is a consequence of a small population size on random drift?

What is a consequence of a small population size on random drift?

• A. Chance effects (genetic drift) are more pronounced
• B. Chance effects are negligible
• C. Drift only occurs in large populations
• D. Drift leads to immediate fixation of all alleles

Answer: (A)

In small populations, random genetic drift has stronger effects because the allele choices passed to the next generation come from a much smaller pool. With few individuals contributing gametes, chance events—like which alleles happen to be carried and transmitted—cause larger, more rapid shifts in allele frequencies from one generation to the next. Over time, these random fluctuations can lead to the loss of genetic variation or the fixation of alleles by chance, independent of any selective advantage. This is why the best answer is that chance effects (genetic drift) are more pronounced in small populations. Drift is a feature of all finite populations and is amplified as population size decreases, it is not negligible or restricted to large populations, and it does not instantly fix every allele.

In small populations, random genetic drift has stronger effects because the allele choices passed to the next generation come from a much smaller pool. With few individuals contributing gametes, chance events—like which alleles happen to be carried and transmitted—cause larger, more rapid shifts in allele frequencies from one generation to the next. Over time, these random fluctuations can lead to the loss of genetic variation or the fixation of alleles by chance, independent of any selective advantage. This is why the best answer is that chance effects (genetic drift) are more pronounced in small populations. Drift is a feature of all finite populations and is amplified as population size decreases, it is not negligible or restricted to large populations, and it does not instantly fix every allele.