The volcano is currently dormant, but in a hypothetical future scenario, satellite cones at the base of Mt. Kilimanjaro spew sulphurous gases and lava, destroying all life located between the base and 1830 metres above sea level. As a result of this catastrophe, how should the frequency of the sickle-cell allele change in the remnant human population that survives above 1830 metres, and which phenomenon accounts for this change in allele frequency?
A)decreases; disruptive selection
B)increases; genetic drift
C)decreases; gene flow
D)increases; nonrandom mating
E)decreases; bottleneck effect

Question

Quizplus · Accepted Answer

The destruction of all life located between the base and 1830 meters would result in a bottleneck effect, where only a small subset of the original population survives. This small population would have reduced genetic diversity and a higher chance of random fluctuations in allele frequencies. The sickle-cell allele frequency may decrease in this population due to chance events, particularly if the frequency was already low in the pre-disaster population. Therefore, the correct answer is choice E, which indicates that the frequency of the sickle-cell allele would decrease due to the bottleneck effect.

The Volcano Is Currently Dormant, but in a Hypothetical Future