Question

scientists hypothesize that modern cheetahs have experienced two genetic bottlenecks. scientists estimate the first occurred during the last ice age and the second occurred during a time of rapid agricultural growth in cheetah habitats. the graph shows the population size before and after the first bottleneck event occurred and just before the second bottleneck event.
cheetah population over time
key
—— bottleneck event 1
------ bottleneck event 2
part a: choose the words that best describe the relative genetic diversity in the cheetah populations.

• before bottleneck event 1

a) low
b) medium
c) high

• after bottleneck event 1 (but before bottleneck event 2)

d) low
e) medium
f) high
□ a
□ b
□ c
□ d
□ e
□ f

Explanation:

A genetic bottleneck reduces population size and genetic diversity. Before a bottleneck, a large, stable population has high genetic diversity. After the first bottleneck (before the second), the population size is drastically reduced, so genetic diversity becomes low.

Answer:

• Before Bottleneck Event 1: C) High
• After Bottleneck Event 1 (but before Bottleneck Event 2): D) Low