Severe droughts may cause 
evolution population growth forest is destroyed species variation major threat to health Dehydration the ground shaking a bottleneck effect
A B C D E F G H
Severe droughts have caused much of the rural population to urbanize.
Severe droughts may cause a bottleneck effect
Severe droughts may cause  (A) evolution (B) population growth (C) forest is destroyed (D) species variation (E) major threat to health (F) Dehydration (G) the ground shaking (H) a bottleneck effect