Which of the following is an example of gene flow?
The movement of people on Earth steadily increases and alters the course of human evolution.
An earthquake results in the formation of a canyon, splitting a population of toads apart.
A fire drastically reduces the size of a white-tailed deer population. The remaining individuals spread out throughout the remaining forest.
A small population of grasshoppers gets blown away and isolated during a storm. The gene pool of the new population is different from the original population.