Which scenario causes gene flow? One flower pollinates other flowers in its population. New mutations arise within new populations. An animal moves to a new population and mates. A population's size decreases after a natural disaster.

The answer would be " An animal moves to a new population and mates. "

Gene flow inside a populace circulates transformations among the people. Emigration and Immigration transport alleles into and out of a populace's quality pool, hence influencing the consequence of common determination.