Answer:
DNA cloning.
Explanation:
PLEASE MARK AS BRAINLIEST
When a animal changes their body over long periods of time with mating with other species to develop different characteristics.
Answer:
b. A deep, narrow river divides a population of hummingbirds.
Explanation:
Hummingbirds can fly across the river. The deep and narrow river can not separate a population of hummingbirds into two patches since hummingbirds from one side of the river can fly and reach to the other side of the river.
Without any geographical isolation, hummingbirds can continue to interbreed among themselves. The continued interbreeding would not allow their reproductive isolation and thereby would prevent the allopatric speciation.