AP BIOLOGY

Detailed explanation-1: -Thus, the correct answer is option ‘Speciation’.

Detailed explanation-2: -In allopatric speciation, organisms of an ancestral species evolve into two or more descendant species after a period of physical separation caused by a geographic barrier, such as a mountain range, rockslide, or river. Sometimes barriers, such as a lava flow, split populations by changing the landscape.

Detailed explanation-3: -A new river separating a population can result in allopatric speciation. When geologic and climatic conditions are stable, punctuated equilibrium occurs. The hummingbird and the flower it pollinates have coevolved. When geologic and climatic conditions are changing, evolution may occur more quickly.

Detailed explanation-4: -Allopatric speciation is a mechanism to evolve reproductive isolation; it is caused by the accumulation of genetic differences between populations while they are geographically isolated.

Detailed explanation-5: -1: Allopatric speciation due to geographic separation: The northern spotted owl and the Mexican spotted owl inhabit geographically separate locations with different climates and ecosystems. The owl is an example of allopatric speciation.