AP Bio Study Guide

Big Idea 1.C

What is speciation and how does it take place?

Speciation is the divergence of a species into two separate species. Speciation begins with reproductive isolation, when two groups of a species are isolated and begin to diverge genetically under the pressure of different selective forces in different environments.

Speciation may take place when populations are divided by natural barriers, such as mountain ranges or rivers. Groups of one species may also develop different mating patterns, pollinate at different times of the year, or encounter each other rarely in the same habitat (e.g. land based vs. water based organisms).