Why are there so many different types of organisms around the world?

Developing Understanding: Biodiversity, which includes genetic, species, and habitat diversity, is critically important to ecosystems. Biodiversity in ecosystems is a key component to sustaining life within the living world. Natural and human disruptions have short and long term impacts on ecosystems. Ecological succession can occur in terrestrial and aquatic ecosystems in both developed and developing areas. Organisms within ecosystems must adapt to the changes created by these disruptions. In subsequent units, students will examine in greater detail how populations change over time.

Enduring Understandings: Ecosystems have structure and diversity that change over time.

Here is the AP College Board Curriculum and Exam Description for Unit 2:

The Living World: Biodiversity Study Guide - THIS IS ONLY A GUIDE OVER CONCEPTS.