Introduction to Week 11

Welcome to week 11! Last week you learned about biological diversity and how scientists classify species.

In this week you will learn about extinction. Every year there are species that become extinct. Although humans are not always responsible, the growing human population has accelerated the number of species that are at risk of disappearing.

This week, you will learn about the loss of biodiversity that is taking place today and explore its causes. You will also learn about extinction events that have happened in Earth's history and what caused them.