Cookie Policy

Our website uses cookies to understand content and feature usage to drive site improvements over time. To learn more, review our Terms of Use and Privacy Policy.

Life in All Its Forms (2:48)

Key Ideas

As this video progresses, key ideas will be introduced to invoke discussion.

Key Ideas

Think about the following questions as you watch the video

  1. 01:29 How have our ideas about the number of species on Earth changed over time?
  2. 02:08 How do scientists determine the number of species there are on Earth?