This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on Earth’s past beginning about 4.6 billion years ago and takes students through the development of our planet from its formation, to first signs of life, to primitive organisms, to modern day humans. By creating a timeline students realize how recent an addition humans are to this planet. It includes objectives, materials, procedures, discussion questions, evaluation ideas, performing extensions, suggested readings, and vocabulary. Videos are available to order which complement this lesson, as well as an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.