Houghton Mifflin Social Studies
Lesson at a Glance Outline

Chapter 4, Lesson 1: Uncovering Clues to Our Past (pp. 90-95)

I. Clues from Archaeology

II. The Ice Age

    A. During the Ice Age, about 2.5. million years ago until about 12,000 years ago, glaciers advanced and stretched over large areas of the earth.

    B. During the colder periods of the Ice Age, early humans had to learn to make shelter, fire, and clothing.

    C. As water froze, ocean levels dropped, allowing land bridges to arise and enabling early humans to colonize every continent except Antarctica.

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