Earth History: Time Flies, No Matter What the Scale

In this two-part activity, which uses discovery and an inquiry approach, the participants will be given cartoon drawings representing significant events in the history of the Earth and asked to place them on a timeline made of colored ribbon. Then they mathematically relate the geologic time scale to a yearly calendar. After the calculations, they return to the timeline to reassess the placement of the events.

Earth History: Time Flies, No Matter What the Scale (PDF)


Intended Audience








Learning Objectives

After completing this activity, students will be able to:

  1. Identify significant events in microbial evolution
  2. Translate information from one mathematical scale to another
  3. Understand the perennial dominance of microbes, past and present
  4. List the order of key events in evolution relating to microbes
  5. Explain the place of microbes in earth's history


Student Background

Students need mathematical (algebraic) skills, should know how to use a calculator, and should have some knowledge about the geological history of Earth.



Earth history, microbial evolution, historical events, time scales.


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