What are some events that all of us have had in our lives? Ask the class "What are some events that all of us have had in our lives?" Make a list of 5 or 6 things on the board. Let’s organize these!

Prehistoric time line, geologic time scale, photos, facts, maps, and more from National Geographic. Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history.

Geologic Time is a crucial concept to understanding the history of the earth—including the evolution of life. Many different representations of the timeline have been created, and many approaches ...