E
ARTH HAS A LONG AND
COMPLEX HISTORY.
TIME AND AGAIN, THE
splitting and colliding of continents
has resulted in the formation of
new ocean basins and the creation
of great mountain ranges.
Furthermore, the nature of life on
our planet has experienced
dramatic changes through time.
F O C U S O N C O N C E P T S
To assist you in learning
the important concepts in this
chapter, focus on the following
questions:
What makes Earth unique among
the planets?
How did Earth’s atmosphere
and oceans form and evolve
through time?
How did the first continents
form?
What is the supercontinent
cycle?
What are some of the important
geological events of Earth’s
history?
What was the Cambrian
explosion?
How has life changed through
geologic time?
Maroon Bells in Autumn, Colorado Rockies
(Photo by Raymond Forbes/Photolibrary)