Extras

Video thumbnail: NOVA These Boulders are Alive

NOVA

These Boulders are Alive

Dive down to rare stromatolites—key clues to the evolution of virtually all complex life.

These Boulders are Alive

Video thumbnail: NOVA How Panama Changed the World

NOVA

How Panama Changed the World

Two scientists scan islands off Panama for clues to determine how the country was formed.

How Panama Changed the World

Video thumbnail: NOVA Making North America: Life Preview

NOVA

Making North America: Life Preview

How did massive volcanic eruptions, inland seas, and land bridges pave the way for life?

Making North America: Life Preview