If you're seeing this message, it means we're having trouble loading external resources for Khan Academy.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

5.1—How Did Life Begin and Change?

2 articles
4 videos
1 skill
For centuries, scientists have searched for the answer to the question, how did life begin? Some have argued it began in a shallow pool of water. Others have argued that it began deep below the surface of the ocean. Still others believe that a meteor from some distant corner of the Universe brought to the Earth the ingredients for life. How life appeared and how it changed over time are some of the most interesting questions you’ll tackle in this course.

How Did Life Begin and Change?

VIDEO 6:11 minutes
A closer look at the Goldilocks Conditions for life, and an animated voyage through evolution on Earth.

Mini Thresholds Of Life

VIDEO 5:48 minutes
Travel through time in a rowboat to consider some of the "mini-thresholds" in the development of life on Earth.

Life In All Its Forms

VIDEO 2:49 minutes
A closer look at the life on Earth and the techniques scientists use to study living organisms.

Crash Course Big History: The Evolutionary Epic

VIDEO 14:34 minutes
Poof and you’re gone! Extinction events are no joke. The Greens and Emily Graslie talk about why they are such a big deal, and what they have to do with evolution. 

Quiz: How Did Life Begin and Change

Quiz 5.1