If you're seeing this message, it means we're having trouble loading external resources on our website.

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

To log in and use all the features of Khan Academy, please enable JavaScript in your browser.

Main content

Unit 25: Evolution and the tree of life

400 possible mastery points

Mastered

Proficient

Familiar

Attempted

Not started

Quiz

Unit test

About this unit

This unit is part of the Biology library. Browse videos, articles, and exercises by topic.

Evolution and natural selection

Learn

Practice

Natural selection and DarwinGet 3 of 4 questions to level up!
Evidence for evolutionGet 3 of 4 questions to level up!

Population genetics

Learn

Practice

Hardy-WeinbergGet 3 of 4 questions to level up!
Selection and genetic driftGet 3 of 4 questions to level up!

Speciation and evolutionary trees

Learn

Up next for you:

Unit test

Level up on all the skills in this unit and collect up to 400 Mastery points!

Biology is brought to you with support from the Amgen Foundation