Instructional Video4:58
TED-Ed

What Is the Tragedy of the Commons?

6th - 12th Standards
What's good for all of us is good for each of us. The Tragedy of the Commons refers to a situation in which one person's decision to act in his or her own best interest negatively affects the rest of the population—and ultimately, him or...
Instructional Video2:22
Teacher's Pet

Types of Natural Selection

9th - 12th Standards
Natural selection—good things come to those who mate. The video introduces the idea of natural selection. Then it details three types: directional, stabilizing, and disruptive. It includes both graphs and examples for each type.
Instructional Video12:51
Crash Course

Population, Sustainability, and Malthus: Crash Course World History 215

9th - 12th Standards
Thomas Malthus posed the most famous, and most easily disproven, theory about projected population growth in economic history. What did he get wrong—and why? Explore the Malthusian Theory of Population with a Crash Course video that...
Instructional Video
PBS

Nova: World in the Balance: Human Population and Global Trends

9th - 10th
A companion site to Nova's film that examines "human populations and environments." Find some fascinating facts in the interactive slide shows "Human Numbers Through Time," and "Global Trends Quiz."
Instructional Video
Sophia Learning

Sophia: Population Growth: Lesson 2

9th - 10th
This lesson will explain the determinants of population growth. It is 2 of 4 in the series titled "Population Growth."
Instructional Video
Sophia Learning

Sophia: Population Growth: Lesson 3

9th - 10th
This lesson will explain the determinants of population growth. It is 3 of 4 in the series titled "Population Growth."