Site Search

In this activity, students use an interactive tool to simulate how scientists collected and used sample data to estimate elephant population sizes.

New research suggests humans lived in South America at the same time as now extinct giant sloths, bolstering evidence that people arrived in the Americas earlier than once thought.

In this Click & Learn, students explore factors that contribute to patterns seen in the Keeling Curve: a continuous record of atmospheric CO₂ starting in 1958.

This Click & Learn traces the flow of energy from the Sun all the way to cells within organisms. The embedded questions and calculations guide students’ understanding of how energy is distributed through a variety of ecosystems.

Scientists have uncovered new clues about a curious fossil site in Nevada, a graveyard for dozens of giant marine reptiles.

This Click & Learn shows that keystone species exist across a variety of ecosystems and can exert their influence in different ways.

Scientists discovered the oldest known DNA and used it to reveal what life was like 2 million years ago in the northern tip of Greenland.

Earth desperately needs people to stop burning coal, the biggest single source of greenhouse gases, to avoid the most catastrophic impacts of climate change. But it is the world’s biggest source of fuel for electric power and so many depend on it for their very lives.

The US government has pushed more aggressive thinning of stands to reduce vegetation that fuels wildfires.

Floods in northern India were set off by a break on a Himalayan glacier upstream. Here’s a look at how glaciers and glacial lakes form and why they may sometimes break.

We broke phosphorus. And the cost of breaking the phosphorus cycle is not just looming scarcity, but also rampant pollution.

In this Jan. 13, 2021, file photo a wind turbine is silhouetted against the rising sun Wednesday, Jan. 13, 2021, near Spearville, Kan.