Showing 1-2 of 2 Resources
Click & LearnDownload the accompanying student worksheet under "Downloads." What did Earth look like 250 million years ago? Or 1 billion years ago? Or 4.5 billion years ago? EarthViewer is an interactive tool that allows you to explore the science of Earth's deep history.
LectureAre we witnessing a sixth mass extinction? What factors threaten ecosystems on land and in the sea? What are researchers doing to try to conserve biodiversity and ecosystems?
Narrow your choices by selecting areas below.