In this video segment from Evolution: "Great Transformations," paleontologist Jenny Clack explains that vertebrates evolved fingers before they invaded land.

In this video segment from Cyberchase, the Teleporter breaks and the CyberSquad must try to fix it using clues given to them by Ms. Fileshare.

In this video segment adapted from NOVA, scientists investigate how farming along the Mississippi River impacts floods and what can be done about it.

This video segment from NatureScene features the area of the Congaree Swamp where the high ground and the flood plain meet. Learn how a few feet of difference in elevation on a floodplain can yield drastic changes in what youŰ__Ű__ŒŒÇll find living there.

In this video segment from Cyberchase, the CyberSquad uses a graph to estimate how much the water level will rise in the Sensible Flats reservoir.

In this lesson designed to enhance literacy skills, students learn about the unique environment of southern Florida's Everglades and gain insights into the interrelatedness of living things, nonliving things, and climate.

In this adaptation of a video that high school students created in collaboration with the Environmental Justice League of Rhode Island, learn what's whack about our current food systems and the many actions individuals can take to address these issues.

In this Cyberchase video segment, the CyberSquad finds the right combination switch, lever and button that will deactivate the force field protecting the stolen Black Crystal.

In this lesson designed to enhance literacy skills, students learn how the forces of gravity and air resistance affect the motion of falling objects.

This media-rich essay from NOVA Online describes the challenges of forecasting volcanic eruptions and includes information about specific cases.

This video segment from NOVA: "The Killer's Trail" investigates the potential for DNA evidence to solve murder cases, even those from the distant past.

This video segment from Nature describes how glaciers eroded the bedrock of IrelandŒë_í_Œ_ landscape.

This video segment adapted from NOVA shows how scientists use the fossil record to trace when early human ancestors and related species began walking on two legs instead of four, and to determine whether they were more apelike or human in appearance.

In this interactive activity adapted from the University of Utah's ASPIRE Lab, investigate frequency in terms of trampoline jumps, pendulum swings, and electromagnetic waves.

The CyberSquad tries to figure out how HackerŒë_í_Œ_ cyberfrog moves when its various buttons are pressed, in this video from Cyberchase.

In this video from Cyberchase, the CyberSquad must figure out the new input/output pattern on HackerŒë_í_Œ_ larger cyberfrog.

Students explore the relationship between input and output values and learn to use algebraic expressions and equations.

Watching plants grow is like watching paint dry: It happens so slowly that the changes are imperceptible from one moment to the next -- and yet the end results are dramatic. This video segment shows just how amazing plant development can be by depicting various phases of the process using time-lapse photography. Footage from NOVA: "The Shape of Things."

In this video excerpt from NOVA, find out how the discovery of a gene defect has led to the development of a new drug to treat patients with cystic fibrosis.