Learn more about the theory that dogs evolved from wolves in this video from Nature. [5:03]

In this video segment from Nature, discover the various roles the cat has played in our history. [6:54]

Wild pandas are treated at the Wolong Conservation Center in this video segment from Nature.

The Baka are a semi-nomadic forest people who live in the republic of Cameroon in central Africa. In this video from Africa, the Baka men meet with a government official for help to protect their forest.

Loggers steal trees from the rainforest of Cameroon, one of Earth's oldest living ecosystems, in this video segment from Africa.

In this video segment from Nature, learn about the role of dogs in the lives of humans.

Perform a virtual heart transplant in nineteen easy steps with this interactive feature from the NOVA: "Electric Heart" Web site. This interactive feature provides an in depth and realistic look at this procedure.

In this ZOOMSci experiment, you're invited to walk through a grassy or weedy field in your stocking feet, then plant a sock and see what grows.

See how the human heart moves blood through the body in this animated feature from the NOVA: "Cut to the Heart" Web site.

This video segment from NOVA: "The Mystery of Animal Pathfinders" explores the migratorial exploits of monarch butterflies. [4:39]

This video segment from ZOOM compares and contrasts the habitat and life forms found in Death Valley with those found in the temperate rain forest of the Pacific Northwest. [3:46]

This video segment from NOVA: "The Mystery of Animal Pathfinders" explores honeybee communication and navigation. [4:45]

This diagram from the NOVA: "Kingdom of the Seahorse" Web site reveals some of the more remarkable traits of this enigmatic creature.

This video segment explains centripetal force and illustrates how roller coasters rely on it to give you a thrilling ride. Includes background reading material and discussion questions. [4:40]

Survey potential bridge sites, research bridge design, and select the right bridge for the right location in this interactive activity from the NOVA: "Super Bridge" Web site.

This interactive activity from the Adler Planetarium explains the "reasons for the seasons." Featured is a game in which Earth must be properly placed in its orbit in order to send Max, the host, to different parts of the world during...

This essay from the NOVA Web site explores the impact Einstein made on physics and most everything we know about the cosmos.

This interactive activity, from the Web site developed for the PBS series "Building Big," use your knowledge of bridge design to match the right bridge location in a fictitious city.

Meet chemistry professor Dr. John Conkling in this interview from the NOVA Web site and learn why fireworks are his passion.

Which dictates our existence? Is it our genetic makeup or the environment we grow up in? Kevin Davies offers an update on this long-standing debate, from the NOVA: "Cracking the Code of Life" Web site.

Against the backdrop of the devastating 1930's Dust Bowl, this video segment adapted from Interactive NOVA profiles an organic farmer and the techniques he uses to conserve topsoil.

When we look up at the night sky, why do we see the Moon's appearance changing over time from a full sphere to a crescent to nothing at all? Find the answers in this interactive resource adapted from the National Air and Space Museum.

Using images and graphs, this interactive resource illustrates scientists' efforts to study Earth's climatic history for the last 250,000 years by drilling into the Greenland Ice Sheet and examining ice cores. Includes background reading...

This animation from NASA illustrates the phases in the formation of a hurricane.