Travel Photo of the Week: Guardian of Karnak Temple, Luxor, Egypt

A diver stumbles across a whale shark trapped in a commercial fishing line. Sensing the diver is there to help, the goliath lies still while the rope is cut.

A Whale Shark Cooperates With a Diver Saving Him (1:28)

Coconut octopuses are among the most intelligent invertebrates around: They use tools, carry their shelters around for when they need them, and, fittingly, adopt an underwater walking motion that's very similar to humans.

A Coconut Octopus Uses Tools to Snatch a Crab (2:34)

Thousands of massive stone monuments, known as Moai, preside over Easter Island. The way they were carved, using only stone tools, seems unfathomable.

How Were Easter Island's Gigantic Statues Actually Carved? (4:11)

Eric Green, director of the National Human Genome Research Institute, explains how genomics are revolutionizing medicine at Smithsonian's "The Future is Here" event

The Human Genome: Unlocking Life's Code (15:37)