For thousands of years, mysterious bacteria have remained dormant in the Arctic permafrost. Now, a warming climate threatens to bring them back to life. What does that mean for the rest of us? SUBSCRIBE: http://goo.gl/8NwXqt

There's a story in every grain of sand: tales of life and death, fire and water. If you scooped up a handful of sand from every beach, you'd have a history of the world sifting through your fingers. From mountain boulders to the shells of tiny ocean creatures, follow the journey that sand takes...

Every winter, California newts leave the safety of their forest burrows and travel as far as three miles to mate in the pond where they were born. Their mating ritual is a raucous affair that involves bulked-up males, writhing females and a little cannibalism. SUBSCRIBE:...