Cosmos: A Spacetime Odyssey

Ninth Episode:
the Lost Worlds of Planet Earth: Congratulations. You're alive. There's an unbroken thread that stretches across more than three billion years that connects us to the first life that ever touched this world. Think of how tough, resourceful and lucky all of our countless ancestors must have been to survive long enough to pass on the message of life to the next and the next and the next generation, hundreds of millions of times before it came to us. . . . Each of us is a runner in the longest and most dangerous relay race there ever was, and at this moment, we hold the baton in our hands.