David Attenborough's acclaimed nature series Life on Earth began production 50 years ago. Now, a PBS documentary captures the host looking back on that series as it's projected in a screening room.
David Attenborough, who turned 100 on May 8, has spent more than 70 years exploring the planet and its living inhabitants filming, and marveling at, a world full of natural treasures. In the process,… [+3471 chars]