With a solid understanding of biology on the small scale under our belts, it's time for the long view - for the next twelve weeks, we'll be learning how the living things that we've studied interact with and influence each other and their environments. Life is powerful, and in order to understand how living systems work, you first have to understand how they originated, developed and diversified over the past 4.5 billion years of Earth's history. Hang on to your hats as Hank tells us the epic drama that is the history of life on Earth.