Welcome to Crash Course Biology! Over the next 50 episodes, Dr. Sammy Ramsey will show you how you are connected to every bug, bat, and bacteria that has ever lived. From itty-bitty cells to vast global systems, we’ll see how biology can help us understand ourselves better—and our relationships with the living (and non-living) things all around us. Now I know some of you might be thinking: “Didn’t you already do a Biology series?” Yes, we did. But we’re using everything that we’ve learned over the past decade of Crash Course to make you an even better series. Biology 2.0, if you will. Extra-shiny!