In which John Green, Hank Green, and Emily Graslie teach you about evolution. So, in the last 3.8 billion years, life on Earth has evolved from single-celled prokaryotes to the dizzying array of life we have today. So how did all this happen? We'll talk about Darwin, evolution, natural selection, and how we got from there to here, and from then to now. Learn more here: www.bighistoryproject.com