Earth, the great killer. Without the cycle of death and sacrifice, from cellular to planetary, life would not be here. From the deaths of stars, to planetary scale mass extinctions and the sacrifice of individuals for a greater genetic good, this is the story of how life evolved hand in hand with death. Death drives evolution. It's hardwired: from our cells to our landscapes, our colorful living planet is only possible because of it. Death leads to opportunity and biodiversity which ironically ensures life on the planet is never wiped out. It's not enough for our planet to be habitable… it also has to be lethal.

• Will Smith
• Michael J. Massimino
• Mae Jemison