Lesson of the Ancient Nazcas: Deforestation Can Kill a Civilization

From an ancient Peruvian civilization comes this warning: Don't chop down all your trees, or there will be hell to pay. The Nazca people are famous for the enormous earthworks they carved into an arid plateau, in designs that range from simple geometrical forms to representations of animals like hummingbirds, lizards, and monkeys. They were previously known to have disappeared around A.D. 500, when massive floods powered by El Niño ravaged the valley where they made their home. Now, a new study that examined the pollen in buried layers of soil in order to trace the horticultural history of the land may have revealed why those floods were so devastating.