Deep in an Ecuadoran rainforest, monkeys overhead and poisonous snakes underfoot, Dr. Maria Fadiman goes to work. “It looks like one big, green mishmash to me, but the people who live here can single out the right plants for medicine, or the one to eat if you cut out the little part in the very center. Each house is made entirely from the forest-the poles that hold it up, the floors, the thatch on the walls, the vines that tie it, the palm leaf sleeping mats, the baskets, everything. It’s strong, it’s waterproof, it works, and it’s all done in a way that’s in balance with nature.”