How did the world as we know it鈥攆rom the soil beneath our feet to the air we breathe and the life that surrounds us鈥攃ome to be? Geologists have proposed one set of answers while biologists have proposed another. Paleontologist and geobiologist Andrew H. Knoll reveals why we should listen to both voices鈥攖he physical and the biological鈥攖o understand how we and our planet became possible. Please join the Smithsonian Associates in welcoming Andrew H. Knoll, author of Earth and Life.