Finalist for the 2009 Los Angeles Times Book Prize in Science and Technology. “A lively blend of popular scientific history and cultural criticism.”—New York Times Book Review Biologist Carol Kaesuk Yoon explores the historical tension between evolutionary biology and taxonomy. Carl Linnaeus struggled in the eighteenth century to define species in light of their mutability while still relying on intuitive, visual judgments. As taxonomy modernized, it moved into labs, yielding results counterintuitive to humanity’s innate predisposition to order the world.