Every day our DNA breaks a little. Special enzymes keep our genome intact while we’re alive, but after death, once the oxygen runs out, there is no more repair. Chemical damage accumulates, and decomposition brings its own kind of collapse: membranes dissolve, enzymes leak, and bacteria multiply. How long until DNA disappears altogether? Since the delicate molecule was discovered, most scientists had assumed that the DNA of the dead was rapidly and irretrievably lost. When Svante Pääbo, now the director of the Max Planck Institute for Evolutionary Anthropology in Germany, first considered the question more than three decades ago, he dared to wonder if it might last beyond a few days or weeks. But Pääbo and other scientists have now shown that if only a few of the trillions of cells in a body escape destruction, a genome may survive for tens of thousands of years.