THE ROMANS built pipes from it. Sixteenth-century women coated their faces in powders containing it. And until a phase-out began in the 1970s it was added to petrol to make cars run smoothly. Poisoning by lead is usually thought of as a disease of relatively modern civilisations. Yet in a paper just published in Science Advances Alysson Muotri, a geneticist at the University of California, San Diego and his colleagues show that it was also common among humanity’s pre-industrial ancestors. Indeed, the toxic metal may have even helped Homo sapiens to become the planet’s sole surviving species of hominin.