Ancient human teeth are telling secrets that may relate to modern-day health: Some stressful events that occurred early in development are linked to shorter lifespans. “Prehistoric remains are providing strong, physical evidence that people who acquired tooth enamel defects while in the womb or early childhood tended to die earlier, even if they survived to adulthood,” says anthropologist George Armelagos, who recently published the first summary of prehistoric evidence for the Barker hypothesis.