Ten Thousand Repairs Before Breakfast

Every cell in your body sustains somewhere between 10,000 and 100,000 DNA damage events each day. Ultraviolet light, free radicals from metabolism, even the ordinary chemistry of breathing — all of it chips away at the microscopic code that makes you you. Left unchecked, that damage would cascade into mutation, disease, and death within hours. But it doesn't. In 2015, the Nobel Prize in Chemistry honored biochemist Tomas Lindahl for discovering that our cells contain an elegant system of molecular repair machines — enzymes that patrol the genome, detect errors, and correct them with stunning accuracy.…