Ten Thousand Repairs a Day

Every single day, the DNA inside each of your cells suffers more than 10,000 molecular injuries. Ultraviolet light, oxidative stress, even the simple act of copying genetic code — all of it damages the double helix that carries your body's instructions. Left unchecked, this damage would spiral quickly into cancer or cellular death. But it doesn't. Because inside each nucleus, teams of proteins act as molecular repair crews, scanning the genome strand by strand, snipping out damaged sections and stitching in corrected sequences.…