Peto's paradox

Peto's paradox observes that larger animals like whales and elephants, which have many more cells and longer lifespans, do not have proportionally higher rates of cancer than smaller animals like mice. This is surprising because more cells and longer lives generally increase cancer risk. The paradox suggests that big, long-lived animals have evolved more effective cancer-preventing mechanisms—such as enhanced DNA repair, immune responses, or tumor suppressor genes—to offset the higher potential for cell mutations and cancer development.