Abstract: | Long viewed as an insoluble enigma, aging is shedding its cloak of mystery as scientists start to understand why and how we age. Many studies support the theoretical argument that aging occurs because natural selection weakens with age, leaving us vulnerable to harmful, late-acting genes. As for what causes aging, scientists have narrowed the pack of candidates to a handful, including free radicals and reactions between glucose and proteins. In recent decades, many mechanisms for lengthening life in animals have come to light. By extending this research, scientists may be closing in on ways to lengthen the human life-span. |