The Boston Globe examines the evidence for mitochrondrial damage as a root cause of aging. "The evidence is piling up but not yet definitive. It is grounded in the knowledge that mitochondrial function deteriorates with age, that mitochondria generate damaging molecules called free radicals, and that mutations accumulate in mitochondrial genes, some of them caused by free-radical assault." This is a hot area for research right now - and deservedly so. We need more research funding for important basic science like this! From the conservative side of the science bench: "Mitochondria are a source of energy and a lot of damage. But the body is designed to deal with a lot of this. I'd like to be a believer, but I also have to remain skeptical until we see rigorous proof."