telomeres

Telomeres are repeat-DNA caps on chromosome ends that shorten with each cell division. See how telomerase works and what telomere length does not prove.

Aging is not a disease, a single clock winding down, or an inevitable consequence of time passing. It is a set of overlapping molecular failures that accumulate faster than cells can repair them. Researchers have now identified twelve distinct hallmarks that drive this process — and several of them can be slowed, at least in model organisms.

For most of history, aging was accepted as inevitable. A growing group of scientists now argue it's a biological process that can be understood, slowed, and perhaps reversed. Here's where the science actually stands.

Some scientists genuinely believe today's children could live for centuries. Here's what aging actually is, what we'd need to defeat it, and what a 1,000-year lifespan would mean for humanity.