Why Scientists Study Long-Lived Animals to Understand Aging

Most of what science knows about aging comes from three animals: the fruit fly, a tiny worm, and the laboratory mouse. They are easy to keep and quick to age. A mouse lives two or three years. That convenience has a cost, and a small group of researchers has taken a different route: study the animals that refuse to age on schedule.

Why study animals that live a long time?

Because evolution has already run the experiment. Steven Austad, an aging researcher and author of Methuselah’s Zoo, told the Boston Globe that nature has had several billion years to try ways of making animals resist aging. The question, as a Knowable Magazine feature frames it, is twofold: why did some species evolve long lives, and what genetic and metabolic tricks let them do it? A house mouse and a naked mole rat are about the same size; one lives three years and the other more than 35.

Which animals are the standouts?

• Naked mole rats. Hairless, nearly blind rodents that live in underground colonies in East Africa. They live past 30 in captivity and show what biologists call negligible senescence: no clear rise in death rate with age, reproduction into old age, and strong resistance to cancer, according to a 2005 review by Rochelle Buffenstein, who has studied them for decades. Their longevity relative to their size is similar to humans’.
• Bowhead whales. The second-largest living mammal, with an estimated lifespan of about 200 years, at least double what their size predicts. A study in Nature found their cells have an unusually strong ability to repair DNA, according to a 2026 feature.
• Bats. Some bat species live more than 40 years in the wild despite being mouse-sized. The bat biologist Emma Teeling has said that is the equivalent of 240 to 280 human years with little sign of aging.
• The Greenland shark. In 2016 scientists used radiocarbon dating of eye tissue to estimate the age of the oldest shark they examined at 392 years, give or take 120, which would make it the longest-lived vertebrate known. Even its century-old eyes showed no sign of degeneration, according to a 2026 feature.
• Others. A clam, Arctica islandica, has been dated to 507 years; a Laysan albatross was still laying eggs at 69 or older.

What have researchers found?

The common thread is that long-lived species accumulate molecular damage more slowly, though they get there by different routes:

• More accurate protein-making. Vera Gorbunova’s lab at the University of Rochester found that the naked mole rat’s ribosome, the cellular machine that assembles proteins, makes about a tenth as many errors as a mouse’s, and that across 17 rodent species longer life went with more accurate ribosomes.
• Better DNA repair. Gorbunova’s team compared 18 rodent species and found longer-lived ones repaired a damaging kind of DNA break more efficiently. Bowhead whale cells are exceptional at it.
• Cancer defenses. All long-lived animals must delay cancer, and they do it differently: naked mole rats through an unusual molecule that makes cells stick together, bowhead whales through DNA repair, according to the Knowable feature.
• Slower epigenetic drift. Steve Horvath at UCLA found that the pattern of chemical tags on DNA, which changes with age, predicts maximum lifespan across species. Teeling’s group found the same across 26 bat species.

Vadim Gladyshev of Harvard Medical School summed up the underlying view to Knowable: damage accumulates over time, and in essence that is aging.

Can any of this help people?

Possibly, but nothing has yet. Scientists have transferred a naked mole rat gene into mice and found the mice aged in better health, with less frailty and fewer markers of cellular aging, according to the Boston Globe. The same report notes that researchers caution there are trade-offs, and that the National Institutes of Health recently funded a study of the 500-year clam. A mouse with a mole rat gene is a long way from a human therapy. For what has and hasn’t worked in people, see can scientists slow biological aging.

What are the limits of this research?

Long-lived animals are hard to study for the obvious reason: an experiment on a bowhead whale’s lifespan would outlast the scientist. Much of the work therefore compares tissues and genomes rather than following animals through life. The animals also evolved their longevity for their own reasons, safety from predators in a burrow or a cave, a cold slow life in the deep sea, and those reasons may not translate. Even so, the field has already changed how aging is understood: not as one clock but as the slow accumulation of damage that some species have learned to limit. See why we age and die and is any animal immortal.

This is general educational information, not medical advice. Research in this area moves quickly and this page reflects sources available at the date shown; check the date and the sources before relying on a specific claim.