Aging brings about a range of changes—often unwelcome—to our bodies: sagging skin, graying or thinning hair, and a decline in muscle strength and vitality. But aging also affects us on the inside, altering proteins and other biomolecules in ways that increase our risk of developing chronic diseases—such as cancer, Alzheimer’s, and diabetes —and raise the likelihood of death. “You live, and by living, you produce negative consequences like molecular damage. This damage accumulates over time,” says Vadim Gladyshev, who researches aging at Harvard Medical School. “In essence, this is aging.” Yet some species (including some humans) age more slowly and live long, healthy lifespans. Why is that?
Why Mammals Have Different Maximal Lifespans
Mammals, for instance, differ dramatically in their maximal lifespans—from the tiny forest shrew, which lives only one or two years, to the bowhead whale, capable of living for more than 200 years. Humans are also notable among primates for their comparatively extended lifespans, living twice as long as chimpanzees, our closest relatives. Larger species tend to have longer lifespans than smaller species. At an average of 100 tons, the bowhead whale is about 100 times heavier than the forest shrew. The African elephant, the largest land mammal, weighs more than six tons and lives up to 65 years.
Larger species’ longevity is usually due to their ability to resist stress and predators. However, size isn’t the only factor, nor is it always definitive. Bowhead whales are enormous—the second-largest living mammal—but their 200-year lifespan is at least double what you would expect given their size. Farther down on the scale, Brandt’s bat, which weighs 5 to 20 grams (0.17–0.70 ounces), can live for more than 40 years, and so can the naked mole rat, which weighs a mere 34 grams (1.9 ounces). Because birds and bats can evade predators by flying, they live longer than their small size would predict.
Researchers have compared 26 mammalian species with diverse maximal lifespans. These ranged from two years (shrews) to 40+ years (naked mole rats). The thousands of genes identified were related to the species’ maximal lifespans. The genes were either positively or negatively correlated with longevity. The disparities in species longevity raise two questions: First, from an evolutionary viewpoint, why do some species have long lives while others don’t? And second, what genetic and metabolic idiosyncrasies allow the long-lived species to live as long as they do?
The Energy Theory of Longevity
Scientists believe that the answer to the first question lies in the energy a species expends to prevent or repair cellular damage. “You want to invest enough that the body doesn’t fall apart too quickly, but you don’t want to over-invest,” says Tom Kirkwood, a biogerontologist at Newcastle University in the United Kingdom. “You want a body that has a good chance of remaining in sound condition for as long as you have a decent statistical probability to survive.” Researchers found that short-lived species tend to have a high number of genes involved in energy metabolism. In contrast, long-lived species tend to have fewer genes that are similarly involved, indicating that those with lower metabolic rates conserve energy over the long term.
According to this theory, a house mouse isn’t going to spend much energy on maintenance because its chances of survival are slim. A predator, such as a cat, is likely to catch the mouse quickly. As a result, the mouse ages rapidly. By contrast, long-lived mole rats spend most of their lives in underground burrows, putting them beyond the reach of most predators; this allows them to allocate their energy to survival, enabling them to live for decades. Whales and elephants are less vulnerable to predators (except for humans, of course) and are likely to survive long enough to benefit from better-maintained cellular machinery.
Genetic Tricks to Delay Aging
But the question that researchers most urgently want to answer is the second one: How do long-lived species manage to delay aging? Researchers have made some progress in deriving an answer. Long-lived species, they’ve found, accumulate molecular damage more slowly than shorter-lived ones do. Comparative genomic analyses identify genes and biochemical pathways associated with complex traits and processes. What are the particular signaling and metabolic networks that might play a role in regulating age-related conditions? Why have specific organisms benefited from using novel evolutionary strategies and genetic determinants of aging in different environments?
Scientists have identified several aging-related genes in mice, fruit flies, and worms. But they still don’t know whether these genes controlled lifespan variations during the evolution of species. Some tantalizing clues, however, have emerged. For instance, the naked mole-rat evolved unique mutations in a gene that confer cancer resistance. DNA repair genes in humans, elephants, and whales, such as those found in the bowhead, help reduce cancer incidence in these species. These genes also appear to be related to longevity.
The risk of cancer poses a significant challenge to increasing the lifespan of mammals. For instance, two of the longest-lived rodent species—the naked mole-rat and the blind mole-rat—have discovered a genetic trick that utilizes interferon secretion to induce cell death, thereby enabling them to combat cancer. They have a gene called TP53, which appears to help prevent cancer by suppressing tumor growth. Indeed, elephants, like blind mole-rats, benefit from similar genes, and humans, too, have a protective equivalent.
Mammals didn’t start living longer only in the last few centuries. On the contrary, evolution has produced long-lived mammals multiple times over millions of years. Among the oldest surviving mammals are bats, tapirs, monkeys, rhinos, horses, bowhead whales, and apes. Humans also enjoy a high ranking. As of 2025, Jeanne Calment, who died in 1997 at the age of 122, is recognized as the longest-lived human; however, some scientists speculate that humans may live up to 150 years or more. Each evolutionary experiment has involved trying out different genetic strategies, such as enhancing homeostasis (biological balance) throughout life or preventing cancer.
The “engine” of evolution is called the pluripotency network. That is, all embryonic or pluripotent stem cells can differentiate into various cell types in different parts of the body, such as the lungs, liver, or pancreas. “We discovered that evolution activated the pluripotency network to achieve a longer lifespan,” says Vera Gorbunova, a biologist at the University of Rochester. The pluripotency network enables the reprogramming of somatic cells—non-reproductive cells—into embryonic cells. Embryonic cells can more readily rejuvenate and regenerate by repackaging DNA, which becomes disorganized as we age.
The pluripotency network is “an important finding for understanding how longevity evolves,” says Andrei Seluanov, a researcher at the University of Rochester. “Furthermore, it can pave the way for new antiaging interventions that activate the key positive lifespan genes. We would expect that successful antiaging interventions would include increasing the expression of positive lifespan genes and decreasing the expression of negative lifespan genes.”
Establishing a link between gene expression and longevity requires more than simply identifying the genes involved or the actions they perform in the body. Scientists need to determine when these genes are activated—turned on—and at what times on a daily, monthly, and yearly basis. Circadian networks also play a role in controlling the lifespans of genes, specifically whether a particular gene’s expression is limited to a specific time of day, which may inhibit the action of that gene in terms of how long, on average, a species can live.
Researchers can determine when specific genes are activated by attaching chemical tags, known as methyl groups, to sites that regulate gene activity. Geneticist Steve Horvath of the University of California, Los Angeles (UCLA), and his colleagues have found that by assessing the status of a set of almost 800 methylation sites scattered around the genome, they can reliably estimate an individual’s age relative to the maximal lifespan of its species. This “epigenetic clock” holds for all 192 mammalian species Horvath’s team has examined so far. He surmises that by reviewing these methylation sites, he will be able to predict a species’ lifespan regardless of any particular individual’s age. This is an advantage in studying species previously unknown to science.
For longer-lived mammals, this means their genes remain active for a longer period. Put another way, their epigenetic marks degrade more slowly, causing their biological clocks to tick more slowly. For example, the longest-lived bats often have the slowest rate of change in methylations, whereas those of shorter-lived species change more quickly.
The Longest-Lived Species
Elephants
Since large size in mammals generally corresponds to a slow metabolic rate, it is hardly surprising that elephants have long lifespans. African elephants are estimated to live up to about 74 years, whereas Asian elephants can live up to about 60 years. Elephants in both parts of the world also possess extra copies of the tumor-suppressor gene TP53, which may help them deal with DNA damage by clearing affected cells, allowing them to live longer.
Marmots
At the other end of the scale are yellow-bellied marmots, which weigh between 7 and 15 pounds and can live for 15 to 18 years. Natives of the United States and Canada, they spend almost half their lives hibernating, entering their burrows each year during September or October and remaining in them until May.
In the other months, marmots, which resemble ground squirrels, prepare for hibernation by fattening themselves on flowers, grasses, insects, and bird eggs. It is their long hibernation period that explains why they can live as long as they do. During hibernation, marmots alternate between periods of metabolic suppression, which last approximately one to two weeks, and shorter periods of increased metabolism, typically lasting less than a day. During metabolic suppression, the animals’ breathing slows, and their body temperatures drop dramatically, allowing them to use a minuscule amount of energy—about a gram per day. By saving energy, marmots can survive prolonged periods without food. Hibernation basically stalls the aging process.
A study of marmots in the wild shows that an antiaging effect kicks in when marmots are two years old, based on the date at which juveniles first emerge from their natal burrows. Researchers at UCLA believe that these hibernation-related adaptations—diminished food consumption, low body temperature, and reduced metabolism—are the reason why marmots outlive other animals of a similar body weight. The UCLA researchers speculate that the marmot may offer a model adaptable to humans, for example, to improve organ preservation for transplantation or to enable long-term space missions.
Bowhead whales
This 100-ton cetacean can live up to 200 years. It is one of the heaviest animals on the planet. Researchers studying its genome have discovered that this species possesses unique genes that aid in DNA repair and resistance to mutations that can lead to cancer. The bowhead whale’s cells were both efficient and accurate at repairing double-strand breaks in DNA—that is, restoring broken DNA so that it’s as good as new. And their cells do this more often than the cells of other mammals. It is thought that the whale’s relatively sluggish metabolism may also account for its longevity. These whales, of which there are now approximately 25,000, inhabit Arctic and subarctic waters. Research conducted in 2025 found that the bowhead whales may live as long as they do because they can repair detrimental mutations in their DNA, thanks to a protein (CIRBP). These mutations, if unchecked, can increase the risk of cancer and age-related diseases over time. Whales have 100 times as much CIRBP as humans do, which may explain why they live beyond the normal human lifespan. The researchers believe that their repair mechanism is enhanced by the frigid Arctic waters in which these whales spend their lives.
Bats
“If we lived as long as bats, adjusted for size, we could live 240 years,” said Gerald Wilkinson, a biology professor at the University of Maryland and the lead author of a 2019 paper about bat longevity. In one case, a small bat, approximately one-third the size of a mouse, was recaptured, still healthy, 41 years after it was initially banded. Bats live longer than mammals of similar size that live on land. There are some 1,400 different types of bats. Not surprisingly, they have different food preferences—flying insects, fruits and nectar, fish and small crustaceans such as scorpions, and blood, which is the sustenance of vampire bats.
Some species can fly at speeds of up to 100 miles per hour, making them the fastest mammals on earth. But what has particularly caught researchers’ attention is their tendency to live in large colonies, where they’re exposed to deadly viruses, including rabies, Ebola, Marburg, Nipah, and Hendra, as well as other pathogens. (Bats are believed to have originated viruses such as COVID-19, and two related strains—SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome), all of which can cause suffering and death in humans.)
Why do bats live so long—30 to 40 years is typical—when they are practically swimming in all these viruses? Bats, it turns out, have a remarkably robust response to viruses. Although scientists have inoculated them with lethal viruses, they exhibit minimal responses, showing no overt symptoms and developing only subclinical infections. Genomic sequences show that bats have an extraordinary innate immunity to viruses and inflammation. This immunity may contribute to their long lives.
Cockatoos
In captivity, a cockatoo, a type of parrot, can generally live for 60 to 70 years. The oldest confirmed bird in captivity was a pink cockatoo named Cookie, who lived to 83. Another famous cockatoo in captivity, named Cocky Bennett, was said to have lived to the age of 119, though this is unconfirmed. In the wild, a sulfur-crested cockatoo typically lives for 40 years, but other cockatoo species—there are 21—may live longer. To explain why cockatoos and other parrot species live as long as they do, whether in captivity or in the wild, researchers at the Max Planck Institute examined two hypotheses.
One question was whether the larger brain size of birds, such as cockatoos, is responsible for their longer lifespans. Because in the wild, more intelligent birds can solve problems more effectively, they tend to live longer. The second was whether their relatively large brains simply take longer to grow, naturally resulting in longer lifespans. The results supported the first hypothesis. Parrots with relatively large brains possessed cognitive capabilities that enabled them to solve problems in the wild that could otherwise have led to their demise. Their intelligence enabled them to live longer lives. The scientists were surprised to find that other factors, such as diet or the longer developmental time required to develop larger brains, had no impact on their longer average lifespans.
Albatrosses
Most albatrosses live to age 50. The oldest wild albatross on record is Wisdom, a female Laysan albatross, estimated to be approximately 72 or 73 years old as of 2024. Researchers first tagged her in 1956, and she was estimated to have hatched around 1951. She has racked up three million miles in her travels around the world since 1956.
One theory to explain the longevity of albatrosses—applicable to other migratory birds as well—focuses on their power of flight. Annual migrations can take these birds thousands of miles, requiring them to remember geographic locations, maintain strong muscles, and keep their eyes and ears in a state of readiness. That means that they can more easily evade predators and find shelter. “They’ve had to be so highly engineered to succeed at flight,” says Steven Austad, who studies aging at the University of Birmingham. “That kind of physiological integrity has allowed them to stay healthy much longer than another animal.” Reproductive success may also account for longevity. In albatrosses and other long-lived seabirds, reproductive success actually increases with age. Wisdom, for example, has hatched 30 to 36 chicks with her mate (albatrosses are monogamous); that is, they have produced at least one chick per year since 2006.
Macaws
Like albatrosses, macaws (which belong to the parrot family) mate for life. They can survive for up to 60 years in the wild and 100 years in captivity. The oldest macaw in captivity lived to be 112 years old. Researchers have found that, as in other parrots, brain size plays a significant role in their longevity. “Large-brained birds might spend more time socially learning foraging techniques that have been around for multiple generations,” says Simeon Smeele, a doctoral student at the Max Planck Institute of Animal Behavior. “This increased learning period could potentially also explain the longer life spans, as it takes more time but also makes the foraging repertoire more adaptive.”
Tuataras
These lizard-like animals are the largest reptiles in New Zealand, and have one of the slowest growth rates of all reptiles, which may help to explain why they can live up to 100 years. They are sometimes referred to as “living fossils,” since they have no extant relatives. Although they share some traits with snakes, they diverged from them 250 million years ago, making them older than the oldest dinosaurs. They are close to impervious to many infectious diseases and demonstrate peak physical activity at shockingly low temperatures for a reptile. Tuataras have the lowest known optimal body temperature of any reptile, ranging from 16 to 21 degrees Celsius (or 60 to 70 degrees Fahrenheit).
Scientists interested in understanding why tuataras live so long have undertaken the first-ever deciphering, or sequencing, of their genetic code. They have found that the animal’s genome is enormous, about five gigabytes, or some five billion DNA base pairs in length, which is about two-thirds bigger than humans’ and is “unusually large” for a reptile. Many of these genes encode selenoproteins, which help protect against aging and cellular deterioration. Tuataras also appear to have an unusually high number of TRP genes, which encode proteins involved in temperature sensitivity and body temperature regulation. This may be why they can tolerate such low temperatures.
Giant tortoises
All tortoises are turtles, but not all turtles are tortoises. Turtles can live only in water, whereas tortoises can live on land, including deserts, grasslands, and wet tropical forests. And although turtles have an average lifespan of 40 years, the Galápagos tortoise—the largest species—can live up to 177 years in captivity, possibly longer. One giant tortoise, called Jonathan, is believed to have been born in 1832 and is alive and well in 2025. The Galápagos tortoise’s name is derived from the Spanish galápago, meaning “tortoise.” Some of the observations that led Charles Darwin to develop his theory of evolution were based on tortoises in the Galápagos Islands during the second voyage of the Beagle in 1835.
Giant tortoises can weigh up to 1,000 pounds. Like other large species, their metabolisms are set at an extremely low level, and their life stages tend to be comparably extended, as it takes them up to 30 years to reach sexual maturity (about twice the time of a human). Animals with lower heart rates tend to live longer than those with higher heart rates. Giant tortoises have a heart rate of approximately 10 beats per minute. Humans have heart rates between 60 and 100 beats per minute, while the pygmy shrew, whose heart rate is 1,200 beats per minute (the fastest rate of any animal), survives for only a few months.
For longevity, several other factors work in the giant tortoises’ favor, including genetic traits related to DNA repair, immune response, and cancer suppression. One study found that tortoises have extra copies of genes (called “duplications”) that may protect against the ravages of aging, including cancer. Giant tortoises can destroy precancerous cells through a process called apoptosis. Cancer is more prevalent as species age, and a defense against cancer may help tortoises to become centenarians more often. In addition, because these larger species have more cells, they have a greater number of cells that are vulnerable to cancer.
Cave salamanders
These blind amphibians can regularly live to be 100 years old. They don’t appear to be resilient; they are pale, eyeless, and about a foot long. As their name suggests, they spend their entire lives in caves (in Southern Europe), where, of course, there is little need for vision. This creature, like most other long-lived species, has an unusually sluggish metabolism. It takes 15 years to mature, mate, and lay its eggs (every 12 years or so). Cave salamanders barely move except to seek food, not that they need much food. They have virtually no predators, and their ability to conserve energy also helps explain their remarkable longevity. For comparison, the next longest-lived amphibian, the Japanese giant salamander, only rarely lives to 50 years.
Glass sponges
These sponges, believed to be the oldest animals on Earth, also have one of the planet’s longest lifespans—more than 10,000 years, possibly 15,000 years. One glass sponge observed by researchers in the Ross Sea, a bay of Antarctica, is thought to be the oldest living animal on the planet. Glass sponges are composed of large, complex, glass-like skeletons made of silica; they spend their lives attached to hard surfaces, filtering water through thousands of holes to consume bacteria and plankton. The filtration is also fast—80,000 liters per second. They also serve as habitats for small crustaceans. The relative simplicity of their structure may explain why these sponges live so long. Glass sponges are among the organisms often classified as biologically immortal, as their cells can regenerate infinitely, thereby preventing biological aging. However, “immortal” is a bit hyperbolic, as these animals are still vulnerable to predation, disease, and environmental changes.
Giant barrel sponge
Another sea sponge, the barrel sponge, is the largest species of any sponge and is found in the Caribbean Sea. It may be more than 2,300 years old, earning its nickname the “redwood of the reef” due to its large size and long lifespan. It typically grows in Caribbean coral reefs at depths up to 390 feet (120 meters). It is usually large, firm, and cone-shaped, although some varieties are low and squat. However, why it lives so long remains a mystery. One clue may come from research conducted in 2025, which proposed that the environment may be a significant factor in its longevity. The sponges, the researchers say, may be resilient to the effects of sediment by producing mucous. The mucous, in turn, removes the sediment from the surface of these ‘redwoods of the reef,’ which may allow the sponges to resist environmental conditions that would inhibit their ability to thrive and survive for millennia.
Black coral
Corals are among the longest-living animals on Earth. Some coral species can live up to 5,000 years, but black corals in the genus Leiopathes are known to be the longest-living of all corals. It takes considerable time to create an entire coral reef; therefore, coral formations grow an average of only 1 to 1.5 inches per year. Corals are constructed out of colonies, which in turn are formed by individual polyps, some of which may have lifespans of a few hundred years, whereas some polyps may only live for a couple of years. Corals, which depend on sunlight and salt to grow, are generally found in clear, shallow saltwater. They require warm temperatures—no more than 70 degrees Fahrenheit—and are susceptible to pollution.
Ocean quahog
This mollusk can live up to 500 years and is found in the North Atlantic from Newfoundland to North Carolina. Like so many long-lived species, it grows very slowly, reaching reproductive maturity only at the age of six. Biologists have yet to figure out why quahogs live so long. However, they suspect that its relatively stable antioxidant levels help to prevent the cell damage responsible for most signs of aging in animals.
Rougheye rockfish
These deepwater fish are found in the North Pacific. They can live for over 200 years. Many other rockfish can only live up to 11 years. Rougheye rockfish, however, generally start breeding at age 25, and they produce more and stronger young as they get older. Because rockfish comprise more than 100 species, with lifespans ranging from 11 to over 200 years, researchers have utilized them to study the phenomenon of longevity. They have found that genes that normally regulate steroid hormones, which affect how long an organism takes to reach sexual maturity, may explain why this particular species has a longer lifespan than its relatives.
The flavonoid metabolic pathway (controlled by these genes) may be among the biological pathways that influence longevity, and this applies not only to rougheye rockfish but also to humans. “Nature presented us with an experimental design in the form of rockfish, and we wanted to see if we could pull data from it,” says Matthew Harris, associate professor of genetics at Harvard Medical School. “It’s incredibly impressive and valuable that this actually worked. It shows how comparative genomics can detect signals from millions of years of evolution to help us understand the networks of genes that interact to regulate complex phenomena such as longevity.”
Koi
These large goldfish, native to Japan and prized especially for their beauty, typically live 15 to 30 years, although some have been known to live up to 200 years. However, they are indulged by humans, which explains why they can live so long. Even in captivity, other fish seldom live 40 years or longer. The koi that reach the century mark and beyond may also owe their longevity to breeding, as Japanese breeders take great care to maintain the gene pool of these fish, keeping the most valuable and longest-lived in Japan and exporting others that don’t meet their exalted standards.
Greenland shark
Also known as the gurry or grey shark, this fish is typically found in the waters of the North Atlantic and Arctic. But because these sharks live at great depths (an average of 2,568 feet), they haven’t been well studied. What is known about them is that they can live to very advanced ages—250 to 500 years, the longest known lifespan among vertebrates. They’re extremely big (they measure between 8 and 23 feet and weigh 3,000 pounds or more) and reach sexual maturity only at 150 years.
Their pups are born alive after a protracted gestation period that ranges from 8 to 18 years. Researchers believe that their slow metabolism is a key factor in their long lifespan. These sharks move through the depths at speeds of less than 10,000 feet per hour (about 1.8 miles per hour). Compare that rate to that of the great white sharks, which can travel up to 35 miles an hour. On the other hand, no other sharks can withstand the extreme Arctic cold year-round. Greenland sharks may also benefit from the protection afforded by the methylated compounds in their muscles. These compounds play a role in gene regulation.
Jellyfish
A standout among jellyfish, Turritopsis dohrnii possesses a unique trait that makes it immortal—or as close to immortal as a living organism can be. This species has the ability to revert to its juvenile polyp stage after reaching sexual maturity. These jellyfish begin their lives as free-swimming larvae that eventually develop into colonies (collections of cloned polyps). In the event of environmental stress, a threat to its well-being, sickness, or age, the jellyfish can revert to its original polyp state and form or join another colony.
Turriopsis dohrnii can pull off this trick through a process called transdifferentiation, which transforms old cells into new cell types. In theory, this process can go on indefinitely. Immortality, though, is seldom reached because of predation or disease in the earliest medusa stage, cutting these creatures off before they can revert. Nonetheless, their capacity to revert—and, in theory, live indefinitely—has attracted the interest of researchers studying aging, which may ultimately lead to the development of regenerative therapies or age-delaying drugs in humans.
The Resurrected Worm
A humble worm may have won the long-life competition. The discovery of an apparently long-dead worm in the Siberian permafrost in 2023 has prompted scientists to reassess the longevity of an organism. After being frozen for approximately 46,000 years in the permafrost, the worm Panagrolaimus kolymaensis—a previously unreported nematode species in the scientific literature—survived and remained alive. It just took a bit of thawing. The worm appears to have benefited from a process known as cryptobiosis, which slows an organism’s metabolism. In this biological strategy, life seems to stop under icy conditions. This process has been observed in other creatures, such as tardigrades and particular species of brine shrimp. Because no significant metabolic activity occurs in a frozen state, animals can survive even lethal conditions until they are restored to an environment in which they can resume growth and reproduction.
The worm extracted from the permafrost appears to have spent most of its life in a state of suspended animation. Scientists believe that these long-lived creatures possess special molecules that stabilize cells, keeping them intact even under extreme dryness or temperature fluctuations. Similar molecules have been found in other organisms that are known to survive dehydration and freezing. A 2023 study of tardigrades, also known as water bears, by the National Aeronautics and Space Administration highlighted their ability to withstand harsh conditions in space. This suggests that these tiny beings may have developed defense systems against extreme radiation and severe temperature fluctuations.
“No one had thought that this process could last millennia, 40,000 years, or even longer. It is simply amazing that life can begin again after so long, in the state between life and death,” said Dr. Phillip Schiffer, a group leader in the Institute of Zoology at the University of Cologne.
Scientists hope that, if they can isolate the genes in these nematodes that protect cells against freezing and radiation, they can store human tissue in cold storage and minimize damage from severe cold or dehydration. Although the worm unearthed from the permafrost has died, this type of worm generally lives for only one or two months. Its offspring remain alive in controlled conditions.
Oaks
The oldest individual oak tree in the United States is the Pechanga Great Oak Tree in Temecula, California, estimated to be around 2,000 years old. The Jurupa Oak in Riverside, California, which is estimated to be 13,000 years old, isn’t one tree; it’s a colony of trees with the same DNA; that is, it has cloned itself. The cloned trees form only after wildfires, when the burned branches of the original trees sprout new shoots.
Baobabs
Found in the savannas of 32 African countries and playing a role in many remedies, the baobab is one of the world’s oldest trees. It predates both human beings and the splitting of continents 200 million years ago. The tree is a succulent, absorbing water during the rainy season and storing it in its wide, cylindrical trunk during the dry season. It produces a nutrient-dense fruit that earns it its nickname, the Tree of Life. An iconic tree with an average height of nearly 100 feet and a crown of distinctively gnarled branches, it can live up to 5,000 years. “Baobabs are particular trees, with unique architectures, remarkable regeneration properties and high cultural and historic value,” says Adrian Patrut, a chemist at Babes-Bolyai University in Romania, noting that “they play an important role in carbon sequestration and create a distinct microenvironment.”
Bristlecone pine
The longest-lived tree is thought to be over 4,789 years old; it is a Great Basin bristlecone pine named Methuselah, located high in the White Mountains of California. Although other trees in the White Mountains and Aspen are older, they are clones of the same species, not individual trees like the bristlecone pine. This tree’s survival is due to its ability to thrive in environments where most other plants can’t. It can spread its roots far and wide in search of nutrients. Apparently, it is also relatively impervious to intense stress. This tree grows slowly because of the freezing temperatures, dry soil, and high winds in the area. Yet it can grow in both good and bad weather. Because it has a tough exterior, it is resistant to insect and pest infestations. Even as it ages and most of its bark dies, enough of the bark remains that the tree never dies entirely.
Redwoods
Individual redwoods can live up to a thousand years, but the species is believed to have lived on the planet for millions of years. There are three types of redwoods—coastal redwoods, giant sequoias, and dawn redwoods—and most are found in California. Some giant sequoias are estimated to be 3,000 years old. Coastal redwoods—some rising as high as skyscrapers 30 stories tall—are the tallest trees known. Because of their thick bark (up to 12 inches), the redwoods can withstand forest fires. Their canopies are vital to their health; by capturing water (often in the form of fog droplets), they effectively create their own rain.
Yews
Yews are among the longest-living trees in the world, capable of surviving for millennia. Some species, like the Pacific yew (Taxus brevifolia) of the Pacific Northwest, live for over 2,000 years, slowly growing into dense, evergreen forms. In Europe, yews have inspired awe for centuries because of their extraordinary age. The Llangernyw Yew in Wales is estimated to be between 4,000 and 5,000 years old, making it one of the oldest living organisms on the planet. Their ability to endure through centuries of environmental change, human activity, and disease highlights yews as a remarkable example of nature’s resilience and longevity.
The world’s oldest tree (possibly)
The Alerce Milenario, also known as Gran Abuelo (Great Grandfather), in Chile, is believed to have begun growing in 1630 BC and may be the world’s oldest tree. Only 28 percent of the tree is alive, primarily in its roots. Its surface is mainly covered with lichens and mosses. Scientists used a bore to penetrate the tree without harming it and found that it had 5,000 rings, which they used to determine its age, concluding that it was 100 years older than any of its rivals.
The Secret to Longevity Remains a Mystery
“The genetics of longevity are notoriously confusing,” says Dr. Mary Armanios, an oncologist and geneticist at Johns Hopkins School of Medicine. Confusing is right. Inflammation, which is associated with diseases of aging, is one factor. So is genetics. “Please study me,” pleaded Maria Branyas Morera, a Spanish citizen who, up until her death in 2024 at the age of 117, was the world’s oldest living person. Scientists have obliged, examining her blood, saliva, urine, and stool. They determined that her cells “seemed younger than her age.”
She lived a healthy life, walking a mile a day until she was over 100, and abstaining from drinking and smoking. And she consumed three yogurts a day. However, a healthy lifestyle wasn’t the only factor that contributed to her longevity. She was also found to have genetic variants reported to protect against common risk factors such as high cholesterol levels, dementia, heart disease, and cancer. In addition, she had a microbiome with an abundance of a type of beneficial bacteria, to which those yogurts might have contributed.
But nearly everyone who lives to a ripe old age—there’s a growing number of supercentenarians (those who live to 110 or more)—has a different explanation as to why they lived as long as they have while retaining all their marbles. The truth is that no one knows the secret to longevity, whether in humans, Greenland sharks, Galápagos tortoises, or bristlecone pines. Good genes are helpful. A healthy lifestyle, curiosity, and strong social relationships also play a significant role in contributing to why some individuals live to a great age. And yogurt can’t hurt, either.
