List of longest-living organisms
This is a list of the longest-living biological organisms: the individuals or clones of a species with the longest natural maximum life spans. For a given species, such a designation may include:
- The oldest known individual that are currently alive, with verified ages.
- Verified individual record holders, such as the longest-lived human, Jeanne Calment, or the longest-lived domestic cat, Creme Puff.
Determining the length of an organism's natural lifespan is complicated by many problems of definition and interpretation, as well as by practical difficulties in reliably measuring age, particularly for extremely old organisms and for those that reproduce by asexual reproduction or cloning. In many cases the ages listed below are estimates based on observed present-day growth rates, which may differ significantly from the growth rates experienced thousands of years ago. Identifying the longest-living organisms also depends on defining what constitutes an "individual" organism, which can be problematic, since many asexual organisms and clonal colonies defy one or both of the traditional colloquial definitions of individuality. Additionally, some organisms maintain the capability to reproduce through very long periods of metabolic dormancy, during which they may not be considered "alive" by certain definitions but nonetheless can resume normal metabolism afterward; it is unclear whether the dormant periods should be counted as part of the organism's lifespan.
Biological immortality
If the mortality rate of a species does not increase after maturity, the species does not age and is said to be biologically immortal. There are numerous plants and animals for which the mortality rate has been observed to actually decrease with age, for all or part of the life cycle. Specimens of the cnidarian genus Hydra were observed for four years without any increase in mortality rate. If the mortality rate remains constant, the rate determines the mean lifespan. The lifespan may be long or short, though the species technically does not "age" in the biological sense.Individuals of other species have been observed to regress to a larval state and regrow into adults multiple times. The hydrozoan species Turritopsis dohrnii is capable of cycling from a mature adult stage to an immature polyp stage and back again. This means no natural limit to its lifespan is known. No single specimen has been observed for any extended period, however, and estimating the age of a specimen is not possible by any known means. At least one other hydrozoan, one scyphozoan and one tentaculata can also revert from a medusa stage into a polyp stage.
Similarly, the larvae of skin beetles undergo a degree of "reversed development" when starved, and later grow back to the previously attained level of maturity. This cycle can be repeated many times. However, repeated cycles result in physiological deterioration, suggesting that these beetle larvae still age.
Revival after dormancy
If the definition of lifespan does not exclude time spent in metabolically inactive states, many organisms may be said to have lifespans that are millions of years in length. Various claims have been made about reviving bacterial spores to active metabolism after millions of years of dormancy. Spores preserved in amber have been revived after 40 million years, and spores from salt deposits in the Salado Formation of New Mexico have been revived after 250 million years, making these bacteria by far the longest-living organisms ever recorded. Similarly, in May 2022 prokaryotic and eukaryotic microorganisms were found in crystals of halite; these could be over 800 million years old but it remains uncertain if they are alive or if they could be revived. In a related find, a scientist was able to coax 34,000-year-old salt-captured bacteria to reproduce. These results were subsequently duplicated independently.In July 2018, scientists from four Russian institutions collaborating with Princeton University reported that they had analyzed about 300 prehistoric nematode worms recovered from permafrost above the Arctic Circle in the Sakha Republic, and that after being thawed, two of the nematodes revived and began moving and eating. One found in a Pleistocene squirrel burrow in the Duvanny Yar outcrop on the Kolyma River was believed to be about 32,000 years old, while the other, recovered in 2015 near the Alazeya River, was dated at approximately 30,000–40,000 years old. These nematodes were believed to be the oldest living non-clonal multicellular organisms on Earth. In 2021, biologists reported the restoration of bdelloid rotifers frozen for 24,000 years in the Siberian permafrost. In 2023, it was reported that nematodes of the previously undescribed Panagrolaimus kolymaensis were revived after 46,000 years in cryptobiosis.
Like bacterial spores, plant seeds are often capable of germinating after very long periods of metabolic inactivity. A seed from the previously extinct Judean date palm was revived and managed to sprout after nearly 2,000 years. Named "Methuselah", it is currently growing at Kibbutz Ketura, Israel. Similarly, the flowering plant Silene stenophylla was grown from frozen fruit found in an ancient squirrel's cache. The germinated plants bore viable seeds. The fruit was dated at 31,800 ± 300 years old. In 1994, a seed from a sacred lotus, dated at roughly 1,300 ± 270 years old, was successfully germinated. In 2024, a never-before-seen species of Commiphora was grown from a successfully germinated seed that is estimated to be 1,000 years old.
During the 1990s, Raul Cano, a microbiologist at California Polytechnic State University, San Luis Obispo, US, reported reviving yeast trapped in amber for 25 million years, although doubts were raised as to its antiquity. Cano founded a brewery and crafted an "amber ale" with a 45-million-year-old variant of Saccharomyces cerevisiae.
List of longest-living organisms
Microorganisms
Some endoliths have extremely long lives. In August 2013, researchers reported evidence of endoliths in the ocean floor, perhaps millions of years old, with a generation time of 10,000 years. These are slowly metabolizing and not in a dormant state. Some Actinomycetota found in Siberia are estimated to be half a million years old.In July 2020, marine biologists reported that aerobic microorganisms, in "quasi-suspended animation", were found in organically poor sediments below the seafloor in the South Pacific Gyre . The sediments had been dated by previous research using cobalt-based techniques to 4.3 to 101.5 million years old, which would make them the longest-living life forms ever found, yet in October 2024, scientists reported aerobic microorganisms in a two billion-year-old rock drilled from 15 meters underground within a formation known as the Bushveld Igneous Complex in northeastern South Africa, though the age of the microorganisms is unknown.
Clonal plant and fungal colonies
As with all long-lived plant and fungal species, no individual part of a clonal colony is alive for more than a very small fraction of the life of the entire colony. Some clonal colonies may be fully connected via their root systems, while most are not interconnected but are nonetheless genetically identical clones that populated an area through vegetative reproduction. Ages for clonal colonies are estimates, often based on current growth rates.- A huge colony of the sea grass Posidonia oceanica in the Mediterranean Sea near Ibiza, Spain, is estimated to be between 12,000 and 200,000 years old. The maximum age is theoretical, as the region it now occupies was dry land at some point between 10,000 and 80,000 years ago.
- The sole surviving clonal colony of the shrub Lomatia tasmanica in Tasmania is estimated to be at least 43,600 years old.
- The Jurupa Oak colony in Riverside County, California, United States, is estimated to be at least 13,000 years old. Other estimates place it at 5,000 to 30,000 years old.
- Eucalyptus recurva clones in Australia have been claimed to be 13,000 years old.
- A box huckleberry bush in Perry County, Pennsylvania, United States, is thought to be around 13,000 years old. If true, it would predate human settlements in the area.
- King Clone is an individual creosote bush in the Mojave Desert of southern California, United States, estimated at 11,700 years old. Another creosote bush has been said to be 12,150 years old, but this is as yet unconfirmed.
- A Huon pine colony on Mount Read, Tasmania, is estimated at 10,000 years old, with individual specimens living over 3,000 years.
- Old Tjikko, a Norway spruce tree in the county of Dalarna, Sweden, is living on top of roots that have been radiocarbon-dated to 9,550 years old. The tree is part of a clonal colony that was established at the end of the last ice age. Discovered by Professor Leif Kullman of Umeå University, Old Tjikko is small, only in height.
- Pando is a clonal colony of Populus tremuloides trees in south-central Utah, United States, that is estimated to be several thousand years old, possibly as much as 14,000 years. Unlike many other clonal "colonies", Pando's above-ground tree trunks remain connected to each other by a single massive subterranean root system.
- "Humongous Fungus", an individual of the clonal subterranean fungal species Armillaria solidipes in Oregon's Malheur National Forest, is thought to be between 2,000 and 8,500 years old. Apart from its extreme age, it is also thought to be the world's largest organism by area, at.
- A huge colony of the sea grass Posidonia australis in the Australian coast over Shark Bay is estimated to be over 4,500 years old and also the world's largest known plant.