Scientists say genetic traits may help explain longevity of tortoise estimated at 194

Jonathan, a giant tortoise on Saint Helena, is described as the world's oldest known living land animal. His age is estimated at about 194 years. The Guardian says he is "believed to be" 194; Reuters says he is "estimated to be about" 194. The reports reviewed by Vocemundi do not describe how his age was estimated.

Scientists who studied Jonathan suggest his longevity may be associated with a combination of genetic traits and cellular systems that function in a more youthful way. The Guardian and Reuters both reported this, based on the same study.

The study

According to the Guardian, an international team led by Benjamin Vaisvil published the research in the journal Science Advances. The reports do not include the publication date.

The Guardian reported that the team found genetic variants in Jonathan's DNA in most of the biological pathways for ageing that scientists have identified. These pathways are involved in DNA repair, metabolic regulation and defence against cancer.

The researchers also compared DNA methylation patterns on Jonathan's genes with those of other giant tortoises, according to the Guardian. On many genes, his patterns resembled those of other old tortoises. On genes linked to mitochondrial function, they matched those of much younger tortoises. The reports do not include how many tortoises were compared, or their ages. According to the Guardian, it is unclear whether, or how much, this patterning contributes to Jonathan's lifespan.

Background

According to Reuters, Jonathan is an Aldabra giant tortoise. The Guardian reported that he lives in the grounds of Plantation House, the governor's official residence on Saint Helena, in the South Atlantic.

According to the Guardian, Joe Hollis, former senior veterinary officer of Saint Helena, took over Jonathan's care in 2009. Jonathan was then blind from cataracts, had lost his sense of smell and had a soft, crumbly beak. After hand-feeding, he regained weight and a hard beak within six months to a year. The Guardian also reported that in April, a fake X account posing as Hollis falsely claimed Jonathan had died. Governor Nigel Phillips then checked on him and found him alive.

What each side says

Stephen Clark, a senior researcher on the project, works at the non-profit Kallel Foundation, according to the Guardian. The Guardian quoted him as saying: "His mitochondria must be especially stable and that’s an insight into longevity in general." Clark said the finding still needs to be validated. "How do we test this idea? Is there a way that makes the mitochondria young, or can we replace the mitochondria and see if it extends longevity? That’s one of the next steps," the Guardian quoted him as saying.

Reuters' summary of the scientists' view was that Jonathan may owe his longevity to genetic traits combined with an ability to keep key cellular systems working in a more youthful way. The reports do not include comment from independent scientists.

Analysis

The study offers a detailed look at one exceptionally long-lived animal, but its conclusions are framed as associations, not causes. The researchers themselves say the mitochondrial finding must be tested. One possible path is experiments of the kind Clark describes, which could support or weaken the idea that stable mitochondria matter for longevity. Another is that findings from a single animal prove hard to generalise. Without independent expert comment, details on the comparison group or an explanation of how Jonathan's age was estimated, readers may wish to treat the results as an early, unconfirmed lead in ageing research.

Produced by the Vocemundi newsroom with AI assistance.