SCIENTISTS LINK 194-YEAR-OLD TORTOISE'S GENES TO LONG LIFE

Scientists studying Jonathan, a 194-year-old Aldabra giant tortoise living on the south Atlantic island of St Helena, have identified genetic and epigenetic traits that may explain his unusually long life. The research, published in the journal Science Advances, found 287 unique gene variants in Jonathan that reduce typical effects of ageing, including genes involved in DNA repair, inflammation reduction, insulin regulation and cancer suppression. The study was led by researchers at the Kallel Foundation, a longevity research nonprofit based in Nashville. Jonathan is recognised as the oldest living giant tortoise and the oldest land animal alive today, having reportedly hatched in 1832. He has outlived the typical lifespan of his species by around a century, according to the researchers.

Researchers compared Jonathan's epigenome, the chemical markers that switch genes on and off, with that of younger tortoises of the same species, and found the switches controlling his DNA repair and metabolism genes remained closely similar to those of his younger relatives. Normally, the epigenome changes with age, which researchers say is a key driver of age-related decline. Samples were collected by vet Joe Hollins using cheek swabs and later cheek scrapes, after island authorities ruled out drawing blood due to infection risk. Study co-author Stephen Clark said the findings offer new insight into the long-studied link between mitochondrial function and longevity.

Dr Justin Gerlach, of Peterhouse at the University of Cambridge, who took part in the study, said the stability of Jonathan's gene regulators for energy production and DNA repair over nearly two centuries was notable. Gerlach, who has studied giant tortoise ecology and conservation for decades, said working with Jonathan felt like collaborating with a research partner rather than studying a subject. The researchers said this marks the first time a giant tortoise's epigenome has been investigated, and that studying extreme longevity in tortoises could provide further insight into the ageing process more broadly.