Jonathan, the world’s oldest known living land animal, is at the centre of a new scientific study examining genetic characteristics that may help explain his remarkable lifespan.
The giant tortoise, estimated to be 194 years old, lives on the South Atlantic island of St Helena. He has far outlived the typical lifespan of his species, attracting scientific interest in the biological mechanisms that may slow ageing.
Jonathan is believed to have been born around 1832 and was brought to St Helena in 1882, when he was already fully grown. He has lived in the grounds of Plantation House, the official residence of the island’s governor, ever since.
What did researchers discover?
The study, published in the scientific journal Science Advances, examined Jonathan’s genetic material and epigenetic markers to identify features that could help explain his longevity.
Researchers identified 287 genetic variants that stand out in his genome and are associated with biological processes linked to ageing. These include DNA repair, insulin regulation, telomere function and tumour suppression.
Particular attention was given to mitochondria, the cellular structures responsible for producing the energy the body needs. The study found that certain regions of DNA regulating genes associated with mitochondrial function retained remarkably organised epigenetic patterns despite Jonathan’s advanced age.
Epigenetic markers influence how genes are switched on or off without changing the underlying DNA sequence. Some of these patterns typically become more disorganised over time.
In Jonathan’s case, the regions examined showed less disruption than researchers would expect, based on comparisons with other tortoises. This could provide clues to how some organisms maintain essential cellular functions over exceptionally long periods.
Could Jonathan help explain human ageing?
The findings may offer new insights into biological processes that help preserve cellular function as organisms grow older. DNA repair and the maintenance of mitochondrial function are also important to human health.
However, researchers have not established that the genetic variants identified are responsible for Jonathan’s longevity. The study is based on a single animal and comparisons with a limited number of other tortoises, meaning further research is needed before firm conclusions can be drawn.
At an estimated 194 years old, Jonathan provides scientists with a rare opportunity to investigate the biology of extreme longevity. Although the reasons behind his exceptionally long life remain unclear, the findings could help guide future research into mechanisms that may slow certain aspects of ageing in humans.
Also read: Navi Pillay wins 2026 Nobel Peace Prize
For more videos and updates, check out our YouTube channel.
