Researchers have sequenced the genome of Jonathan, a giant tortoise who has lived for 194 years on St Helena island — more than double the average lifespan for his species. The analysis points to specialised DNA repair systems that appear to protect his cells from the cumulative damage typically associated with ageing.
The study highlights specific genes involved in DNA repair that are unusually active or well-preserved in Jonathan's genome. These mechanisms likely help maintain genomic stability over decades, allowing him to avoid many age-related diseases that affect shorter-lived animals.
While the findings are based on a single individual, they offer a concrete genetic explanation for extreme longevity in tortoises. The authors suggest that further comparative studies across long-lived species could reveal universal strategies for slowing ageing, with potential implications for human health.