194-Year-Old Jonathan Has 5-Year-Old Mitochondria — SkimNews
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- Jonathan, the ~194-year-old Aldabra giant tortoise on St Helena, has had his genome sequenced for the first time, revealing mitochondrial function genes as efficient as those of a 5-year-old tortoise — energy the researchers say fuels his DNA repair systems to fight ageing.
- Stephen Clark at the Kallel Foundation led the study, identifying 287 genes with changes unique to Jonathan, of which 41 are functionally significant and a dozen overlap with aging databases of other long-lived species.
- St Helena authorities refused requests to draw Jonathan's blood due to his fame and infection risk, forcing the team to assemble the genome from saliva and cheek swabs, then fill gaps using DNA from another Aldabra tortoise.
- Manel Esteller at the Josep Carreras Leukaemia Research Institute had previously found the same exceptionally efficient mitochondrial pattern in a 117-year-old woman, prompting Clark's team to suspect — and confirm — the same signature in Jonathan.
- Kousuke Hashimoto at the University of Osaka called the work "fascinating" but cautioned that Jonathan's genome was compared against only a few other tortoises, which may themselves carry unique genetic changes.
- The study, published in Science Advances, puts the average Aldabra tortoise lifespan at around 80 years, making Jonathan's estimated 194 years a dramatic outlier and the oldest known land animal on record.
Why it matters: The study strengthens the case that aging mechanisms are conserved across species: the same efficient-mitochondria pattern appeared in a 117-year-old human and now a 194-year-old tortoise. The catch — a genome compared against only a handful of other tortoises — limits how far those conclusions can stretch, and researchers will need broader samples before translating the findings to human healthspan interventions.
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