Dr Michelle Dickinson: We're not talking about living forever, but extending the lifespan

While some of us might want to live forever, realistically, humans on average live until about the age of 80. Scientists have often wondered what determines how long a species of mammal lives for. What makes a South Asian rat only live for six months but a bowhead whale for 200 years? Initially, it was thought to be to do with size or heart rate, with smaller mammals living shorter lives and having faster heart rates than large ones, but with the naked mole rat living to the ripe old age of 25 – the same as a giraffe – the size theory didn't stack up. Now new research out this week in the journal Nature points the finger at DNA mutation rate. https://www.nature.com/articles/s41586-022-04618-z Genetic changes, known in science as somatic mutations, occur in all cells and are largely harmless, however, some of these mutations can start a cell on the path to cancer or prevent normal function. The researchers took stem cells from the intestines of 16 species of mammal and genetically analysed the errors in them. They found that the longer the lifespan of a species, the slower the rate at which mutations occur. Their research indicated that the average number of mutations at the end of lifespan across species was around 3200 – some animals get to that number much faster than others. In their study, they found that mice produce around 796 mutations a year and live for 3.7 years while humans have a mutation rate far of around 47 per year and live to an average of 83.6 years. This new knowledge added to the recent advances in DNA sequencing will open up new doors into studies looking at the roles that somatic mutations play in ageing and in multiple diseases and maybe one day will help us to slow these mutations down even further. Dr Michelle Dickinson joined Francesca Rudkin. LISTEN ABOVESee omnystudio.com/listener for privacy information.