From Prospect Magazine:
Old age hardly exists in wild animals. Accident, illness or predation usually kill long before the potential lifespan has been reached. Humans, though, especially in the developed world, are pushing in ever larger numbers towards the maximum lifespan, thought by most gerontologists to be around 120. (The world longevity record is held by the Frenchwoman Jeanne Calment, who died in 1997 aged 122 years and 164 days.)
In Britain in 1901, life expectancy at birth was 49 for women and 45 for men. By 2002, this had risen to 81 and 76 respectively. This rapid increase in longevity has created hopes among gerontologists not just of an extended “quality of lifespan” well into the nineties, but of lifting the 120-year limit. The optimists point out that all animals have immortal reproductive cells (“germlines”), and argue that ageing and longevity are genetically determined through programmes that can in principle be amended. They argue that biology has the tools to cope with wear and tear almost indefinitely, if only there were an evolutionary route to get there.
Right now the optimists are in the ascendant, bolstered by recent experiments that have extended the life expectancy of mice from around two years to three, with some reports of up to five. (Picture).