Narrator: This is Science Today. How long can humans live? The widely held belief is that there's an absolute maximum lifespan of 120 years and that this figure cannot change over time. But John Wilmoth, a professor of demography at the University of California, Berkeley, says they've found the first evidence that challenges the belief that the human life span has a set end point.
Wilmoth: We showed that there's been a steady increase in the age at death in Sweden over a long period of time. We have a hundred and forty years of clean data - that's to say it's been checked very carefully to make sure that the ages at death that are being reported are accurate.
Narrator: The data found that increases in the age at death accelerated in 1970.
Wilmoth: Because of this improvement in our progress in reducing death rates at older ages. So whether it's going to keep going up at this pace - about one year of age for every decade - whether that will continue, that all depends on our ability to maintain the current pace of progress in improving survivorship at older ages.
Narrator: For Science Today, I'm Larissa Branin.