Scientists at Glasgow University say they have found a key genetic indicator of how long an individual will live.
They say the lengths of tiny pieces of DNA called telomeres indicate whether a young creature is likely to live long into old age.
But before you rush out to get your telomeres stretched - were such a process possible - it is worth pointing out that the creatures they have been working with are not humans but altogether shorter-lived zebra finches.
Everything that is made up of living cells contains chromosomes: the genetic code that makes us what we are.
At the ends of each chromosome lie the telomeres. They have been likened to the caps on the ends of shoelaces - they stop things from unravelling.
Over time they wear down - and when they do, the DNA they protect is compromised and the cell can malfunction or die.
This is where the zebra finches came in: how early and accurately could longer telomeres predict a longer life?
To find out, the Glasgow researchers collaborated with colleagues at Exeter University, with Glasgow's Prof Pat Monaghan leading the team.
Tiny blood samples were taken from a group of 99 zebra finches and the lengths of their telomeres measured. They were tested again throughout their lifetimes.