This is where the zebra finches came in: how early and accurately could longer telomeres predict a longer life?

BBC: Glasgow scientists say telomeres indicate life length

That makes sense because previous work has shown that skinny female zebra finches are less likely to survive and reproduce than skinny males so when resources are poor, parents should prefer to produce sons.

ECONOMIST: Sexy sons, dutiful daughters | The

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.

BBC: Glasgow scientists say telomeres indicate life length