New research from Glasgow University has shown that life expectancy can be predicted from DNA.

Scientists studying Alpine swifts have been able to predict the life span of the birds by measuring their telomeres - specialised bits of DNA that mark the ends of the chromosome in cells of all higher animals including humans.

The telomere also protects the DNA from loss of important genetic information during the cells life.

In the lab the length of the telomeres is known to have a role in the ageing of cells.

A chromosome gets shorter every time a cell divides and this loss is from the telomeres.

Once the telomere gets shortened to a certain length, the cells stop dividing and either remain inactive or die.

Professor Pat Monaghan, from the university's ecology & evolutionary biology department, said in a statement: "Studies in a wide range of species, including humans, show that telomeres tend to get shorter as the tissues get older. Most work on telomeres however, has been done on cells grown in the laboratory, and it has been unclear how the rate of change in telomere length affects lifespan."

Researchers from Glasgow University and the Lusanne University, Switzerland studying wild birds have shown that change in telomere lengths in blood cells can be used to predict life expectancy of the animals.

Pierre Bize from Lausanne University collected blood samples from Alpine swifts breeding in clock towers in Swiss towns every year.

Dr Bize said: "Since the birds can live for over 20 years and come back every year to the same colony to breed until they die, I have been able to get samples from the same birds at different ages and to record their survival."

The blood samples were analysed in Glasgow, where a research group specialises in animal telomeres.

The results showed that a combination of the initial telomere length and the rate of shortening, rather than the bird's actual age, predicted whether or not the bird would survive to the next year.

Ms Monaghan said: "It was very striking that this was a much better predictor than the birds' actual ages, even though birds up to 19-years-old were present in the sample."

She added: "As yet we don't know why individuals differ in the rate at which their telomeres get shorter, but it may be linked to factors in the environment since humans that are under stress are known to have shorter telomeres.

"Whether the length of telomeres and the rate at which they are shortening also predicts future life expectancy in other species - including humans - remains to be seen. But would you want to know?"