2 August 2012 Last updated at 12:50 ET

Scientists believe they have discovered a clue to why women tend to live longer than men - by studying fruit flies.

Writing in Current Biology, they focus on mutations in mitochondrial DNA - the power source of cells.

Mitochondria are inherited only from mothers, never from fathers, so there is no way to weed out mutations that damage a male's prospects.

But one ageing expert said there were many factors that explained the gender difference in life expectancy.

By the age of 85, there are approximately six women for every four men in the UK, and by 100 the ratio is more than two to one.

And females outlive males in many other species.

In the research, experts from Australia's Monash University and the UK's Lancaster University analysed the mitochondria of 13 different groups of male and female fruit flies.

Mitochondria, which exist in almost all animal cells, convert food into the energy that powers the body.

I certainly don't think this is a discovery that explains why women live five-to-six years longer than men

Read the rest here:
DNA clue to why women live longer