By a study in fruit flies, Scientists believe they have revealed a clue to why women tend to live longer than men. Mitochondria are inherited only from mothers, never from fathers, so there is no way to weed out mutations that harm a male's prospects. Through the age of 85, there are just about six women for every four men in the UK, and by 100 the ratio is more than two to one.
According to Dr Dowling, if a mitochondrial mutation occurs that harms fathers, other than has no effect on mothers, this change will slip through the look of natural selection, ignored. All animals have mitochondria, and the affinity for females to outlive males is frequent to many different genuses.