Why women live longer than men
Women are genetically programmed to live longer than men, a study has found according to Daily mail.
It is well known ladies tend to live longer than gentlemen.
But now scientists have discovered that this ‘male disadvantage’ is not just a human phenomenon – because of men having higher likelihoods of men dying in war, violence or exposure to industrial accidents.
A study of monkeys and apes find that males in primate species also live shorter lives.
The study, analysed data from more than one million births and deaths from the 18th century to the present day.
Included in the data, were people from post-industrial societies, people born in pre-industrial times, and modern hunter-gatherers, who provide a baseline for how long people might have lived before supermarkets and modern medicine.
This data was measured against similar data for six wild species of primates from the past five decades, including, muriqui monkeys, capuchins, baboons, chimpanzees and gorillas.
Co-author Professor Susan Alberts, said: ‘The male disadvantage has deep evolutionary roots.’
She added: ‘Males are generally disadvantaged relative to females in both life expectancy and lifespan equality, across the primate order and at all levels of human life expectancy.’
The data confirmed that humans are making rapid and dramatic gains in term of life-expectancy.
The oldest human populations across the world have an average of 40 or 50 years advantage over populations who life a traditional lifestyle.
But modern hunter-gatherers live an average of between ten and 20 years longer than the chimpanzees from which human ancestors diverged millions of years ago.
Professor Alberts said: ‘We’ve made a bigger journey in lengthening our lifespan over the last few hundred years than we did over millions of years of evolutionary history.’
The prevalence of child mortality had dropped from more than one in ten two centuries ago, to less than three in 1,000.
But to the author’s surprise, the gap between male and female life-expectancy has barely shifted.
Two hundred years later, and with 45 years added to lifespan, that three- or four-year gap between the sexes has barely changed.
Professor Alberts said; ‘It’s puzzling. If we can make life last so long, why can’t we shrink the male-female gap?’
A number of explanations have been suggested, including genetics.
Males only carry one copy of the X chromosome, meaning females who carry two are better able to compensate for harmful gene variants.
Another possibility, Professpr Alberts said, was that men more often engage in risk behaviours.
N.H.Kh