Why Do Women Outlive Men? "Mother's Curse", According To New Study
Ever since records have been kept, women have consistently outlived men. While many theories abound--including, for example, men's role in history to participate in wars and combat--there never was a definite, scientific proof.
And with the latest reports that Hong Kong women have the longest average lifespan of any other humans on earth, the question "Why?" has been on many scientists' mind.
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Well, a new study has another theory: women's longetivity over men may be the result of an evolutionary hoophole.
According to a Fox News report, this loophole lies in the mitochondria, the energy-generating parts of our cells. These cells, which are specifically passed down from females to females, each have its own DNA, and it's completely independent from the rest of the DNA in our body.
As studies have shown over time, cells could develope harmful mutations over generations, but natural selection tends to keep these harmful mutations at bay by ensuring they don't get passed down. But if a mitochondrial DNA mutation is dangerous only to males and doesn't harm females, there's nothing to stop mom from passing it to her daughters and sons.
"If a mitochondrial mutation pops up that is benign in females, or a mutation pops up that is beneficial to females, this mutation will slip through the gates of natural selection and go through to the next generation," study researcher Damian Dowling, an evolutionary biologist at Monash Univeristy in Australia, told Fox News.
Dowling achieved this conclusion, dubbed the "mother's curse", by testing standardized nuclear genomes in flies.
"The only genetic difference across the strains of flies lay in the origin of the mitochondria," Dowling said in a previous interview.
The researchers then recorded how long each strain of flies lived. Their findings revealed a big difference for males, but not for females.
"There was a lot of variation in terms of male longevity and male aging, but almost no variation in the female parameters of aging," Dowling said. "This provides very strong evidence that there are lots of mutations within the mitochondrial genome that are having an effect on male aging, but are having no effect whatsoever on female aging."
With an average lifespan of 86.7, Hong Kong's women are the longest living in the world, an amazing feat given the city's notorious smog and claustrophobic, stressful enviroment. If Dowling's report is to be believed, these women could thank the mutation in their genes.
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