Worldwide, women outlive men. There’s been several theories proposed to explain this. However, just this week new findings point to a mother’s genes as the sole reason men have shorter lifespans than women.
Previous beliefs for this trend included the idea that men work harder than women, and that lifestyle leads to earlier death. The idea that women are affected by health issues later in life than men has also been questioned. If women tend to get ailments like heart disease 10 years later than men, their death ages would naturally be later, on average.
The fact that women tend to have healthier habits than men has been a theory before, too. It was even once believed that estrogen led to longevity. But while all of these ideas seemed logical at one point, they’ve since been disproven.
So, why are women outliving men by an average of five years? This week the journal Current Biology released findings that may have the complete answer.
According to an article from Live Science writer Stephanie Pappas, the answer to this trend is in the mitochondria – the energy-producing parts of our cells. Mitochondria have their own, separate DNA, and this DNA is passed only from mother to child.
In most instances, if a mutation occurs, natural selection prevents it from being passed to the next generation. However, with the mitochondrial DNA, it can be passed from the mother with mutations that are harmful to males. The mutation essentially doesn’t “register” as bad if it’s still positive or benign for females.
The study researcher, Damian Dowling, is an evolutionary biologist at Monash University in Australia. Dowling explained how the passing of mitochondrial DNA affects different genders, as reported by Live Science.
“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.”
Pappas clarified what that means by saying the mutations don’t harm or negatively affect females, and they add up to a shorter life span for males. If these tests are conclusive, it would appear there’s nothing men can do about their inferior longevity. Sorry fellas, women are not only smarter, they apparently live longer, too.
August 4th, 2012