There have been many instances and studies which clarify that woman are less healthy than man in older age but according to a recent survey, genes that act late in life could explain why women have poorer health than men in older age.
The answer, according to scientists from the University of Exeter in the UK, is intralocus sexual conflict — genes that benefit one sex but harm the other.
RESEARCH USING MATHEMATICAL MODELS AND EXPERIMENTAL DATA ON FLIES
The researchers used mathematical models and experimental data on flies to show that such genes can easily spread if they take effect after female reproduction stops.
“Shared genes tether the sexes together in an evolutionary tug of war,” Professor David Hosken from the University of Exeter said.
“Selection is trying to push females and males in different directions, but the shared genome means each sex stops the other from reaching its optima. Basically, certain genes will make a good male but a bad female, and vice versa. However, after females reach menopause, they no longer reproduce to pass on their genes which means selection (which is reproduction) on females is greatly weakened,” Hosken said.
“So after that point, any genes that improve late-life male fitness will accumulate, even if they harm female fitness,” Hosken added.
He said it was important to note that survival and health are not the same thing — and that the accumulation of late-life male benefit genes hinged upon males’ ability to continue reproducing after the age of female menopause.
The experimental data on flies (Drosophila) supported the findings of the mathematical models on humans, as genes that were better at late-life male reproduction tended to be worse for females.