A team led by Jean-François Lemaître, a CNRS researcher at the Biometry and Evolutionary Biology laboratory (CNRS / Claude Bernard Lyon 1 University / VetAgro Sup), compiled demographic data for 134 populations of 101 mammalian species-from bats to lions, orcas to gorillas-making their study the widest reaching and most precise to date.
The research finds that, on average, females live 18.6% longer than males from the same species.
This is much greater than the well-analyzed variety between men and women, which is about eight percent.
An global team of scientists studying lifespans of wild mammals have found that, just like humans, females tend to live significantly longer than their male counterparts.
This pattern, researchers say, has been consistent since the first accurate birth records became available in the 18th Century.
Although the same premise has been held about animal species, widespread information on mammals in the wild has been little. Now, an global team of experts has analyzed age-specific mortality rates for a large-scale, diverse group of 101 species.
In 60% of the analysed populations, the scientists found that females outlived the males - on average, they had a lifespan that's 18.6% longer than males. However, in one location where winters were particularly severe, the males lived much shorter lives.
Although females lived longer than males, the researchers determined that it did not mean that the threat of dying is enhancing more in males than females as they get older. The expected male mortality is always higher, but the rate of mortality is about the same in both genders as they age.
Recent research on this matter implied that the genetic variations between males and females were significant. In humans, our cells are filled with various chromosomes, relying on the gender. We previously thought this was mostly due to sexual selection - because males fight with each other to overtake a pride and thus have access to females, however our data do not support this. The hypothesis is that the additional X in women has a defensive effect against risky mutations and that this is also seen in other species.
Lemaître said that the findings of his study suggested that the differences in male and female longevity were shaped by an animal's environment and reproductive roles.
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