'Women have a longer lifespan than men' is not limited to humans, why is the same trend observed in wildlife?
That women who have a longer life span than men
Sex differences in adult lifespan and aging rates of mortality across wild mammals | PNAS
It's Not Just Humans: Across Mammal Species, Females Outlive Males
A team from Evolutionary Biologist Tamas Kesley at Bath University re-evaluated a statistical study of wildlife populations and found that 60% of 101 mammals have longer female lives than males Was shown. On average, the life of females was 18.6% longer than the life of males.
'We did not find a consistent gender difference in the rate of aging, which means that the longevity of females does not mean' slow aging. 'Simply, the mortality rate at older age is low.' It says.
It has generally been thought that the longevity of wildlife females is due to the risk behavior of males fighting violently for females, but Kesery does not support this hypothesis.
'The lion female lives in a flock of sisters, mothers and daughters, hunts together and care for each other, while adult male lions live alone or live only with their brothers. , And the support network is different from females, 'Kessery explained. We believe that differences in lifestyles have been one of the factors that contribute to differences in life expectancy.
In another study published on March 16, 2020, lifespan data of 229 species including birds, insects, fish, mammals was investigated, and it was found that there are two sex chromosomes of the same type. 'Has been shown to favor survival. In the case of mammals, female sex chromosome 'XX' corresponds to this, but in the case of birds, male sex chromosome 'ZZ' corresponds, and males have longer lifespan than females. This is also seen as a piece that solves the puzzle of gender life differences.
Attention has also been focused on the gender differences in life expectancy of animals of the same species depending on the environment. For example, big horns that experience harsh environments during the winter have been found to have a gender difference in lifespan. This is thought to be related to the fact that the bighorn male has a large body of 230 kg, while the female body weighs only 91 kg. Because big creatures need more food to keep their lives.
Based on the results of these studies, researchers believe that the 'environment' factor is related to many factors, including sexual selection and breeding, creating gender differences in lifespan. 'We believe that the high prevalence of pathogens that affect males and females differently also creates gender differences in lifespan,' said Kesery, who will study wildlife and zoos in future research. He is considering comparing animals.