Elinikä|According to researchers, lifespan is affected, for example, by taking care of offspring.
The summary is made by artificial intelligence and checked by a human.
Female mammals usually live longer than males, but in birds the age difference can often be the opposite.
An extensive study investigated the lifespan of 1,176 animal species by sex at the Max Planck Institute in Leipzig.
In mammals, the longer lifespan of females is partly explained by genetic factors and the fact that the female invests in caring for her offspring.
Males sometimes have to invest their resources in certain characteristics in order to mate. It can reduce the lifespan of a male.
Ladies live longer than men. Many people can notice it in their family as well: there are more aging grandmothers than grandfathers.
The same age difference applies to tribes and nations. The calculated life expectancy for women on Earth is currently around 74 years and for men around 68.
The difference in favor of the woman has remained. Reasons for the separation have been sought for a long time.
An increasingly accurate understanding of why women and females generally live longer on average than men and males is emerging.
An evolutionary anthropologist Johanna Stärk has done a comprehensive study with his group on the differences in the lifespan of male and female mammals. The age differences of the birds were also investigated.
Stärk works at the Max Planck Institute in Leipzig, Germany.
He analyzed the life expectancy of no less than 1,176 species. There were 528 mammal species and 648 bird species on the list. The data included both wild and zoo populations.
Females live longer than males in about 72 percent of the mammal species studied. Females accumulate about 12–13 percent more than their age, says news service Eurekalert.
In birds however, dogs do better. In about 68 percent of the studied bird species, the male lives longer. The age difference is about five percent good for the dog.
The differences between people have been explained, among other things, by the fact that young males and men die young more often. The reasons are accidents and risk taking.
Another explanation is that women’s bodies are more protected.
Men and males have two different sex chromosomes, X and Y. Females and females, on the other hand, genetically have two copies of the X chromosome.
So, the X chromosome is a backup in a way. It protects against sex chromosome mutations.
With birds gender is defined differently. Female birds have two different sex chromosomes, Z and W.
Dogs, on the other hand, have two Z chromosomes. It reverses the arrangement of the sexes in birds compared to mammals.
Stärk and his colleagues also found that the sex that invests more in raising offspring lives longer. In mammals it is usually female.
By mating also matters.
Some polygamous mammals compete fiercely for willing partners. These include, for example, baboons, gorillas and chimpanzees.
“Because there is competition for mating, males invest in characteristics that affect gender selection,” says a member of Stärk’s group Fernando Colchero of science according to the newspaper New Scientist.
Such characteristics can be decorative feathers and, for example, large horns, says Colchero.
“Producing these characteristics is expensive for the organism. There are other costs associated with mating, for example fighting with males,” says Colchero.
Because of competition, males usually die earlier than females, he says Eurekalert.
Namely, the individual has less resources to invest in his survival. The same applies to birds that have polygamous mating.
Sexual the life span differences between them are smaller in zoos than in the wild. There are hardly any fights or diseases in zoos, and there is no need for prey either.
The difference in life expectancy between men and women is perhaps narrowed by the fact that health improves. According to Stärk, however, we cannot expect that the differences will disappear completely.