Until now it was thought that humans aged more slowly than other animals. A new study published in the journalScience, which compares data from humans, chimpanzees, gorillas and other primates for the first time, concludes thatour rate of aging is not “so exclusive”.
There was good reason to believe that human aging was unique. As Anne Bronikowski, co-author of the article and researcher at Iowa State University (USA) explains, humans live longer than most animals, although there are exceptions: some parrots, seabirds, clams and turtles are capable of exceeding the human life expectancy. “Humans live many more years after our fertile reproductive period is over. If we resemble other animals, we should begin to die much more quickly after reaching middle age, but this is not the case, “says Bronikowski.
The new study has combined long-term research data on seven species of wild primates: capuchin monkeys from Costa Rica, muriqui spider monkeys from Brazil, baboons and blue monkeys from Kenya, chimpanzees from Tanzania, gorillas from Rwanda and sifaka lemurs from Madagascar. . The team focused their attention on the risk of dying for each species. When comparing thehuman aging rates(calculated as therate of increase in mortality risk with age) with similar data for 3,000 monkeys, apes and lemurs, the human data fit perfectly within the primate continuum. “Human patterns do not present any shocking differences, even though wild primates are exposed to causes of mortality from which humans can protect themselves,” the authors write.
Females live longer
The results also show that as humans and other animals age,males die before their mates. The mortality gap between males and females is narrower for species with less aggressiveness between males, such as the muriqui monkey. And of all the species considered in the study, the lémures sifaka (Sifakaverreauxi) present the maximum difference between the male and female aging index.
“Male and female sifaka have an equivalent body mass and have similar mortality rates in adulthood, but males age twice as fast as females, probably due to risky behaviors, such as competition for sex. mating in the breeding season, and aggressions to control the group, “says Diane Brockman, co-author and anthropologist at the University of Charlotte in North Carolina (USA). According to the expert who has spent 26 years of her life studying these primates, female sifaka stay in their natal groups, with their maternal relatives, for most of their lives. ? They are not as highly competitive in males, although they are exposed to the same extrinsic causes of mortality as males, including predation and falling from trees ,? adds Brockman.
Regarding humans, the researchers emphasize that modern medicine now helps them to live longer than ever. “But we continuenot knowing which mechanism controls the maximum life span. Some studies on humans suggest that we could live many more years than we live now, “says Alberts.
