As Jose Manuel Aburto from Oxford’s Leverhulme Centre for Demographic Science, explains: “Our findings support the theory that, rather than slowing down death, more people are living much longer due to a reduction in mortality at younger ages.”
“We compared birth and death data from humans and non-human primates and found this general pattern of mortality was the same in all of them,” said Aburto. “This suggests that biological, rather than environmental factors, ultimately control longevity. The statistics confirmed, individuals live longer as health and living conditions improve which leads to increasing longevity across an entire population. Nevertheless, a steep rise in death rates, as years advance into old age, is clear to see in all species.”
Scientists have long posited the question of just how much longer we can live as a species, but few studies have sought to address this question while simultaneously comparing lifespans of multiple animal populations with humans to see just what is driving mortality. That is, until this study. Now, Aburto believes we can finally compare mortality differences both within and between species. The data suggests a general pattern of mortality: a high risk of death in infancy which then rapidly declines int he immature and teenage years, remains low until early adulthood, before continually rising in advancing age.
“Our findings confirm that, in historical populations, life expectancy was low because many people died young,” said Aburto. “But as medical, social and environmental improvements continued, life expectancy increased. More and more people get to live much longer now. However, the trajectory towards death in old age has not changed.”
As Aburto adds, “This study suggests evolutionary biology trumps everything and, so far, medical advances have been unable to beat these biological constraints.”