A study led by Fernando Colchero, University of Southern Denmark, and Susan Albert’s, Duke University North Carolina that included researchers from 42 institutions across 14 counties, provides new insight into the ageing theory: “the invariant rate of ageing hypothesis,” which states that all species have a relatively fixed rate of ageing.
“Human death is inevitable no matter how many vitamins we take, how healthy our environment is or how much we exercise, we will eventually age and die,” said Fernando Colchero.
Cholchero is an expert in applying statistics mathematics to population biology and an associates professor at the Department of Mathematics and Computer Science, University of Southern Denmark.
“We were able to shed light on the invariant rate of ageing hypothesis by comparing births and deaths patients on nine human population with information from 30 non-human primate population including gorilla, chimpanzee and baboon living in the wild and Zoos”, said Fernando Colchero.
In order to explore this hypothesis, the researchers analyzed the relationship between life expectancy, which is the average age at which an individual dies in a population and lifespan equality which measures how concentrated death are around older ages.
Their results show that, as life expectancy increases, so does lifespan equality. So, lifespan equality is very high when most of the individuals in a population tend to die at around the same age such as observed in modern Japan or Sweden- which is around their 70s or 80s. However in the 1800s lifespan equality was very low in those same countries, since deaths were less concentrated at old age, resulting also in lower life expectancy.
“Life expectancy has increased dramatically and still does in many parts of the world, but this is not because we have slowed our rate of ageing; the reason is that more and more infant children and you people survive and this brings up the average life expectancy said Fernando Colchero.
Previous research from some of the authors of the study unravelled the striking similarity between life expectancy and lifespan equality among human populations, from pre-industrial European countries, Hunter gathered, to modern industrialised countries.
However, by exploring those pattering among our closest relatives, this study shows that this pattern might be universal among primates while it provides unique insight into the mechanism that produces it.
“We observe that not only humans but also other primates species exposed to a different environment succeed in living longer by reducing infant and juvenile mortality. However, this relationship only holds if we reduce early mortality and not by reducing the rate of ageing”, said Fernando Colchero.
Using statistics and mathematics the author shows that even small changes in the rate of ageing would make a population of, say, baboons, to demographically behave as a population of chimpanzees or even humans.
Not all is lost, said Fernando Colchero, Medical science has advanced at an unprecedented pace, so maybe science might succeed in achieving what evolution could not, to reduce the rate of ageing.
By: Peace Chigozie