A study led by Fernando Colchero, University of Southern Denmark and Susan
Alberts, Duke University, North Carolina, that included researchers from 42
institutions across 14 countries, provides new insights into the aging theory
"the invariant rate of ageing hypothesis," which states that every species has
a relatively fixed rate of aging.
"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.
He is an expert in applying statistics and mathematics to population biology
and an associate professor at Department of Mathematics and Computer
Science, University of Southern Denmark.
"We were able to shed light on the invariant rate of ageing hypothesis by
combining an unpresented wealth of data and comparing births and deaths
patterns on nine human populations with information from 30 non-human
primate populations, including gorillas, chimpanzees and baboons living in
the wild and in zoos," said Fernando Colchero.
In order to explore this hypothesis, the researchers analyzed the
relationship between life expectancy, this is the average age at which
individuals die in a population, and lifespan equality, which measures how
concentrated deaths 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 ages, 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 aging; the
reason is that more and more infants, children and young people survive and
this brings up the average life expectancy," said Fernando Colchero.
Previous research from some of the authors of the study has unraveled the
striking regularity between life expectancy and lifespan equality among
human populations, from pre-industrial European countries, hunter gatherers,
to modern industrialize countries.
However, by exploring these patterns among our closest relatives, this study
shows that this pattern might be universal among primates, while it provides
unique insights into the mechanisms that produce it.
"We observe that not only humans, but also other primate species exposed to
different environments, 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 authors show 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," says 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."
Reference:
Fernando Colchero, José Manuel Aburto, Elizabeth A. Archie, Christophe
Boesch, Thomas Breuer, Fernando A. Campos, Anthony Collins, Dalia A. Conde,
Marina Cords, Catherine Crockford, Melissa Emery Thompson, Linda M. Fedigan,
Claudia Fichtel, Milou Groenenberg, Catherine Hobaiter, Peter M. Kappeler,
Richard R. Lawler, Rebecca J. Lewis, Zarin P. Machanda, Marie L. Manguette,
Martin N. Muller, Craig Packer, Richard J. Parnell, Susan Perry, Anne E.
Pusey, Martha M. Robbins, Robert M. Seyfarth, Joan B. Silk, Johanna Staerk,
Tara S. Stoinski, Emma J. Stokes, Karen B. Strier, Shirley C. Strum, Jenny
Tung, Francisco Villavicencio, Roman M. Wittig, Richard W. Wrangham, Klaus
Zuberbühler, James W. Vaupel, Susan C. Alberts. The long lives of primates
and the ‘invariant rate of ageing’ hypothesis. Nature Communications, 2021;
12 (1) DOI:
10.1038/s41467-021-23894-3
Tags:
Biology & Health