The notion of extending the human lifespan has captured imaginations for millennia. Among scientists, enthusiasm for the idea has grown in recent years with a host of Silicon Valley companies springing up to join academic institutions in attempting to chip away at issue of longevity – among them Google’s California Life Company, or Calico, as it is known – with big-buck prizes such as the Palo Alto Longevity Prize adding to the clamor. Last month Nature scientific journal published a high-profile paper that concluded “maximum longevity has hit a ceiling of 114.9 years” – a claim that prompted extraordinary levels of criticism from the scientific community. The original study used the International Database on Longevity, which compiles lists of the age of the oldest person to die in a given year. It found the maximum reported age of death increased rapidly between the 1970s and early 1990s, but then appeared to plateau in the mid-1990s at 114.9 years.
Five separate research teams have launched critiques of the work in a series of papers in the journal Nature, arguing that there is no compelling evidence that we are approaching an upper limit on our mortality – or at the very least, that such a limit may be considerably higher than 115 years. One complaint was that the paper’s analysis partitioned the data into two time periods – before and after 1995 – on the back of a visual inspection that appeared to show a levelling off around this year. When the two underlying trends were calculated, the period after 1995 had a flat gradient, appearing to confirm the hypothesis. When any data series is segmented, there may appear to be temporary plateaus or even declines, despite an overall upward trend – as seen in long-jump records, for instance.
Maarten Rozing of the University of Copenhagen said there was little to suggest the existence of a “biological clock” programmed to limit the length of life. “We now know not only that the idea of such a clock is highly implausible, but also that ageing is proving to be more amenable to change than used to be supposed,” he told The Guardian. Jan Vijg, the geneticist at Albert Einstein College of Medicine in New York who authored the original paper, said he accepts “absolutely nothing” in the latest criticisms, dismissing them as statistical nitpicking by those who “hadn’t read his paper properly”, while implying that his critics are, to some extent, simply upset at being confronted with their own mortality.
The only sure thing is that any extension of the human longevity influences directly the waste management systems and the resource recovery efforts, as elder people behave different than the average person both in waste generation and participation to recycling schemes. In any case, allow me to finish with a lovely quote by Carl G. Jung.
“Life really does begin at 40 – Up until then, you are just doing research”