Humans have a “natural” lifespan of around 38 years. This is the result of a new method developed for estimating the lifespans of different species by analysing their DNA:
Biological ageing and its mechanistic underpinnings are of immense biomedical and ecological significance. Ageing involves the decline of diverse biological functions and places a limit on a species’ maximum lifespan. Ageing is associated with epigenetic changes involving DNA methylation. Furthermore, an analysis of mammals showed that the density of CpG sites in gene promoters, which are targets for DNA methylation, is correlated with lifespan. Using 252 whole genomes and databases of animal age and promotor sequences, we show a pattern across vertebrates. We also derive a predictive lifespan clock based on CpG density in a selected set of promoters. The lifespan clock accurately predicts maximum lifespan in vertebrates (R2 = 0.76) from the density of CpG sites within only 42 selected promoters. Our lifespan clock provides a wholly new method for accurately estimating lifespan using genome sequences alone and enables estimation of this challenging parameter for both poorly understood and extinct species.Mayne, Benjamin, et al. ‘A Genomic Predictor of Lifespan in Vertebrates’. Scientific Reports, vol. 9, no. 1, Dec. 2019, pp. 1–10. http://www.nature.com, doi:10.1038/s41598-019-54447-w.
If this is true (and honestly, it sounds very plausible) the human species would be at the verge of an eerie transition.
The median age in North America, Australia, Russia, China, Europe, and Japan is about or well the 38 years limit (Germany, Italy, and Japan more than 45).
The median age in the world is 29.8 years, still below the limit but growing very fast.
Being over our “natural” lifespan sounds a lot as being undead. So I cannot resist the temptation to call it the “zombie” transition.