Biological aging is observed in almost all animal species. Aging involves the decline of diverse biological functions, and the dynamics of this process limit a species’ maximum lifespan.
Associated with epigenetic changes involving DNA methylation, an analysis of mammals showed that the density of CpG sites in gene promoters, which are targets for DNA methylation, is correlated with lifespan.
Scientists, in a new study, used 252 whole genomes and databases of animal age and promotor sequences and showed a pattern across vertebrates. They also derived a predictive lifespan clock which provides accurate maximum age estimates for vertebrates, a key variable in the study of both living and extinct animals.
The clock is developed based on CpG density in a selected set of promoters. It predicts maximum lifespan invertebrates from the density of CpG sites within only 42 selected promoters.
Scientists noted, “The lifespan clock estimated a 38-year lifespan for humans, in line with the accepted maximum life expectancy of 40 years for pre-modern man but less than half that of his contemporary today.”
During experiments, the clock was tested to look at two of man’s immediate predecessors—Denisovans and Neanderthals.
Scientists noted, “We estimated that Denisovans and Neanderthals both had a lifespan of 37.8 years. This suggests that these extinct Hominidae species had similar lifespans to their early humans… counterparts.”
Although the clock can not be used to determine the lifespan of any individual human, and the purpose of this study was to determine an essential parameter of ecological significance which may assist in wildlife management.
The paper is published in the journal Scientific Reports.