This process is partly regulated by methylation, whereby methyl groups are added to our DNA. In specific locations, genes with high methylation levels are deactivated.

The behavior of organs and tissues in the body depends on which of our genes are activated. As we age, some genes are switched on, while others are switched off. Professor Bram Bekaert said, "This process is partly regulated by methylation, whereby methyl groups are added to our DNA. In specific locations, genes with high methylation levels are deactivated."
Researchers were able to predict individuals' age on the basis of a set of four age-associated DNA methylation markers. The methylation levels of these markers can be used for highly accurate predictions of age. The team was able to determine individuals' age with a margin of error of 3.75 years for blood samples and 4.86 years for teeth.
The authors said, "The new technique is potentially useful in the context of police investigations because it can help determine the age of criminals or unidentified bodies, which in turn can lead to identification."
Source-IANS