In 1988, the first detailed description of the rate of mutation in humans at the DNA level was reported by geneticist Alec Jeffreys from the University of Leicester who devised a technique which would greatly enhance a scientist’s ability to see how DNA changed between generations.

This enabled the DNA of millions of sperm to be examined to directly measure the mutation rate and for first time observe these minisatellites or other regions of DNA before and after the mutational changes occurred during the process of sperm production. By using direct evidence from sperm analysis, Sir Alec  unraveled the secrets of when, how and why these DNA mutational changes occurred.

In 1984, Jeffreys, and technician Vicky Wilson at the University of Leicester discovered minisatellites leading to the development of genetic fingerprinting.