'A new study has found that three-fourths of the human genome is non-functional or “junk DNA,” which might mean it doesn’t do anything … or it could just mean that scientists have no idea what it is used for yet. They do know, however, what it doesn’t do: These garbled sequences of nucleotides do not encode the proteins responsible for our bodies’ chemical reactions.
In the 1950s, it was widely assumed that most DNA coded for proteins, but over the years it has become clear that only a portion of a genome is responsible for encoding functional proteins. The term “junk DNA” was first used in 1972 to refer to DNA that has no known function.
University of Houston researchers, led by Dan Graur, used mathematical calculations to determine that only somewhere between 10 and 25 percent of our DNA is functional. They made their calculations using the deleterious mutation rate, which is the rate of harmful mutations, along with the replacement fertility rate. The study was published in Genome Biology and Evolution.'
Read more: Scientists admit they really have no idea what 75% of human genetic code is actually used for