Making little or no difference to our daily lives, comes the claim that most of our human genome is not functional.
Dan Graur an (evolutionary) biologist at the University of Houston and other academics made the claim in a paper published in an online journal, Genome Biology and Evolution.
The group's calculations suggest that not more than 25% of the human genome is functional - the rest is seen as 'junk' DNA,
See Science Dailys coverage of the report at: https://www.sciencedaily.com/releases/2017/07/170714140234.htm
Coverage of similar research at the UK's Oxford University (reported in The Guardian Aust. web edition)
added comments by Gerton Lunter, a member of that research team:
Who (it is reported), "said that based on the comparisons, 8.2% of human DNA was "functional", meaning that it played an important enough role to be conserved by evolution. ...
Researchers have known for some time that only 1% of human DNA is held in genes that are used to make crucial proteins to keep cells – and bodies – alive and healthy. The latest study, reported in the journal Plos Genetics, suggests that a further 7% of human DNA is equally vital, regulating where, when, and how genes are expressed.
But if much of our DNA is so worthless, why do we still carry it around? ... " Lunter said. "We haven't been designed. We've evolved and that's a messy process. This other DNA really is just filler. It's not garbage. It might come in useful one day. But it's not a burden."
Some of our DNA is left over from ancient viruses that inserted their genetic material into our DNA – or our ancestors DNA – and got mutated to pieces over millennia of evolution. Some still have the ability to jump around in our genomes, adding to the filler as they do so, but are so crippled they cannot break out."
NB: The Guardian report explains what these scientists mean by "functional."