Over 90 Percent of DNA is 'Useless?'

A new study claims that only about eight percent of a person's DNA actually has some sort of function that impacts human life. The rest, they claim, is pretty-much just "junk" left over from millions of years of evolution.

"We tend to have the expectation that all of our DNA must be doing something. In reality, only a small part of it is," researcher Chris Rands explained in a University of Oxford release.

Rands is the lead author of a study recently published in PLOS Genetics, which claims that only between 7.1 and 9.2 percent of the human genome has any biological meaning.

Rands and his colleagues determined this after taking a computational approaching to DNA sequencing of various mammals, including mice, guinea pigs, rabbits, dogs, horses, and of course, humans.

Instead of looking specifically at which genome did what in each specific mammal, the researchers looked for general trends in essential function. The researchers claim that during evolution, chunks of DNA will be dropped and replaced constantly, but additional mutations will always arise to protect what's essential in all mammals. It was these protected portions of the genome they paid special attention to.

According to Rands, only a little over one percent of human DNA dictates the protein production that carries out nearly all of the critical biological processes in the body.

"The proteins produced are virtually the same in every cell in our body from when we are born to when we die," he explained. "Which of them are switched on, where in the body, and at what point in time, needs to be controlled... it is the [other] seven percent that is doing this job."

Amazingly, that leaves more than 90 percent of the human DNA just sitting there, unused, or at least not functional.

"This is in large part a matter of different definitions of what is 'functional' DNA," said joint senior author Professor Chris Pointing of the MRC Functional Genomics Unit at Oxford University.

"There appears to be a lot of redundancy in how our biological processes are controlled and kept in check," he added. "It's like having lots of different switches in a room to turn the lights on. Perhaps you could do without some switches on one wall or another, but it's still the same electrical circuit."

So what's the significance of this? For one, Pointing explains, knowing this will save a ton of time.

"When sequencing the genomes of patients, if our DNA was largely functional, we'd need to pay attention to every mutation."

Instead, professionals will simply have to keep doing exactly what they have been doing - paying attention to what they suspect is a prevalent part of the genome. Now, they simply can do it with a bit more certainty.