Only a TENTH of human DNA does something important


  • Scientists at Oxford University claim we only use 8 per cent of our DNA
  • Genes make up just over one per cent of the useful genetic material
  • Remaining 7 per cent is littered with switches that control these genes
  • It was previously estimated that 80 per cent of our DNA was ‘functional’

By
Fiona Macrae

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We only use eight per cent of our DNA, scientists say.

An Oxford University study has concluded that just 8.2 per cent of our DNA is likely to be doing something important.

The rest is junk DNA – an evolutionary hangover that, much like the appendix, doesn’t do any good but also doesn’t do any harm. Much of it is doing nothing at all.

An Oxford University study has concluded that just 8.2 per cent of our DNA is likely to be doing something important. The rest is junk DNA – an evolutionary hangover that, much like the appendix, doesn’t do any good but also doesn’t do any harm

Dr Gurton Lunter, the study’s joint lead researcher, said: ‘The vast majority of it is sitting there doing nothing. It is taking up space.’

It was previously estimated that 80 per cent of our DNA was ‘functional’ – or doing something useful.

Being able to separate the wheat from the chaff is important because it will enable medical researchers to zero in on the DNA behind disease and so speed the search for new treatments and cures.

Co-lead researcher Professor Chris Ponting said: ‘This isn’t just an academic argument about the nebulous word ‘function’. These definitions matter.

The researchers came up with the estimate of 8.2 per cent after comparing our DNA with that of various other mammals and looking for chunks that have stayed the same despite millions of years of evolution (stock picture used)

WHAT IS ‘JUNK’ DNA? 

Oxford University says that 91.8 per cent of our bodies is made up of ‘junk’ DNA.

Junk DNA is essentially non-coding DNA which describes components of an organism’s DNA that do not encode for protein sequences.

This, claim scientists, is an evolutionary hangover that, much like the appendix, doesn’t do any good but also doesn’t do any harm. 

The latest estimate was very different from one given in 2012, when some scientists involved in the Encyclopedia of DNA Elements (Encode) project stated that 80 per cent of our genome has some biochemical function.

‘From a medical point of view, this is essential to interpreting the role of human genetic variation in disease.’

The researchers came up with the estimate of 8.2 per cent after comparing our DNA with that of various other mammals and looking for chunks that have stayed the same despite millions of years of evolution.

This lack of change was taken as a sign that it was doing something important.

What is more, despite the common perception that our DNA is packed with genes, they make up just over one per cent of the eight per cent of useful genetic material.

The other seven per cent or so is littered with switches that control these genes.

Researcher Dr Chris Rands said: ‘We tend to have the expectation that all of our DNA must be doing something.

‘In reality, only a small part of it is.’

The study is published in the journal PLOS Genetic.

 

 

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