The Uselessness of DNA

Several of the greatest ever scientific projects and discoveries over the last 100 years have been to do with DNA.

  1. First there was the discovery that DNA is the code for life.
  2. Next there was the discovery of the structure of DNA, allowing us to interpret the code.
  3. This carried on, we learnt about transcription and translation.
  4. Then eventually there was the Human Genome Project (HGP), which mapped out every single codon in all of our DNA.  And it was the HGP that gave us all a big shock.

Most people were expecting (probably because of media hype) to finish the HGP with a full understanding of DNA and what it does. That was completely wrong.

Firstly, we found that there are two kinds of DNA:

  1. Stretches of codons that are called genes. If you transcribe and translate these, you will get a protein.
  2. Stretches of codons that are ‘nonsense‘. If you transcribe and translate these you will get something completely useless.

This was expected to some point. There would always be areas of DNA which wouldn’t be genes. But guess how much of the DNA was nonsense…

Over 98%. That means we only use 2% of our DNA to make proteins. So why the hell do we have so much of it? This baffled scientists when we discovered it almost 10 years ago, and it still baffles a lot of us today.

What we do know is that it probably isn’t useless and instead does something. It may even be involved in regulating the DNA, making sure we don’t produce too many proteins.

One other possibility is that by having so much nonsense DNA, we protect the useful DNA from being mutated (protection in numbers).

Realistically however no-one knows.

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3 Comments

  1. animalover19

     /  21/04/2012

    I really love your blog, especially since I recently went on biology camp! I have a question though: isn’t a lot of non-protein-coding DNA used to make other things? Like, some of the ‘nonsense’ DNA you talked about is used to make rRNA, tRNA, promoters for genes, telomeres and other things, isn’t it?

    Reply
    • Thanks! Your partly right. A lot of nonsense DNA is used to make RNA’s, and a fair amount are actually promoter regions for actual genes. That is why a lot of scientists are claiming that this nonsense DNA does have a hidden use that we don’t know about.

      However this again only takes up a small portion of the DNA so doesn’t quite explain the rest of the DNA.

      Although it is a good start.

      Reply
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