A book which has 98% of its text written in gibberish surely wouldn’t sell, and I think we all could agree that we won’t purchase a copy of that book.
Biology does not care about the business industry. However, it still writes a charming guidebook that everyone needs to live: DNA.
DNA is the genetic manual that instructs the proteins that make up and power our bodies. However, only a part of the whole DNA — namely, less than 2% of it (specifically, 1.5%) — codes for the proteins.
The rest — 98.5 percent of DNA sequences — is so-called “junk DNA” that scientists long thought useless. The non-protein-coding stretches looked like gibberish sentences in a book draft — useless, perhaps forgotten, writing. But new research is revealing that the “junky” parts of our genome might play important roles nonetheless.
In other words, what scientists call “junk DNA” is not just junk, but useful junk. (So is it still junk if it is useful?)
Other research advances in the last decade also suggest “junk DNA” might just be misunderstood genetic material. Scientists have now linked various non-coding sequences to various biological processes and even human diseases. For instance, researchers believe these sequences are behind the development of the uterus and also of our opposable thumbs. A study published in Annals of Oncology last year showed that a non-coding DNA segment acts like a volume knob for gene expression, ultimately influencing the development of breast and prostate cancer. And a study in Nature Genetics this year found mutations outside of gene-coding regions can cause autism.
Exploring the role of non-coding sequences is now an area of intense research. Increasing evidence suggests these noncoding sequences might help cancer defeat treatment, and experts now see them as promising tools for cancer diagnosis.
Head over at Discover to know more about this topic.
(Image Credit: qimono/ Pixabay)
I think that's why biologists call it "non-coding DNA" instead. While these areas of the genome don't code for proteins, they may have other functions.
Another note is that biology is messy. Even completely nonfunctional things get preserved from generations to generations if they don't present negative evolutionary selection. Evolution doesn't necessarily select for efficiency. It selects for survival!