"Junk" DNA: Trash or Treasure?

By Andrew Gao


A Mystery in Our Genes

Many people think of the human genome as being an elegant, efficient entity, carefully refined throughout the years by the guiding hand of evolution. The reality is far from this. In fact, scientists estimate that around 98.5 percent of the billions of nucleotides of our DNA is “junk.” The vast majority of our DNA does not lead to the creation of proteins, which are the workhorses that carry out actions such as metabolism and movement. Only a mere 1.5 percent of our genome actually codes for proteins. From an evolutionary standpoint, this makes little sense.

The process of DNA replication, which is necessary for growth and reproduction, is energy-intensive and error-prone. Why would cells bother to produce and assemble six billion nucleotides (the building blocks of DNA) every time they needed to divide—when ninety million would suffice?

Even some of the world’s top minds have been stumped by this curiosity. Francis Crick, who famously won the Nobel Prize for co-discovering the structure of DNA, commented that most of the genome seemed to be “little better than "junk"” for no apparent reason. Until recently, many biologists were of the opinion that "junk" DNA is nothing more than trash, floating around our genome.

Is There Value in “Junk” DNA?

As biotechnology and our understanding of DNA has improved, scientists have begun to unravel the mysteries of "junk" DNA. In fact, recent findings are causing a major paradigm shift in the field of biology. Emerging evidence indicates that "junk" DNA may not be "junk" after all, thanks to the efforts of the ENCODE group. The ENCODE group is a team of over 400 researchers who have been painstakingly deciphering the human genome for years. Their experiments have focused on discovering the functions of the 98.5 percent of our genome that is supposedly "junk."

In 2012, the ENCODE team published papers in several journals, including the prestigious Nature, that caused a buzz in the scientific community. The work had uncovered previously unknown elements of "junk" DNA,