The term "junk DNA" has been under attack lately, but a pair of geneticists are now making the case for this much maligned and misunderstood concept. There are significant chunks of our DNA, they argue, that really are utterly useless.
By the end of the Human Genome Project, biologists had discovered that over 98% of our DNA has no apparent biological function. Apparent being the keyword, because by the end of the 2012 ENCODE project — a kind of encyclopedia of human DNA — geneticists learned that 80% of what was thought to be junk, or noncoding, DNA did in fact have a purpose. Since then, many researchers and science writers have shunned the term, regarding it as a kind of silly placeholder for parts of the genome that we still don't understand (leading some to call it the "dark matter" of DNA).