EHRC Homepage | New Category | Your Questions

That assertion has been made in the past, but it is no longer tenable. In fact "Junk DNA" provides a good illustration of the advantage of keeping an open mind regarding things we do not understand. Creationists had been predicting for years, ON A GOOD SCIENTIFIC BASIS, that so-called "junk DNA" would turn out to have a critical function in the cell. If "junk DNA" were really such, the cell would have dispensed with it long since. The persistence and conservation of this non-coding DNA provided clear evidence for its functionality, but this was overlooked for more than 20 years by evolutionists in their zeal for some mechanism to explain the increase in complexity of organisms. So what functions does this non-coding DNA have? A recent article in the New York Times summarizes the current state of our meager understanding:

DNA Junk or Not?


Q. How do scientists know that there aren't sections of junk DNA (the introns between genes) that have some biological function?

A. For years, more and more research has, in fact, suggested that introns are not junk but influence how genes work. Though they are discarded when a gene's directions for making a protein are read from the exons and carried out, introns do have active roles.

For one recent example, scientists have found that changes in just two genetic letters, one in each of two introns, determine whether a gene that causes lactose intolerance after weaning is switched on or off.

Also, certain so-called junk DNA sequences persist in many organisms over thousands or even millions of years, suggesting that they are essential to these organisms.

Other possible functions for introns include enhancing or damping the level of gene activity; shaping the folded arrangement of chromosomes within the cell nucleus; and providing reservoirs of change that allow DNA to be shuffled and rearranged in novel patterns that may eventually contribute to evolution, or conversely acting as a buffer against interloping DNA sequences that might cause a change too quickly. Copyright 2003 The New York Times Company

A recent Scientific American article contained the following admission regarding so-called "junk DNA"

“I think this will come to be a classic story of orthodoxy derailing objective analysis of the facts, in this case for a quarter of a century,” Mattick says. “The failure to recognize the full implications of this particularly the possibility that the intervening noncoding sequences may be transmitting parallel information in the form of RNA molecules—may well go down as one of the biggest mistakes in the history of molecular biology." Wyatt Gibbs, The Unseen Genome: Gems among the Junk, Scientific American, November 2003, pp 45-53

As time goes on we will be seeing an increase in our understanding of what the "junk" DNA is doing and we will be increasingly awestruck by the complexity of what we once viewed as a straightforward DNA->RNA->Protein story. Many of the key players have not yet entered the arena of our understanding. Humility is in order in the face of what we are privileged to glimpse of the complexity of living systems.


Ó 2010 Arthur V. Chadwick, Ph.D.