Reasons to Believe

Functional DNA amid Piles of Junk

Sometimes my daughters' bedrooms are unbelievably messy. Junk everywhere. It often looks like a clothes bomb detonated. I have no idea how they can find anything in the aftermath of such devastation.

Like a teenager's sloppy bedroom, evolutionary biologists regard the genomes (the entire genetic makeup) of organisms as a mess—with functional DNA sequences buried amidst piles of "junk" DNA. This seemingly useless DNA varies from organism to organism, ranging from 30% to nearly 100% of the genome.1

New work, however, indicates that researchers have overlooked a significant amount of functional DNA in genomes, mistaking it for genetic rubbish.2

Evolutionary biologists consider junk DNA to be one of the most potent pieces of evidence for biological evolution.3 According to this view, junk DNA results when undirected biochemical processes and random chemical and physical events transform a functional DNA segment into a useless molecular artifact. Junk pieces of DNA remain part of an organism's genome solely because of its attachment to functional DNA. In this way, evolutionists say, junk DNA persists from generation to generation.

Evolutionists also highlight the fact that in many instances identical (or nearly identical) segments of junk DNA appear in a wide range of related organisms. Frequently, the identical segments reside in corresponding locations in the creatures' genomes. For evolutionists, this consistency indicates that these organisms shared a common ancestor. Accordingly, the junk DNA segment arose prior to the time the creatures diverged from their shared evolutionary ancestor. Such scientists then ask, "Why would a Creator purposely introduce nonfunctional, junk DNA at the exact location in the genomes of different, but seemingly related, organisms?"

Recent studies on junk DNA provide a response to this question—one that evolutionists find surprising, yet hard to deny. Junk DNA possesses function.4

And the latest research adds to this important insight. It now appears that the computer programs used to search for functional DNA sequences in genomes may miss a significant fraction. Researchers demonstrated the holes in the search routines by evaluating their effectiveness at recognizing useful DNA sequences in the regions before and after the gene phox2b. (This gene plays a role in brain development.) The functional sequences associated with this gene regulate its activity. Standard search protocols missed 39 to 71% of the operational DNA elements associated with phox2b. And this estimate is most likely the tip of the iceberg. According to the researchers, "The noncoding functional component of vertebrate genomes may far exceed estimates predicated on evolutionary constraint."5

Even though evolutionary biologists see the genome as a mess, mounting evidence continues to reveal an underlying, elegant structure that points to the work of a Creator. Come to think of it, somehow my daughters always manage to find the clothes they are looking for in their bedrooms. Maybe there's an underlying structure to that disorder, too, that I just can't perceive.

References:
1 Wen-Hsiung Li, Molecular Evolution (Sunderland, MA: Sinauer Associates, 1998), 379-84.
2 David M. McGaughey et al., "Metrics of Sequence Constraint Overlook Regulatory Sequences in an Exhaustive Analysis at phox2b," Genome Research published online December 10, 2007, DOI: 10.1101/gr.6929408.
3 Edward E. Max, "Plagiarized Errors and Molecular Genetics: Another Argument in the Evolution-Creation Controversy, (accessed March 10, 2008).
4 For a detailed discussion of some of these discoveries see the book I coauthored with Hugh Ross, Who Was Adam? These advances are also discussed on the Today's New Reason To Believe feature at www.reasons.org.
5 McGaughey et al., "Metrics of Sequence."

Subjects: Bad Designs?, Biochemical Design, Junk DNA

Dr. Fazale Rana

In 1999, I left my position in R&D at a Fortune 500 company to join Reasons to Believe because I felt the most important thing I could do as a scientist is to communicate to skeptics and believers alike the powerful scientific evidence—evidence that is being uncovered day after day—for God’s existence and the reliability of Scripture. Read more about Dr. Fazale Rana