For decades, scientists have used the term “junk DNA” to talk about the useless leftovers from our supposed evolutionary history. In fact, as much as 98% of our DNA has been deemed “junk.”
But is this term accurate?
From a biblical perspective, no. And it seems scientists are beginning to realize this as well.
A new study of the platyhelminth worm, Schistosoma mansoni, in the Genome Biology and Evolution journal reveals that repetitive DNA on the female W-chromosome isn’t useless after all. Instead, it’s a crucial part of determining the worm’s sex.
In part, the authors wrote:
The days of “junk DNA” are over. When the senior authors of this article studied genetics at their respective universities, the common doctrine was that the nonprotein coding part of eukaryotic genomes consists of interspersed, “useless” sequences, often organized in repetitive elements such as satDNA. The latter might have accumulated during evolution, for example, as a consequence of gene duplication events to separate and individualize gene function. This view has fundamentally changed…
Granted, these authors still adhere to an evolutionary worldview, but it’s interesting that science is beginning to confirm what we’ve known to be true all along—God didn’t create junk, not even “junk DNA.”
Where Did the Term ‘Junk DNA’ Come From?
The term stems back to the 1960s, but it wasn’t formalized until 1972 when Susumu Ohno used it to describe the parts of DNA that don’t seem to have a function.
After all, only a small percentage of our DNA is made up of genes, which work to encode the proteins we need to live and grow. The rest of our DNA—about 98%—was called “junk DNA” because scientists weren’t sure what it did. They figured it was the DNA leftovers from our so-called evolutionary history of going from a single cell to complex human beings.
In 2003, the ENCODE project began with the goal of understanding the human genome sequence, including the parts of our DNA that seemed useless. By the time the ENCODE project finished in 2017, scientists found that as much as 80% of the human genome was functional (that is, had a purpose). However, that same year, a biologist at the University of Houston claimed that at least 75% of the human genome was just junk DNA.
Why Is ‘Junk DNA’ Incorrect?
Even though scientists believe a large portion of our DNA is useless, nothing could be further from the truth.
“We know these sequences are important because they didn’t just evolve. They came from a Designer—God,” says geneticist Dr. Georgia Purdom.
Instead of being a simple, linear string of information, human DNA is incredibly complex. Think of it as a three-dimensional, multilayer program that tells our body how to function, live, and grow.
As mentioned earlier, the ENCODE project found that much of the DNA they had deemed junk actually affected the activity of genes. Some of our non-coding DNA helps produce RNA components that are non-coding, such as transfer RNA, regulatory RNA, and ribosomal RNA, according to News Medical.
“Once again, we see that observational science is consistent with historical science based on God’s Word,” says Dr. Purdom. “Scientists have observed, tested, and discovered that ‘junk’ DNA is key to genome function. This is consistent with an omniscient and omnipotent Creator God who designed and created all living things, including their DNA, during Creation Week approximately 6,000 years ago.”
Is most of our DNA leftover junk from evolution? Some people still say so despite research suggesting that most of the human genome is biochemically active. Let’s think biblically and critically about scientists’ claims regarding junk DNA.
One popular argument for junk DNA says that since onions have more non-coding DNA than humans but are less complex than humans, onions’ DNA must be mostly useless junk. Therefore, the non-coding DNA in humans is likely junk as well. Is that true? Let’s apply critical thinking and scriptural wisdom.