The human genome has around three billion base pairs of DNA, and yet our best estimates are that this massive amount of DNA only includes about 20,000 protein-coding genes. These genes amount to a mere 1.5% of the total genome. Scientists have known that some portion of the remaining “non-coding” DNA has regulatory functions but the vast majority of the genome appeared to have no function. When I started a PhD program in molecular biology in 1992, the functionless DNA was sometimes called, “junk DNA” and was considered an artifact of evolution. “No intelligent being would make a genome this inefficient” was a common refrain.
Nearly twenty-five years later it turns out that “junk” is just another name for our ignorance. Many new regulatory mechanisms have been discovered, and we are beginning to realize that we had no idea how complex the genome really is. The Human Genome Project, which resulted in the sequencing of the entire human genome in 2003, has spawned another public project called the “Encyclopedia of DNA Elements” (ENCODE). ENCODE is a consortium of research groups from all over the world that is dedicated to trying to determine the function of the large percentage of our DNA that was previously referred to as “junk.”
In the fall of 2012 the ENCODE researchers published their preliminary findings in 30 papers in several different scientific journals. One of the striking claims they made was that instead of being largely functionless, most of our DNA (80%) is actively involved in at least one biochemical reaction within our cells. Although the significance of these findings has been disputed, there is no question that the whole concept of “junk DNA” is being challenged. Last year Francis Collins, the director of the National Institutes of Health said when asked about junk DNA, “We don’t use that term anymore… It was pretty much a case of hubris to imagine that we could dispense with any part of the genome – as if we knew enough to say it wasn’t functional” (quoted by Carl Zimmer writing in the New York Times Magazine).
So it turns out that the story of how our genome works is far more complicated than we once thought. The more we learn, the more we realize how much we don’t know. Pride tells us that if we do not understand the purpose of something, then it does not have a purpose. This is an important concept for scientists to remember, but it is also critical for you to understand as you think about the ups and downs in your life. Many times things happen to us that we do not understand. We are tempted to say, “God, what is this junk in my life?” God is the author of all life and all things and in His economy there is nothing that is truly junk. The function may not be clear to you, but that does not mean there is no function.
When God finally appeared to Job after 37 chapters of suffering and arguing and wrestling with the meaning of it all, He begins by asking Job a question: “Who is this who darkens counsel by words without knowledge?” The Lord then proceeds to ask Job a series of questions designed to show Job just how little Job knows. The end result is to drive Job to repentance and to an enlarged experience God’s greatness. The end result is worship (Job 42:5-6).
Our world is fallen, but it is still ruled by an all-powerful and gracious God. Be assured that there is no “junk” in His world or in your life if you are one of His children. When confronted by something that you do not understand, seek Him and remember that things are far more complicated than they may appear to you. One of the most helpful things you can do to keep this truth in mind is to worship Him in the assembly of His people every week where you are reminded again and again of just Who He is.
“O LORD, how manifold are Your works! In wisdom You have made them all. The earth is full of Your possessions” (Psalm 104:24, NKJ).