IN 1953, molecular biologists James Watson and Francis Crick published a discovery that was critical to our scientific understanding of life. They had discovered the double-helical structure of DNA.* This threadlike substance—mostly found in the nucleus of cells—contains encoded, or “written,” information, making cells living libraries, as it were. This amazing discovery opened up a new era in biology! But what purpose is served by the “writing” in cells? More intriguing, how did it get there?
WHY CELLS NEED INFORMATION
Have you ever wondered how a seed becomes a tree or how a fertilized egg becomes a human? Have you ever wondered how you inherited your traits? The answers involve the information found in DNA.
Nearly all cells have DNA, complex molecules that resemble long twisted ladders. In the human genome, or our complete set of DNA, the ladders have approximately three billion chemical “rungs.” Scientists call these rungs base pairs because each rung is made up of two chemical substances, of which there are four altogether. Using the first letter of each, these substances are abbreviated A, C, G, and T—a simple, four-letter alphabet, as it were.* In 1957, Crick proposed that it is the linear sequence of the chemical rungs that forms coded instructions. In the 1960’s, that code began to be understood.
Information, whether in the form of pictures, sounds, or words, can be stored and processed in many ways. Computers, for example, do this all digitally. Living cells store and process information chemically, DNA being the key compound. DNA is passed on when cells divide and organisms reproduce—abilities that are considered defining characteristics of life.
How do cells use information? Think of DNA as a collection of recipes, each one involving step-by-step processes, with each step carefully scripted in precise terms. But instead of the end result being a cake or a cookie, it might be a cabbage or a cow. In living cells, of course, the processes are fully automated, adding yet another layer of complexity and sophistication.
The information in a bacterial cell would fill a 1,000-page book
Genetic information is stored until it is needed, perhaps to replace worn out or diseased cells with healthy new ones or to pass on traits to offspring. How much information does DNA hold? Consider one of the smallest organisms, bacteria. German scientist Bernd-Olaf Küppers stated: “Carried over to the realm of human language, the molecular text describing the construction of a bacterial cell would be about the size of a thousand-page book.” For good reason, chemistry professor David Deamer wrote: “One is struck by the complexity of even the simplest form of life.” How does the genome of a human compare? “[It] would fill a library of several thousand volumes,” says Küppers.
“WRITTEN IN A WAY THAT WE CAN UNDERSTAND”
To describe the writing in DNA as “molecular-genetic language” is more than “mere metaphor,” says Küppers. “Like human language,” he points out, “the molecular-genetic language also possesses a syntactic dimension.” Put simply, DNA has a “grammar,” or set of rules, that strictly regulates how its instructions are composed and carried out.
The “words” and “sentences” in DNA make up the various “recipes” that direct the production of proteins and other substances that form the building blocks of the various cells that make up the body. For example, the “recipe” might guide the production of bone cells, muscle cells, nerve cells, or skin cells. “The filament of DNA is information, a message written in a code of chemicals, one chemical for each letter,” wrote evolutionist Matt Ridley. “It is almost too good to be true, but the code turns out to be written in a way that we can understand.”
The Bible writer David said in prayer to God: “Your eyes even saw me as an embryo; all its parts were written in your book.” (Psalm 139:16) Of course, David was using poetic language. Nevertheless, in principle, he was right on the mark, which is typical of the Bible writers. None were even slightly influenced by the fanciful folklore or mythology of other ancient peoples.—2 Samuel 23:1, 2; 2 Timothy 3:16.
HOW DID THE WRITING GET THERE?
As is often the case, when scientists explain one mystery, they open a door to another. That was true regarding the discovery of DNA. When it was understood that DNA contains coded information, thoughtful people asked, ‘How did the information get there?’ Of course, no human observed the formation of the first DNA molecule. So we have to draw our own conclusions. Even so, these conclusions need not be speculative. Consider the following comparisons.
In 1999, fragments of very ancient pottery with unusual markings, or symbols, were found in Pakistan. The marks still remain undeciphered. Nevertheless, they are considered man-made.
A few years after Watson and Crick discovered the structure of DNA, two physicists proposed searching for coded radio signals from space. Thus began the modern-day search for extraterrestrial intelligence.
The point? People attribute information to intelligence, whether that information is in the form of symbols on clay or signals from space. They do not need to see the information being created to draw that conclusion. Yet, when the most sophisticated code known to man—the chemical code of life—was discovered, many shoved that logic aside, attributing DNA to mindless processes. Is that reasonable? Is it consistent? Is it scientific? A number of respected scientists say no. These include Dr. Gene Hwang and Professor Yan-Der Hsuuw.* Consider what they say.
Dr. Gene Hwang studies the mathematical basis of genetics. At one time he believed in evolution, but his research changed his view. “The study of genetics,” he told Awake! “provides insight into the mechanisms of life—an insight that fills me with awe for the Creator’s wisdom.”
Professor Yan-Der Hsuuw is the director of embryo research at Taiwan’s National Pingtung University of Science and Technology. He too once believed in evolution—until his research led him to conclude otherwise. Regarding cell division and specialization, he said: “The right cells must be produced in the right order and at the right places. First they assemble into tissues that will in turn assemble themselves into organs and limbs. What engineer can even dream of writing instructions for such a process? Yet the instructions for embryo development are superbly written in DNA. When I consider the beauty of it all, I’m convinced that life was designed by God.”
DOES IT MATTER?
Justice says yes! If God created life, then God deserves the credit, not evolution. (Revelation 4:11) Also, if we are the work of an all-wise Creator, then we are here for a reason. That would not be so if life were a result of undirected processes.*
Indeed, thinking people long for satisfying answers. “Man’s search for meaning is the primary motivation in his life,” said Viktor Frankl, who was a professor of neurology and psychiatry. To put it another way, we have a spiritual hunger that we yearn to satisfy—a hunger that makes sense only in the light of special creation. But if we are the handiwork of God, did he give us the means to satisfy our spiritual need?
Jesus Christ answered that question, saying: “Man must live, not on bread alone, but on every word that comes from Jehovah’s [or, God’s] mouth.” (Matthew 4:4) Jehovah’s words, which are recorded in the Bible, have satisfied the spiritual hunger of millions, giving meaning to their lives and providing them with a hope for the future. (1 Thessalonians 2:13) May the Bible do the same for you. At the very least, this unique book merits your consideration.
Watson and Crick built on the work of earlier researchers into DNA, which stands for deoxyribonucleic acid.—See the box “DNA—Key Dates.”
The letters stand for adenine, cytosine, guanine, and thymine.
A number of interviews with respected scientists can be found on our website, jw.org. Click the Search button, and enter “interview scientist.”
The creation-evolution question is discussed more fully in the brochures The Origin of Life—Five Questions Worth Asking and Was Life Created? available at www.jw.org.