Researchers have learned that for a cell to survive, at least three different types of complex molecules must work together​—DNA (deoxyribonucleic acid), RNA (ribonucleic acid), and proteins. Today, few scientists would assert that a complete living cell suddenly formed by chance from a mix of inanimate chemicals. What, though, is the probability that RNA or proteins could form by chance?a

Many scientists feel that life could arise by chance because of an experiment first conducted in 1953. In that year, Stanley L. Miller was able to produce some amino acids, the chemical building blocks of proteins, by discharging electricity into a mixture of gases that was thought to represent the atmosphere of primitive earth. Since then, amino acids have also been found in a meteorite. Do these findings mean that all the basic building blocks of life could easily be produced by chance?

“Some writers,” says Robert Shapiro, professor emeritus of chemistry at New York University, “have presumed that all life’s building blocks could be formed with ease in Miller-type experiments and were present in meteorites. This is not the case.”²b

Consider the RNA molecule. It is constructed of smaller molecules called nucleotides. A nucleotide is a different molecule from an amino acid and is only slightly more complex. Shapiro says that “no nucleotides of any kind have been reported as products of spark-discharge experiments or in studies of meteorites.”³ He further states that the probability of a self-replicating RNA molecule randomly assembling from a pool of chemical building blocks “is so vanishingly small that its happening even once anywhere in the visible universe would count as a piece of exceptional good luck.”⁴

What about protein molecules? They can be made from as few as 50 or as many as several thousand amino acids bound together in a highly specific order. The average functional protein in a “simple” cell contains 200 amino acids. Even in those cells, there are thousands of different types of proteins. The probability that just one protein containing only 100 amino acids could ever randomly form on earth has been calculated to be about one chance in a million billion.

Researcher Hubert P. Yockey, who supports the teaching of evolution, goes further. He says: “It is impossible that the origin of life was ‘proteins first.’”⁵ RNA is required to make proteins, yet proteins are involved in the production of RNA. What if, despite the extremely small odds, both proteins and RNA molecules did appear by chance in the same place at the same time? How likely would it be for them to cooperate to form a self-replicating, self-sustaining type of life? “The probability of this happening by chance (given a random mixture of proteins and RNA) seems astronomically low,” says Dr. Carol Clelandc, a member of the National Aeronautics and Space Administration’s Astrobiology Institute. “Yet,” she continues, “most researchers seem to assume that if they can make sense of the independent production of proteins and RNA under natural primordial conditions, the coordination will somehow take care of itself.” Regarding the current theories of how these building blocks of life could have arisen by chance, she says: “None of them have provided us with a very satisfying story about how this happened.”⁶

Why do these facts matter? Think of the challenge facing researchers who feel that life arose by chance. They have found some amino acids that also appear in living cells. In their laboratories, they have, by means of carefully designed and directed experiments, manufactured other more complex molecules. Ultimately, they hope to build all the parts needed to construct a “simple” cell. Their situation could be likened to that of a scientist who takes naturally occurring elements; transforms them into steel, plastic, silicone, and wire; and constructs a robot. He then programs the robot to be able to build copies of itself. By doing so, what will he prove? At best, that an intelligent entity can create an impressive machine.

Similarly, if scientists ever did construct a cell, they would accomplish something truly amazing​—but would they prove that the cell could be made by accident? If anything, they would prove the very opposite, would they not?

What do you think? All scientific evidence to date indicates that life can come only from previously existing life. To believe that even a “simple” living cell arose by chance from nonliving chemicals requires a huge leap of faith.

What do many scientists claim? All living cells fall into two major categories​—those with a nucleus and those without. Human, animal, and plant cells have a nucleus. Bacterial cells do not. Cells with a nucleus are called eukaryotic. Those without a nucleus are known as prokaryotic. Since prokaryotic cells are relatively less complex than eukaryotic cells, many believe that animal and plant cells must have evolved from bacterial cells.

In fact, many teach that for millions of years, some “simple” prokaryotic cells swallowed other cells but did not digest them. Instead, the theory goes, unintelligent “nature” figured out a way not only to make radical changes in the function of the ingested cells but also to keep the adapted cells inside of the “host” cell when it replicated.⁹a

What does the evidence reveal? Advances in microbiology have made it possible to peer into the awe-inspiring interior of the simplest living prokaryotic cells known. Evolutionary scientists theorize that the first living cells must have looked something like these cells.¹⁰

If the theory of evolution is true, it should offer a plausible explanation of how the first “simple” cell formed by chance. On the other hand, if life was created, there should be evidence of ingenious design even in the smallest of creatures. Why not take a tour of a prokaryotic cell? As you do so, ask yourself whether such a cell could arise by chance.

THE CELL’S PROTECTIVE WALL

To tour a prokaryotic cell, you would have to shrink to a size that is hundreds of times smaller than the period at the end of this sentence. Keeping you out of the cell is a tough, flexible membrane that acts like a brick and mortar wall surrounding a factory. It would take some 10,000 layers of this membrane to equal the thickness of a sheet of paper. But the membrane of a cell is much more sophisticated than the brick wall. In what ways?

Like the wall surrounding a factory, the membrane of a cell shields the contents from a potentially hostile environment. However, the membrane is not solid; it allows the cell to “breathe,” permitting small molecules, such as oxygen, to pass in or out. But the membrane blocks more complex, potentially damaging molecules from entering without the cell’s permission. The membrane also prevents useful molecules from leaving the cell. How does the membrane manage such feats?

Think again of a factory. It might have security guards who monitor the products that enter and leave through the doorways in the factory wall. Similarly, the cell membrane has special protein molecules embedded in it that act like the doors and the security guards.

Some of these proteins (1) have a hole through the middle of them that allows only specific types of molecules in and out of the cell. Other proteins are open on one side of the cell membrane (2) and closed on the other. They have a docking site (3) shaped to fit a specific substance. When that substance docks, the other end of the protein opens and releases the cargo through the membrane (4). All this activity is happening on the surface of even the simplest of cells.

INSIDE THE FACTORY

Imagine that you have been allowed past the “security guard” and are now inside the cell. The interior of a prokaryotic cell is filled with a watery fluid that is rich in nutrients, salts, and other substances. The cell uses these raw ingredients to manufacture the products it needs. But the process is not haphazard. Like an efficiently run factory, the cell organizes thousands of chemical reactions so that they take place in a specific order and according to a set timetable.

A cell spends a lot of its time making proteins. How does it do so? First, you would see the cell make about 20 different basic building blocks called amino acids. These building blocks are delivered to the ribosomes (5), which may be likened to automated machines that link the amino acids in a precise order to form a specific protein. Just as the operations of a factory might be governed by a central computer program, many of the functions of a cell are governed by a “computer program,” or code, known as DNA (6). From the DNA, the ribosome receives a copy of detailed instructions that tell it which protein to build and how to build it (7).

What happens as the protein is made is nothing short of amazing! Each one folds into a unique three-dimensional shape (8). It is this shape that determines the specialized job that the protein will do.b Picture a production line where engine parts are being assembled. Each part needs to be precisely constructed if the engine is to work. Similarly, if a protein is not precisely constructed and folded to exactly the right shape, it will not be able to do its work properly and may even damage the cell.

How does the protein find its way from where it was made to where it is needed? Each protein the cell makes has a built-in “address tag” that ensures that the protein will be delivered to where it is needed. Although thousands of proteins are built and delivered each minute, each one arrives at the correct destination.

Why do these facts matter? The complex molecules in the simplest living thing cannot reproduce alone. Outside the cell, they break down. Inside the cell, they cannot reproduce without the help of other complex molecules. For example, enzymes are needed to produce a special energy molecule called adenosine triphosphate (ATP), but energy from ATP is needed to produce enzymes. Similarly, DNA (section 3 discusses this molecule) is required to make enzymes, but enzymes are required to make DNA. Also, other proteins can be made only by a cell, but a cell can be made only with proteins.c

Microbiologist Radu Popa does not agree with the Bible’s account of creation. Yet, in 2004 he asked: “How can nature make life if we failed with all the experimental conditions controlled?”¹³ He also stated: “The complexity of the mechanisms required for the functioning of a living cell is so large that a simultaneous emergence by chance seems impossible.”¹⁴

What do you think? The theory of evolution tries to account for the origin of life on earth without the necessity of divine intervention. However, the more that scientists discover about life, the less likely it appears that it could arise by chance. To sidestep this dilemma, some evolutionary scientists would like to make a distinction between the theory of evolution and the question of the origin of life. But does that sound reasonable to you?

The theory of evolution rests on the notion that a long series of fortunate accidents produced life to start with. It then proposes that another series of undirected accidents produced the astonishing diversity and complexity of all living things. However, if the foundation of the theory is missing, what happens to the other theories that are built on this assumption? Just as a skyscraper built without a foundation would collapse, a theory of evolution that cannot explain the origin of life will crumble.

What do many scientists claim? Many biologists and other scientists feel that DNA and its coded instructions came about through undirected chance events that took place over the course of millions of years. They say that there is no evidence of design in the structure of this molecule nor in the information that it carries and transmits nor in the way that it functions.¹⁷

What does the evidence reveal? If evolution is true, then it should seem at least reasonably possible that DNA could have come about by means of a series of chance events.

THE STRUCTURE OF AN AMAZING MOLECULE

Let us simply call this part of the model chromosome a rope. It is about an inch (2.6 cm) thick. It is looped tightly around spools (4), which help to form the coils within coils. These coils are attached to a kind of scaffold that holds them in place. A sign on the display explains that the rope is packed very efficiently. If you were to pull the rope from each of these model chromosomes and lay it all out, from end to end it would stretch about halfway around the earth!a

One science book calls this efficient packaging system “an extraordinary feat of engineering.”¹⁸ Does the suggestion that there was no engineer behind this feat sound credible to you? If this museum had a huge store with millions of items for sale and they were all so tidily arranged that you could easily find any item you needed, would you assume that no one had organized the place? Of course not! But such order would be a simple feat by comparison.

In the museum display, a sign invites you to take a length of this rope in your hands for a closer look (5). As you run it between your fingers, you see that this is no ordinary rope. It is composed of two strands twisted around each other. The strands are connected by tiny bars, evenly spaced. The rope looks like a ladder that has been twisted until it resembles a spiral staircase (6). Then it hits you: You are holding a model of the DNA molecule​—one of the great mysteries of life!

A single DNA molecule, tidily packaged with its spools and scaffold, makes up a chromosome. The rungs of the ladder are known as base pairs (7). What do they do? What is all of this for? A display sign offers a simplified explanation.

THE ULTIMATE INFORMATION STORAGE SYSTEM

The key to the DNA, the sign says, lies in those rungs, the bars connecting the two sides of the ladder. Imagine the ladder split apart. Each side has partial rungs sticking out. They come in only four types. Scientists dub them A, T, G, and C. Scientists were amazed to discover that the order of those letters conveys information in a sort of code.

You may know that Morse code was invented in the 19th century so that people could communicate by telegraph. That code had only two “letters”​—a dot and a dash. Yet, it could be used to spell out countless words or sentences. Well, DNA has a four-letter code. The order in which those letters​—A, T, G, and C—​appear forms “words” called codons. Codons are arranged in “stories” called genes. Each gene contains, on average, 27,000 letters. These genes and the long stretches between them are compiled into chapters of a sort​—the individual chromosomes. It takes 23 chromosomes to form the complete “book”​—the genome, or total of genetic information about an organism.b

The genome would be a huge book. How much information would it hold? All told, the human genome is made up of about three billion base pairs, or rungs, on the DNA ladder.¹⁹ Imagine a set of encyclopedias in which each volume is over a thousand pages long. The genome would fill 428 of such volumes. Adding the second copy that is found in each cell would make that 856 volumes. If you were to type out the genome by yourself, it would be a full-time job​—with no vacations—​lasting some 80 years!

Of course, what you would end up with after all that typing would be useless to your body. How would you fit hundreds of bulky volumes into each of your 100 trillion microscopic cells? To compress so much information so greatly is far beyond us.

A professor of molecular biology and computer science noted: “One gram of DNA, which when dry would occupy a volume of approximately one cubic centimeter, can store as much information as approximately one trillion CDs [compact discs].”²⁰ What does that mean? Remember, the DNA contains the genes, the instructions for building a unique human body. Each cell has a complete set of instructions. DNA is so dense with information that a single teaspoonful of it could carry the instructions for building about 350 times the number of humans alive today! The DNA required for the seven billion people living on earth now would barely make a film on the surface of that teaspoon.²¹

A BOOK WITH NO AUTHOR?

Despite advances in miniaturization, no man-made information storage device can approach such a capacity. Yet, the compact disc offers an apt comparison. Consider this: A compact disc may impress us with its symmetrical shape, its gleaming surface, its efficient design. We see clear evidence that intelligent people made it. But what if it is embedded with information​—not random gibberish, but coherent, detailed instructions for building, maintaining, and repairing complex machinery? That information does not perceptibly change the weight or the size of the disc. Yet, it is the most important feature of that disc. Would not those written instructions convince you that there must be some intelligent mind at work here? Does not writing require a writer?

It is not far-fetched to compare DNA to a compact disc or to a book. In fact, one book about the genome notes: “The idea of the genome as a book is not, strictly speaking, even a metaphor. It is literally true. A book is a piece of digital information . . . So is a genome.” The author adds: “The genome is a very clever book, because in the right conditions it can both photocopy itself and read itself.”²² That brings up another important aspect of DNA.

MACHINES IN MOTION

As you stand there in the quiet, you find yourself wondering if the nucleus of a cell is really as still as a museum. Then you notice another display. Above a glass case containing a length of model DNA is a sign that reads: “Push Button for Demonstration.” You push the button, and a narrator explains: “DNA has at least two very important jobs. The first is called replication. DNA has to be copied so that every new cell will have a complete copy of the same genetic information. Please watch this simulation.”

Through a door at one end of the display comes a complex-looking machine. It is actually a cluster of robots closely linked together. The machine goes to the DNA, attaches itself, and begins to move along the DNA as a train might follow a track. It moves a little too fast for you to see exactly what it is doing, but you can easily see that behind it, there are now two complete DNA ropes instead of one.

The narrator explains: “This is a greatly simplified version of what goes on when DNA is replicated. A group of molecular machines called enzymes travel along the DNA, first splitting it in two, then using each strand as a template to make a new, complementary strand. We cannot show you all the parts involved​—such as the tiny device that runs ahead of the replication machine and snips one side of the DNA so that it can twirl around freely instead of getting wound up too tight. Nor can we show you how the DNA is ‘proofread’ several times. Errors are detected and corrected to an amazing degree of accuracy.”​—See the diagram on pages 16 and 17.

The narrator continues: “What we can show you clearly is the speed. You noticed this robot moving at a pretty good clip, didn’t you? Well, the actual enzyme machinery moves along the DNA ‘track’ at a rate of about 100 rungs, or base pairs, every second.²³ If the ‘track’ were the size of a railroad track, this ‘engine’ would be barreling along at the rate of over 50 miles (80 km) per hour. In bacteria, these little replication machines can move ten times faster than that! In the human cell, armies of hundreds of these replication machines go to work at different spots along the DNA ‘track.’ They copy the entire genome in just eight hours.”²⁴ (See the box “A Molecule That Can Be Read and Copied,” on page 20.)

“READING” DNA

The DNA-replicating robots trundle off the scene. Another machine appears. It too moves along a stretch of DNA, but more slowly. You see the DNA rope entering one end of this machine and emerging from the other​—unchanged. But a single strand, a new one, is coming out of a separate opening in the machine, like a growing tail. What is going on?

Again the narrator provides an explanation: “DNA’s second job is called transcription. The DNA never leaves the safe shelter of the nucleus. So how can its genes​—the recipes for all the proteins your body is made of—​ever be read and used? Well, this enzyme machine finds a spot along the DNA where a gene has been switched on by chemical signals coming in from outside the cell nucleus. Then this machine uses a molecule called RNA (ribonucleic acid) to make a copy of that gene. RNA looks a lot like a single strand of DNA, but it is different. Its job is to pick up the information coded in the genes. The RNA gets that information while in the enzyme machine, then exits the nucleus and heads to one of the ribosomes, where the information will be used to build a protein.”

As you watch the demonstration, you are filled with wonder. You are deeply impressed by this museum and the ingenuity of those who designed and built its machines. But what if this entire place with all its exhibits could be set in motion, demonstrating all the thousands upon thousands of tasks that go on in the human cell at the same time? What an awe-inspiring spectacle that would be!

You realize, though, that all these processes carried out by tiny, complex machines are actually going on right now in your own 100 trillion cells! Your DNA is being read, providing directions to build the hundreds of thousands of different proteins that make up your body​—its enzymes, tissues, organs, and so on. Right now your DNA is being copied and proofread for errors so that a fresh set of directions is there to be read in each new cell.

WHY DO THESE FACTS MATTER?

Again, let us ask ourselves, ‘Where did all these instructions come from?’ The Bible suggests that this “book” and its writing originate with a superhuman Author. Is that conclusion really out-of-date or unscientific?

Consider this: Could humans even build the museum just described? They would run into real difficulty if they tried. Much about the human genome and how it functions is little understood as yet. Scientists are still trying to figure out where all the genes are and what they do. And the genes comprise only a small part of the DNA strand. What about all those long stretches that do not contain genes? Scientists have called those parts junk DNA, but more recently they have been modifying that stance. Those parts may control how and to what extent the genes are used. And even if scientists could create a full model of the DNA and the machines that copy and proofread it, could they make it actually function as the real one does?

Famous scientist Richard Feynman left this note on a blackboard shortly before his death: “What I cannot create, I do not understand.”²⁵ His candid humility is refreshing, and his statement, obviously true in the case of DNA. Scientists cannot create DNA with all its replication and transcription machinery; nor can they fully understand it. Yet, some assert that they know that it all came about by undirected chance and accidents. Does the evidence that you have considered really support such a conclusion?

Some learned men have decided that the evidence points the other way. For example, Francis Crick, a scientist who helped to discover DNA’s double-helix structure, decided that this molecule is far too organized to have come about through undirected events. He proposed that intelligent extraterrestrials may have sent DNA to the earth to help get life started here.²⁶

More recently, noted philosopher Antony Flew, who advocated atheism for 50 years, did an about-face of sorts. At 81 years of age, he began to express a belief that some intelligence must have been at work in the creation of life. Why the change? A study of DNA. When asked if his new line of thought might prove unpopular among scientists, Flew reportedly answered: “That’s too bad. My whole life has been guided by the principle . . . [to] follow the evidence, wherever it leads.”²⁷

What do you think? Where does the evidence lead? Imagine that you found a computer room in the heart of a factory. The computer is running a complex master program that directs all the workings of that factory. What is more, that program is constantly sending out instructions on how to build and maintain every machine there, and it is making copies of itself and proofreading them. What would that evidence lead you to conclude? That the computer and its program must have made themselves or that they were produced by orderly, intelligent minds? Really, the evidence speaks for itself.