DNA by Design:
Signs of Intelligenceby Stephen C. Meyer, Discovery Institute
Contrary to media reports, intelligent design is not a religious-based idea, but instead an evidence-based scientific theory about life’s origins—one that challenges strictly materialistic views of evolution. According to Darwinian biologists such as Oxford’s Richard Dawkins, living systems “give the appearance of having been designed for a purpose.” But for modern Darwinists, that appearance of design is entirely illusory. Why? Because the undirected processes of natural selection acting on random mutations can produce the intricate structures found in living organisms.
In contrast, the theory of intelligent design holds that there are telltale features of living systems and the universe that are best explained by a designing intelligence. The theory does not challenge the idea of evolution defined as change over time, or even common ancestry, but it does dispute Darwin’s idea that the cause of biological change is wholly blind and undirected. What telltale signs of intelligence do we see?
Over the last 25 years, biologists have discovered an exquisite world of nanotechnology within living cells—complex circuits, sliding clamps, energy-generating turbines and miniature machines. For example, bacterial cells are propelled by tiny rotary engines called flagellar motors that rotate at speeds up to 100,000 rpm. These engines look as if they were designed by the Mazda Corporation, with many distinct mechanical parts (made of proteins) including rotors, stators, O-rings, bushings, U-joints and drive shafts.
Biochemist Michael Behe points out that the flagellar motor depends on the coordinated function of 30 protein parts. Re-move one of these necessary proteins and the rotary motor simply doesn’t work. The motor is, in Dr. Behe’s terminology, “irreducibly complex.” This creates a problem for the Darwinian mechanism. Natural selection preserves or “selects” functional advantages. If a random mutation helps an organism survive, it can be preserved and passed on to the next generation. Yet the flagellar motor does not function unless all of its 30 parts are present. Thus, natural selection can “select” or preserve the motor once it has arisen as a functioning whole, but it can’t produce the motor in a step-by-step Darwinian fashion.
Natural selection purportedly builds complex systems from simpler structures by preserving a series of intermediate structures, each of which must perform some function. In the case of the flagellar motor, most of the critical intermediate stages—like the 29- or 28-part version of the flagellar motor—perform no function for natural selection to preserve.
This leaves the origin of the flagellar motor, and many complex cellular machines, unexplained by the mechanism—natural selection—that Darwin specifically proposed to replace the design hypothesis.
Is there a better explanation? Based upon our uniform experience, we know of only one type of cause that produces irreducibly complex systems—namely, intelligence. Indeed, when-ever we encounter such complex systems—whether integrated circuits or internal combustion engines—and we know how they arose, invariably a designing intelligence played a role.
Consider an even more fundamental argument for design. In 1953, when James Watson and Francis Crick elucidated the structure of the DNA molecule, they made a startling discovery. DNA’s structure allows it to store information in the form of a four-character digital code. Strings of precisely sequenced chemicals called nucleotide bases store and transmit the assembly instructions—the information—for building the crucial protein molecules and machines the cell needs to survive.
Mr. Crick later developed this idea with his famous “sequence hypothesis,” according to which the chemical constituents in DNA function like letters in a written language or symbols in a computer code. As Bill Gates has since noted, “DNA is like a computer program, but far, far more advanced than any software we’ve ever created.” Clearly, the informational features of the cell at least appear designed. And to date, no theory of undirected chemical evolution has explained the origin of the digital information needed to build the first living cell. Why? There is simply too much information in the cell to be explained by chance alone. And the information in DNA has also been shown to defy explanation by the laws and forces of chemistry. Saying otherwise would be like saying that a newspaper headline might arise as the result of the chemical attraction between ink and paper. Clearly “something else” is at work.
DNA functions like a software program. We know from experience that software comes from programmers. We know generally that information—whether inscribed in hieroglyphics, written in a book or encoded in radio signals—always arises from an intelligent source. As the pioneering information theorist Henry Quastler observed, “Information habitually arises from conscious activity.” So the discovery of information in the DNA molecule provides strong grounds for inferring that intelligence played a role in the origin of DNA, even if we weren’t there to observe the system coming into existence.
Thus, contrary to media reports, the theory of intelligent design is not based on ignorance or religion, but instead on re-cent scientific discoveries and on our uniform experience of cause and effect, the basis of all scientific reasoning.
In short, intelligent design, unlike creationism, is not based on the Bible. Design is an inference from biological data, not a deduction from religious authority. Even so, ID may provide support for theistic belief. But that is not grounds for dismissing it. Those who say otherwise confuse the evidence for a the-ory with its possible implications. Many scientists initially rejected the Big Bang theory because it pointed to the need for a transcendent cause of matter, space and time. But science eventually accepted the theory despite such potentially unsettling implications because the evidence strongly supported it. Antony Flew, the long-time atheistic philosopher who has come to accept the case for design, insists correctly that we must “follow the evidence wherever it leads.”
©Stephen C. Meyer, Ph.D. Reprinted by permission of the author. Stephen directs Discovery Institute’s Center for Science and Culture in Seattle, Washington. His new book Signature in the Cell: DNA and the Evidence for Intelligent Design will be released on paperback this June by HarperOne.