Intelligent design is a scientific theory which states that some aspects of nature are best explained by an intelligent cause rather than an undirected cause such as natural selection. Design theorists argue that we can find biological structures with the same informational properties we commonly find in objects we know were designed.
Design theorists observe that intelligent action produces large amounts of “complex and specified” information. Language and the finely-tuned, purposeful arrangement of parts in machines are prime examples of this encoded information. If the cell was designed, then we would expect to find language-like encoded information commonly throughout biology.
The cell confirms our expectations from design. Our DNA contains incredible amounts of encoded information. Living cells transform this encoded chemical message into machines which are engineered to perform necessary biochemical functions. The conversion of DNA into protein relies upon a software-like system of commands and biochemical codes. This is an information processing system which Bill Gates has described as “like a computer program, but far, far more advanced than any software we’ve ever created.”
The protein-machines produced by our DNA are often “irreducibly complex.” Irreducible complexity is a purposeful arrangement of parts, where if any part is removed or mutated, the structure ceases to assemble or function properly. For example, the “bacterial flagellum,” is a rotary-engine on bacteria which fails to assemble or function properly if we mutate any one of its 50 genes. Natural selection cannot account for this irreducible complexity because it only preserves structures which provide a functional advantage. In this “all-or-nothing” game, mutations cannot produce the complexity needed to provide a functional flagellar rotary engine one incremental step at a time, and the odds are too daunting for it to do it in a great leap.
Darwinists counter that parts can be “co-opted” from one job to another in the cell to build complexity. But there’s a problem with the Darwinist explanation: biological parts are not necessarily easily interchangeable. Complex assembly instructions dictate how these precise parts will combine to interact with one-another. The specific ordering of interacting parts in the cell can’t be produced by chance any more than keeping my old Jeep in an autoshop full of HEMI engines will increase its horsepower.
Yet design is not a negative argument against evolution. Design is fundamentally based upon our positive knowledge and experience that a code is produced by a coder, that an algorithm-based information processing system implies a software programmer, and that complex and specified information in the cell, which conforms to a “language” and produces sophisticated machines, points to the mind of some engineer. Critics like Krauthammer and Will don’t have to agree with my argument. But there’s no denying that its basis is in scientific observations and empirical data — not faith, revelation, or religious texts. Intelligent design is a bona fide scientific approach to studying biological origins.