Irreducible Complexity

The cells of living organisms contain a tremendous amount of coded information. This information is found not only in the varying sequences of the four “base” molecules in the interlocking coiled strands of DNA (deoxyribonucleic acid) of the nucleus, but also in other parts of the cell that govern the developing “body plan” of the organism as its cells reproduce. The amount of information in one cell has been compared to that in a large stadium, the seats of which are all stacked with volumes of the Encyclopedia Britannica.

This vast information in the cell was unknown to Charles Darwin when he developed his theory of evolution, the idea that life on earth originated from accidental causes acting on nonliving matter. Darwin believed that this primitive life evolved into various species of plant and animal life through a gradual process of mutation, as slight changes in an organism rendered it more adaptable to its environment and therefore able to reproduce and pass its characteristics to a subsequent generation. In this way, Darwin thought, new species of living things arose from earlier species.

Darwin, however, had no concept of how the information in a cell functions to govern an organism’s development and reproduction. He didn’t realize that any single mutation in a living organism is more likely to render the organism less adaptable to its environment, or even to kill it. In order for an organism’s structure to change in a way that made it more “naturally selectable” for survival, through the production of some useful new feature or trait, a large number of informational mutations (in the DNA or elsewhere in the cell) would have to occur simultaneously and be coordinated with one another. This aspect of cellular structure is what biologists refer to as irreducible complexity. An arm, for example, could not gradually evolve into a wing through a long series of incremental changes, because the intermediate stages of such an evolution would have no useful function and would, most likely, be harmful or fatal to the animal.

The phenomenon of irreducible complexity means that chance, and the passage of time, can’t explain the simultaneous occurrence of the many mutations required to alter the useful function or part of an organism. Chance depends on probability, and probability depends on the number of possible events that could occur over a given period of time. Mathematicians have calculated that not enough events have occurred in the entire history of the universe to create a probability that even the type of small evolutionary change Darwin postulated could occur by chance. Or, as philosopher of science Stephen Meyer puts it, the “probabilistic resources” of the universe are not great enough to allow for the needed informational changes in a cell nucleus to appear simply by accident.

There is only one reasonable explanation for the “irreducible complexity” of the information that governs the development and reproduction of living organisms, and that explanation is that a Mind has designed life and its characteristics, purposely embedding that design in the information coded into the nucleus and other features of the cell. From the tiniest bacterium to the most accomplished human being, only the activity of the Creator can explain the origin of the highly coordinated information without which life could not exist. As the Psalmist exclaims, “Thy eyes beheld my unformed substance; in thy book were written, every one of them, the days that were formed for me, when as yet there was none of them." (Psalm 139:16).