A ratchet is a mechanism that limits the mechanical motion of a device to a pre-specified direction while preventing its motion in the opposite direction. Some common examples include a socket wrench, an old-fashioned car jack, a winch mounted on a truck or on a ship to haul up an anchor, the ratchet in the wheel train of a clock, or even the simple securing mechanism of a cable tie.

An information ratchet would be some mechanism or process that causes the information content of a system to increase with the passage of time and prevents or limits its decrease. Key to understanding any ratchet mechanism is to grasp that its performance is predetermined by its mechanism. A winch can gradually hoist a heavy anchor out of the sea, and prevent it from falling away, only because its ratchet mechanism was designed to accomplish this task. A cable tie can be tightened and not come loose only because of the design of its teeth and catch mechanism.

Ratchets in Nature

Do natural ratchets exist in the physical, non-living world? Examples of natural mechanisms that approach the specific functionality of human-designed ratchets seem to be lacking. We might, however, claim that gravity is a sort of natural ratchet seen on Earth, in that it moves objects down and limits them from moving up. However, its target direction is only generally located, so that material may take any circuitous route in moving to a region of lower elevation, and that region could be anywhere on, or even within the planet. 

While acknowledging the ratchet-like effect of gravity to move objects down (to a lower gravitational potential) we must avoid the error of attributing additional abilities to this natural ratchet-like phenomenon. For example, while gravity can cause rocks to slide down a mountain slope, it cannot assemble those rocks into a castle in the valley. Why not? Simply because the mechanism is not designed to accomplish this task. 

Random outcomes of a rockslide might include one slab-shaped rock leaning against another, resembling a lean-to, but any structure with the complexity of stonework typically seen in a castle could never happen within the spacetime limits of our universe. For most people, this is common sense. As Douglas Axe writes in his book, Undeniable, our design intuition is correct regarding the improbability of functionally coherent outcomes (such as a castle) occurring by chance. For such complex, functional results, the ratio of “correct” outcomes to “incorrect” outcomes is too small to be obtained by any undirected process in a finite universe such as ours. 

Pearls with Rotational Symmetry

An interesting proposal for a natural ratchet, albeit facilitated by a living organism, is the formation of pearls with rotational symmetry. Researchers suggest that this example is without comparison:

We argue that pearl rotation is a self-organized phenomenon caused and sustained by physical forces from the growth fronts, and that rotating pearls are an example — perhaps unique — of a natural ratchet.

Could a natural information ratchet exist? Since our goal is to understand whether life is an information ratchet, we first need to examine what kind of mechanism might be required to cause a living system to ratchet up its information content over time. To increase information means to select outcomes that correspond to a greater level of functional or meaningful complexity. The only way for this to happen is if the selection mechanism (in other words, the ratchet) is designed to produce the target outcome, and this means that the mechanism must already contain the information specifying the target. A physical mechanism cannot produce any information beyond what it already contains.

Darwin’s Proposed “Ratchet”

What about Darwin’s proposed “ratchet” mechanism of natural selection based on survival of the fittest? The mechanism invoked here already contains a high degree of functional complexity (all the complexity residing in a living organism). But what can this “ratchet” do? No more than it was designed to do — namely to reproduce daughter organisms according to its inherent mechanism of reproduction. Variations in the organism’s genome, by any unguided process, may lead to an increase in fitness and therefore survivability. But natural processes cannot produce unnatural results. Selection based on the ratchet mechanism of increased fitness cannot of itself produce novel complex functionality if each successive small change does not give some increased advantage towards survival and reproduction.

The allure of Darwinism is that it suggests a process by which a population of organisms can ratchet up information and increase organismal functionality. A common misunderstanding of evolution is to assume that it can do more than steadily lock in natural variations that increase survivability. The error is in ascribing to this process the ability to ratchet up the information content of a simple common ancestor until all the complex, functionally coherent species of life on Earth have formed. But as shown in our examination of the functionality of any ratchet mechanism, it cannot produce an outcome beyond what it was designed to achieve. With information as the outcome, the mechanism can only reproduce the level of information it already contains.

Another Process at Work

Given the obvious, that the complexity of organisms on Earth has increased through time from single-cell archaea to functional multicellular creatures, some process other than a supposed evolutionary information ratchet must have been at work. The genomic information content of the prokaryotic cells descriptive of the earliest life on Earth falls far short of the greater information content and complexity of advanced life. An intelligent mind is the only known source for the necessary input of complex specified information throughout biological history. Attributing the vast diversity of life on Earth to intelligent design provides an explanation more in line with reality than the misguided concept of an information ratchet.