The Evolutionary Problem of Feedback Mechanisms

by Dr. Robert Elam on December 26, 2014
Also available in Español

Many believe that life developed by evolution, or random chance happenings, but one of the major problems of evolution deals with a principle called biological feedback or positional change caused by data return for correctional control. Where does that enter into the evolution of life? All forms of life have it! It is a design feature.


One of the things that becomes a total contradiction to the proposition of biological evolution is the reality of feedback (the scientific principle involving sensing and repositioning by a distant controller). Engineering feedback was not described until the early 1900s; however, biological life functions have had feedback ever since the first cell was created.

Biological life functions have had feedback ever since the first cell was created.

Engineers that design moving parts on automatic machines run into a problem called overshoot. To demonstrate, let us say that we have a machine that has a moving arm, and we desire that arm to move to a certain position and stop. The arm has kinetic energy that is created by the movement. As it approaches the desired position, let us say that we put a metal block to stop it at the desired position, the arm keeps swinging and begins to bend due to the sudden stop. This causes the arm to be stressed and causes a potential failure point. The bigger the arm, the more the stopping problem weighs into the design.

Brakes were developed, but engineers still had to determine when and where to begin the stopping force in order to stop the arm at the precise moment that it needed to stop. Later, men began to build robots that needed to twist and turn. Autopilots for aircraft and boats were developed, and more and more sophisticated machines began to come on the scene. These all have desired positional stops requiring feedback.

As engineering continued to develop, there arrived a need to control the movement of motors by incremental movements, parts of circular motion, or steps. These motors were called step motors or step servos. Each small step allowed the controller to place the objective part at the desired position. With these step-servo motors, engineers began to see that the limits of the movements had to be known to the operator. When computers began the task of running machines, computer programmers began to see that the real problem was not the stopping of the component in motion, but rather the damping of the “overshoot.” The problem then became slowing down the component to reduce the stress on the machine as it stops the moving component.

As artificial hands and arms for machines were developed, control circuits were needed to tell when applied pressure was excessive to the product being handled, so engineers studied living arms and legs. They discovered that animals, fish, birds and, in fact, all living creatures had what are known as feedback circuits so that the brain knew where that functioning component was at all times.

What Is Feedback?

A sensor control circuit returns information concerning the position and speed of a moving component in a machine to the control part. This circuit must transmit the speed of movement as well as the position of the component. This is not an easy task. There must also be a sensor that determines the stopping position if necessary, and how fast the moving component should come to a stop. This requires planning and design. It is a very real engineering problem that involves minute details and controls. The sensors should allow the component in movement to approach the position slowing it down as it approaches the stop position. As it approaches the position where it must stop, the kinetic energy must be removed from the component in motion. This requires a braking system or a reverse acceleration. Reverse acceleration is more difficult to control. Braking systems allow the component to slow down by frictional forces. This does create stress on the component that is moving, but not as much as a stop-block would.

Living Creatures

As we consider living creatures, we need to understand that all creatures have feedback controls that function perfectly. Generally people do not consider the problems until they see how the lack of control causes problems.

Let us consider several creatures in order to understand the importance of feedback. Each one of these creatures is complex and increasing in size.


A fly has the ability to fly as well as land on surfaces. In comparing a fly to a beetle, we see that the heavy weight of the beetle makes it hard for it to land “just anywhere,” whereas the fly has no problem landing just about anywhere. The fly is able to change direction, change speed, and to land where it desires.

If feedback is an engineering problem, someone had to program the fly’s tiny brain.

A fly senses food, determines the direction, and then flies until it arrives at the location. As the fly flies, it has to choose the landing spot. As it approaches this spot, it must control its speed, allowing its body to set down on the landing spot without overshooting it. If we were to complicate the fly’s flight by adding wind, it would have to correct the flight by visual perception and by recognition of the conditions via other sensory means such as the feel of the breeze. It would also have to adjust the speed and power given to the wings. So who taught the fly to fly and be able to address the myriad of problems of flight? If feedback is an engineering problem, someone had to program the fly’s tiny brain. That is some amazing engineering!


Birds have the ability to fly. Many have the ability to catch insects on the wing while they themselves are flying. A bird needs to have continual feedback as it flies in order to keep out of danger and at the same time track the food that it is seeking. Watch a video of a bird tracking an insect: as the insect changes course the bird corrects its flight and changes speeds. As the bird flies it is constantly receiving feedback as it travels. This is needed in order to do anything whatsoever, whither that would be to fly a certain course, land on a branch, or pick up a worm or a seed.


We started with the description of the mechanical arm; now let us consider even more. Motor nerves and skeletal muscles are similar in all living creatures that have them. Feedback is accomplished via a nerve connection to each muscle cell. Each cell has a commanding nerve that comes from the brain to command the muscle cell; the cell receives instructions for contracting by means of the nerve. These nerves send the commands for how much contraction, and the feedback nerves return the signal as to how much contraction is done. At the same time there are sensors that sense the pressure being applied to the skin and surrounding structures, sending signals back to the brain. Some of this feedback even comes from the eyes.

Even picking up a glass of water is an elegant, complex process.

Even picking up a glass of water is an elegant, complex process: the eye helps us locate and recognize the glass as the object desired; the brain commands the body to position itself to pick up the glass; the arm moves and extends the hand; the fingers and thumb spread out in order to grasp the glass; sight tells the brain that the glass is in reach and the hand then is told to close. As the fingers and thumb close around the glass, the brain senses the weight of the glass and applies the amount of pressure needed to pick up the glass. The fingers do not function as a group, but rather as individual components. The thumb works in counter-directions to the fingers. It is also an individually controlled component. In other words, the hand is not a unit that automatically opens and closes. Eyes and arm give the position of the glass as it is moved upward toward the mouth. We see the level of fluid in the glass, and the feedback information is returned to the brain to direct the glass’s tilting and positioning.

Certain diseases can cause feeling sensors to malfunction, causing the person to lose the sense of pressure so that the person does not know how much pressure is being put on the glass. As a result, the glass can slip out of the person’s hand and fall on the floor. Each muscle has to have command/motor nerves and sensory nerves. The simple task of picking up a glass is not so simple when we consider the muscle functions and the pressures needed to pick it up. The “secret” is in the electronic messaging of the nerves. Electrical signals are given out by the brain and so control the many bundles of muscles just to move the fingers and thumbs. All this must be controlled, and that by means of intelligence using an existing well-designed system.

Feedback is essential to the operation of the body. It makes no difference what part of the body and function you desire to describe. In fact, we have to come up with an explanation as to where feedback began!

The Cell and Feedback

As we look at the individual cell, or unicellular structure, we see that even in these “simple structures” there exists feedback in the most complex way. The nucleus is the center of control for the cell and contains the DNA that works together with RNA to produce and regulate the proteins necessary for the living cell to function and be a living creature.

DNA produces the protein template while the RNA executes the protein fabrication. In order to obtain the correct function in producing the thousands of proteins that are produced in sequence for cell, and ultimately organism, function, there must be feedback in the process. It is impossible to have a production line that is automatic and controlled without feedback.

Let us further consider DNA, described as a twisted helix that is wound around other protein structures (for a frog, the DNA from one cell would stretch out to a distance of almost three meters). As we look at the structure, there are questions that have yet to be answered. How much is really “trash” or non-functioning structures in the DNA sequences? Recent studies are showing that the non-coding portions are primarily regulators, which must function with some form of feedback.

The truth of the matter is that the cell’s feedback becomes a product of greater design and intellectual engineering than could ever be neatly explained by random happenings. Feedback makes the case even stronger for the all-knowing God of the Bible to have been the Creator of life.

General Processes

Whether the life-form be “simple” or “complex,” we still have to deal with all of the aspects of design, quality, capacity of the processes, and the multi-complex nature of the cell with its feedback mechanisms. Each step has its own feedbacks and internal controls for its fabrications and functions. In many cases, the function of the feedback is so complex that no one has yet interpreted the process or the full far-reaching results.

Feedback has an automatic correction mechanism. In order to function there must be an automatic testing of the results as well as the feedback for quality control. When man is able to watch and control a process, he is always on the lookout for any production that is wrong. All adjustments to the production are done by the observer (line inspector), and action is taken to correct the error at the time. In a living cell there is no apparent “line inspector,” yet errors are caught and corrected.

In many cases, the function of the feedback is so complex that no one has yet interpreted the process or the full far-reaching results.

When there is a “sick” organism (meaning that some outside factor has invaded the organism), the organism has an immune system that identifies and removes the invader in an attempt to return the organism to its normal function. In some cases it is impossible to return to normal function and death results, but there was a response nonetheless.


Plants are relatively non-moving, rooted creatures that have no “feelings,” and yet there seems to be a means of communication between them. Feedback is necessary to develop this communication as well.

Auditory and body language transmits messages to other creatures. Both monkeys and birds can communicate among themselves. Ravens and crows are able to resolve problems and use “tools” to do tasks. All of these problem-solving abilities come from feedback. There is therefore intracellular, intercellular, physical, species, and even interspecies feedback: a mechanism that could never realistically be developed by blind, accidental processes. It is a design feature, created by God within living creatures and life-forms, from the simple to the complex. In every part of life, in every function that has been observed, we see the need and the very application of engineering design for control. No creature that is growing or is living has existed, exists, or could exist, without feedback.


Evolutionists cannot provide us with a good answer to usage of feedback and functional origin. Neither can they tell us the reason for such concurrent development within and between life-forms. It is a fully-designed function. Feedback processes, on the other hand, need better answers than the trite expression of “Mother Nature” and “survival of the fittest.” When we talk about God and His creation, we see the intelligent answer to the complex phenomena of feedback. “Mother Nature,” who does not exist, explains nothing at all.

When a diver in the Adriatic Sea brought up a metallic object from the sea floor called the “Antikythera Mechanism,” no one made any statement about how smart Mother Nature was to have formed that metallic object. The first comment questioned its purpose; then, what is the design function? After years of study, the question is now, how did the ancients build such an astrolabe or mechanical computing object? They now understand a little of what that computer did: it was an “astrolabe” (for navigation). Exactly who built it still remains unanswered, but we do know it was built by an intelligent person and not random processes. Should we not recognize the intelligence and oversight that the feedback processes evident in living creatures of all sizes and shapes clearly demonstrates (Romans 1:20)? How does evolution explain feedback? It does not and cannot adequately explain it. It is a design function created by the intelligent, purposeful, almighty God of the Bible from the beginning as described in His Word.


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