An Overview of the Body’s Amazing, Irreducibly Complex Systems


Physicians have a special place among the thinkers who have elaborated the argument for intelligent design. Perhaps that’s because, more than evolutionary biologists, they are familiar with the challenges of maintaining a functioning complex system like the human body, writes Dr. HOWARD GLICKSMAN who practices palliative medicine for a hospice organization.


At the end of his introduction to What We Can’t Not Know, philosopher and Center for Science & Culture fellow, J. Budziszewski, quotes George Orwell, who wrote that “We have now sunk to a depth at which re-statement of the obvious is the first duty of intelligent men.” In this [essay], I have tried to follow his example.

It is an awesome mystery that allows the trillions of cells in your body to live within the laws of nature. Each cell works like a computerized micro-machine made up of many components. All of these components must have enough energy to produce many different molecules for its structures and functions. They must be protected from the outside world by a surrounding plasma membrane. To get what it needs to live and get rid of what can kill it, the cell must let chemicals pass through its plasma membrane, which makes it vulnerable to the forces of diffusion and osmosis.

Scientists know that if these effects of nature are not resisted by the cell, it will die due to its inability to control its volume of water and chemical content. To offset this natural effect, the cell has a million or more sodium-potassium pumps within its plasma membrane that constantly pump sodium ions out and bring potassium ions back in to stay alive. The cell obtains the energy it needs to drive these pumps and do everything else it needs to live using specific enzymes to break down glucose in the presence of oxygen in a process called cellular respiration. But how does the cell get its supply of oxygen, water, glucose, and everything else it needs?

The body has many different organ systems that together help bring in and deliver the chemicals its cells need while getting rid harmful ones. The respiratory system brings oxygen into the body and gets rid of carbon dioxide. The gastrointestinal system brings in water, salt, sugar, and other vital chemicals and the renal system gets rid of excess water, salt, acid, and metabolic waste. All of these chemicals are transported in the blood that circulates throughout the body by way of the cardiovascular system. But that’s not enough to allow the body to survive within the laws of nature.

The neuromuscular system not only tells us when to breathe, drink, and eat, but also makes these things possible. It makes us aware of our surroundings, controls our breathing, and cardiovascular system and gives us the ability to move around and manipulate things. The bones give support and protection to the body’s organs. They also provide a solid framework for the muscles so we can be active. The skin provides a barrier to the outside world while performing numerous other tasks. The immune system protects the body from invasion by micro-organisms. The clotting system prevents us from bleeding from trivial injuries. The endocrine system helps the body control many aspects of its growth, development, and metabolism. And the reproductive system allows for new human life.

However, just having each of these systems in place to perform different functions does not automatically mean that an individual body and the human race will continue to survive. Since our survival hinges on our cells having enough oxygen to work properly, the final common pathway to death, no matter the cause, is cardiopulmonary arrest. This is when your heart stops, or your breathing stops, or they both stop at the same time. Clinical experience shows that significant malfunction of any one or more of the abovementioned systems has the potential to lead the body down this path. So how do these organ systems take control to allow for survival? Without any one of them our earliest ancestors could never have lived long enough to reproduce and continue the battle for the survival of the fittest.

Common sense tells us that to control something, you need to have a sensor that can detect what needs to be controlled; an integrator to take this information, decide what needs to be done, and send out orders; and an effector to receive the orders and do what needs to be done to maintain control. A good example of this is how a driver knows whether her car is working properly. The manufacturer places sensors exactly where they need to be to monitor the status of things like fuel, oil, and anti-freeze. The information from these sensors is integrated by being sent to calibrated gauges on the dashboard. When any one of these gauges indicates a potential problem, the driver, acting as the effector, pulls into a gas station to take care of the problem.

So too, for chemicals (like oxygen) and physiological parameters (like blood pressure), the body has specific sensors located exactly where they need to be (like in the main arteries) that send the information to an integrator (like the brain) where it is analyzed, decisions are made about what needs to be done, and orders are sent out (like to the respiratory and cardiovascular systems).

Dr. Michael Behe says that an irreducibly complex system is “a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.” Clinical experience shows that not only are all of the organ systems as a whole irreducibly complex on the macro level, because without any one of them the body ceases to function, but each of them is irreducibly complex on the micro level as well. That is because without specific sensors, or integrators, or effectors, to allow each to take control of a particular chemical or physiological parameter, the body is likewise as good as dead.

It takes an extremely vivid imagination to believe that all of the parts needed to keep you alive came together in exactly the right places, with the ability to do exactly the right things at exactly the right times, solely by chance and the laws of nature. This effectively is what evolutionary biologists believe and teach: that life came about from random chemicals coming together to form primitive cells that eventually developed into multi-system organisms with complex body plans, like us. But the point of departure for evolutionary biologists is only how life looks and not how it actually works, particularly how it works within the laws of nature to survive. After all, the body is made up of matter and therefore, like all atoms and molecules, is affected by the laws of physics and chemistry. It must take these into account.

Clinical experience shows that just because a system is irreducibly complex and can function does not mean that it can perform well enough to do what is needed. Place an engine with too little horsepower in too large of a car and it may roll downhill, but it won’t have enough energy to counteract the inertia, friction, and wind resistance it encounters on a level plane, or gravity as it tries to go uphill. Every engineer can tell you the reason: when it comes to performing well within the laws of nature, real numbers have real consequences. If the engine doesn’t have enough horsepower to match the weight of the car and the other forces of nature that would prevent it from moving, then it’s just not going to work properly.

So too, every medical scientist knows that no amount of imagining could have allowed for the survival of the human race unless the body had the right levels of oxygen, carbon dioxide, hydrogen ion, water, sodium, potassium, glucose, calcium, iron, ammonia, albumin, transport proteins, insulin, glucagon, thyroid hormone, cortisol, testosterone, estrogen, aldosterone, parathormone, digestive enzymes, bile, red blood cells, white blood cells, platelets, clotting and anti-clotting factors, complement, antibodies, temperature, heart and respiratory rates, blood pressure, lung volume, airway velocity, cardiac output, liver and kidney function, hypothalamic function, and nerve impulse velocity — just to name the ones described in previous articles in this series.

When it comes to these forty factors, the Goldilocks principle is in force. By that I mean, unless they are all just right, life is impossible. So the organ systems and mechanisms they use to maintain control are irreducibly complex, but they must also have what I call natural survival capacity and inherently know what the levels of these forty factors should be.

It is a universal experience to wonder about what it means to be human, why we are here, how we should live, and the nature of our destiny. But how can someone even begin to seek the answers to these questions if they have been misled about its origin? The human intellect is ordered to the truth. It is only the irrational person who wants to be lied to when they ask a sincere question. When Darwin proposed his theory, he knew nothing about molecular and cellular biology, and in particular, human physiology.

As Stephen Meyer says (see The Information Enigma), the cause in operation that drives life is information, specifically digital or typographic information that experience tells us comes from a mind and not a material process. In other words, when it comes to life being able to survive within the laws of nature, it all comes down to numbers. Information to drive cell structure and function and develop irreducibly complex organ systems is not enough. Creatures must also have the natural survival capacity to know what they must do and when and to what degree and how fast, all of which can be objectively measured in a digital form.

Some people believe that life — all of this — came about by chance and the laws of nature alone. Others employ critical thinking and use the methods of historical science to infer the most plausible explanation. We conclude that the evidence, considered objectively, points to intelligent design…

That evidence includes our own bodies and their functions. It is indeed a mystery. Look at yourself in the mirror, and wonder.



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