We live in a world made up of matter. Matter consists of atoms and molecules that follow the laws of nature. All life is made up of atoms and molecules that are organized into cells. Our body has trillions of them. Although “heat” and “temperature” are related to each other, they are not the same thing. Heat is the transfer of energy from one object to another. When a machine uses energy to do work it naturally gives off heat. This applies to the body as well. When our cells use oxygen to help release energy from glucose, so they can do work, they naturally give off heat. In contrast, temperature is a measure of an objectís internal energy, how much random motion its molecules have. This energy is often derived from heat and other sources (like electrical and nuclear energy). The higher an objectís temperature the more random motion its molecules have and the lower an objectís temperature the less random motion its molecules have. For some molecules, like water (H 2 O), the degree of random motion can even affect its physical state. If the temperature of H 2 O is below 32 F (0 C) it becomes a solid called ice. And when its temperature is between 32 F Ė 212 F (0 C Ė 100 C) H 2 O is a liquid called water. Finally, when the temperature of H 2 O is greater than 212 F (100 C) it becomes a gas called water vapor. The effects of heat on an objectís temperature apply not only to working machines but also to the cells of the body as well.
Everybody knows that going outside in the sun during the summer will probably make you feel hot. And going outside without a coat in the winter will probably make you feel cold. And most people know that the temperature inside the body (core temperature) is usually higher than the one on the skin (surface temperature). All you have to do is blow on your hand to figure that out. There are even some people who know that as humans, we are warm-blooded, as compared to most reptiles, amphibians, fish and insects, which are cold-blooded. But what most people do not understand, or appreciate, is why the body must keep its core temperature within a certain range and how it does it. Without the bodyís ability to control its core temperature, life as we know it would be impossible. The proof of this is that when the body loses control of its core temperature, it dies. In other words, control is the key to life. But how does the body do it?
As noted in previous articles, one of the most important sets of molecules which work to give the body control is hormones. However, although hormones are involved in helping the body control its core temperature, the moment to moment control is provided by the nervous system. After all, the time needed for glands and their hormones to react and take effect usually requires several minutes. But when the bodyís temperature suddenly changes it must be able to respond in a matter of seconds or else risk severe debility and even death. Similar to gland cells, the nerve cells control things by sending out chemical messengers called neurohormones. Experience teaches that the nervous system can respond in a split second to what we encounter in life. Letís first look at what is needed to control something and then where hormones and neurohormones fit into the function of thermoregulation to keep the bodyís core temperature under control and keep us alive.
To be able to control something requires having at least three different parts all working together in harmony. The first thing you need is a sensor to detect what needs to be controlled. If you have no way of being aware of what needs to be controlled how can you control it? The sensor is like the reconnaissance team that an army sends out to check on the whereabouts and activities of its enemy. Without this information the army would be working in the dark. The second thing you need to control something is an integrator which interprets the information from the sensors, makes decisions about what needs to be done, and then sends out orders. If you donít understand the information from the sensors and canít make decisions about what should be done then what use are the sensors in the first place and how can you control something? The integrator is like army headquarters where the information from the reconnaissance team is analyzed, decisions are made about what needs to be done and orders are sent out. Without army headquarters there would be no coordinated action in the field. The third thing you need to control something is an effector which receives the orders from the integrator and does something. If you have a sensor to detect what needs to be controlled and an integrator to know what needs to be done, but not an effector to do it, then whatís the use of having the first two and how can anything be controlled? The effector is like the soldiers, who at the orders received from headquarters go and do what needs to be done. Without soldiers there is no army and the battle is already lost.
Hormones are protein molecules that are sent out by gland cells into the blood to help regulate specific functions of the body. They usually take several minutes to take effect. Nerve cells can transmit messages much faster than gland cells, literally in a split second or two. Just like gland cells they release different chemicals, called neurohormones, that stimulate or inhibit muscles, glands or other nerve cells. The hormones sent out by the gland cells, and the neurohormones sent out by the nerve cells, are chemical messengers which are just like the orders sent out by army headquarters. In particular, specialized nerve cells, located in strategic places in the body, have sensors on their surface to detect certain physical signs (like temperature). In other words, the nervous system has its own reconnaissance team that can detect a specific physical sign which the body must control to survive. The information from these special nerve cells is sent rapidly to the brain where it is analyzed. The brain then sends out other nerve messages to the target tissues. The nerve cells in the brain act as the integrator, just like army headquarters, to send out orders to direct the activities in the field. These actions, done at a distance from the sensors and the brain, are designed to achieve a specific goal; the control of a specific physical sign (like temperature) so the body can function properly and stay alive. The specific messages from the brain travel along specific nerves which release specific neurohormones in the specific target organs to pass on their orders. The cells in these specific organs act as the effector, which, like the soldiers in the field, receive the orders and perform a specific action. This effect, done at the direction of the integrator, helps to control the specific physical sign (like temperature) that was sensed by the specialized nerve cells in the first place.
However, army headquarters must send out different orders to different soldiers telling them to do different things. So too, the bodyís different nerve and gland cells must send out different messages to different target cells to get different things done. And just as the soldiers canít take just any message or do whatever they want, the target cells must respond to the right message and do the right thing, otherwise the body wouldnít be able to control anything. The way the body ensures that the right target cells receive the right orders so they can do the right thing is for them to have specific receptors. The receptors in the target cells are proteins with a special shape that allow them to attach to specific molecules when they come in contact with them. Think of it like a key fitting into a lock, or tuning your radio or television to a specific station. When the neurohormone or hormone attaches to its specific receptor this signals the target cell to do something. And what the target cell does directly affects the specific physical sign (like temperature) that the sensory nerve cell detected in the first place. Now weíll look at how the laws of nature affect temperature and how the body takes control to stay alive. Be prepared to exercise your wonder as you never have before!
Just as a machine can malfunction if it is too hot or too cold, so too, the cells that make up the organs of the body can malfunction if the core temperature is too high or too low. Recall, the core temperature is a reflection of the amount of random molecular motion within the cell. Most of the enzymes the body uses for its metabolic processes work best within an ideal temperature range. For the human body the normal range for the core temperature is 97-99 F (36-37 C). If the core temperature rises too high or drops too low it may affect not only the function of the enzymes but also the integrity of the proteins and the cell membrane as well. A core temperature greater than 107 F (42 C) usually causes structural and enzymatic protein breakdown causing impairment of cellular respiration and destabilization of the cell membrane. This ultimately results in brain malfunction, loss of temperature control itself, muscle breakdown and multi-system organ failure, culminating in death. A core temperature below 92 F (33 C) usually causes a significant reduction in enzyme activity and metabolic function resulting in a marked decrease in energy production. This leads to brain malfunction, loss of temperature control itself, impaired muscle function and multi-system organ failure, culminating in death. So, one can see that it is important for the body to control its core temperature. Before you can understand how thermoregulation is accomplished in the body you must first understand how the laws of nature affect the body with respect to heat and temperature.
The core temperature of the body is mainly affected by two main processes; how much heat the body produces from the energy its cells use to survive and function, and how much heat the body gains from, or loses to, its surroundings. The chemical reactions that take place in the body can either release or use up energy. The sum total of all of these chemical reactions is called the metabolism. Chemical reactions that release energy while breaking down molecules, like glucose (C6 H12 O6), into simpler molecules, like carbon dioxide (CO2) and water (H 2 O), are called catabolic reactions. Chemical reactions that use energy to build more complex molecules, like proteins, from simpler ones, like amino acids, are called anabolic reactions. Both, catabolic and anabolic reactions take place side by side in the cell. The cell is only able to harness about 25% of the energy that is released from the breakdown of complex molecules like carbohydrates, fats and proteins. It then places this energy in special energy-storage molecules. The remaining 75% of the energy is released into the body as heat. The energy-storage molecules then transfer their energy within the cell so it can be used for anabolic processes and functional activities. These include things like the synthesis of proteins for cell structure and enzymes that promote vital chemical reactions, ion pumps (like the sodium-potassium pump) for cellular integrity and function, muscle contraction, gland and nerve cell function and gastrointestinal absorption. Ultimately, all of these processes result in the release of heat as well. So most of the energy the body uses eventually results in the release of heat.
When the body hasn't eaten for a while and is at total rest the amount of energy it requires to maintain its cellular integrity and total organ function is called its basal metabolic rate (BMR). Think of the BMR as being like the amount of fuel a car uses while standing still idling in traffic. It needs a minimum amount of energy just to keep the engine running while it waits for the driver to step on the accelerator. So too, the BMR is a measure of the amount of energy the body uses just to maintain its cellular and organ function while it waits to be put into action. And just like a car, the faster it goes the more energy it needs, the more heat it releases, and the higher its internal energy and temperature as well. So, one can see that the laws of nature regarding the release of heat when energy is used to do work affects the body's core temperature, not only when it is at complete rest (BMR) but also with any level of activity.
The laws of nature not only cause the release of heat when energy is used to do work, they also cause the transfer of heat from a warmer object to a cooler object when they come in contact with each other. Touch a hot stove for a few seconds and the transfer of heat from it to your fingers will cause them to burn. Grab an ice cube and the transfer of heat from your hand to it will cause it to melt. Since the body is always surrounded by air (and sometimes water) it is therefore always losing heat to, or gaining heat from, its environment. Since most people prefer to stay in surroundings where their core temperature (97-99 F, 36-37 C) is higher than the ambient temperature, it is much more common for the body to be constantly losing heat to its surroundings.
In the same way that heat radiates from the sun, much of the heat produced by the body's metabolism is lost through its skin to its surroundings. This accounts for about 50% of the bodyís heat loss. Conduction involves the transfer of heat from one object to another by direct contact. If the body comes in contact with something cooler or warmer than itself, like swimming in a cold river, or sitting in a hot sauna, then it loses, or gains, heat by conduction. Heat loss by conduction usually takes place between the skin and the air surrounding the body and is often aided by convection. Convection is the phenomenon where heated air at the surface of the skin moves away from the body and is replaced by cooler air which is more effective in taking away heat. This is why a cool breeze against the skin causes more heat loss. Conduction aided by convection generally accounts for about 25% of the bodyís heat loss. Finally, evaporation takes place when water on a surface absorbs heat from it and is released into the air as water vapor. Heat loss by evaporation takes place from the lungs, the mouth and, most importantly, from the perspiration on the surface of the skin. Evaporation accounts for about 25% of the total heat lost from the body.
To summarize, the laws of nature demand that heat be released when energy is used to do work. The body invariably produces heat from its metabolism which allows it to live and function normally within its environment. The laws of nature also demand that a warmer object transfer heat energy to a cooler object when they come in contact with each other. Since the body is surrounded by air (and occasionally water) that is usually cooler than its core temperature, this means that it is usually losing heat to its environment. The body's core temperature is therefore determined by its total production of heat through its metabolism and how much heat it loses to, or gains from, its surroundings. The molecules that make up the cells and perform the functions of the body work best within a given temperature range. Therefore, to control its core temperature and stay healthy the body must take into account these two laws of nature which naturally cause internal heat production and the transfer of heat to, or from, the environment. Now let's look at how the body does it!!
The first part of thermoregulation that needs to be looked at is the basal metabolic rate (BMR). Recall, the BMR is the minimum amount of energy the body needs to keep its cells intact and its organs working when it is at complete rest. The BMR also represents the minimum amount of heat the body releases and contributes to its core temperature. Any activity level above complete rest increases the body's use of energy above the BMR while at the same time increasing the release of heat as well. Thyroid hormone, which is produced in the thyroid gland located in the neck, is the dominant molecule that controls the BMR. It affects almost every chemical reaction in almost every cell of the body. Thyroid hormone does not dissolve well in water so it needs a special protein (made in the liver) called thyroid-binding globulin (TBG) to carry it in the blood. The exact mechanism of how thyroid hormone affects the metabolism in the cell is as yet poorly understood. However, studies seem to indicate that thyroid hormone binds to a specific receptor in the nucleus of the cell and stimulates protein synthesis and cellular respiration (the breakdown of glucose in the presence of oxygen to release energy). All of this activity causes an increase in oxygen consumption and heat production.
To control its BMR and how much heat it produces when at total rest, the body must be able to control its production of thyroid hormone. Recall, the first thing you need to control something is a sensor that can detect what needs to be controlled. The hypothalamus and the pituitary gland have sensors that allow them to detect the blood level of thyroid hormone. Recall, the second thing you need to control something is an integrator to take the information from the sensors, compare it with a standard and decide what needs to be done. The hypothalamus monitors the level of thyroid hormone and adjusts its release of a hormone called thyrotropin-releasing factor (TRF). If the thyroid hormone level is too high the hypothalamus reduces its release of TRF and if the thyroid hormone level is too low it increases its release of TRF. The pituitary gland monitors the thyroid hormone level in the blood and adjusts its release of a hormone called thyroid-stimulating hormone (TSH). TSH is also known as thyrotropin. If the thyroid hormone level is too high the pituitary gland reduces its release of TSH (thyrotropin) and if the thyroid level is too low it increases its release of TSH. Recall, the third and final thing you need to control something is the effector which receives the messages from the integrator and does something to change the situation. The pituitary gland has receptors for TRF and when stimulated this causes it to release TSH. The more TRF sent to the pituitary gland by the hypothalamus the more TSH it releases and the less TRF sent to the pituitary gland by the hypothalamus the less TSH it releases. In turn, the thyroid gland has receptors for TSH and when stimulated this causes it to produce and release thyroid hormone. The more TSH the pituitary gland sends out to the thyroid gland the more thyroid hormone it makes and releases and the less TSH sent to the thyroid gland from the pituitary gland, the less thyroid hormone it makes and releases. If the body has too much thyroid hormone this increases the BMR, speeds up the chemical reactions in the body, causes the release of more heat, and the person often feels too hot. If the body has too little thyroid hormone this decreases the BMR, slows down the chemical reactions in the body, causes the release of less heat, and the person often feels too cold.
The other part of thermoregulation involves moment to moment control which must take into account, not only the heat released by the bodyís activity, but also the heat lost to, or gained from, its surroundings. Recall, any activity level causes the body to use up more energy and release more heat, above the BMR. And since the body is always in contact with its surroundings (usually air, but sometimes water) it is always losing or gaining heat from its environment. Since these changes can take place rapidly and can have serious effects the body must have the ability to react quickly enough to correct the situation and keep its core temperature under control. Hereís how it does it.
Recall, the first thing you need to control something is a sensor to detect what needs to be controlled. The body has two different sets of temperature sensors which are called thermoreceptors. There are peripheral thermoreceptors in the skin which detect either hot or cold. Their main function is to warn the body when it is being exposed to high or low temperatures which may result in tissue damage (burn or frostbite). However, these peripheral thermoreceptors do play a role in helping the body control its core temperature. In addition, the body has central thermoreceptors, which detect the core temperature, and are located within the chest and the abdomen, and also the hypothalamus in the brain.
Recall, the second thing you need to control something is an integrator that can take the data it receives from the sensors, compare it with a standard, and then decide what must be done. The hypothalamus is the integrator for core temperature control. How it “knows” what the proper core temperature should be for survival is at present poorly understood. However, it is thought that the hypothalamus keeps the body's core temperature around a "set-point" value which for most healthy people is 97-99 F (36-37 C). If the core temperature rises above the set-point value the hypothalamus sends out messages to limit heat production and promote heat loss. If the core temperature drops below the set-point value the hypothalamus sends out messages to promote heat production and limit heat loss. Besides sending messages to make you aware of being too hot or too cold, the hypothalamus also uses the neurohormones of the sympathetic nervous system to keep a moment to moment control of the bodyís core temperature.
Recall, the third and final thing you need to control something is an effector that can do something about the situation. When it comes to thermoregulation the effectors that the body uses can be divided into being either voluntary or involuntary.
Experience teaches that when the hypothalamus makes you conscious of a significant rise or fall in the core temperature with respect to the set-point value, making you feel too hot or too cold, you can voluntarily do certain things to try to correct the situation. If you are too hot you can reduce the amount of heat your body produces by stopping your present activity and coming to a complete rest. If you are too hot you can remove some of your clothing to allow the heat to leave your body easier. If you are too hot you can get out of direct sunlight to prevent its heat from warming you too much. If you are too hot you can turn on a fan or pour cold water on yourself to help your body lose more heat. In contrast, if you are too cold you can increase the amount of heat your body produces by increasing your activity level, like rubbing your hands together, stamping your feet, or moving around more. If you are too cold you can put on heavier clothing to prevent your body from losing too much heat. If you are too cold you can go out into the sunshine or stand near something hot, like a fire or wood stove, so you can receive more heat. If you are too cold you can warm yourself with a hot water bottle or jump into a hot tub instead.
Besides being able to do things that promote heat loss and limit its production when we are too hot, or promote heat production and limit heat loss when we are too cold, our body has several involuntary (automatic) mechanisms in place to achieve this as well. When, despite all efforts, the body is still too cold, the hypothalamus can activate two other effectors which promote heat production. One of these is to make the muscles shiver and tremble. This shaking activity does not move the bones to perform some sort of task but instead produces more heat for the body. The other effector for increased heat production causes the release of certain hormones to increase the body's metabolic rate and release more heat from cellular respiration.
However, the main effector for thermoregulation is the skin. The skin is the outer layer of the body which is in direct contact with its surroundings. The skin is made up of many different types of cells that together serve to protect the body from many natural things, like friction, chemicals, and microbes. It is the unique nature of the skin's circulation and the presence of millions of sweat glands that provide it with the equipment to help the body control its core temperature.
The blood flow within a given tissue or organ is usually related to its metabolic needs. In other words, how hard it is working. However this is not the case for the skin. In fact, the amount of blood flow in the skin is usually much more than its metabolic needs demand. The skin (particularly in the hands, feet, ears, nose, and lips) have blood vessels which allow direct connections between the arterial and venous systems. These arterio-venous connections facilitate rapid blood flow by shunting blood directly from the arteries to the veins while bypassing the capillaries. Being so close to the surface of the body, the warm blood that travels in the circulation of the skin has a tendency to cause the body to lose heat by radiation and conduction aided by convection. In general, the more blood flow to the skin surface the more heat loss from the body, and the less blood flow to the skin surface the less heat loss from the body.
When the bodyís core temperature changes, the hypothalamus adjusts the amount of messages it sends along the sympathetic nerves to the muscles surrounding the blood vessels in the skin. These nerve messages cause the release of a neurohormone called norepinephrine. Norepinephrine attaches to specific receptors on these muscles and tells them to contract. When the body's core temperature drops so that you feel too cold, the hypothalamus responds by sending out more messages along the sympathetic nerves which makes them release more norepinephrine. More norepinephrine makes the blood vessels in the skin contract more. This results in less blood flow to the skin surface and less heat loss from the body. When the body's core temperature rises so that you feel too hot, the hypothalamus responds by sending out fewer messages along the sympathetic nerves which causes the release of less norepinephrine. Less norepinephrine makes the blood vessels in the skin relax more. This results in more blood flow to the skin surface and more heat loss from the body by radiation and conduction aided by convection.
In summary, when the body is too cold it reduces the blood flow to the skin, to limit its heat loss, by sending out more norepinephrine from the sympathetic nervous system. And when the body is too hot it increases the blood flow to the skin, to increase its heat loss, by sending out less norepinephrine from the sympathetic nervous system.
In addition, the skin also has millions of sweat glands that can release perspiration onto its surface. This promotes further heat loss by evaporation as the water on the skin picks up heat from the body and is turned into water vapor. The hypothalamus triggers sweating also through the sympathetic nerves but instead of using norepinephrine as the chemical messenger it uses a neurohormone called acetylcholine. Acetylcholine attaches to specific receptors on the sweat glands to turn them on. When the bodyís core temperature rises so that you feel too hot, the hypothalamus responds by sending out more messages along the sympathetic nerves that supply the sweat glands making them release more acetylcholine. More acetylcholine makes the sweat glands secrete more perspiration. This results in more heat loss from the body by evaporation. When the bodyís core temperature drops so that you feel too cold, the hypothalamus responds by sending out fewer messages along the sympathetic nerves that supply the sweat glands making them release less acetylcholine. Less acetylcholine makes the sweat glands secrete less perspiration. This results in less heat loss from the body by evaporation.
In summary, thermoregulation of the bodyís core temperature involves not only thyroid function but also the sympathetic nervous system as well. The hypothalamus and the pituitary gland control the amount of thyroid hormone that is released by the thyroid gland which determines how much heat is produced in the body at total rest (BMR). Also, when the hypothalamus receives data from the thermoreceptors and decides that the body is too hot or too cold it tells the conscious mind to do something to try to correct the situation. In addition, the hypothalamus sends out messages along the sympathetic nerves to the blood vessels and the sweat glands in the skin which either promotes or limits heat loss. The final result is that the body is able to control its core temperature and thereby live and function within its surroundings.
Points to Ponder
The body is made up of chemicals that must follow the laws of nature, like those governing heat production and heat transfer, to live and function properly. To control its core temperature the body needs several different parts all working together. Its basal metabolic rate (BMR), which produces a constant amount of heat, is mainly determined by thyroid function. This requires (1) The hypothalamus to make thyrotropin-releasing factor (TRF), (2) TRF receptors on the pituitary gland cells and for these specific gland cells to make (3) thyroid-stimulating hormone (TSH) in response to TRF, the thyroid gland cells to have (4) TSH receptors and to produce (5) thyroid hormone in response to TSH, the presence of (6) thyroid binding globulin (TBG) to transport thyroid hormone in the blood, (7) thyroid hormone receptors to be present in the nucleus of the cell to affect its metabolism, and finally (8) the ability of the hypothalamus and pituitary gland to detect the level of thyroid hormone in the blood to keep track of thyroid function.
In addition, to take care of the heat generated by activity and how much is gained from, or lost to, the environment, the hypothalamus needs (9) thermoreceptors throughout the body to detect its core temperature, the ability to adjust the amount of messages it sends out along the sympathetic nerves using (10) norepinephrine for the blood vessels in the skin and (11) acetylcholine for the sweat glands which must have (12) norepinephrine receptors and (13) acetylcholine receptors respectively to respond to these messages. If any one of these thirteen parts were to be missing, or not working properly, the whole system would fail and the body would not be able to properly control its core temperature resulting in death. Each part that contributes to the sensor, the integrator, and the effector is needed to perform this vital function for body survival. Dr. Michael Behe has called a system where the absence of any one part renders it useless as being irreducibly complex. The system our body uses to control its core temperature demonstrates irreducible complexity.
One must then wonder how an irreducibly complex system with so many vital parts could have come into existence? Does it make sense that this system could have come about one step at a time? First the sensor, with no integrator or effector, or the integrator with no sensor or effector, or the effector with no sensor or integrator? The idea is totally absurd. They must have all come together as a system to perform a function to keep the body alive. And which system came first? The ones mentioned previously to control oxygen transport, blood glucose, water content, the levels of sodium, potassium, and calcium, and blood pressure, or this one for temperature? Remember, without any one of these abovementioned systems working properly we die. Each of these systems has its own sensor(s), integrator(s) and effector(s). And if just one of these parts is missing the whole system fails and the body dies. But if a system is irreducibly complex does that make it automatically capable of supporting life? If you think about it youíll realize that thereís one more piece of the puzzle thatís needed, a piece that goes beyond irreducible complexity, to enable these systems to keep us alive within the laws of nature.
Cold-blooded creatures, like most reptiles, amphibians, fish and insects, mainly depend on their surroundings to supply them with enough heat to live and cannot control their core temperature as well as warm-blooded creatures like us. This also affects how they function and survive. The function of a cold-blooded creature is like one of the earliest cars which needed a crank to start it up, had a herky-jerky manual transmission and was very drafty, whereas the function of a warm-blooded creature is like a modern car with its ability to be started electronically at a distance, has a smooth automatic transmission and is sound proof with climate control. But cold-blooded creatures have many different enzyme systems which kick in at different temperatures to keep them functioning and alive. Unfortunately, we warm-blooded creatures do not have this luxury and therefore must maintain tight control of our core temperature to let our metabolism work properly to survive. In other words, real numbers have real consequences when it comes to dealing with the laws of nature. The same applies to the body and how it functions. Not just any core temperature will do. Based on what we know about how the body actually works our ancestorsí ability to survive and reproduce depended on them being able to maintain the right core temperature no matter where they were or what they were doing. But what if the system that uses thyroid function and the sympathetic nerves to control the core temperature had been set differently? What if the core temperature was always allowed to drop below 92 F (33 C) or rise above 107 F (42 C)? Then, all clinical experience tells us that our prehistoric ancestors could never have survived.
Real numbers have real consequences when it comes to dealing with the laws of nature. For, not just any core temperature is needed for survival. It has to be the right one to preserve protein integrity and cell function in order to keep the brain and all the other organs and tissues in the body working properly. Just because a system is irreducibly complex does not automatically mean that it will be able to function well enough to allow for life. Besides being irreducibly complex, systems that allow for life must also have a “natural survival capacity”. By this I mean that each system must give the organism the capacity to survive by taking into account the laws of nature. This usually involves having a knowledge of what is needed to keep the organism alive within the laws of nature and then being able to do what needs to be done. The system that uses thyroid function and the sympathetic nerves to usually keep the bodyís core temperature between 97-99 F (36-37 C) seems to inherently know what is needed to get the job done and it does it naturally. The same can be said for each of the other control systems that manage oxygen transport, glucose, water, sodium, potassium, calcium and blood pressure as well. Not only are each of these systems irreducibly complex with a natural survival capacity, but without any one of them the body dies.
The laws of nature have put up many obstacles to prevent life from existing. Just as a car can die from not having enough gas for energy, or oil for seizing parts, or anti-freeze for engine overheating, so too, all physicians know that there are many different pathways to death. If you really want to begin to understand how life came into existence, you first have to understand how easily it can become non-existent. Did life really come about solely by random chemicals coming together to form cells, then simple organisms, and then complex ones like us? In other words, without “a mind at work” to make it happen?
Do you think the Model T Ford developed into a Lexus solely by the random forces of nature? No, when it comes to the origin of life it seems to me that Science still has a lot of explaining to do!
Be sure to catch all of the articles in Dr. Glicksman's series, "Beyond Irreducible Complexity."
Howard Glicksman M. D. graduated from the University of Toronto in 1978. He practiced primary care medicine for almost 25 yrs in Oakville, Ontario and Spring Hill, Florida. He now practices palliative medicine for a Hospice organization in his community. He has a special interest in how the ethos of our culture has been influenced by modern science’s understanding and promotion of what it means to be a human being.
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