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Saturday, 30 April 2016

Bats vs. Darwin

Bats as Fighter Pilots
Evolution News & Views 


Bam! Bam! That's how fast a bat can hit two targets separated by different angles. Japanese scientists were intrigued at the accuracy of bats hunting their prey, so they decided to investigate. They found out something interesting. Bats can plan their attack trajectories to hit multiple targets in sequence with a minimum amount of energy. To do this, they have to focus their attention on multiple targets at once. And, as we all know, they do it primarily with sound, not sight.

Most hunting animals focus on the immediate object of prey. It's quite a skill to sense multiple targets and quickly plan the best way to hit them. Good skeet shooters can do this with lots of practice, but bats come with the programming built in. Writing in the Proceedings of the National Academy of Sciences, the researchers summarize what they found:

When seeing or listening to an object, we aim our attention toward it. While capturing prey, many animal species focus their visual or acoustic attention toward the prey. However, for multiple prey items, the direction and timing of attention for effective foraging remain unknown..... Here we show that bats select rational flight paths to consecutively capture multiple prey items. Microphone-array measurements showed that bats direct their sonar attention not only to the immediate prey but also to the next prey. In addition, we found that a bat's attention in terms of its flight also aims toward the next prey even when approaching the immediate prey. Numerical simulations revealed a possibility that bats shift their flight attention to control suitable flight paths for consecutive capture.... These findings indicate that bats gain increased benefit by distributing their attention among multiple targets and planning the future flight path based on additional information of the next prey. These experimental and mathematical studies allowed us to observe the process of decision making by bats during their natural flight dynamics. [Emphasis added.]
A human fighter pilot with this ability would be able to dart into oncoming planes and shoot them down in rapid succession, turning on a dime between hits. This is Star Wars tech. Han Solo in the Millennium Falcon could hardly do better.

A bat can capture two insects in less than a second. What's required to achieve this level of flight performance? For one, the bat has to be able to adaptively change the characteristics of its sonar beam depending on the situation. It also has to be able to turn the beam quickly to the next insect while approaching the first. Then, it needs to design a flight path to hit them both in rapid succession by the most economical path.

Using both experimental and mathematical models, the scientists determined that bats routinely design the most "rational" flight path to successfully hit multiple targets.

Hence, wild echolocating bats plan their flight paths by distributing their attention among multiple prey items, which means that the bats do not forage in a hit-or-miss fashion but rather spatially anticipate their future targets for optimum routing.
If you've ever watched bats on the hunt in the evening, you know that they continue this rational flight planning continuously for hours, sometimes all night. It would be like a shooter facing a thousand skeet launched every 1-5 seconds in a 360-degree, 3D field and hitting every one for hours on end -- all while avoiding other individuals that are doing the same thing in the same space. And insects, we know, don't fly in straight lines or curves like skeet; they make sudden turns, too. Yet every night, each bat takes on this challenge as a matter of course.

In the past we have discussed optimization as an example of intelligent design science in action. One way the bat selects the optimum flight path is by getting both insects into the sonar beam.

This result demonstrates that the bats select their flight paths to effectively capture multiple prey items. Such parameter sets suggest that bats take a path in the direction of the next prey just before capturing the immediate prey, so that they can acoustically view both prey items (Fig. 1C). In other words, bats might select their flight paths to keep both prey items within their sonar beam.
The actual behavior of the bats, though, is even more complex than the scientists' mathematical model.

On the other hand, bats in the wild varied dynamically their parameter set (flight attention) from moment to moment as they approached multiple prey items (Figs. 3F and 4A). This result implies that the bats actually use a more complex behavioral strategy that has not been assumed by the current mathematical model.
Insect hunting on the wing is hard work. Bats expend 14 times their basal metabolic rate while hunting. They can't afford to waste energy. By rationally designing the most efficient routes, we might say they get the "most buck for the bang" -- i.e., the most caloric intake for the exercise.

Computer techs might be familiar with time-sharing algorithms. When multiple processes are competing for the same CPU, the operating system gives each one a time slice. It returns to unfinished work when a given process gets its next turn. But not all processes are equal; some have higher priority. An operating system designer's challenge is to rank the processes by priority and distribute the time slices fairly so that no process is ignored, but the higher priority processes get preference. Bats do this automatically. They have two competing processes, sonar and flight. In addition, each insect in the vicinity must get its share of attention:

For multiple targets, it is beneficial for bats in the wild to distribute their sonar attention and flight attention among multiple targets and to plan the future flight path based on the next prey for effective foraging. On the other hand, pipistrelle bats in the wild alternately and rapidly shift their sonar attention. This fact suggests that bats process echo streams from multiple targets in a time-sharing manner and then select the optimal flight path to capture and hunt a lot of airborne insects. These findings and suggestions originated from the unique capabilities of bats to fly while actively emitting sonar signals.

Does anybody know of a time-sharing central processor that was not designed by intelligent agents? Maybe that's why the Japanese scientists never referred to evolution in their paper. The scientists selected the bats, and the bats selected their targets, but "natural selection" never got a time slice in the research.

Darwinism vs.the real world XXVIII

Understanding Temperature: Cold-Blooded versus Warm-Blooded Animals
Howard Glicksman

Editor's note: 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, the human body. With that in mind, Evolution News is delighted to offer this series, "The Designed Body." For the complete series, see here. Dr. Glicksman practices palliative medicine for a hospice organization.



Among the other dynamics of nature, the body must contend with heat (the transfer of energy from one object to another) and temperature (the random motion within an object or its internal energy). The body's core temperature is directly related to how much heat it produces through metabolism, the sum total of all of its chemical reactions. The human cell is able to harness only about one-quarter of the energy released from the breakdown of complex molecules like carbohydrates, fats, and proteins. The remaining three-quarters is released as heat into the body. As with any working machine, the more active the body, the more heat it releases.

In addition to the heat released by its metabolism, the body's core temperature is also directly related to how much heat it loses to, or gains from, its environment. Sit directly in the sun on a tropical island and your body will quickly gain a lot of heat. Go out at night on the frozen tundra wearing just a T-shirt and jeans and your body will quickly lose a lot of heat. The body must take control of its core temperature because if it isn't just right, it can adversely affect enzyme function and the integrity of the plasma membrane and other cellular structures.

In my last few articles, I've shown that the body's normal core temperature is set by the hypothalamus at 97o- 99oF (36o-37oC). Studies indicate that this temperature range is the one in which the enzyme systems of the body work best. Thyroid function contributes to the core temperature by setting the basal metabolic rate (BMR), which is how much heat the body generates at complete rest. But life is a dynamic process where to survive the body must stay active, releasing more heat while living within an environment where temperatures fluctuate. The hypothalamus receives data from the central thermoreceptors and keeps the core temperature at its set-point by using both voluntary means (shedding or donning clothing) and involuntary means (shivering or sweating).

These irreducibly complex systems use their natural survival capacity to keep the core temperature right where it should be so the enzyme systems within the cells can work at peak efficiency. Clinical experience teaches that if our earliest ancestors could not have kept their core temperature within the normal range they never could have survived long enough to reproduce. Since humans, like other mammals and birds, can control and keep their core temperature relatively high through internal processes, scientists consider them warm-blooded. In contrast, the core temperature of most insects, amphibians, reptiles and fish is dependent on their surroundings and so they are considered cold-blooded. This article will look at what it means to be cold-blooded and warm-blooded and what might be required for one to develop into the other as evolutionary biologists claim.

Humans, like birds and most mammals, are able to regulate their core temperature at a level that is usually above their surroundings, and sometimes lower than it as well. They accomplish this through increasing their cellular respiration and releasing more heat from their metabolism, altering blood flow in the skin, sweating, panting, shivering, and releasing heat by breaking down fat. In this way they are able to control their core temperature from within. They are therefore called endotherms (endo = within + therm = heat). Since they can keep their core temperature relatively stable, they are also known as homeotherms (homeo = same). The increased need for energy to accomplish this type of thermoregulation requires a high resting metabolic rate, so these organisms have a tachymetabolism (tachy = fast + metabol = to change). In general, birds and mammals are endotherms and homeotherms with a tachymetabolism and are called warm-blooded.

Most insects, reptiles, fish, and amphibians, are not able to maintain a regular core temperature from within, and are therefore more dependent on the temperature of their surroundings. They are therefore called ectotherms (ecto = outside + therm = heat). Since their core temperature is quite variable, they are also known as poikilotherms (poikilo = varied). In order to live within these temperature guidelines, these creatures do not need to provide themselves with as much heat energy as those that are warm-blooded. These creatures tend to have a lower resting metabolic rate or bradymetabolism (brady = slow). In general, insects, reptiles, fish, and amphibians are ectotherms and poikilotherms with a bradymetabolism and are called cold-blooded.

There are advantages and disadvantages to being either cold-blooded or warm-blooded. In particular, since the efficiency of chemical reactions in the cell is dependent on the core temperature, being warm-blooded allows for more activity in colder environments. Warm-blooded animals are, in general, able to forage for food faster and defend themselves better in a wider temperature range than cold-blooded animals. Additionally, warm-blooded animals can support highly-complex energy-dependent organs like the mammalian brain.

However, to maintain a core temperature that is often far higher than its environment, warm-blooded animals must use more of the energy they obtain from food as heat. This means that warm-blooded animals require much more food (often about five to ten times more) than cold-blooded animals to survive. Compared to cold-blooded animals, warm-blooded ones are nature's equivalent to the gas-guzzling and energy-inefficient automobile, since they use so much energy to maintain their core temperature to keep their organ systems working properly. Cold-blooded ones are eco-friendly, energy efficient, and more in tune with their environment because they don't need to use up as much fuel to keep their organ systems working properly.

Conventional scientific wisdom says that warm-blooded animals evolved from cold-blooded ones. Little else is said about how this evolutionary development could have taken place or what viable transitions between these two steps would look like. Converting a cold-blooded animal into a warm-blooded animal would be like converting a Model-T Ford into a Lexus. Instead of cranking the engine to start, sitting in a drafty vehicle, and moving in a herky-jerky motion from shifting gears, the modern driver electronically starts the engine from a distance, sits comfortably in a climate-controlled airtight vehicle, and enjoys smooth acceleration from the automatic transmission.

An Exercise in Critical Thinking

The more you understand what it takes for life to survive within the laws of nature, the more you realize how inadequate and simplistic the theories of evolutionary biologists are. Imagine an exercise in critical thinking: Given the facts of current biology, determine the challenges that face evolutionary biologists in explaining how cold-blooded animals evolved into warm-blooded ones. Consider these three questions and responses for the exercise.

(1) Whether cold or warm-blooded, all life forms, even bacteria and amoebae, have some sort of thermoregulatory mechanism. Since temperature is one of many physiological parameters that must be controlled to maintain life, shouldn't evolutionary biologists have to describe each of these thermoregulatory mechanisms and how they became more sophisticated?

Each of these thermoregulatory mechanisms requires that the organism sense the change in temperature, decide what needs to be done, and then effect an adequate change in function to correct the situation. For example, when the core temperature of warm-blooded animals drops below the set-point, they can automatically increase their production of heat while at the same time limiting heat loss. Most cold-blooded animals, on the other hand, can only get warmer by lying out in the sun. How could such an irreducibly complex system have evolved while remaining functional and allowing for survival?

(2) One of the main differences between warm-blooded and cold-blooded organisms is that the former can generate more heat from their metabolism than the latter. It is important to note that when cold-blooded animals increase their level of activity, they give off more heat just like warm-blooded ones do. The key difference between them is that, in general, whether at complete rest or with activity, warm-blooded animals tend to give off more heat than cold-blooded ones. Wouldn't you think that in trying to show how cold-blooded animals evolved into warm-blooded ones, evolutionary biologists would first need to explain the mechanism behind this phenomenon and the changes that must have taken place along the way?

In fact, it appears that not only do the cells of cold-blooded organisms have fewer mitochondria and so release less heat through cellular respiration, but the process of cellular respiration seems to be different as well. In the last few decades, scientists have shown that there are uncoupling proteins (UCPs)within the cells of most organisms, which, particularly in warm-blooded ones, seem to reduce the amount of energy their cells store as ATP and cause the release of more heat. Although thyroid activity is present in most invertebrates and vertebrates, it would appear that one of its unique functions in warm-blooded animals is to activate these UCPs and increase the production of heat. The production and control of thyroid hormone is irreducibly complex and requires natural survival capacity because having too little or too much of it is incredibly harmful. This is a second very important point that should be addressed by evolutionary biologists before claiming to understand how cold-blooded animals evolved into warm-blooded ones.

(3) If, to keep the enzyme systems that make up the metabolism in their cells working at peak efficiency, warm-blooded animals must maintain their core temperature within a certain range to survive, how do cold-blooded animals stay alive at these lower temperatures? In other words, before claiming to know how cold-blooded animals evolved into warm-blooded ones, don't you think evolutionary biologists should address this other obvious difference in basic cellular function?

It appears that, when it comes to very important metabolic reactions, most cold-blooded animals have several different enzyme systems in place that are able to work at different temperatures to allow for survival. This means that, in general, when it comes to the genes that code for important metabolic processes, the cells of cold-blooded organisms usually have more than warm-blooded ones. This would mean that while cold-blooded animals were evolving into warm-blooded ones they would have been removing the genes for these various important metabolic processes at each step along the way. How the intermediate organisms could have survived during this transition -- involving a loss of metabolic flexibility and the development of increased heat production along with thermoregulatory control -- is another conundrum that evolutionary biologists need to address.

As biologist Ann Gauger has pointedly noted here at Evolution News, "Evolutionary biology's explanatory power is inversely proportional to its rigor." I maintain that if thoughtful adults were educated not just about how life looks, but how it works to survive within the laws of nature, views about evolution would look very different from how they do today.


Friday, 29 April 2016

Is Darwinism playing with loaded dice?

Evolution Appears to Converge on Goals -- But in Darwinian Terms, Is That Possible?
Denyse O'Leary 

Very different life forms frequently converge on eerily identical patterns of development (convergent evolution). That is odd if evolution is purely undirected and unplanned. There isn't enough time, given the history of the universe.

And, as I've noted before, the welter of data coming back from paleontology, genome mapping, and other studies are changing paleontology from a discipline dependent on grand theories to one more like human history, dependent on identified facts.

A century or so ago, British anatomist St. George Mivart noted that Darwin's theory of evolution "does not harmonize with closely similar structures of diverse origin" (convergent evolution). There is more evidence for Mivart's doubts now than ever.

According to current Darwinian evolutionary theory, each gain in information is the result of a great many tiny, modest gains in fitness over millions or billions of years, due to natural selection acting on random mutations. The resulting solutions should then follow inheritance laws, in the sense that the more similar life forms are according to biological classifications, the more similar their genome map should be.

That just did not work out. Different species can have surprisingly similar genes. For example, kangaroos are marsupial mammals, not placentals. Yet their genes are close to humans. Researchers: "We thought they'd be completely scrambled, but they're not."

Kangaroos? Shark and human proteins, meanwhile, are also "stunningly similar." Indeed, sharks are genetically closer to humans than they are to aquarium zebrafish. Researchers: "We were very surprised... "

Sharks? But does all this not raise a serious question? The popular science literature claims that a near identity between the human and chimpanzee genome is irrefutable evidence of common descent. Why then do we hear so little about any of these findings, which muddy the waters? Why are science writers not even curious?

There is also the question of how easily a life form can "evolve" a complex solution to a difficult problem. Birds are said to have evolved ultraviolet vision at least eight times.

Similarly, whether large bird and mammal brains arise from common descent or convergent evolution is actually uncertain. Two distantly related groups of reptiles are thought to have given rise to mammals and birds, both featuring a much higher brain to body weight ratio than in their ancestors. Paleontologist R. Glenn Northcutt writes that the matter is "contentious and unresolved," because brains rarely fossilize.

It's not just mammals and birds. Two different species of deadly sea snake, with "separate evolutions," were found to be identical. Dolphins and insects, we are told, share components of a hearing system.

The smartest invertebrates, the molluscs (including squid, octopuses, and cuttlefish), seem to have evolved brains four times. From one study we learn, "The new findings expand a growing body of evidence that in very different groups of animals -- and mammals, for instance -- central nervous systems evolved not once, but several times, in parallel."

Cambridge paleontologist Simon Conway Morris's Map of Life website provides many other examples of convergence, listing, for example, the convergent evolution of foul smelling plants ("Love me, I stink"), convergence in sex (love-darts), eyes (camera-style eyes in jellyfish), agriculture (in ants) or gliding (in lizards and mammals).

Convergent evolution is evidence that evolution can happen. But the Darwinian model does not seem to be the right one. The life forms appear to be converging on a common goal.

That said, the problem presented for Darwinism by convergent evolution has hardly penetrated the world of pop science writers, high school teachers, politicians, judges, theologians, and entertainers. Mere evidence could not compete with a position so compelling as Darwin's.

Alternatively, however, there is the position taken by many great physicists: The universe is about information and consciousness, not matter. A sense of the results having been directed would not, then, be surprising. For more on that, consult William Dembski's Being as Communion.



Concern about inequality,a big deal about nothing?:Pros and Cons.

How a bill becomes a fruitless talk session.

Thursday, 28 April 2016

Darwin of the gaps logic continues to collapse. II

Behold, a Further Use for Body Hair

In the Netherlands the abyss stares back.

The Culture of Death Is Like the Universe

How Darwinism undercuts reason.

Lawyer, Scientist, or Animal? Choosing Between Evolution and Human Reason


Tuesday, 26 April 2016

Maths in the dock for design.

How Did Mathematics Come to be Woven Into the Fabric of Reality?


We all learned pi in school in the context of circles.  Pi is the ratio of a circle’s circumference to its diameter.  It is an irrational number approximated by 3.14.
It turns out that pi shows up all over the place, not just in circles.  Here is just one instance.  Take a piece of paper and a stick.  Draw several lines along the paper so that the lines are the length of the stick from each other.  Then randomly drop the stick on the paper.  The probability that the stick will land so that it cuts a line is exactly 2/pi, or about 64%.  If one were to perform millions of trials, one could use the results to perform a very precise calculation of the value of pi without ever considering its relation to circles.
This is just one of many places pi pops up in reality, and pi is just one of several mathematical constants that appear to be woven into the fabric of the universe. One mathematician likened it to looking out over a mountain range, where the bases of the mountains are shrouded in fog, and the symbol for pi is etched into the top of each mountain – one intuitively knows that it is all connected at some basic level even if one has no idea why.
What are we to make of what physicist Eugene Wigner called the “unreasonable effectiveness of mathematics” in describing reality?  The word “unreasonable” makes sense only in the context of expectations.  If one expects the mathematical structure of the universe to be elegant and beautiful, the fact that it turns out to be elegant and beautiful is not unreasonable at all.  It is only unreasonable if one approaches it from the perspective of the metaphysical materialist.  In his universe reality consists of nothing but particles in motion randomly bumping into each other.  In that universe there is no reason to expect any underlying mathematical order, no reason to expect mountain tops etched with pi to pop up all over the place, and no reason to suspect that those mountain tops are connected by a unifying order at the base.
Given materialist premises, none of this makes the slightest bit of sense.  It is just a brute fact.  It cannot be denied or explained.  Yet there it is.
MIT cosmologist Max Tegmark has a theory.  He says consider a character in a computer game (let’s call him Mario) that is so complex and sophisticated that he is able to achieve consciousness.  If Mario were to begin exploring his environment, he would find a lot of mathematical connections.  And if continued to explore, Mario would ultimately find that his entire world is mathematical at its roots.  Tegmark believes we live in a universe that is not just described by mathematics; he believes that mathematics defines all of reality, just as the reality of Mario’s computer game world is defined by mathematics.
Here is the interesting part.  Tegmark makes no design inference.  (He is a multiverse fanatic).  This is astounding.  All he needs to do is take his own analogy one step further.  Why is Mario’s computer game world connected mathematically?  Obviously, it is because that mathematical structure was 
imposed on the game by the game designer.
Why is the universe we live in connected by an unreasonably beautiful, elegant and effective mathematical structure?  Come on Max.  You are a smart guy.  I know you can figure it out.

Cicadas vs. Darwin

The Cicada Challenge to Darwinian Evolution

Monday, 25 April 2016

Rogues II



Barbarians at the gate III:Rogues.



Barbarians at the gate II:The opening engagement.

Wistar and DNA Day: A Fifty-Year Fuse Under Neo-Darwinism

Sunday, 24 April 2016

Another failed Darwinian prediction XX

Cell death

According to evolutionary theory, biological variation that supports or enhances reproduction will increase in future generations—a process known as natural selection. The corollary to this is that biological variation that degrades reproduction will not be selected for. Clearly, natural selection could not result in destructive behavior. Here are two representative statements from Origins:

we may feel sure that any [biological] variation in the least degree injurious would be rigidly destroyed. (Darwin, 63)

Natural selection will never produce in a being any structure more injurious than beneficial to that being, for natural selection acts solely by and for the good of each. (Darwin, 162-3)

But are not examples of such “injurious” behavior obvious? When the rattlesnake rattles its tail, is this not injurious to its hunt for food, and ultimately to its reproductive chances? Darwin argued that this and other such examples are signals to frighten away enemies, not warn the intended prey.

But today we have many examples of injurious behavior that falsify Darwin’s prediction that natural selection “will never produce in a being any structure more injurious than beneficial to that being.” In bacteria, for example, phenomenally complicated mechanisms carefully and precisely destroy the individual. Clearly, this suicide mechanism is more injurious than beneficial to the bacteria’s future prospects.

One such mechanism consists of a toxic gene coupled with an antitoxic gene. The toxic gene codes for a protein that sets the act of suicide into motion and so ultimately kills the bacteria. The antitoxic gene inhibits the toxic gene from executing its mission. Except, that is, when certain problems arise. Lack of proper nutrients, radiation damage and problems due to antibiotics can all cause the antitoxin to be diluted, thus allowing the toxin to perform its mission. (Chaloupka, Vinter; Engelberg-Kulka, Hazan, Amitai; Engelberg-Kulka, Amitai, Kolodkin-Gal, Hazan; University Of Nebraska)

This bacterial suicide is probably good for the bacteria population on the whole. If nutrients are running low, then better for some bacteria to die off so the neighbors can live on. Not only will the reduced population require less nutrients, but the dismantled bacteria help to replenish the food supply. Therefore evolutionists can explain the suicide mechanism as having evolved not for the individual bacteria, but for the population. But the explanation introduces major problems for the theory.

Suicide is probably good for the bacteria population, on the whole, in challenging conditions. Since gene sharing within a bacteria population is at its maximum, evolutionists have no problem explaining such altruism as a result of kin selection (see Altruism). Such a facile response, however, misses the profound problem of how such a design could arise in the first place, for the mechanism is immensely complex.

In this example of bacteria suicide, the antitoxic gene normally inhibits the toxic gene from executing its mission. When the antitoxic gene is diluted then the toxic gene can perform its mission. The toxin does not, however, single-handedly destroy the cell. The toxin is an enzyme that cuts up the copies of DNA (i.e., messenger RNA, or mRNA) that are used to make other proteins. By slicing up the mRNAs, the cell no longer produces the proteins essential for normal operation. But the toxin does not cut up all mRNAs. Some mRNAs escape unscathed, and consequently a small number of proteins are produced by the cell. These include death proteins that efficiently carry out the task of disassembling the cell.

Death proteins are not the only proteins that the toxin allows to be produced. As researchers reported, the toxin “activates a complex network of proteins.” (Amitai) While some of the proteins bring death to the bacteria, others can help the cell to survive. The result is that most cells in the population are destroyed, but a fraction is spared. This of course makes sense. The suicide mechanism would not help the bacteria population if every individual was destroyed. Instead, some survive, and they can be the founders of a new population when conditions improve.

This suicide mechanism and “behavior” is altruistic. Some bacteria die off to save others. And the explanation that this bacteria suicide is due to kin selection adds tremendous complexity to the theory of evolution. Kin selection can select from only that which is available. This elaborate suicide mechanism must have just happened to arise from some combination of random mutations, and then remained in place until the time when it would succeed in surviving a stressful environment. The toxin and antitoxin genes with their clever functionality, the death and survival proteins, the inter cellular communications—all these were needed to be in place and to be coordinated before the kin selection could even begin to act. This is highly unlikely and adds considerable complexity to the theory.

References

Amitai, Shahar, Ilana Kolodkin-Gal, Mirit Hananya-Meltabashi, Ayelet Sacher, Hanna Engelberg-Kulka. 2009. “Escherichia coli MazF leads to the simultaneous selective synthesis of both ‘death proteins’ and ‘survival proteins’.” PLoS Genetics 5:e1000390.

Chaloupka, J., V. Vinter. 1996. “Programmed cell death in bacteria.” Folia Microbiologica, 41:6.

Engelberg-Kulka, Hanna, Ronen Hazan, Shahar Amitai. 2005. “mazEF: a chromosomal toxin-antitoxin module that triggers programmed cell death in bacteria.” J Cell Science 118:4327-4332.

Engelberg-Kulka, Hanna, Shahar Amitai, Ilana Kolodkin-Gal, Ronen Hazan. 2006. “Bacterial programmed cell death and multicellular behavior in bacteria,” PLoS Genetics 2:e135.

University Of Nebraska. 2007. “New Hope For Fighting Antibiotic Resistance,” ScienceDaily April 27.

Darwinism vs.the real world XXVII

Temperature Control: Too Hot, Too Cold, or Just Right?
Howard Glicksman

Editor's note: 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, the human body. With that in mind, Evolution News is delighted to offer this series, "The Designed Body." For the complete series, see here. Dr. Glicksman practices palliative medicine for a hospice organization.

Since the body is made from matter, it must follow the laws of nature that affect the atoms and molecules making up its trillions of cells. These laws tell us that heat is the transfer of energy from one object to another and temperature is a measure of the random motion within an object or its internal energy. The body's core temperature is directly related to how much heat it produces from its metabolism, whether at complete rest or with activity, and how much heat it loses to or gains from its environment. The body must control its core temperature because, if it isn't just right, it can adversely affect enzyme function, the integrity of the plasma membrane, and other cellular structures.

The body's normal core temperature is set by the hypothalamus at 97o-99oF (36o-37oC). It receives data from the central thermoreceptors and keeps the core temperature at this set-point

using both voluntary and involuntary means. When your core temperature rises or falls outside the normal range, and you feel too hot or too cold, there are things you can do, like take off or put on warm clothes, to help bring the core temperature back towards normal. At the same time, the hypothalamus, using the sympathetic nerves, automatically sends out messages to the blood vessels and sweat glands in the skin to either promote or limit heat loss. Using both of these mechanisms, the body is usually able to keep its core temperature where it should be while staying active. Let's look at what happens when the numbers dictating core temperature just aren't right.

The commonest cause of an elevated core temperature is fever, also called pyrexia. Thistakes place when, under the influence of pyrogens, the hypothalamus increases the set-point. The body responds by reducing heat loss through the skin and increasing production through shivering to preserve this abnormally high temperature. That's why you feel chilly and shake prior to developing a fever. Pyrogens are chemicals released by invading bacteria, immune cells involved in inflammation and fighting infection, and even some types of cancer cells.

Hyperthermia, another common cause of high core temperatures, is when the core temperature is above 99oF (37.2oC) despite having normal thermoregulatory mechanisms in place. This usually takes place when a person is working or playing hard, generating excessive amounts of heat within a hot and humid setting, and the mechanisms for thermoregulation become overwhelmed.

Whether due to a very high fever (hyperpyrexia) from illness or heat stroke from physical and environmental factors, a core temperature above 107oF (42oC), means that several life-threatening reactions are likely to take place. These include things like protein and enzyme breakdown, impairment of mitochondrial function, and loss of plasma membrane stabilization. All of this culminates in severe brain dysfunction, muscle breakdown, loss of thermoregulation, and multi-organ system failure, resulting in death.

Hypothermia exists when the body's core temperature drops below 95oF (35oC) despite having normal thermoregulatory mechanisms in place. This usually happens when people are in a very cold environment without adequate protection. Hypothermia affects every tissue in the body by reducing cell metabolism and diminishing enzymatic activity, including the enzymes needed for energy production and usage. As the core temperature drops below 91oF (33oC), mental confusion is soon followed by loss of consciousness and thermoregulation itself.

Based on our knowledge of how the body works, the ability for our earliest ancestors to survive and reproduce depended on their ability to maintain the right core temperature no matter where they were or what they were doing. For if the system of control they used allowed the core temperature to drop below 91oF (33oC) or go above 107oF (42oC), they would have died. Real numbers have real consequences when it comes to dealing with the laws of nature. Not just any core temperature works 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 natural survival capacity. By this I mean that each system must take into account the laws of nature. This involves having an inherent knowledge of what is needed to keep the organism alive and the ability to do what needs to be done.

The system that uses thyroid function and uses the sympathetic nervous system to adjust the blood vessels and sweat glands in the skin to keep the body's core temperature between 97o-99oF (36o-37o C) seems to naturally know how to get the job done. The same can be said for each of the control systems discussed in this series that manage things like oxygen, carbon dioxide, hydrogen ion, hemoglobin, iron, water, sodium, potassium, glucose, respiratory and heart rate, and blood pressure. Not only do each of these systems demonstrate irreducible complexity with natural survival capacity, but the absence or serious dysfunction of any one of them results in death.

Given what you have learned so far about what it actually takes to keep you alive, are you, like Richard Dawkins, intellectually satisfied about the explanatory power of evolutionary biology?

The more you understand what it takes for life to survive within the laws of nature, the more you will come to realize how inadequate and overly simplistic the theories of evolutionary biologists. How cold-blooded animals evolved into warm-blooded ones is a case in point. That's what we'll consider next time.