|Section 1: Design in Nature|
Design in Living Creatures
|The beetle that carries a gun. The Bombardier beetle, Brachinus,
protects itself from its enemies by firing a hot charge of chemicals from two little
swivel tubes in its tail. In 1961 Professor Schildknecht in Germany published the results
of a careful investigation.1 Brachinus
possesses in its body twin sets of apparatus consisting of two glands producing a liquid
mixture, two connected storage chambers, two "combustion chambers" (this term is
Professor Schildknecht's), and the two external tubes which can be aimed like flexible
guns in the tail of a bomber.
Upon analysis, the stored liquid was found to contain ten percent hydroquinones and twenty-three percent hydrogen peroxide (used in rockets). Such a mixture, Schildknecht reported, will immediately begin to react in a test tube, rapidly turning brown. In the beetle's storage chamber the liquid is preserved unreacted for long periods of time. Why? The explanation is still unknown to science. Some undiscovered physical or chemical principle prevents reaction until some of the liquid is squirted into the combustion chambers, where two enzymes (catalase and peroxidase) bring about an immediate, violent explosion. The resulting products are vaporized and fired boiling hot at the enemy (as a temperature of 212oF.) Spiders, ants, and even predators as large as toads are effectively repelled by Brachinus' chemical warfare.2
Note that a rational evolutionary explanation for the development of this creature must assign some kind of adaptive advantage to each of the millions of hypothetical intermediate stages in the construction process. But would the stages of one-fourth, one-half, or two-thirds completion, for example, have conferred any advantage? After all, a rifle is useless without all of its parts functioning. One small part missing or malfunctioning renders the rifle useless except, perhaps, as a club.
Is the Bombardier's artillery any different in this respect? Before this defensive mechanism could afford any protection to the beetle, all of its parts, together with the proper explosive of chemicals, plus the instinctive behavior required for its use, would have to be assembled in the insect. A partially developed set of organs would not work. Therefore, according to the principles of evolutionary theory, there would be no selective pressure to cause the system to evolve from a partially completed stage toward the final completed system. This singular defense mechanism, so perfectly designed, raises a major problem for evolutionary theorists who imply that their theory explains everything.
In recent years some efforts have been made to show how beetles which produce evil smelling, corrosive chemicals related to hydroquinones could have evolved into Brachinus.3 Another carabid beetle apparently mixes hydroquinones with a little hydrogen peroxide in a chamber in its tail. A noxious repellent foam is exuded on its back. To evolve into Brachinus all this beetle had to do was to evolve its chamber into two chambers separated by a valve, evolve glands to produce two enzymes, find out how to store a mixture of hydroquinones with a 15-fold excess of hydrogen peroxide without having them react immediately, evolve the gun turrets aimable around an arc of 270 degrees, and evolve the necessary control systems and instinctive behavior. Simple, wasn't it? Prof. Thomas Eisner of Cornell University says it really happened.4 He makes it sound easy, but we can be excused for our skepticism.
To recapitulate, the general problem is as follows: If a particular type of organism, organ, or behavior did, in fact, originate by natural selection of random mutations and natural selection, it should be possible to devise a reasonable series of hypothetical mutations covering the entire assumed history of the supposed evolutionary process. Furthermore, it should be possible to demonstrate logically that each proposed intermediate stage or mutation would confer a selective advantage upon the organism. According to the theory, there would be no reason for selection of intermediate stages unless they were advantageous. But such an explanation, including description of the intermediate stages and their advantageous character, is rarely accomplished. This is why we say that evolutionary theory fails to explain Brachinus and the other organisms which are described below. If a theory fails to explain the data in any science, that theory should be either revised or replaced with one that is in agreement with observation. Now examine the following evidence and draw your own conclusions.
A lizard on the ceiling. The gecko lizard can walk across your ceiling upside-down without falling off. How? Until a few years ago scientists did not know, though they proposed several theories. Examination of the toe pads of the gecko with optical microscopes at up to 2000 diameters magnification revealed thousands of little fibers arranged like the tufts of bristles in a toothbrush. Yet the question remained unanswered. An answer was finally provided by the powerful scanning electron microscope, which was able to take a series of remarkable photographs magnified to 35,000 diameters or more.5 What was revealed?
The gecko has on its toe pads many millions of fine fibers tipped with little suction cups, each about eight millionths of an inch in diameter. In conjunction with this, the lizard's feet are designed so that the toe joints bend or curl upward (try it sometime) so that he can peel the suction cups off gradually at each step and not get himself too firmly stuck to the surface.
Click here to see a larger image.
|Figure 1-2. Each chevron-shaped ridge of the gecko's foot pads is composed of millions of fibers tipped with microscopic suction cups.|
|It is estimated that the gecko has at least 500
million suction cups on his toes. The extraordinary microscopic structure of the gecko
lizard's toe pads clearly suggests intelligent, purposeful design. No remotely plausible
scheme for the origin of the gecko's suction cups by random mutations and natural
selection seems possible. Just try to imagine such a scenario yourself. Did an ancient
species of lizard start with one suction on each toe, then go to two, four, eight....? And
should some scientist with a clever imagination succeed in devising a plausible scheme, he
or she would still be without a scrap of fossil evidence to demonstrate that it was
actually a fact of earth history.
Do drinking giraffes have headaches? Darwin wrote in his Origin of Species that he had no difficulty in imagining that a long period of drought could have caused some hypothetical short-necked ancestors of the giraffe continually to stretch their necks higher and higher to reach the diminishing supply of leaves. He had no fossil evidence, of course, for such an evolutionary history. He also apparently was not aware of certain problems peculiar to giraffes which made his easy assumption of giraffe evolution even more difficult to accept.
The giraffe heart is probably the most powerful in the animal kingdom, because about double normal pressure is required to pump blood up that long neck to the brain. But the brain is a very delicate structure which cannot stand high blood pressure. What happens when the giraffe bends down to take a drink? Does he "blow his mind?" Fortunately, three design features have been included in the giraffe to control this and related problems. In the first place, the giraffe must spread his front legs apart in order to drink comfortably. This lowers the level of the heart somewhat and thus reduces the difference in height from the heart to the head of the drinking animal, and thus reduces the excess pressure on the brain.
Second, the giraffe has in his jugular veins a series of one-way check valves which immediately close as the head is lowered, thus preventing blood from flowing back down into the brain. But what of the of the blood flow through the carotid artery in the neck leading to the brain? A third design feature is the "wonder net," a spongy tissue filled with numerous small blood vessels and located near the base of the brain. The arterial blood first flows through this net of vessels before it reaches the brain. It is believed that when the animal stoops to drink, the wonder net in some way controls the blood flow so that the full pressure is not exerted on the brain. It is also believed by scientists that probably the cerebrospinal fluid which bathes the brain and spinal column produces a counter-pressure which prevents rupture or leakage from the brain capillaries. The effect is similar to that of a g-suit worn by fighter pilots and astronauts. Leakage from the capillaries in the legs due to high blood pressure is also probably prevented by a similar pressure of the tissue fluid outside the cells. In addition, the walls of the giraffe's arteries are thicker than in any other mammal.
Some careful investigations and measurements of blood pressure have been made in live giraffes in action. However, the exact manner in which the various factors operate to enable the strange creature to live has still not been clearly demonstrated. Nevertheless, the giraffe is a great success. When he has finished his drink he stands up, the check valves open up, the effects of the wonder and the various counter-pressure mechanisms relax, and all is well. Not even a headache.6
Bats and whales that "see" with their ears. Bat echo-location capabilities are well-known but bear another look.7 The small insect-eating bats are master sound technicians. When hunting in the dark, they emit rapid sequences of ultrasonic chirps, for the most part inaudible to human ears. Each chirp lasts about two milliseconds and is frequency-modulated; that is, it begins at a very high frequency, around 100,000 cycles per second, and sweeps down to about half of the initial frequency. It is believed that this enables the bat to determine the size and other characteristics of objects which reflect echoes to the bat's ears. The shorter wavelengths reflect better from the smaller objects. The bat cannot be fooled by a pebble but will only capture insects.
We will only briefly allude to the underwater sonar capabilities of dolphins, porpoises, and whales, which enable these creatures to perceive their obscure watery surroundings with amazing accuracy. The United States Navy has failed to duplicate their sonar technology.
Each creature a designed, integrated system. Every living creature is an integrated system which lives and functions as a whole. An excellent example of this is provided by the worker honeybee. Consider certain parts of the worker bee's body and their vital functons.8
Without all of these design features and many more the worker bees could not function in the hive; as a result the hive would perish. Actually, the entire hive of bees functions as a single living organism. The queen controls the life and development of the hive by means of chemical substances called pheromones which circulate throughout the hive population in the food supply. The social organization in the hive is truly marvelous. One of the most remarkable features of this organization is the dance language used by a returning worker to inform other bees of the location and preferred course to a new source of nectar. The honeybee is surely the result of intelligent design.
|Figure 1-3. The honeybee was created according to a highly integrated design. The numbers refer to the numbered design features listed above.||
Click here to see a larger image.
|The same may be said of the orb weaving spider. The selection of several protein formulations which she incorporates in up to seven different kinds of silk and the complex spinnarets having hundreds of microscopic holes through which the precisely formed threads are spun have not been explained on the basis of accidental, purposeless evolution.9 The beautiful design of the orb web is a miniature engineering wonder, but the spider learns her web-building technique from no one. The spider was, so to speak, hatched with a degree in web engineering. It may also be pointed out that no fossil evidence exists to prove the evolutionary origin or ancestor of spiders. The mute little spider bears eloquent witness to the reality of design in nature.|