by

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If you are looking for a brief but substantive discussion of the core issues in the debate over evolution in American education, this publication is for you! We have written this booklet with the non-technical, non-scientific reader in mind. We have minimized the technical terminology and used a conversational style for easy reading, but we have addressed the important scientific information without diluting the content. Our goal has been to clearly communicate the essential arguments in this debate to the general public, to parents and teachers, to school board members and education policy-makers, and to students from the high school level and beyond. We have taken the Ph.D. material and translated it into everyday language so that anyone can understand the scientific controversy over evolutionary theory.

A primary motivation for producing this booklet has been the need to correct the typical mistreatment of this issue by the mainstream media and the scientific establishment. Almost without exception, the public portrayal of this debate has been the stereotypical view of "religion vs. science." We think it is time that the debate shifted to the scientific controversy over certain aspects of Darwinian evolution.

A second, but equally important, impetus for producing this booklet has been the growing body of empirical, observable evidence for design in living systems. Though intelligent design theory is often mischaracterized as an essentially religious theory that adds scientific trappings for credibility, in fact it has grown out of the accumulated empirical evidence that points to design (events arranged by a mind with purpose), rather than natural processes (chance and natural law), as the cause for the origin and diversity of life.

We trust that this booklet will give you a foundation in the important scientific arguments in this debate. For those who are already skeptical of evolution from a religious standpoint, this short treatise will expand your understanding of the scientific basis for that skepticism. For those who are interested in the evidence that supports intelligent design in the origin of life, we offer an introduction to this side of the debate. For all readers, we hope that it will encourage you to learn more about why this controversy is so critical to our society, to our children's future, and to our purpose on earth as human beings.

Jody F. Sjogren, M.S. Robert Lattimer, Ph.D. Douglas D. Rudy, B.S.

Medical Illustrator Industrial Scientist Software Developer

Director, Idnet-Ohio Founder, SEAO Director, SEAO

Preface *

Contents *

Executive Summary *

Section One: The Big Debate *

Section Two: Definitions of Evolution *

Section Three: The Naturalistic Foundation of Evolutionary Theory *

Section Four: The Historical-Experimental Distinction *

Section Five: The Evolutionary History of Life on Earth *

Section Six: Replicating molecules, DNA, and the "biological language" *

Section Seven: Molecular Machines *

Section Eight: New Feature-Producing Agents *

Section Nine: The Evidence for Macroevolution *

Section Ten: How to Teach Biological Origins Objectively *

Notes To The Text *

List of Figures *

Bibliography and Suggestions for Further Reading *

The science of origins attempts to answer the question, "Where do we come from?" The answer to this question has profound implications that affect our view of the universe and our moral and religious values. Evolution theory is the reigning paradigm used by most scientists to explain the origin and diversity of life. We believe that biological origins should be taught with objectivity. Evidence that both supports and challenges evolution should be presented, and the naturalistic assumption behind it should be disclosed.

Evolution is a word with numerous meanings. It is sometimes defined as "change over time" or as "minor genetic variation" (microevolution). These definitions are well accepted and are not problematic. A third definition, however, views evolution as the theory that all living things are related by descent with modification from a common ancestry. This is Darwinian evolution, or macroevolution. This is the aspect of evolution theory that has generated much controversy.

Darwinian evolution rests on the fundamental assumption that biological origins can be explained by natural processes (i.e., the laws of chemistry and physics and random chance acting upon matter and energy). Evolutionary biology is a historical science; it attempts to explain events and processes that have already taken place in the distant past. This is different from current-day laboratory science, in which hypotheses can be tested directly by planned experiments. In historical sciences, the only way to "test" a hypothesis is to consider competing explanations. Since evolutionary theory assumes that life came about only by natural causes, it purposely (and wrongly) excludes from consideration any hypothesis that involves intelligent or supernatural causes.

Evolutionary theory as a historical science includes two parts. "Chemical evolution" proposes that the first living organisms arose on the early Earth from chemical reactions and processes involving nonliving matter. "Biological evolution" proposes that all the diversity of life we observe today arose from gradual changes in the initial life forms.

DNA contains coded instructions needed for assembly of proteins in living cells and for carrying out the processes associated with life. The great question to be addressed in determining how life originated is "where did the instructions (i.e., biological information) come from?" This is a great mystery. Biologists have no satisfactory answer as to how this information could have arisen by natural causes. Intelligent sources are the only known entities that can produce such instructions or information.

A large number of biological systems have the characteristic known as "irreducible complexity." An irreducibly complex system (e.g., the bacterial flagellum) has a large number of necessary interacting parts, the removal of any one of which causes the system to cease its function. Gradual Darwinian mechanisms do not have the capacity to generate irreducibly complex systems. This suggests that purposeful design by intelligence is a more likely explanation for their origin. Living systems are in many ways analogous to human-made machines. Since we know that mechanical machines are made by intelligent engineers, it is reasonable to infer that "living machines" are also the product of intelligent design.

If evolution is the true explanation for the diversity of life, then there must be one or more naturalistic mechanisms that are capable of generating new features (novel body plans and body parts). Natural selection and genetic mutation, the primary Darwinian mechanisms, have not clearly shown themselves capable of generating these new features. A more reasonable explanation of new features would be design by intelligence.

The three major types of evidence that are used to support evolutionary theory (macroevolution) are the fossil record, homologies, and embryology. The principal features of the fossil record are the abrupt appearance of new species (e.g., the Cambrian explosion), stasis (equilibrium) over long periods of time, and then extinction. This discontinuous pattern is more consistent with the theory of intelligent design.

Homologies are similarities in structure and form among different organisms. Homologies may suggest either a common ancestry or a common designer (archetype), depending on how the evidence is interpreted. The argument from embryology proposes that similarities in the stages of developing embryos from different species suggest a common ancestry. However, the findings of modern embryology show that embryos from different organisms are different at all stages of development.

Overall, macroevolution is only about 5% of a typical biology curriculum. Thus it is relatively easy to modify this part of the curriculum. We believe that a "teach the controversy" approach is the best way to present biological origins in an objective, unbiased manner. This calls for (a) teaching the evidence for and against biological evolution (common descent), (b) permitting, but not requiring, teachers to discuss alternative theories (like intelligent design), and (c) adopting a definition of science that allows for consideration of all logical explanations for phenomena in nature.

With regard to teaching the evidence, we suggest that at least three types be covered - fossils, homologies, and embryology. Modern definitions of science are typically naturalistic, e.g., science is finding "natural explanations for natural phenomena." Students should know that this type of definition is controversial, and that science also has the capability to empirically detect when non-naturalistic (e.g., intelligent) causes may be at work. We believe that teachers should have the freedom to discuss scientific alternatives to evolution, if they so choose, and that they should not be required to provide only a "natural explanation" of how life arose on earth.

Teaching both sides of the biological origins debate has numerous benefits, including intellectual honesty, academic freedom, critical thinking, consistency with new federal law, and support of the principle of government neutrality toward religion. Public opinion polls have also shown that the great majority of Americans support this objective approach.

Section One:
The Big Debate

We are living in an age in which technology has defined the landscape of our lives. Scientific research has propelled the development of this technology, and thus science has earned its place as the highest common denominator in our society. Indeed, science is now considered to be, as Berkeley law professor Phillip Johnson says, "the only universally valid form of knowledge in Western culture." Among most of our modern population, there is a generally held perception that science is the objective pursuit of evidence about how the universe works. The successes achieved by experimental science and technology have validated the methods of science over and over.

Because of this, the average citizen is willing to accept much of what science claims to be true without serious reservation. But in one area of science there is enormous and vocal debate over foundational ideas, both within science and within the public arena. That controversial area is the science of origins, and specifically biological origins. Scientists who study the origin of life are attempting to answer the question, "Where do we come from?" The answer to this question has profound implications for how we view ourselves and our universe, what kind of moral and ethical values we adopt, how we structure our lives and our societies, and what or whom we worship. Consequently, the debate over origins ignites strong feelings, and most people have an innate sense about the importance of this question.

In recent years, the controversy over the origin of life has been most vociferously debated in the context of state science education standards. Typically the controversy is framed as a debate between religious extremists who are looking for ways to get the Bible into school classrooms versus the science establishment, which claims to have settled the question of origins with overwhelming evidence for evolution. But this simplistic view completely misstates the situation, and it is our purpose here to accurately state what the debate is about.

The debate is about whether or not there is convincing scientific evidence to indicate that purely natural causes (i.e. those processes involving only random chance and the laws of chemistry and physics) were responsible for the origin and diversity of life. If natural causes alone cannot be demonstrated to have led to the origin of life, then might another cause (design) more reasonably explain the origin of certain features of living systems? If there is reasonable scientific evidence that challenges the naturalistic explanation of the origin of life and its diversity, then shouldn't our students have an opportunity to learn about this evidence?

This paper is in agreement with recent federal legislation that addresses this issue. On January 8, 2002, President George W. Bush signed into law H.R. 1, the Leave No Child Behind Act of 2001. During the debate concerning H.R. 1, Senator Rick Santorum (R-PA) introduced an amendment regarding the teaching of controversial elements of scientific theory. The Santorum amendment passed the Senate by a vote of 98 to 1 and was included as report language in the final version of H.R. 1. Specifically, the H.R. 1 Conference Report states:

We think that students should become conversant with the scientific controversy over biological evolution so that they can participate in the debate as informed citizens. To this end, we suggest that science education standards should include scientific evidence both for and against evolution, and that the science of origins should be taught without religious, philosophic, or naturalistic bias or assumption. While not mandating the inclusion of evolutionary alternatives like intelligent design, we believe that state science standards should provide academic freedom for teachers who wish to discuss scientific theories that differ with evolution in their interpretation of scientific data about the origin of life and its diversity.

Because intelligent design theory has received so much attention in the media during recent debates over state science standards, and because it is often misunderstood and mischaracterized, it is important to clarify just what intelligent design is.

When our local newspapers report the latest developments in the Science Standards debate, the typical description of Intelligent Design theory goes something like this: Intelligent design is "the idea that living things are too complex to have arisen without a guiding force." Or, intelligent design is "the idea that life is too complex to have evolved from strictly naturalistic processes. Advocates say this complexity required an intelligent creator, which may or may not be God." Or, more expansively, "intelligent design is a belief that a higher power is responsible for charting the way individual species progress. It embraces the spiritual realm, which certainly has a place in society, and even in some public-school classes. Science classes, however, exist not only to teach scientific facts and theories, but to teach the scientific method of testing theories using experimentation and measuring observable phenomena. Presenting intelligent design as science would be a perversion of that teaching." (Quotes are from the Cleveland Plain Dealer, Sept. 10, 2002; Columbus Dispatch, March 23, 2002; Plain Dealer, June 11, 2002)

While it may be journalistic reflex to equate intelligent design theory with religion, this simplistic assumption mischaracterizes the primary claim of intelligent design theory. It takes a more inquisitive approach to fully grasp its essence. Intelligent design is a scientific hypothesis or theory about the origin of life. The theory holds that intelligent causes (as compared with naturalistic causes) best explain the origin of many features of living systems. It is based on the testable assumption that structures which exhibit high information content and "specified complexity" are more likely to be the result of intelligent design than of undirected natural causes. (We discuss specified complexity at greater length in the next section.)

Intelligent design theorists propose that design can be empirically detected, e.g. in living systems, and that there is evidence of design in nature.

Intelligent design theorists look for complex arrangements or patterns in nature that are unlikely to occur by chance. From these arrangements and patterns, scientists can infer design, based on comparisons with other things that exhibit similar complexity and are known to be designed. Examples of design inferences in other areas of investigation include:

1. The Search for Extraterrestrial Intelligence (SETI): looking for communication signals or signs of intelligence from outer space.
2. Fire investigation: looking for clues as to whether a house burning is the result of arson (design) or an accident.
3. Criminal investigation (forensic pathology): determining whether a death is the result of murder (design) or accidental cause.
4. Signs of intelligence in the natural world: birds' nests, arrowheads, etc.

Logical inferences of design can be drawn, and are drawn, all the time in such areas of investigation. Intelligent design theorists who examine evidence for the origin of life draw a design inference when they observe high information content and high "specified complexity" in the molecules that make up living systems.

In order to understand the concept of "specified complexity," picture the letters of a Scrabble game tossed at random on the floor. The pattern of the letters will be "complex" in the sense that there will be an irregular pattern of letters. But this pattern does not exhibit "specified complexity" because there is no information in this pattern and because few instructions are needed to describe it. A pile of Scrabble letters in this type of pattern is random and can be described with just two instructions:

On the other hand, picture a string of Scrabble letters arranged in a sentence which spells out the first line of Lincoln's Gettysburg Address, "Four score and seven years ago our fathers brought forth on this continent a nation dedicated to the proposition that all men are created equal." Written messages such as this are examples of "specified complexity" because their constituent parts (the letters) are arranged in irregular, aperiodic patterns and in a specified manner. These kinds of patterns have high information content, which means that many instructions are necessary to specify or describe them. In the example of Lincoln's Gettysburg Address, the instructions necessary to write it out would be as long as the address itself. Every letter would have to be specified in the correct sequence, one at a time.

As applied to biology, the concept of specified complexity is illustrated by information-laden molecules such as DNA, RNA, and proteins. For example, the coded instructions in the DNA molecule reveal specific, complex, and flexible programming which results in directed activities within the living cell. As we will see in a later chapter, the flexible, irregular, aperiodic pattern of "biological letters" on the DNA molecule is like a written message. It exhibits high information content and specified complexity. These characteristics are always, in our experience, associated with - and evidence of - intelligent activity.

A design inference is compatible with belief in a creator, but intelligent design theory, as a scientific endeavor, is limited to the observation and detection of design in nature, not the identification of the designer. Intelligent design theory draws its authority from investigation, observation, and logical analysis according to the scientific method, not from a religious text. Intelligent design theory has no sacred text, no clergy, no creed or sacraments. It prescribes no form of worship, nor does it require of its adherents any rites or rituals.

Thus, while the evidence of design is consistent with belief in a supernatural deity (i.e. theism), rather than atheism, and many intelligent design theorists have their own personal religious faiths, intelligent design theory limits itself to the scientific investigation of nature and the logical inferences that can be drawn from the evidence. It addresses biological origins and examines all of the evidence to determine which characteristics of living systems can be explained by chance and natural law (i.e. natural processes), and which characteristics appear to be the result of intelligence operating on matter (i.e. design).

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Because we have become accustomed to hearing the word "evolution" in so many different contexts, most of us have only a vague understanding of the word. In fact, we might find it difficult to state an accurate scientific definition. Part of the confusion over the definition of "evolution" comes from the varied contexts within which the word is used. We use it to refer to everything from the "evolution of flight from Kitty Hawk to the Space Shuttle" to the "evolution of man from molecules in the primordial soup."

When we speak of evolution in biology, any of several definitions may be implied. Some definitions are not problematic. For instance, evolution is commonly defined as simply "change over time." This definition is non-controversial, as no one would disagree that the living world looks different now than it has in the past. Another well-accepted definition is "minor genetic variation," otherwise known as microevolution. Typical examples of microevolution include drug-resistance in bacteria and variations in domestic animal breeding. While there is evidence that these minor genetic variations can produce changes within species, microevolution has not been shown to produce the new body plans and parts that would be needed if life evolved from simple to more complex forms of life.

When biologists talk about the theory of Darwinian Evolution (or macroevolution), they have a specific definition in mind. This overall claim has generated vigorous scientific controversy for over a century:

When Charles Darwin published his 1859 book, The Origin of Species, he proposed to explain something that nobody else in the history of the world had been able to explain before, i.e. how the great variety and complexity of the living world might have come about solely by random chance and undirected natural forces. Since Darwin, evolution has become one of the most influential theories because, as its proponents tell us,

The theory of evolution is controversial, however, because it claims to provide a completely naturalistic explanation of who we are and how we got here. What do we mean by "naturalistic?" We mean that all the phenomena we see around us - including life - are the result of nothing more than chemical and physical processes and the operation of natural laws and blind chance. Stop and read that again! By "naturalistic," we mean that everything that we see around us in the universe and the living world is simply the result of chemical and physical processes and the operation of natural laws and blind chance. Any intelligent cause for the origin of life is not only considered superfluous, it is disallowed as a possible explanation right from the start. According to naturalistic theories, the origin of life and its diversity can be accounted for solely by undirected, unguided natural processes.

George Gaylord Simpson, a leading evolutionist who has written the influential book, The Meaning of Evolution, gives some insight into the application of naturalistic thinking to the theory of evolution. He says,

Douglas Futuyma, author of a college-level text entitled Evolutionary Biology, says in his preface to the student,

Futuyma comments on the revolution that this way of thinking has caused in Western thought, and then compares evolution to its apparent arch-enemy, divine creation, in a summary statement in the first chapter of the book:

Almost every current biology education book assumes evolutionary biology as its central dogma, and most of them contain statements reflecting the naturalistic presumptions of biology (with accompanying comparisons to theistic views of origins), similar to the quotes above.

Evolutionary scenarios for the development and diversification of life on earth are thus based on naturalistic hypotheses. The two primary hypotheses are (1) chemical evolution (the origin of life), and (2) Darwinian evolution (the origin of the diversity of life. This simply means that a naturalistic assumption underlies all evolutionary explanations, i.e. the assumption that matter and energy are the only realities. All explanations for where life came from must therefore be attributed to the material elements of the universe as they operate within natural law, or to random chance events occurring within the chemical and physical framework of the universe. Thus, natural law and chance are the causal agents for everything, including the origin of life.

The naturalistic assumption is problematic for science in two ways. First of all, no matter how much evidence is brought against it, the assumption cannot be contradicted or challenged because modern scientists have defined science itself in terms of the naturalistic assumption. This is why we find definitions in state science standards (for example, Kansas) that read: "Science is the human activity of seeking natural explanations for what we see around us in nature." The naturalistic assumption has become a tautology which requires acceptance, and thus cannot be contradicted or challenged. Anyone who attempts to refute it is dismissed as operating outside the domain of science. Secondly, the naturalistic assumption is problematic for science (and for science education) because it is usually not disclosed. Consequently, sometimes even scientists within the scientific community do not appreciate its effect on studies of the origin of life, and students in public education are not taught about its use. This failure to disclose the naturalistic assumption is like a major corporation failing to disclose a hidden capitalization of billions of dollars of expenses, thereby deceiving its investors into believing it was making a profit while it was hiding real expenses.

Section Four:
The Historical-Experimental Distinction

In order to understand why the naturalistic hypothesis is controversial in origins science, whereas it is foundational to arriving at true explanations for how things work in real time, we need to examine the difference between historical sciences and experimental sciences. With historical sciences, scientists study events that have happened in the past. With experimental sciences, scientists conduct experiments in the laboratory or in the natural world, in real time.

Historical sciences attempt to find the best explanation for events that have happened in the past. Finding the best explanation for past events involves postulating multiple competing hypotheses to account for the evidence left by historical events, and then examining the evidence objectively to demonstrate which hypothesis provides the best explanation. If scientists rule out all but one hypothesis from the start, and then consider only the evidence that supports that hypothesis, they will likely ignore critical evidence that might challenge their conclusion. This may lead to erroneous conclusions about events that have happened in the past.

Historical science includes hypotheses in fields such as astrophysics, planetary science, evolutionary biology, paleontology, archaeology, and forensic pathology.

Experimental (laboratory) sciences attempt to find the best explanation for processes that can be observed in the present. To do this, laboratory scientists focus on a single hypothesis (or set of mutually compatible hypotheses) and then attempt to confirm or disprove that hypothesis by conducting controlled experiments and/or observations. Their experiments are designed to explore the causal factors (variables) that could confirm or negate the hypothesis. When laboratory scientists study different processes in nature, they purposely restrict their observations to natural explanations, because they want to be able to describe and understand the chemical and physical processes that they are studying.

Experimental sciences include chemistry, biochemistry, physiology, cell and molecular biology, embryology, and genetics.

Experimental science is thus concerned with describing what is happening in biological processes, i.e. how things work.

Historical science, by contrast, is concerned with explaining how those processes or evidences came to exist in the first place, i.e. how things came to be.

These are two completely different questions, requiring fundamentally different methods of study in order to arrive at reasonable answers.

Because the science of origins attempts to answer the question, "Where did life come from?" it is necessarily a historical science, rather than an experimental science. In an article from Scientific American in July 2000, the eminent evolutionist Ernst Mayr agreed. He states in the article,

Ernst Mayr is correct when he says that scientists who are studying historical events cannot do experiments to recreate what happened, but instead they try to understand past events by constructing hypothetical scenarios. If this is the method by which scientists seek to answer the question, "Where did life come from?", then the only way to arrive at the best answer is to consider multiple competing hypothetical scenarios. But evolutionary biology does not do this. It assumes one story from the outset and then rules out all others from consideration. Evolutionary biology operates on an assumption that life came about by purely natural causes, and it purposely excludes from consideration any competing hypothesis that involves intelligent or supernatural causes (see earlier quote from Futuyma).

This assumption allows only one story: a "historical narrative" that explains the origin of life by purely natural processes, using a naturalistic assumption. This is not objective science, but if this assumption were at least admitted or disclosed freely in biology textbooks, it would be honest. Disappointingly, this naturalistic assumption is rarely revealed or discussed; it is simply assumed to be true. The scientific community is well aware of this "unwritten rule," but this assumption is seldom explained to the student and nonscientific reader. Without considering other scientific hypotheses, particularly those that postulate intelligent design as a potential explanation for the origin of life, evolutionary biology becomes simply "storytelling" in the name of science. But this is not objective science.

Section Five:
The Evolutionary History of Life on Earth

Let us review the story of life's origin, according to evolutionary theory.

According to evolutionary scenarios, living organisms arose from nonliving matter via a series of chemical and physical "synthesis" reactions on the early earth. The idea is that simple chemical compounds reacted to form increasingly complex molecules until at some point in time, a "replicating molecule" appeared. The chief characteristic of this replicating molecule was its ability to reproduce itself. As it reproduced, mutations occurred. Mutations are random changes in the sequence and composition of the chemical components of the molecule. Through many generations, enough mutations occurred that diverse replicating molecules were formed. Eventually, through a process that science has yet to identify precisely, the first cell came into being.

Once the first cell appeared, the process of biological evolution began. Through further mutations and biochemical processes, eventually multi-cellular organisms appeared, and these diversified into various species, genuses, and families, etc. After the lower divisions of plant and animal life diversified, the higher divisions appeared, eventually culminating in the phyla in the animal kingdom (plural for phylum, the technical name for the major groups of organisms in the animal kingdom) and divisions in the plant kingdom. As living organisms multiplied, natural selection weeded out the less survivable organisms and allowed the stronger members to flourish. In this way, with no need for intelligent input (i.e. design), all of the plants and animals that have existed on earth came into being by purely natural processes. According to this scheme, chemistry and physics, natural law and chance are responsible for the development and diversity of life. The evolutionary "branching trees" that appear in biology books, showing different groups of animals as they are hypothetically related to common ancestors, are derived from this fundamental dogma.

If you look at virtually any biology textbook today, this basic scenario is presented as THE scientifically accepted story of the origin of life. What's wrong with this picture?

Section Six:
Replicating molecules, DNA, and the "biological language"

Let's go back to the "replicating molecule" mentioned in the early evolutionary scenario. Scientists do not know exactly what that molecule might have looked like, but we do know what a "replicating molecule" looks like today. This molecule (Figure 1), which is able to reproduce itself and direct the development of life, is called DNA (deoxyribonucleic acid). DNA contains coded instructions for assembling the proteins that our cells use.

DNA has a double-helix structure, with two strands that wind around each other. Think of it as a ladder that has been twisted into a helical shape (Figure 2). A ladder has two vertical struts and a number of horizontal rungs. Similarly, a DNA molecule has vertical "struts" and horizontal "rungs."

The vertical "struts" of DNA are composed of chemical units called "sugars" and "phosphates." This "sugar-phosphate backbone" functions as the support structure for the molecules that make up the rungs. Each of the horizontal "rungs" of DNA is composed of a pair of chemical units. One unit of each pair is attached to one "backbone" strand of the helix, and the other unit of each pair is attached to the other "backbone" strand. In the DNA molecule, there are a total of four different chemical units, which pair up as the "rungs" of the ladder. Scientists have named them A, C, G, and T. These letters are abbreviations for their chemical names (Adenine, Cytosine, Guanine, and Thymine). When they are arranged on the backbone strands, these letters tend only to pair up in combinations of A with T, and C with G. (Figure 3).

The letters A, C, G, and T are like the alphabet of the cell. If we think of the English alphabet as having 26 letters, we can think of the alphabet of DNA as having just four letters or symbols. When we speak or write English, we put the 26 letters together in various sequences to form words. When the cell speaks its own biological language, which we will call "Cell-ish," it puts the four letters (A, C, G, and T) together in various sequences to form biological words.

In our English language, words have meaning to us, and some words act as commands or instructions. When we receive instructions, we carry out the actions demanded by the instructions. The same thing happens in DNA. The DNA double-helix is millions of "units" or "letters" long. The "letters" are arranged in segments of DNA, called genes. The genes function like "words" in the cell's biological language. We can think of the genes as "words" and "sentences" in the "Cell-ish" language. A biological "sentence" that codes for the production of a single protein might be 300 to 30,000 "letters" long!

Each gene is composed of a sequence of "letters," which is a particular combination of the letters A, C, G, and T. Just like in the English language, the sequence of the letters in "Cell-ish" spells biological "words." These "words" are like instructions that tell the cell to build a large molecule called a protein.

Proteins are composed of long chains of amino acids arranged in specific sequences. Because of the specific sequence of amino acids that make up each protein molecule, it folds up into a specific shape that makes it capable of biological activity. The sequence of amino acids that compose each protein is determined by the coded instructions on a specific segment of DNA. Protein molecules play important roles in all of the body's functions, such as digestion, breathing, blood circulation, immune response, and reproduction. Proteins are the molecules that "get the job done" to keep us alive, and DNA is the "blueprint" for building proteins.

From this brief description of the DNA molecule, you can see that it is very complex in its structure. But the most important aspect of DNA is that it carries instructions for the cell. These "instructions" are very specific, because they tell the cell how to build the thousands of proteins and other molecules that your body needs in order to live. The vast amount of information stored in the DNA molecule makes it by far the most compact information storage/retrieval system known to mankind.

The "words" that are formed by the sequence of "letters" on the DNA backbone are, in biological terms, like the words that compose this document. We could jumble up the letters, and this paragraph would be meaningless. It takes a very specific grammatical construction to communicate the meaning in this written message. Furthermore, the "language" of this writing must be understood by both the writer and the reader in order for communication to happen.

Similarly, the letters on the DNA backbone have to be arranged in specific sequences to form all those biological "words," to give the cell its instructions. Furthermore, the instructions have to be understood by both the gene (the "sender") and the cellular components that receive the message. Without these basics, communication in the living cell doesn't happen, and hence, biological functions do not happen either.

If we are to answer the question, "Where did life come from?" it is not enough to simply describe chemical reactions and processes, nor is it enough to decode the sequences of chemical "letters" in the human genome. As we mentioned earlier, experimental science can tell us how things work and describe events in the biological world as they happen. But if we are interested in knowing where life came from, then we must know the answer to a more specific question. Since many life processes are orchestrated by the coded instructions contained in the DNA molecule, the real question is, where did the instructions (i.e. information) come from?

Scientists have been unlocking the mysteries of DNA since 1953, when Francis Crick and James Watson (Nobel prize winners) first described its molecular structure. The physical structure of DNA is enormously complex, and scientists have no idea how such a molecule could have physically originated by natural processes alone. But the real mystery lies in the origin of the coded instructions on the DNA molecule. These instructions are of a fundamentally different nature than the physical molecules on which they are carried. The molecules and chemical reactions are material (i.e. physical) in nature. But the instructions are non-material. The instructions are carried by the chemical components of DNA, but the instructions are not physical entities. The instructions cause the molecules of our cells to do specific things, so they can obviously influence and affect the physical world. But the instructions are non-physical, non-material.

To illustrate this concept in more familiar terms, let's compare a simple command in English with a simple command in "Cell-ish," (the language of the cell).

Here's a command in English. Let's say that you get a sudden craving for something sweet, and you decide that a chocolate chip cookie would do the job. So you think,

"Go to the kitchen and get a chocolate chip cookie."

Notice that you start with a thought in your mind, and you have a purposeful intention to carry out some action related to that thought. This activity of formulating thoughts is mental and intellectual; it grows out of your personal will and intention. Notice also that the activity of generating a thought is non-physical. True, it expresses itself in brain waves and nerve synapses, but the initial thought is generated by something intangible, which we call our will.

Now let's say that you want to communicate this command to someone else, so they can get the cookie for you, because you're busy watching TV. The next thing you do is to say this sentence verbally to share your thought with another person (who presumably understands the English language). Your communication, which originated as a thought in your mind, must be carried by some physical entity, so you use words traveling through the air as sound waves. If you were communicating through written means, then the physical carrier for your message might be ink on paper or pixels on a computer screen. The physical means of transferring the thought from your mind to the receiver's mind is the chemical and physical part of the communication. But the instruction - the thought that originated in your mind and will - is non-physical, i.e. mental and intellectual.

Now let's see how this applies to DNA. After you've eaten the chocolate chip cookie, your body needs an enzyme (a protein molecule that helps chemical reactions go more quickly) to start digesting the sugar in the chocolate chip cookie you've just eaten. The "biological thought" which starts the process of making the enzyme would be something like this:

That's a simplified version of the command, of course, but you can see that this purposeful "biological thought" or "instruction" precedes the action that the molecules of your body take in order to start digesting the chocolate chip cookie. The biological thought, like your own thought, is the non-physical part of the process. The physical part starts when the chemical components respond to the command and begin assembling the enzyme.

Now the question is, where did the biological thought come from? Clearly it precedes all of the chemical reactions that take place to assemble and transport the enzyme. And clearly, it expresses prior knowledge of the process that needs to occur, and it demonstrates a will to make that process happen. This mental, intellectual aspect of life cannot be reduced to mere chemical and physical processes.

The origin of the instructions in DNA is the great mystery of biology. At present, scientists do not know where the instructions in DNA came from. In our human experience, generating instructions is always the activity of a conscious, purposeful, intelligent agent. It is at this level of biological function that scientists are seeing evidence for intelligent design in the origin of life. This is where evolutionary theory neglects an important piece of evidence in its attempt to explain the origin of life. Evolutionary theory is naturalistic, and therefore appeals exclusively to matter and energy (chemical and physical processes) as sources for the origin and function of life. And yet, clearly we have another fundamental reality at work not only in the complex processes of living organisms, but in the origin of life itself. This fundamental reality is called information (i.e. instructions). As we have seen, biological information (the instructions encoded in DNA), like human thoughts and will, transcends chemistry and physics.

This brings us to a quick review of the four fundamental realities or entities in our universe. We have matter and energy, which are physical realities. And we have information and will, which are non-physical realities (i.e. mental, intellectual, spiritual). Any theory of the origin of life that fails to acknowledge all four of these realities is at best incomplete, and at worst fundamentally mistaken about the nature of life.

Section Seven:
Molecular Machines

When Charles Darwin published his revolutionary book, The Origin of Species by Means of Natural Selection (subtitled Or the Preservation of Favored Races in the Struggle for Life), he proposed to explain something that nobody else in the history of the world had been able to explain before: how the great variety and complexity of the living world might have come about solely by undirected natural processes and laws. His mechanism for explaining this was natural selection acting on the random variation in populations of organisms.

What is natural selection? Ernst Mayr, one of the towering figures in the history of evolutionary biology, describes it as follows:

Darwin observed that all living species on earth showed a certain amount of variation in their physical attributes. Some members of a species were bigger than others, some were faster, and some were brighter in color. Darwin also knew that the available food supply was limited and would not support all of the creatures that were born. So he reasoned that the individuals whose chance variation gave them some advantage in the survival game, would survive and reproduce. If the genetic variation of these successful individuals could be passed on to their offspring, then over time these individuals would predominate, and the characteristics of the species would change. And over great periods of time, perhaps great changes could occur.

It seemed like an elegant idea, and many scientists in Darwin's time quickly saw that it could explain many things (for instance, why certain individuals or species die out and why others survive). But others were skeptical that it could explain everything. Some scientists suggested examples of organs and systems that they thought Darwin's theory could not explain, and Darwin tried to counter these examples. But at one point in his book, The Origin of Species, he did say what could upset his theory. He wrote that,

Now it could be argued that Darwin was asking his opponents to do something which is essentially impossible in science, i.e. to prove a negative, to show that something could not possibly have happened. Nevertheless, it is certainly reasonable to take him at his word and ask, "Is there any organ or system in the biological world that looks like it might not have been produced by 'numerous, successive, slight modifications?'" In other words, what kind of a system looks like it might be a challenge to Darwin's idea of natural selection?

Michael J. Behe (pronounced "Bee-hee"), a biochemist at Lehigh University in Pennsylvania, has written a book that addresses this question. In his book, Dr. Behe describes some of the biological systems that he thinks might pose a challenge to Darwin's idea of natural selection. The book is called Darwin's Black Box, referring to the idea that in Darwin's time, the cell was essentially a "black box" to scientists. They knew it existed and that it did interesting things, but the inner workings of the cell were essentially unknown to them. In the past century, however, great strides have been made in understanding the cell's machinery and functions, and we now have a great deal of knowledge about how it works at the biochemical level. We now know what many of the molecules of life do. A whole new level of complexity, of which Darwin knew nothing, has been revealed by modern science.

So what kind of a system might pose a challenge to Darwin's idea that increasingly complex systems arise by natural selection acting on random variation? Dr. Behe proposes that a system which has the property of irreducible complexity might be a big difficulty for Darwin's theory. Putting this into descriptive terms, Dr. Behe explains:

As a simple example to illustrate this concept, Dr. Behe points to a household mousetrap (a single system), which is made up of a wooden platform, a metal hammer, a spring, a holding bar, a sensitive catch for the bar, and assorted staples that hold the parts together. (Figure 4)

These interacting parts contribute to the mousetrap's function, which is, of course, to kill the little rodents before they get too comfortable living in your pantry.

Each part of the mousetrap is essential to the intended function of the trap, and without any one of the parts, the trap ceases to function as a mousetrap (though some enterprising critics, having rendered it useless as a mousetrap by removing some of its parts, have nonetheless found other creative uses for it, e.g. as a tie clasp).

Well, mousetraps make interesting examples in the world of man-made objects, but what about biological systems? Are there any systems in the world of living organisms that have the property of irreducible complexity? It turns out that there are many of them, and Dr. Behe describes one system in particular that clearly illustrates the difficulty of explaining its origin by natural selection and Darwin's process of "numerous, successive, slight modifications."

As "Exhibit A," Dr. Behe points to the bacterial flagellum, a system composed of an inboard motor that is connected to a whip-like tail structure on a single-celled bacterium, which enables the bacterium to propel itself towards a food source through watery environments (such as your body) where it lives. (Figure 5)

Examining the structure of the flagellum at the point where it is connected to the back end of the bacterium (Figure 6), we can see that it is composed of many different parts (proteins) that have specific shapes related to their function. Each of the 40 or so parts is necessary for the function of the whole system, and if any of the parts is not formed properly while the cell is building this propeller system, then the whole thing fails to function.

The bacterial flagellum includes a rotary motor that spins around at speeds of 6,000 to 17,000 rpm. Even more remarkable, it can change direction in as little as a quarter turn, and then spin 17,000 rpm in the other direction. The long "propeller" whips around and pushes against the water to propel the bacterium forward. The propeller is attached to the "driveshaft" by a structure known as the hook region. The "hook region" acts as a "universal joint," allowing freedom of rotation for the propeller. The driveshaft is attached to the "motor," which uses a flow of acid from the outside to the inside of the cell, in order to power the turning of the motor. While the driveshaft and propeller are turning, the machine itself has to be kept stationary in the bacterial membrane, just like an inboard motor has to be kept stationary on the boat. And that is the job of a couple of rings of proteins called the "stator." The driveshaft has to poke up through the bacterial membrane, so there are some other proteins that act as "bushing" material.

Although this looks complex, there is much more to the story. Thorough genetic studies have shown that about 40 different types of proteins are necessary for the flagellum to function in a real cell. About half of those are components of the flagellum itself, and another 20 are needed to put this system together in the cell, to construct it in the cellular membrane.

The Random House dictionary defines a machine as an apparatus consisting of interrelated parts with separate functions, used in the performance of some kind of work. The bacterial flagellum, by this definition, IS a machine. It's not just LIKE a machine, it's a REAL machine. It is a marvel of engineering on a miniaturized scale, perhaps the most efficient machine in the universe. Since its discovery, scientists have tried to understand how a rotary motor could have arisen through natural selection. As yet, they have failed to offer any detailed Darwinian explanation.

So if not a Darwinian explanation, then what might account for the origin of a living "machine" as efficient and complex as the bacterial flagellum?

Recall our earlier discussion of historical versus experimental sciences. Whenever we ask the question, "where did life (or in this case, some aspect of a living system) come from?" we enter the realm of historical science. When we do that, we must consider multiple competing hypotheses and then look at the evidence to see which hypothesis best squares with that evidence. If Darwinian mechanisms have thus far failed to explain the origin of the flagellum, what might be a logical competing hypothesis?

Some scientists are beginning to look to intelligent design as a more likely explanation for the origin of complex features like the bacterial flagellum in living systems. Intelligent design theory hypothesizes that where we see structures that have high information content and "specified complexity," it is more reasonable to attribute the origin of those structures to purposeful design by an intelligent agent, than to the purposeless natural processes of chance and the forces of chemistry and physics. (Behe's "irreducible complexity" is one type of "specified complexity.")

A useful way to think of this is in terms of the similarities between living systems and man-made machines. When we compare the similarities between two different objects or entities, and then, based on those similarities, we infer probable further similarities, we are using an analogy. An analogy is a useful tool (though not a positive proof) for situations that involve historical reconstructions. As we have seen, the science of origins is an historical science, meaning that we are looking at evidence in the present to help us discern what might have happened in the past. We are looking at life in the here-and-now, and trying to figure out how it got here.

In this case, we might look at a comparison of a man-made machine (an inboard motor) and a biological machine (the bacterial flagellum), and use the analogies between the two in order to make a logical inference about the origin of the bacterial flagellum. An inboard motor, as we all know, is the product of human engineering. If you trace the production of an inboard motor back to its origin, i.e. back in time through the assembly of parts, the fabrication of the parts, the design drawings of the parts, and the mathematical calculations for horsepower requirements, etc., you will find that the inboard motor began as a thought or a picture in the mind's eye of the engineer who designed it.

Eugene Ferguson is an engineer who writes about the visual, nonverbal process that is the essence of engineering design. He talks about the impact of technology on our lives and helps his readers to understand the importance of nonverbal thought in engineering. In his book, Engineering and the Mind's Eye, Ferguson makes the following comment about the means by which engineers envision the products they design:

He goes on to explain,

Ferguson is saying here that natural processes (thermodynamics, in this example) are not the explanation for engineered objects. Not even mathematics and theories, as elegant as they are, can assemble a motor. The whole process begins as a picture in the mind of a designer, who then uses his knowledge of natural laws, mathematics, and theories to help him construct the object he has envisioned in his mind.

It is obvious how this applies to an inboard motor on a boat, but how does it apply to our bacterial flagellum? Here we have a living system that completely upstages the finest inventions of mankind, in terms of its miniaturization, its performance specifications, and its fabrication and assembly (after all, it reproduces itself!). How are we to most logically explain how it got here? Admittedly, Darwinian processes have failed to provide a reasonable explanation. Must we confine our search to natural laws and chance, when in the case of human engineering we have an applicable analogy?

Darwinian scientists insist that we confine our explanations to natural processes, even when things appear to have been the product of intelligent design. Richard Dawkins, author of the popular book, The Blind Watchmaker (subtitled Why the Evidence of Evolution Reveals a Universe without Design) makes the following comment in the first chapter of his book:

And then he writes the whole book to explain why there is no designer, there is no engineer, and there is no architect of the living world.

Now, every engineer knows that a project begins with a Request for Proposals - the RFP. In the RFP, the client specifies exactly what he needs to have the system do (the performance specs), along with timeframe, budget, and other considerations. If we look again at the bacterial flagellum, what might an RFP for this machine look like? We could put this in the form of a "biological thought" such as we used for the sugar enzyme in the chocolate chip cookie illustration earlier. Expressed this way, the bacterium might submit this Request for Proposals for its means of propulsion:

Now the problem here is quite obvious. As we saw in the sugar enzyme example earlier, the bacterial flagellum also is front-loaded with an immense amount of information (instructions). It is a complex system that appears to have required a very sophisticated "biological thought" preceding its construction. Is this evidence for design, or evidence for naturalism?

Darwinian evolution says that natural selection can account for how a machine like this can be built up gradually by "numerous, successive, slight modifications" from precursor systems. In theory, this may be possible. But evolutionary biology has yet to suggest - let alone demonstrate - a convincing progression of steps by which simpler precursor systems might have eventually evolved into a bacterial flagellum.

Now let's pose a practical question. From an engineering standpoint, what would an engineer have to do if he was given the unenviable assignment of designing and constructing a bacterial flagellum? Well, assuming that he was given a comprehensive RFP so that he knew the performance specifications, he would then develop a mental picture of the needed machine, convert his mental image to some sort of design drawings, work the calculations, write his specifications for the fabrication and assembly of parts, and coordinate with the manufacturer, who would manipulate components from the environment to construct it. And that's the simplified version! This bacterial flagellum is so complex and so miniaturized that at this point in time, it completely defies human ingenuity to design and construct it. And lest we lose sight of the bigger picture, we must remember that the flagellum is just part of a larger system that reproduces itself. Here we have a design problem that makes an inboard motor for a boat look like a kindergarten project.

So a logical question to ask is this: how could nature ever produce a bacterial flagellum? Could this feature be produced naturally, without intervention by an intelligent, master engineer? That is the subject of our next section.

Section Eight:
New Feature-Producing Agents

From nature shows in the popular media to biology curricula, the theory of evolution is presented as fact. Sometimes subtly, and often overtly, we are told that evolution has the ability to completely explain the origin and diversity of life. But let's think about the kinds of evidence that would actually confirm evolution as fact.

One part of the theory of evolution has truly been well demonstrated: Natural selection tends to preserve features that enhance a species' ability to survive. Experiments confirm what basic logic tells us. If you have a group of living things, and there are differences between the individuals in the group that improve the ability of some individuals to survive and leave offspring, then the group as a whole will improve in its ability to survive. For example, if a herd of zebras contains some individuals that can run faster than others, and the herd is repeatedly chased by lions, the lions will tend to catch and kill the slower zebras. The baby zebras that become the next generation might tend to be quicker, since it was their quicker parents who survived the lions. And so, without any designing hand or intelligence, the overall survivability of the herd will be improved.

But if life evolved according to the evolutionary scenario (see Section 5), then naturalistic mechanisms - such as natural selection - must also provide an explanation for the appearance of all the new characteristics and features of organisms that have evolved since the first cell in the primordial soup. Features such as fins and scales, lungs and heart valves, and wings and feathers had to originate by some process. It is one thing to explain how natural selection determines the individuals or groups that will survive because they have certain advantageous features. It is another thing altogether to explain how those features came about in the first place.

As we saw in the bacterial flagellum example, scientists have not provided a Darwinian explanation for how natural selection could have produced such a feature by "numerous, successive, slight modifications" to some precursor system. Natural selection acts more like a gardener pulling weeds out of a garden than like a landscape designer creating the garden to begin with. Natural selection does not add anything fundamentally new to a system. It simply selects the fittest individuals for survival, and the less fit for extinction. Too often, however, popular teaching on evolution points to evidence of natural selection, and then assumes that it has just explained all the diversity of life. Evolutionist Richard Dawkins, in his book The Blind Watchmaker, reflects this faith:

But how does natural selection create new species? In addition to natural selection, evolutionary theory needs a mechanism for producing increasingly complex systems. As engineer-author Dr. Walter L. Starkey terms it in his book, The Cambrian Explosion: Evolution's Big Bang or Darwin's Dilemma, a "new feature-producing agent"¹⁴ is needed. This new feature producing-agent needs to be able to change one kind of living thing into others. And here is a key requirement that is often overlooked: evolution's new feature-producing agent must be capable of constructing all living things from earlier ones through an unbroken line of intermediate forms, each of which must work well enough to survive and reproduce.

Today, evolutionary theory claims that genetic mutation is its primary new feature-producing agent, and that small, accidental mutations are capable, over many generations, of gradually changing one type of living thing into a very different kind, with each step along the way being an improvement. Mutations are accidental changes to the DNA of an organism. Assuming that the mutations are beneficial to the organism, these mutations can be passed on to the next generation. Let's consider what is known about mutations, and whether or not genetic mutation is the new feature-producing agent that evolution needs.

Segments of DNA are a bit like an English sentence, as we noted earlier in Section 6. Just as you can rearrange the 26 letters in an English sentence to communicate a different thought, so you can rearrange the sequences of the four chemical "letters" (A,C,G, and T) that are bonded together in DNA to "spell" a different meaning (construct a different protein). Let's consider the implications of this analogy as it relates to the capabilities of mutation to produce new features. Just as with sentences, so it is with DNA: you can sometimes change one letter and the sentence is still valid, but in other cases, a change of just one letter makes the whole sentence invalid.

Suppose you were given the first sentence below, spelled out on a chalkboard, and then you were asked to change the first sentence into the second one, changing one letter at a time:

In approximately nine steps, or "mutations," you could change the first sentence into the second by replacing some letters and adding others. However, each "mutation" would not produce a sensible sentence. Only when the final arrangement of letters is reached does the new sentence makes sense. But that is not biological evolution. Evolution faces the requirement that as each accidental change is made to the "letters" in a genetic sequence, the result is a viable sequence that successfully codes for another protein, (so natural selection will preserve it). What happens to something whose DNA has become invalid? It is sick, damaged, or dies. It is removed by the gardener, natural selection, and is an evolutionary dead end.

So here is the question: can you transform the first sentence into the second one by a series of steps in which you replace, delete, or add just one letter, leaving a valid sentence at each step? Try it!

What we see from this and other analogies (like computer software programming) is that complex systems are incapable of unlimited, gradual change. Sure, you can make minor modifications, but to change one sentence into something very different, you have to change many things at once. If you are a clever computer software programmer, you can design systems that can do a range of different things by varying parameters to the program. But accidental, small changes to a computer program will never change your word processing program into, say, a tax preparation program. To do that, many changes to the information in the program must be made at once.

Is there any evidence that mutations are capable of changing many of the "letters" of DNA at once in order to produce brand new functionality? What we know of mutations confirms what these analogies tell us. Many accidental changes to DNA are neutral in their effects on the individual. Of the rest, the harmful mutations far outweigh the helpful mutations. Those that are helpful tend to be minor adjustments to existing systems. Making large-scale, random changes at once is consistently harmful.

To produce new functionality, evolution needs a new feature-producing agent capable of jumping the vast distances between one type of living thing and another, and evolution does not have such a new feature-producing agent.

Scientists have much yet to learn about DNA, and there is much more that could be said about the research that is currently underway in information theory, statistics, and the detection of design. But based on what we know today, the evidence for the appearance of new biological features supports the tentative conclusion that we reached in the sugar enzyme and bacterial flagellum examples. The high degree of information that is needed in living systems suggests that intelligent design is a more likely explanation for their appearance than purposeless, random natural processes. Chance mutations and natural selection may provide a good explanation for survivals and extinctions, but they do not provide a very reasonable explanation for the appearance of new, increasingly complex features that make survival possible. Certainly our teaching on evolution needs to include an accurate presentation of what we do and don't know about its new feature-producing agent.

Section Nine:
The Evidence for Macroevolution

Thus far we have looked at three powerful challenges to the naturalistic evolutionary theme. In Section 6, we examined the coded instructions and information carried by the DNA molecule. In Section 8, we considered molecular machines such as the bacterial flagellum. In Section 8, we tackled the question of how new features might have arisen from simpler ancestral organisms by genetic mutation and natural selection. In each case, we have seen that scientists have either no explanation, or at best problematic explanations, for the origin of these entities by naturalistic processes. Surprisingly, these problems are rarely, if ever, addressed in the biology textbooks that our children study in the classroom.

Instead, as we discussed earlier in Section 5, our children are learning that life originated and diversified by completely natural processes, and that every living organism on the earth today can trace its origin back to a common ancestor, perhaps even back to a hypothetical first cell. The central tenet of evolution is that all living things are related by descent with modification from a common ancestor. On what scientific basis does evolutionary biology make this claim?

Like any scientific theory, the theory of evolution requires evidence to support it. Darwin based his theory on three major categories of evidence: fossils, homology, and embryology. Modern evolutionary biology uses these major categories, and also includes evidence from biogeography (the distribution of plants and animals around the world) and biochemistry (the similarity of molecules such as DNA and proteins in all living organisms). Let's take a look at the scientific evidence for evolution from three basic categories:

• Fossils
• Homology
• Embryology

The purpose of the following discussion is to describe the evidence from each of these three categories as it is typically presented in classroom textbooks. In almost all cases, it is presented without challenge, in support of evolutionary theory. As we examine each category of evidence here, however, we will also do something that your child's textbook will not do: We will examine some of the scientific challenges to each line of evidence.

Why does your child's textbook not contain this challenging information? Because the national science organizations deny that any scientific challenge to evolution even exists. For example, the National Academy of Sciences makes this confident assertion in its 1998 booklet entitled "Teaching About Evolution and the Nature of Science,"

We shall take a closer look and see if this statement is reliable.

Long before Darwin's time, it was clear that fossils preserved the remains of extinct plant and animal species, as well as species that still exist. Two aspects of the fossil record tend to support evolutionary theory. One is that simpler, single-celled organisms appear in the fossil record first, and are followed by more complex multi-cellular life later on. This is what evolutionary theory would predict. The second is that for certain animal types (e.g. horses, elephants, and from recent data, whales) the record contains clusters of similar types which, according to the theory, suggest a common ancestry and therefore an inference of evolutionary origin from a common ancestor.

But if the theory of evolution is the correct explanation for the origin of all living things, then all living and extinct organisms were connected by unbroken sequences of transitional forms, each differing only slightly from those before and after it.

In order to understand the concept of "transitional forms," we need to know something about how biologists classify animals into hierarchies based on their similarities and differences. A century before Darwin, a Swedish taxonomist named Carolus Linnaeus invented a system of biological classification, which is still in use today. The species is the lowest level of the hierarchy, where we see the greatest degree of similarity between its members. As we move up the levels, from species to genus to family to order to class to phylum to kingdom, the members of these groups become more diverse and more different.

The following table and brief discussion are excerpted, with permission, from Dr. Jonathan Wells' book, Icons of Evolution (Regnery Publishing, Inc., 2000)

The accompanying table¹⁶ shows an example of how two different organisms, human beings and fruit flies, are classified according to the Linnaean system.

The phyla (plural of phylum) are the basic body plans of animal life.

And so on all the way up to the higher taxonomic levels, until the major animal body plans (the phyla) appeared.

Now let's return to our point about "transitional forms." According to Darwin's theory, we would expect to see in the fossil record a large number of organisms that would have been "transitional" between different levels of the taxonomic hierarchy. A transitional form is a species that exhibits traits from a common ancestor of that species and also traits that were not possessed by the ancestor.

When the fossil was discovered in the 1860s and 1870s, Archaeopteryx was hailed as a possible missing link that confirmed Darwin's theory.

This beautifully preserved fossil showed an ancient creature, believed to be about 140 million years old, that had wings and feathers like a bird, but unlike modern birds, it had teeth like a reptile (Figure 7). Now in the 21^st century, however, the role of Archaeopteryx as an evolutionary link between birds and reptiles is very much in question. Paleontologists now agree that Archaeopteryx is not an ancestor to modern birds. So this missing link is still missing.

Though Darwin's theory predicts that a large number of transitional forms would eventually be found, the fossil record contains surprisingly few examples of transitional forms. This fact was known to Charles Darwin, who wrote:

In Darwin's day it was thought that we simply hadn't collected enough fossils to find the transitional forms. However, a century and a half later, this explanation has become less and less credible.

In the 1980s, evolutionists Stephen Jay Gould and Niles Eldridge argued, as part of their theory of Punctuated Equilibrium, that we should openly acknowledge the nature of the fossil record. What we see in the fossil record are long periods in which the animal forms show little or no change (stasis or equilibrium). These periods of stasis are then "punctuated" by the sudden appearance of new forms. Gould and Eldridge have argued that, rather than looking for more fossils to fill in the missing transitions, evolutionists should search for different mechanisms for evolution that are capable of producing the sudden appearance of new forms.

While there are some fossils that share characteristics of different groups, the overall characteristics of the fossil record do not match what we would expect to see from evolutionary theory. Instead, as the noted evolutionist George Gaylord Simpson says,

In other words, whereas the theory of evolution would predict that there would be the strongest evidence for linking the highest level groupings (because they are the most dissimilar and would require vast numbers of transitional forms), the fossil record demonstrates the opposite...instead, the gaps between the higher-level groupings are universal and complete.

Not only is the fossil record lacking in the number of transitional forms that evolutionary theory requires, but the sudden appearance of complex, multi-cellular life is even more problematic for Darwinian "gradualism."

A chart of geologic time (Figure 8), as calculated by modern geologists and paleontologists, shows that although it is postulated that the earth is approximately 4.6 billion years old, for most of earth's history only primitive one-celled organisms have existed.

During the Cambrian Era, which evolutionary paleontologists say occurred about 540 million years ago, all of the basic animal body plans of life (phyla) suddenly appear in the fossil record. This "explosion" of complex, multi-cellular life comes after a long fossil history of some 3 billion years in which the fossil record contains almost entirely single-celled organisms. In the Cambrian Explosion, the major phyla appear without ancestors or precursors, and this is exactly backwards from the prediction of evolutionary theory.

If, as Darwin predicted, all animals were descended from a common ancestor, major differences in their form should appear LAST in the fossil record, after a long accumulation of differences in a large number of transitional forms. But in the Cambrian Era rock layers, we suddenly encounter highly complex organisms without ancestors or precursors. In Cambrian rocks found in Canada, Greenland, and China, we see examples of species from most of the major animal phyla. The Cambrian rocks have preserved such diverse animal life as crustaceans, segmented worms, echinoderms, platyhelminthes, arthropods, round worms, mollusks, and even primitive chordates. In what amounts to a geologic blink of an eye - maybe 5 to 10 million years - suddenly the major phyla appear at about the same time, fully formed, with very complex and sophisticated biological features. This event is so dramatic, and the fossil evidence so plentiful, that it has become known as "biology's big bang," or the Cambrian Explosion.

Darwin was aware of the Cambrian fossils, and he admitted that this phenomenon was at odds with his theory that life had evolved and diversified slowly through numerous transitional forms, from simple to complex and from species to phyla. This evidence caused him to remark in his book, The Origin of Species,

For over 100 years, paleontologists have searched for the ancestors of these forms without success. As Stephen Jay Gould puts it in his book on the Cambrian Explosion, called Wonderful Life, the Cambrian Explosion is exactly backwards from the prediction of evolutionary theory. Whereas evolutionary theory predicts a cone of increasing diversity, what we actually find is the greatest diversity at the beginning with refinements and extinctions after that, in what he calls the cone of decreasing diversity. He says this poses a problem for evolutionary theory:

When critics of evolution bring up this evidence regarding the fossil record, evolutionists object that they are using worn-out arguments and ignoring copious examples of transitional forms. But transitional forms are the exception, not the rule. And when certain fossils are claimed to be transitional, this interpretation is always open to question. The overall lack of "transitional" forms is at odds with the predictions of evolutionary theory as we understand it today.

Evolutionists often insist that such debates are only about "the tempo and mode" of evolution, not about its factuality. Critics of evolution rightly respond that the "mode" of evolution is precisely the issue. If we see the relatively rapid appearance of new forms, so that we are led to question whether the mutation/selection mechanism is sufficient to explain what we see, then we are indeed questioning the heart of evolutionary theory.

Such questions ought to be taught along with the theory, not hidden from the public view. And science ought to be free to consider alternative explanations for the sudden appearance of the major body plans of animal life, such as we see in the Cambrian Explosion. Rapid appearances of new forms are more consistent with a theory of intelligent design than with the theory of Darwinian gradualism.

For centuries, biologists have noticed that different organisms show certain similarities in their structure and form. This similarity of structure is referred to as homology, meaning same structure, or common anatomical structure. It is supposedly one of the most pervasive "evidences" for macroevolution.

The classic example of homology that appears in virtually all introductory biology books is the similarity of bone structure in vertebrate forelimbs. An illustration such as Figure 9 (next page) is usually presented, showing a bat wing, a porpoise flipper, a horse leg, and a human arm. The illustration may include other vertebrate forelimbs as well. Captions for the illustration typically point out that each forelimb is composed of similar bones in the same basic pattern, although the shapes of the individual bones differ. This unity of plan is then cited as evidence for a common ancestor.

In recent textbooks, charts of genetic similarity are also included, with the unavoidable implication that if certain organisms have a higher percentage of identical sequences in their DNA, they must be more closely related. Diagrams in these books show a series of modern animals with a comparison of their DNA. Those with higher percentages of identical DNA are believed to share a more recent common ancestor than those whose DNA is less similar. DNA studies, of course, are a 20^th century discovery of which Darwin knew nothing, but this evidence has now been incorporated into the evolutionary scheme as another aspect of homology.

After this concept of homology is introduced in biology textbooks, it is reinforced with other examples, showing how evolutionary biologists infer ancestral relationships based on the link between homology and common descent. Some of the most popular examples are the evolution of modern birds from extinct two-legged dinosaurs, the evolution of the horse from a primitive dog-sized animal, and the evolution of man from ape-like creatures.

Before Darwin, biologists thought that homologous features were derived from a common "archetype." An "archetype" might imply one of a number of concepts, from a plan in the mind of a Creator to a prototypical organism, but most biologists before Darwin's time regarded this structural similarity as evidence that these organisms were constructed on a common pattern or design, by a supernatural Designer.

By contrast, Darwin was firmly convinced that homology was evidence that these creatures had descended from a common ancestor. He argued in his book, The Origin of Species, that

On first consideration (which is usually all that an average student will give it), the connection between structural similarity and descent from a common ancestor seems logical enough. It is a powerful visual suggestion, especially given the human inclination to automatically infer relationships between things with similar shapes. Because the observation of structural similarities between different organisms seems obvious enough, the unsuspecting reader then accepts an additional supposition without much thought. The additional supposition, which is foundational to evolutionary theory, is that this structural similarity (homology) is proof of common ancestry. In other words, structural similarity and common descent go hand-in-hand...or wing-in-hand...or flipper-in-wing...or leg-in-flipper... or - well, you get the picture.

Sometimes biologists refer to "evolution" in technology as an analogy for evolution in living organisms. In his 1990 book, Evolution and the Myth of Creationism, Ohio State University biologist Dr. Tim Berra uses the so-called evolution of the Corvette to illustrate the idea of "descent with modification" (Figure 10).

Tracing the changes in Corvette models from 1953 to the present, he notes that,

But we all know that the "evolution of the Corvette" was the product of intelligent human designers. The names Zora Arkus-Duntov, Harley Earl, Ed Cole, Dave McLellan, and Dave Hill may not mean anything to Dr. Berra, but they are the designers and chief engineers for GM who made those transitional forms so famous. The so-called "evolution of the Corvette" was anything BUT the purposeless, unguided process that biologists assume for the "evolution of organisms."

In his book, Berra's example of Corvette evolution appears at the end of a chapter which is devoted to a discussion of the similarities in skull structure between fossil hominid species and modern humans. Unfortunately for Dr. Berra, in his zeal to show that homologies between apes and humans point to a common ancestor for both, he unwittingly throws a monkey wrench into his wheels. By capping off his discussion of ape-to-human evolution with a pictorial history of Corvettes, he reminds us that there are at least two possible explanations for homology. Homologies may be attributable to descent with modification from a common ancestor, but they might just as reasonably be attributed to the pre-Darwinian idea of design on a common archetype.

Clearly, intelligent design is the mechanism that explains why "homologous features" such as engines, transmissions, and differentials are found on different Corvette models. But what about living organisms? The mere appearance of homologous structures such as vertebrate limbs doesn't tell us how they got that way. A mechanism is needed to explain this appearance. In biology, intelligent design is ruled out by definition, of course, because evolutionary theory is committed to naturalistic mechanisms. But is it logical to rule out design as a possible cause for biological origins, or is this merely an imposed tautology?

According to modern Darwinism, the mechanism for the appearance of homologous structures is genetic. If certain structures in different animals are similar because they share a common ancestor, then theoretically those structures should be produced by similar genes, and they should go through a similar developmental process in the embryos. Therefore, genetic programs (genes) and developmental patterns are the Darwinian mechanism for production of homologous features.

But contrary to these predictions, biologists know that homologous structures can be produced by different genes and can result from different patterns of development.

Two examples will illustrate the difficulty of correlating genes with homologous features. In the first example, we have homologous structures that originate from different genes. In the second example, we have an identical gene that produces non-homologous structures.

In our first example of genes as a mechanism, biologists consider the body segments of fruit flies and wasps to be homologous. Darwinism predicts that these similar structures should be due to the same genes. But in fact, different genes direct the development of body segments in these insects. This contradicts the idea that homology is evidence for common ancestry.

In our second example of genes as a mechanism, biologists have noted cases where an identical gene accounts for NON-homologous structures. A gene called "Distal-less" (because a mutation in this gene blocks the normal development of limbs in fruit flies) is shared by several different types of animals. The Distal-less gene has been found in mice, spiny worms, butterflies, sea urchins, and velvet worms.

These five animals are in altogether different phyla, meaning that they are even more different from each other than the vertebrates in Figure 11. The Distal-less gene is involved in the development of appendages in all five of these animals, yet the appendages are not homologous either by similar structure or by common ancestry.

According to modern Darwinism, developmental pathways also provide a mechanism for the appearance of homologous structures. In this view, homologous structures should be produced by similar processes or pathways during embryonic development. But contrary to the theory, many body structures that are considered to be homologous go through fundamentally different developmental pathways.

One example is the gut in vertebrates (i.e., animals with a backbone). If Darwinian theory is correct, and the vertebrates share a common ancestor in the distant past, then the process by which the gut is constructed should also be homologous. But this is not the case. In vertebrates, the gut is constructed in very different ways during development. In sharks, the gut develops from cells in the roof of the embryonic cavity. In lampreys (eel-like fishes), the gut develops from cells in the floor of the embryonic cavity. And in frogs, the gut develops from cells in the roof AND the floor of the embryonic cavity. Thus, in each animal a very different developmental pathway converges to the same (homologous) structure, i.e. the gut. This is very difficult to reconcile with Darwinian common descent.

As you can see, the process of trying to determine common ancestry by homology is extremely difficult and subjective. We need some objective evidence! Of course, this whole question of ancestry could be settled if we just had a pedigree or a birth certificate for every fossil and living creature on the planet. But since we all know that this objective piece of evidence is unavailable for all but a small number of recent species (like dogs, cats, horses, and humans), scientists are left with a challenge. The challenge is to provide an objective standard for telling the difference between fossils and living organisms that merely resemble each other in some respects, and those that are in a genuine ancestor-descendant relationship. Obviously, no one is able to do this.

Nevertheless, because the connection between homology and common ancestry is so central to Darwin's theory, evolutionary biologists have found another way around these difficulties: they have simply tinkered with definitions. They have re-defined homology to mean features inherited from a common ancestor. For example, a discussion of homology in a popular current textbook tells us,

And in the same discussion,

In other words, common descent explains homology, and homology is evidence for common descent. This is circular reasoning (Figure 12)!

Philosophers of science have been criticizing this approach for decades. As Ronald Brady wrote in 1985,

Perhaps dogmatic endeavors of this kind never WERE in the realm of science. Perhaps they were in the realm of art, imagination, and persuasion right from the start. For so many decades, we have been presented with visual progressions of organisms changing into other organisms that now we seldom question these metamorphoses as evidence for evolution. (Figure 13). Is this because of overwhelming scientific evidence, or because evolutionists have a naturalistic story of origins to promote, they understand the power of a visual suggestion, and they employ artists to create compelling pictures?

We should be more discerning. If you came across a metamorphosis painting between a bird and an airplane, what would be your immediate thought? "Oh, look at the evolution!" Right? Think a little deeper. You know that the aircraft was designed by human engineers. And you know that, in spite of centuries of wishful fancy inspired by the birds, it wasn't until A.D.1903 that human beings had acquired enough knowledge and know-how to build a successful heavier-than-air flying machine. Airplanes are designed by intelligent human engineers.

So why do we believe the theory that birds, which are far more complex than airplanes, have "evolved" by purely natural processes from two-legged dinosaur ancestors (Figure 14)? Or that humans evolved from apes? Or that vertebrates evolved from a common ancestor?

Some Darwinists believe that a two-legged dinosaur such as this may have given rise to modern birds, hence the assumption of feathers on this reconstruction, which is based on reconstruction of Bambiraptor displayed at April 2000 Florida Symposium on Dinosaur Bird Evolution.

We believe it because the alternative possibility, design on a common archetype or pattern, is never stated or considered. In other words, the competing theory has been censored. We also believe it because of the power of visual suggestion. The constant message from homology is that if it looks similar, it must be related. But this is art, not science. More correctly, this is art in the service of a scientific theory that has no objective supporting evidence. In other words, we believe it because we've been duped by effective propaganda.

So your child trundles off to college and comes home four months later on break, after his first semester of biology classes. In an effort to show off his newfound knowledge, he confidently quotes this high-sounding phrase, "Ontogeny recapitulates phylogeny." You instantly beam with amazement that your young genius can sound so erudite, and for a moment you're convinced that your hard-earned dollars are, in fact, being well spent on his education. After your initial glow of satisfaction subsides, however, your curiosity overcomes your pride, so you ask tentatively, "What does that mean?" Your budding biologist then explains, trying not to sound too superior:

"Well, Mom, it means that embryos from different groups of animals look similar when they're going through their early stages of development because they had a common ancestor. 'Ontogeny' means the embryonic development of the individual animal. 'Phylogeny' means the evolutionary history of the species. So the individual animals pass through - or recapitulate - the forms of their ancestors as they develop, and then they become more like their own species in the later stages."

"Oh," you say, knowing only a little more now than you did before. "How do they know that?"

He pulls out his biology book and points to some drawings of vertebrate embryos (Figure 15). "See, you can tell that a fish, a salamander, a turtle, chicken, pig, cow, rabbit, and human all had a common ancestor because they look almost identical in their early stages. Darwin thought that this was some of the strongest evidence for his theory of evolution."

The drawing convinces you, or at least ends the discussion as far as he's concerned, and then he's off to your fridge to help himself to something other than dorm food.

If you sat down and studied his textbook for further information, you would learn that embryological similarities are used in biology books as one of the primary evidences for common ancestry. In newer textbooks, the drawings are usually replaced by photos of at least a few of the most similar-looking embryos from different classes of vertebrates (animals with a backbone). Embryos of a chicken, a pig, and a human are most often shown because they are more similar to each other at one particular stage of development than are other embryos. The photos are accompanied by captions that note the remarkable similarity of structures in these vertebrates at the "tailbud stage" of development. The suggestion is that they share these similar features because they evolved from a common ancestor.

This idea was originally illustrated by the German biologist/artist Ernst Haeckel (1834-1919), in his now-famous drawing, shown in Figure 15. Darwin considered embryonic similarities to be "by far the strongest single class of facts in favor of" his theory that these animals are the modified descendants of some ancient common ancestor. For over a century, despite an undercurrent of dissatisfaction in scientific circles, Haeckel's embryos have persisted in biology textbooks as evidence for common ancestry.

In 1997, an international team of experts published an extensive study of the embryos of various vertebrate classes. Led by British embryologist Michael Richardson, the team compared photographs of actual vertebrate embryos with the drawings done by Ernst Haeckel. The real embryos look noticeably different from Haeckel's stylized drawings.

Figure 16 shows an illustration comparing Haeckel's embryos with actual vertebrate embryos (based on the photographs by Richardson et al.)

Although Richardson's belief in the overall story of evolution is not shaken, he comments on the Haeckel's embryos situation this way:

Textbooks that have been published in recent years have begun eliminating Haeckel's embryos, which is good. Nevertheless, the concept of evolutionary relatedness through embryological similarity continues to be illustrated by selective photographs of the most similar embryos at their most similar stage.

But there is another important point that is overlooked in these textbooks. The stage of development that Haeckel illustrated is not the earliest stage in the growth of an embryo. Darwin based his inference of common ancestry on the belief that the earliest stages of embryonic development are the most similar. Yet scientists have known for a long time that different species are distinguishable from the very earliest stages all through development. If you look at the same set of embryos in the stages BEFORE Haeckel's first stage (i.e. earlier in their growth and development), you will see that embryos from these vertebrate classes look different, literally from the moment when the fertilized egg begins to divide.

Figure 17 shows a comparison of the early stages of development in embryos from five vertebrate classes. Reading the chart from the top down, the vertical columns show the development of a fish, a frog, a turtle, a chicken, and a human from the time when they are just one-celled fertilized eggs until they reach the so-called "tailbud" stage. The stages are (from top to bottom): fertilized egg; early cleavage; end of cleavage; gastrulation; and Haeckel's "first" stage. The fertilized eggs are drawn to scale relative to each other, while the scales of the successive stages are normalized to facilitate comparisons. From left to right, the embryos are a bony fish (zebrafish), amphibian (frog), reptile (turtle), bird (chicken), and mammal (human).

This chart shows three important stages of development between the time the egg is fertilized and the time it gets to Haeckel's so-called "first stage." At every stage, from the first cell division on, you can see that these embryos (fish, frog, turtle, chicken, and human) are very different in their development.

This fact is conveniently ignored in virtually every introductory biology book on the market. The reason is because this evidence challenges Darwin's idea that embryological similarities indicate common ancestry. Why not just tell the truth? Embryos are not most similar in the early stages, and biologists have known it since the late 1800s. Embryologist Adam Sedgwick pointed this out in 1894. He wrote,

Numerous researchers since then have pointed out the same observation.

Are we trying to support a theory, or teach our students how things really are? How long must the evidence from embryology be stifled, contorted, faked, and selectively presented in order to prop up a theory? Let's just tell our students the truth. Embryos from different classes of animals are different and clearly identifiable from the earliest stages all through development.

The evidence from embryology is NOT "by far the strongest single class of facts in favor of" Darwin's theory, if it requires that embryos from different animals look similar in their early stages as evidence that they share a common ancestor. Embryos from different classes of animals are different and distinguishable from the very beginning, i.e. the fertilized egg.

Having examined evidence from fossils, homology, and embryology, we can see that there is indeed a significant debate over the evidence for Darwinian evolution. What are we to do with this information? Should we expose our students to this critical examination, or not?

Section Ten:
How to Teach Biological Origins Objectively

In the previous section, we looked at three major areas of evidence and examined how biological origins is currently taught in introductory biology textbooks and courses. In our discussion, we presented evidence for evolution, and evidence that challenges evolution. However, all biology textbooks used in public schools teach origins from a purely evolutionary (Darwinian) perspective. Only evidence that seems to support evolution is presented, and alternatives (such as intelligent design) are either not covered or else are marginalized. In short, evolutionary theory is presented as "fact," and students are left with the impression that Darwinism has been proven to be true (as they say in court) "beyond a reasonable doubt."

The problem is not that evolutionary theory occupies a large part of the typical biology textbook or curriculum. Taking the 2002 Ohio Science Standards as an example, in Grade 10 biology the "Evolution Theory" section occupies only about 20% of the total material. And most of the material in the Evolution section deals with well-accepted microevolutionary concepts (minor genetic variation). Overall, the troublesome macroevolution part (common descent) is only about 5% of the total biology curriculum.

There are basically three problem areas that need to be addressed. One is the factual way that macroevolution is taught. The second difficulty is that the textbooks fail to disclose that evolution is a naturalistic theory. The third problem is that biology textbooks are written so that evolutionary principles are interwoven into just about every sub-topic in biology. This third area is more subtle and is not really amenable to a short-term fix.

In the short term, it seems most practical to address only the first two items. Fortunately, these can be addressed without a great deal of change in the way the overall subject of biology is taught. That is, since macroevolution (the theory of common descent) occupies only 5% or so of the total, this part of the curriculum can be easily modified, using outside material to supplement the coverage in current textbooks.

We believe that a teach the controversy approach is the best way to present biological origins in an objective, unbiased manner. This methodology was first introduced by Dr. Stephen Meyer (Discovery Institute) at a Panel Presentation sponsored by Ohio's State Board of Education in March of 2002. "Teaching the controversy" calls for (a) teaching the evidence for and against biological evolution (the theory of common descent), (b) permitting, but not requiring, teachers to discuss alternative theories (like intelligent design), and (c) adopting a definition of science that allows for consideration of all logical explanations for phenomena in nature.

One basis for "teaching the controversy" is language in the conference report of the new federal "No Child Left Behind" education bill (H.B. 1). This language, originally proposed by Sen. Rick Santorum, says in part: "Where topics are taught that may generate controversy (such as biological evolution), the curriculum should help students to understand the full range of scientific views that exist, why such topics may generate controversy, and how scientific discoveries can profoundly affect society."

With regard to the first point in "teaching the controversy," the curriculum should concentrate on the scientific evidence and show how it can be interpreted either in terms of evolutionary theory (a naturalistic explanation) or intelligent design (a non-naturalistic explanation). We suggest that at least three types of evidence be covered - the fossil record, homologies, and embryology. These are discussed in some detail in the previous section.

Just to recap how one might cover one of these areas, consider the fossil record. Point out to students that scientists see a general progression in fossils from simple life forms to more complex forms over time. One way to explain this is evolution, or descent from a common ancestry - a progression in complexity from a simple "first cell."

But also point out that the general trend observed in the fossil record is the abrupt appearance of new species (e.g., the Cambrian explosion), stasis over long periods of time, and finally extinction (often catastrophic). A problem with an evolutionary explanation of the fossil record is the glaring lack of "transition forms" (intermediate species) that would be expected from gradual Darwinian mechanisms (mutation and natural selection). The pattern of abrupt appearance, stasis, and extinction seems to be more consistent with the theory of intelligent design.

There are several areas in which the scientific evidence can be interpreted either in terms of evolution or design. The three areas mentioned previously (fossil record, embryology, and homologies) are probably the key ones. Other areas can also be considered if the instructor chooses. Some of these are the origin of life ("chemical evolution" vs. abrupt appearance by design), vestigial organs (i.e., organs that appear to serve little or no purpose), biochemical similarities (comparisons of molecular structures and life processes in various species), biogeographical distribution (comparisons of different life forms in different locales), and the origin of biological complexity and information.

Accompanying the instruction on evidence should be a discussion of the controversy over the definition of science. Students should know that there are two basic views of the nature of science. Most scientists believe that science should restrict itself to "natural explanations for natural phenomena." It is said that the integrity of science would be lost if non-naturalistic (supernatural) explanations were allowed, and that experimental science would lose its problem-solving power. These scientists also say that supernatural causes cannot be studied by science. Along these lines, students should know that evolutionary theory is naturalistic; it operates on the assumption that the origin and diversity of life can be explained solely by natural laws and random chance.

Students should know that an opposing viewpoint calls for a "traditional" definition of science, particularly for use in historical sciences like biological origins. In this view, proper use of the scientific method requires that all logical explanations for phenomena in nature be considered. An arbitrary decision to consider only natural causes restricts the objectivity of investigations. Design detection methodology is used in numerous fields to detect intelligent causes (e.g., forensic science and archaeology). Supporters of a traditional definition of science believe that design detection can be used reliably to search out intelligent causation in living systems.

Many teachers who have been brought up in the "evolution only" tradition will not know much about intelligent design or the evidence that supports it. At this point in time it seems best for teachers to choose whether or not to include design theory in their coverage of biological origins. Thus the "teach the controversy" proposal requires teachers to present evidence supporting and not supporting evolution (common descent), and it permits teachers to discuss alternatives like intelligent design. Teachers should have the academic freedom to either discuss, or not to discuss, the ongoing controversy between the evolution and design theories.

Before ending this section, it should be noted that it is sometimes argued that "teaching the controversy" would be difficult to carry out because of the lack of available instructional materials. Certainly it is true that public school biology textbooks do not give an objective treatment of biological origins. However, it is likely that once suitable state science standards are in place, the textbooks will quickly "fall in line" and start to include the relevant material. Publishers do want to sell textbooks, and in order to be successful they need to align their materials with state curriculum standards.

Also, many supplemental evolution/design resources (videotapes, books, articles) have become available in recent years. Some websites that provide excellent resources are at www.discovery.org, www.arn.org, and www.intelligentdesignnetwork.org. There is plenty of supplemental material available for those teachers who wish to present the subject of biological origins objectively.

Teaching biological origins objectively may not sound easy to some teachers who are accustomed to an "evolution only" approach. But there are numerous benefits to "teaching the controversy" about explanations for the origin and diversity of life:

1. It presents evolution with intellectual honesty. It makes little sense to present only the evolution viewpoint, when growing numbers of scientists are questioning the adequacy of the theory of common descent.
2. It avoids conflict over the definition of science. Schools have chosen to ask the question: "Where do we come from?" We cannot address this question without considering the possibility that some features of living systems may have arisen via the action of an intelligent source. Thus the definition of science must not be restricted to purely "naturalistic" causes.
3. It promotes academic freedom for teachers and critical thinking for students. The educational process is enhanced when students study both sides of a controversial issue and think carefully about the alternatives.
4. It generates interest in science. The controversy over biological origins is a very interesting topic. It engages both students and teachers in a rather unique way.
5. It aligns Ohio with the Santorum language in the conference report of the federal H.B. 1. The "No Child Left Behind" Act specifically encourages that biological evolution be taught objectively.
6. It maintains government neutrality on a matter (biological origins) that touches on religion. Teaching "evolution only" is not being neutral; this actually fosters an indoctrination of students in the philosophy of naturalism. Only by presenting both sides can the government maintain the constitutional mandate of neutrality.

Finally, and perhaps surprisingly to some, Charles Darwin would likely endorse this approach! In his famous book, The Origin of Species, Darwin said: "A fair result can be obtained only by fully stating and balancing the facts and arguments on both sides of each question." We couldn't agree more. Let the debate continue!

1. Charles Thaxton, "A New Design Argument," p. 17, Cosmic Pursuit, Spring 1998.

2. Theodosius Dobzhansky, The American Biology Teacher 35 (1973) p. 125-129.

3. George Gaylord Simpson, The Meaning of Evolution (New Haven: Yale University Press, 1949, rev. ed. 1967).

4. Douglas J. Futuyma, Evolutionary Biology, 3^rd edition, p. xvii (Sinauer Associates, Inc., 1998).

5. Ibid p. 15.

6. Ernst Mayr, Darwin's Influence on Modern Thought, p. 80 (July 2000, Scientific American).

7. Ibid p. 80

8. Charles Darwin, The Origin of Species, Chapter VI, p. 135 (1859). In this and subsequent references, all citations to Darwin's Origin of Species are from the Modern Library Reprint Edition (New York: Random House, 1936), which included Darwin's Descent of Man with Origin of Species in one volume. Chapter and page number are included in all citations from this volume.

9. Michael J. Behe, Darwin's Black Box, p. 39 (Simon & Schuster, 1996).

10. Eugene S. Ferguson, Engineering and the Mind's Eye, p. xi (The MIT Press, 1997).

11. ibid, p. xi.

12. Richard Dawkins, The Blind Watchmaker, p. 1 (W.W. Norton & Company, 1987).

13. ibid, p.5.

14. Walter L. Starkey, The Cambrian Explosion: Evolution's Big Bang? Or Darwin's Dilemma?, pp. 139-149 (Fairway Press, 1998)

15. National Academy of Sciences, Teaching About Evolution and the Nature of Science, (Washington, D.C.: National Academy Press, 1998). The booklet is available online at www.nap.edu/readingroom/books/evolution98.

16. Jonathan Wells, Icons of Evolution, p. 33 (Regnery Publishing, Inc., 2000)

17. ibid, p. 32

18. ibid, p. 32

19. ibid, p. 33

20. Charles Darwin, The Origin of Species, Chapter VI, p. 125 (New York: Random House, 1936).

21. George Gaylord Simpson, "The History of Life" in The Evolution of Life, ed. Sol Tax (University of Chicago Press, 1960).

22. Charles Darwin, The Origin of Species, Chapter 10, pp. 252-254 (New York: Random House, 1936).

23. Stephen Jay Gould, Wonderful Life, p. 227 (W.W. Norton & Company, 1989).

24. Charles Darwin, The Origin of Species, Chapter XV, p. 366 (New York: Random House, 1936).

25. Tim M. Berra, Evolution and the Myth of Creationism, pp. 118-119 (Stanford University Press, 1990)

26. Sylvia S. Mader, Biology, Seventh Edition, p. 296 (The McGraw-Hill Companies, Inc., 2001)

27. ibid, p. 296

28. Ronald Brady, "On the Independence of Systematics," Cladistics 1 (1985), pp. 113-126.

29. Michael K. Richardson et al., "There is no highly conserved embryonic stage in the vertebrates: Implications for current theories of evolution and development," Anatomy & Embryology, pp. 91-106 (Springer-Verlag, 1997)

30. Adam Sedgwick, "On the Law of Development commonly known as von Baer's Law; and on the Significance of Ancestral Rudiments in Embryonic Development," Quarterly Journal of Microscopical Science 36 (1894), pp.35-52.

Figure 1: The DNA Molecule *

1. Phillip E. Johnson. Darwin on Trial. InterVarsity Press, 1991.

2. Jonathan Wells. Icons of Evolution: Science or Myth? Why Much of What We Teach About Evolution is Wrong. Regnery Publishing, 2000.

3. George Gaylord Simpson. The Meaning of Evolution. New Haven: Yale University Press 1949, rev. ed. 1967.

4. Douglas J. Futuyma. Evolutionary Biology, Third Edition. Sinauer Associates, Inc., 1998.

5. Ernst Mayr. "Darwin's Influence on Modern Thought." Scientific American, July 2000.

6. Charles Darwin. The Origin of Species. The Modern Library, Random House, New York, 1936.

7. Michael J. Behe. Darwin's Black Box: The Biochemical Challenge to Evolution. Simon & Schuster, 1996.

8. Eugene S. Ferguson. Engineering and the Mind's Eye. The MIT Press, 1997.

9. Richard Dawkins. The Blind Watchmaker: Why the evidence of evolution reveals a universe without design. W.W. Norton & Company, 1987.

10. Walter L. Starkey. The Cambrian Explosion: Evolution's Big Bang? Or Darwin's Dilemma. Fairway Press, 1999.

11. Michael Denton. Evolution: A Theory in Crisis. Adler & Adler, 1986.

12. Stephen Jay Gould. Wonderful Life. W.W. Norton & Company, 1989.

13. Tim M. Berra. Evolution and the Myth of Creationism. Stanford University Press, 1990.

14. Sylvia S. Mader. Biology, Seventh Edition. The McGraw-Hill Companies, Inc., 2001.

15. Michael K. Richardson et al. "There is no highly conserved embryonic stage in the vertebrates: implications for current theories of evolution and development." Anatomy & Embryology (1997) 196: 91-106

16. William Dembski. No Free Lunch: Why Specified Complexity Cannot be Purchased Without Intelligence. Rowman and Littlefield, 2002

17. Werner Gitt. In the Beginning was Information. Christliche Literatur-Verbreitung e. V., 1997

18. Unlocking the Mystery of Life: The Scientific Case for Intelligent Design (video documentary by Illustra Media, 2002). Available in VHS or DVD from Illustra Media, www.illustramedia.com

19. Icons of Evolution (video) Available in VHS or DVD from Coldwater Media or Discovery Institute, www.discovery.org

20. The website of Discovery Institute's Center for Science and Culture, www.discovery.org/crsc, which archives many articles by I.D. scholars.

21. The website of Intelligent Design Network, www.intelligentdesignnetwork.org

22. The website of Science Excellence for All Ohioans, www.sciohio.org

23. For books, tapes, and other educational materials: the website of Access Research Network, www.arn.org