PART I
Attempting to Resolve the Debate
The Need for Science; the Need for FaithâSeparately
by Mark Nathan Cohen
Mark Cohen defines two separate cultures, a culture of science and a culture of faith, each of which provides for essential human needs, but which need to be clearly separated from one another, each defended against unwarranted attacks by the other. The issue isnât faith but attempts to insinuate faith into science, as well as attempts by some scientists to attack faith in unwarranted ways. Cohen defines science in terms of two central properties: (1) an open market of competing ideas ultimately refining our knowledge; and (2) the absolute insistence on âuniformitar-ianâ logic (without magic, miracles, or divine interventions), as the central rule of the competition. He argues that creationists simply miss or ignore these principles and that, whatever they are doing, it isnât science. Pretending that creationism is science undermines the understanding of all science and threatens to undermine its great value. Cohen gives a basic outline of what evolution means and rebuts attempts to undermine the argument or the evidence provided in support. He also argues for the importance of another faith-, emotion-, or social-based paradigm, perhaps the result of evolved human mental abilities, to which students should be exposedâbut not in science classes.
The issue isnât primarily about evolution and creation. It is about science as a way of knowing, and rational thought as a way of solving problems. We are threatened with the death of science at the hands of a religious and political agenda that would subordinate thought and human responsibility to faith and obedience to authorityâwhich may in fact well be its goal. We are also threatened with a further dilution of science skills among American students, already falling well behind those of other countries, even though science increasingly is also under attack in many other parts of the world. Yet, many Americans demand teaching creationism as science even though it further erodes all science skills. One cannot defeat evolution in the manner proposed by creationists without destroying science. Evolution is the Trojan horse; science is the citadel to be destroyed.
The issue isnât religious faith, which, as discussed in the following text, is as important as science, but in a context and for purposes that are distinct from science. The problem is creationism foisted off as science often with the use of political force. âCreation Scienceâ is an oxymoron (i.e., the phrase is self-contradictory) because its methods deny the very essence of science and rational problem solving.
I should define what Darwinâs theory of evolution, badly understood by many, actually says (in highly simplified form but sufficient for our purposes). First, he argued that all of life is part of an enormous family tree extending over vast periods of time. That is, all living forms are distant cousins. (We are not descended from apes as commonly portrayed, or from any other modern organisms.) Second, he argued that the process involved (family) descent with modification from generation to generation through thousands of generations, the modifications eventually adding up to produce very different organisms. Third, he argued that natural selection, the differential reproductive success of individuals, was the major (but not the only) mechanism of change.
In outline, natural selection is very simple and most of it should be quite obviousâand unthreateningâto most readers. It results from several things that Darwin noticed: fairly obvious things that others could see, but only Darwin assembled into a coherent package. It results also from fairly simple and obvious deductions he made from his observations that other people had not thought about. None of the observations or deductions by themselves are startling.
Observation 1: Animals produce many babies. For example, a mother cat can easily produce eight or more daughters, one mother becoming eight daughters, sixty-four granddaughters, and so on in very few years. Were this to continue, the world would very soon be physically packed with an ever-expanding mass of cats.
Observation 2: The populations of any species arenât expanding at the rate that their reproductive rate would predict. We are not packed with cats.
Deduction 1: By simple subtraction, that means that there must be a very high failure rate in order to account for the difference between birthrates and the actual growth of the species (i.e., most of the kittens apparently do not reproduce successfully).
Observation 3: Animals vary. Just as people all look different and are different in myriad other ways (shape, chemistry, bone structure, etc.), so do members of all other species.
Deduction 2 (the first bit that is even mildly controversial and the key one): Some members of a species are more successful at reproducing than others, and their success often is not mere luck; it results from design variations that are better adapted for survival and reproduction in a particular environment. The measure of relative reproductive success is called âfitness,â which is purely and simply a measure of the relative number of successful offspringâand ultimately the number of descendentsâthat a parent produces. (That is the only thing that âfitnessâ means in Darwinian terms, no matter how the concept was distorted by later scholars and politicians, as will be discussed.) It is worth noting that natural selection does not mean âNature Red in Tooth and Clawâ as it is often envisioned, because the overwhelming majority of reasons for fitness are fairly passive. Natural selection doesnât necessarily even involve direct competition. The features that make an animal fit are situational. Selection refers to success in a particular environment with a particular challenge. The features contributing to an organismâs fitness come in an enormous variety, and are situational, depending on the barriers to an organismâs success at a particular time. For weeds, fitness can mean chemical resistance to competitors, parasites, pesticides, or poor soil. It can mean resembling a protected plant so it is missed in the weeding process. It can mean having roots too strong to be pulled out, or a stem so weak that it breaks when pulled, leaving the living roots intact. For animals, fitness can involve protective coloration; powerful, accurate senses; good behavioral instincts; proper mating rituals; appropriate care of offspring; disease resistance; and myriad others. For people it may include the cuteness of babies and the god-awful noise they make (carrot and stick) to stimulate and command attention, or a motherâs instinctive attention or ability to nurse. A quiet, ugly baby might well not receive adequate care. Fitness, often perceived as a scary concept, is in fact an everyday matter-of-fact quality, visible all around us.
Observation 4: Offspring tend to resemble their parents (in internal as well as visible characteristics), a fact obvious to anyone who looks.
Deduction 3: Therefore, because âfitâ parents produce more successful offspring than others, more members of the next generation will resemble those parents and (hopefully) carry on the traits that made the parents successful. The result is that the relative frequency of (possibly new mutant) fit and unfit traits in a population will change in favor of the fitter designs.
Thatâs it!
Science
To begin to explain the controversy over the Darwinian model, I need to define science. Science isnât Ph.D.âs; it isnât test tubes, white coats, field or laboratory techniques, or correct procedures. It is not simply biology, chemistry, physics, or anthropology. Science isnât defined simply by testable hypotheses or âscientific method.â Confusion over the definition opens doors to creationists and other pseudoscien-tists who can claim one or more of those attributes. Many creationists and other pseudoscientists have Ph.D.âs in one of the sciences and purport to use scientific methods. But they arenât doing science when they pursue creationist goals.
Real science is defined by two central properties. If these conditions arenât met, there is no science.
The Scientific Marketplace
First, science is a marketplace of competing ideas about the workings of nature and our potential use of natureâs processes. The market is hardly perfect, and some of its imperfections relate to its inevitable ties to values and politics (both internal and external) that can result in distraction, misdirection, and abuse.
Moreover, as many people point out in this volume, science is never as free of values, expectations, politics, and economics as we would like. Social atrocities like eugenics, racism, and ethnic cleansing have often been defended on the grounds of misguided and misapplied evolutionary theory. But they are caused most often by distorted religious or political beliefs. Remember the Inquisition or any number of recent and historic wars? (The teachings of Jesus are as easily twisted as those of Darwin, and historically, the distortion of Jesusâ teachings have been far more numerous and more destructive.) But in the long run, the science market is self-correcting; it comes closer to being a fair market than most we know.
Science resembles the childhood game of âking of the mountain.â Scientists compete and try to improve or replace explanations they donât believe. That is our job. We criticize each otherâs ideas to hone, or perhaps ultimately displace them (âknock them off the mountainâ) in a constant pursuit of âtruth.â
Success generally hinges on six main factors:
1. Whether a theory makes sense in light of related knowledge. For example, it fits the known laws and other observations of the scientific field in question rather than defying them.
2. Whether it makes explicit or implicit testable predictions (i.e., predictions about existing conditions not yet fully described, that can be studied and tested, not vague future conditions that obviously cannot be checked) and makes more accurate testable predictions than competing theories. For example, in the fifteenth century, the theory of a round earth predicted (or at least accounted for the fact) that a ship sailing away would not suddenly disappear as if falling off the edge of the earth, but rather would disappear gradually, hull first, mast last, as if it were going over a very large hill, a pattern for which flat earth theory could not account.
3. Whether the theory is âelegantâ or âparsimoniousâ (i.e., whether it can explain all observed phenomena in terms requiring the fewest logical leaps or untested assumptions). For example, if you are late arriving somewhere it is probably because you stopped or your car broke down, not because you were kidnapped by Martians or stopped by an earthquake. It makes no sense to invoke the improbable if a simpler explanation can be found that fits easily into existing experience.
4. Whether successful tests of the theory can be replicated by other scientists. For example, a specific experiment in a laboratory consistently produces similar results when done by other people, or a pattern of fossils is found repeatedly. Recently, two scientists thought that they had demonstrated cold fusionâpotentially a source of enormous amounts of energyâin a laboratory. But no one else could make it work, so the claim was dismissed.
5. Whether results can be crosschecked with results derived from other test methods, as when the once controversial results of radiocarbon dating were matched by dates provided by other methods such as calendar dates associated with previously dated objects.
6. Whether apparent exceptions can be explained satisfactorily. (Exceptions test or probe, not prove, the rule. The Latin has been mistranslated.) Eskimos have darker skin than would be predicted by a common theory of skin color related to ultraviolet radiation and the production of vitamin D in the body. This puzzled scientists and challenged the theory, a fact that might have led to the dismissal of the whole theoryâuntil it was realized that the apparent exception could be explained by the fact that the Eskimoâs fish-based diet provided rich sources of vitamin D, making their color irrelevant.
A particular theory remains on top of the mountain only as long as a consensus of knowledgeable scientists in related fields concur that, judged by those rules, it is the best explanation of an observation yet devised. What may start as a hypothesis approaches the status of truth or fact as it is questioned but withstands all challenges. But, further challenge is never precluded; the game never ends. We never get at final truth or fact. Hopefully, we get closer. Almost everyone on both sides of the evolutionâcreation debate uses the words fact and truth inappropriately. What we are taught in classes or textbooks is not the truth; it is whatever idea or theory is accepted (on top of the mountain) at the time the lecture is given or the text written.
I donât think that evolution (as any other complicated idea or conclusion) is fact because, unlike trivia, complicated ideas and concepts never become fact. (It is a fact that I am writing this on a computer, but it is also trivial.) Darwinâs model of evolution, originally a mere theory, has been attacked and criticized in the scientific marketplace almost constantly for 150 years. It has been modified many times so that, hopefully, our knowledge gets more and more accurate.
But the core of Darwinâs argument, described previously, hasnât yet been refuted, although many people have tried. We are, after all, highly motivated to challenge it because a successful challenge would bring great fame. But, the theory elegantly, parsimoniously explains many observations (such as those of the fossil record and strange features of anatomical design, discussed below) and it has made many successful predictions about what we would and did observe in nature. It is as close to fact or truth as a complex concept ever gets.
But, if you arenât competing in the scientific marketplace and abiding reasonably by its rules and âdecisions,â you arenât being a scientist. You can disagree with a market decision and challenge it, and you can modify your theory or add new evidence to sway a market decision, but you canât just ignore the decision, or attempt to circumvent it by political rather than scientific means.
Doing science is time and context specific. I am a scientist when I submit my ideas to the market, as I have many times with mixed or sometimes temporary success. But my political opinions are not science nor are the opinions of so-called creation scientists despite our Ph.D.âs, just because we behave as scientists in other contexts. (A trained physicist, even a Nobel Prize winner in physics offering an idea about biology isnât being a scientist unless he or she submits the arguments to his or her adopted part of the market and abides by its decisions.)
It is precisely the reasoning involved in the research, the methods by which the market operates, and the recognition of bad or âpseudoâ (fake) science that our students must learn if they are to begin to compete again in the world scientific market and if the world as a whole is to proceed to rational solutions to its problems. Teaching bad science simply adds confusion, delaying the development of scientific maturity.
Creationist arguments do enter the market. Some force scientific response, but their efforts to overturn evolution on scientific grounds fail repeatedly and disappear from the market. Attempts to modify creationist ideas to make them more palatable to the scientific market have repeatedly failed. Modern âscientificâ creationists want to use appealing slogans (âfairness,â âequal time,â âbalanced presentationâ) or political force to thrive in a market where they have lost repeatedly. Fairness does not dictate that good and bad meat be sold equally. Creationism being forced politically on the public, as science, is like politicians demanding that meat that has failed inspection be sold anyway to a consumer population not trained to make good choices. In attempts to put creationism in science classes, the inspections are not being done or are being overruledâand the meat is bad and damaging to our scientific health.
Uniformitarianism
The second major principle of all science by definition is uniformitarianism. Any attempt at science must abide by it. Uniformitarianism means that the world operates by natural laws that, at their core, are unchanging, even if they may be shaped by individual circumstances. It means that there are no miracles in defiance of those laws. If there is a God who created, He doesnât interfere, so we can rely on the laws to be unchanging, hence predictable and usableâor, in the case of prehistory or evolution, reconstructableâif we know enough and think clearly. Laws of gravity, for example, predict that things will fall down until they land on an existing surface. So, the lowest layers in a geological or archaeological deposit must be the oldest, newer layers landing progressively on top of them, aiding us in establishing the relative order of fossils embedded in the various layers.
By these same principles, we know that some things are impossible because they defy natural laws. If a great flood once occurred, it could not, by scientific reckoning, have been a miracle. It must have resulted from natural processes we can understandâand it must have left residues that we know accompany flooding. There are many known mechanisms, such as rivers overflowing their banks, that can produce a flood in one location. And they produce the expected residues, generally undifferentiated mud, or gradients of particle size resulting from the fact that heavier particles tend to settle faster in water than fine particles...