DEPARTMENT OF BIOLOGY
The Evolution/Creation Controversy
My thanks to many of my Creationists friends, and to religious and
spiritual advisors, for articulating many of the concepts discussed here .
Why do creationists call evolutionists babykillers?
For some, the argument is about morality, not science.
For others, the argument stems from the possibility of losing Salvation.
We all learn from our elders and hold their beliefs as true.
It is not true that acceptance of evolution requires abandonment of religion.
Creationism is by no means homogeneous.
We may not establish a state religion…
The Creationists' new clothes.
If we teach the controversy scientifically, creation comes up short. Creationists don't want this.
Many anti-evolution arguments exist. Are they valid?
Most students have genuine questions or fears. So do their parents. Respect them.
Young-Earth Creationists accept microevolution.
…and how did we get over a million species of animals, when the Ark carried only 8000? The answer given by many Creationists.
The Intelligent Design movement's lesson plan.
Just What is the Controversy, Anyway? back to top
When the Kansas School Board voted to remove the word, "evolution," from the State Science Standards, scientists began making Kansas jokes. You know the type--when evolution is outlawed, only Kansans will evolve. Personally, I started writing evolution exam questions based on fossils I have collected in Kansas. Of course, there was also considerable spirited discussion, out of which grew a campaign of public education that resulted in replacing the School Board members at the next election. When the new School Board members voted to put "evolution" back into the Standards, they received death threats and nasty letters addressed to "babykiller." These are wildly different responses. And, we might ask, why the epithet, babykiller? What's going on here? It is clearly not a matter of the interpretation of scientific observations.
Morality back to top
The short answer is that, to scientists, this may seem to be a debate about the interpretation of scientific data. In contrast, to some of the creationists, it is a fight to the death to save the world as we know it. Robert Pennock, in his book, Tower of Babel, expressed the creationist reasoning this way:
1. The Bible--God's word--is the only source of a moral code for humanity.
2. The Bible describes the origin of life, and of humanity, in Genesis.
3. Evolution is not the same as Genesis.
4. If Evolution is right, then Genesis must be wrong.
5. If Genesis is wrong, it cannot be God's word.
6. If Genesis is not God's word, then the rest of the Bible may not be God's word.
7. If the Bible is not God's word, then humanity has no moral code--and chaos will ensue!
Personally, I don't think that the Bible is so weak that it can be undermined by a mere scientific finding. It was once thought that Copernicus' theory of geocentrism was in conflict with scripture, but, eventually, we figured out how to accommodate the science and maintain Faith. The same can occur with evolution--as, indeed, it has for most of the major religions. The controversy exists almost exclusively for fundamentalist denominations that interpret the text of the Bible literally (or, at least, the King James version of the Bible, and at least, parts of the text; other parts are recognized as metaphorical). In particular, the problems arise from the concept that humans and apes are related, and therefore humans are actually animals, and (as noted above) cannot be governed by divine laws of morality.
It is this interpretation that leads to the belief that the teaching of evolution is responsible for homosexuality, abortion, feminism, communism, the Holocaust, incest, rape, murder, and virtually any other flavor of immoral behavior. (Yes, even feminism [equal rights for women] has been said to be a result of the teaching of evolution!)
How can all of these things be linked to the teaching of evolution? Quite simply because, as outlined above, the assumption is that evolution would nullify the Bible, and thus nullify our moral code. Humans, being animals, would behave like animals or worse because there would be nothing to constrain them from doing anything they please. Hence, the rationale to call the Kansas School Board members babykillers.
Interestingly, the idea that we would behave like animals if we knew we are animals, assumes that the only possible source of morality is the Bible's teachings. This assumption ignores several important facts. One is that there are vast numbers of people on earth who do adhere to other faith traditions, and do not follow the Bible, yet seem to behave in perfectly moral ways. Another is that there are a great many animal behaviors that are as moral as our own. -- and sometimes moreso.
Eternity back to top
There is a personal aspect to denying evolution as well. It was phrased thus by a member of the audience in a seminar of Massimo Pigliucci's: "I am concerned about what will happen to me after I die." Christianity promises eternal bliss for the righteous, and eternal suffering for all others. For those who believe that these are the two options, there is a great cost to sinning. Perhaps, even evil thoughts are enough to condemn one to eternal suffering -- and evil thoughts may include thinking about evolution seriously.
It is stated in Genesis that there was no death while Adam and Eve resided in the Garden of Eden. After The Fall, however, God created death. Banishment from Eden and the prospect of death were serious problems for Mankind, which God balanced with his covenant with humanity: upon death, the soul would come to live in heaven for eternity. Eternity, then, is a concept that depends upon this covenant with humanity, which in turn depends upon the concept that there was no death before The Fall.
However, if life arose naturally, and if evolution is the normal process by which life has worked for millions of years, then as long as there has been life, there has always been death in the world. If there has always been death, then there would be no need for God's covenant, and no need for heaven. This would mean that if evolution is true, then heaven and hell might not exist at all. But do you really know that? You're not quite sure that both heaven and hell will disappear if you accept evolution, but you are certain, based on your teaching, that if you accept evolution and it's not true, then your fate is sealed for all eternity, and it's not bliss.
That is, if you deny evolution, you can fully believe in eventual Salvation. If you accept evolution, however, there might not be Salvation. But do you dare risk it, given the alternative?
Craig Nelson, in his discussion of Effective Strategies for Teaching Evolution and Other Controversial Topics, describes this conundrum with the rusty hand grenade analogy. When faced with a rusty hand grenade, which you are virtually certain will not explode if you pull the pin, do you pull the pin? The consequences of doing so would almost certainly be trivial, but could be disastrous. Although this possibility is remote, it seems safer not to risk it. So it is with the consequences of abandoning faith in heaven and hell. A disastrous consequence may seem very remote, but is it safe to risk it at all?
By contrast, the consequences of denying evolution are relatively mild -- a poor grade in Biology in school, perhaps the loss of a few lucrative career choices in the Life Sciences, but otherwise, it is possible to live quite happily in current society without a working knowledge of evolution.
Faced with this set of options -- the possibility of eternal suffering, vs a brief, mortal lifetime not accepting a scientific theory -- many people choose to deny evolution.
Apparently, personal denial is not enough. It is essential to fight against evolution politically, both from fear of the loss of morality, and from a certain sense of guilt, that if evolution persists, and you didn't stop it, then you are partly to blame.
The Formative Years back to top
Young children are adept at learning languages. They can make many sounds, but tend to adopt and use only those of their associates. What Mom says, the child repeats. In time, as we use our language's preferred set of neural connections, we tend to lose the neural connections that make all of the other sounds easy. Hence, it becomes more difficult to learn to make those sounds later in life.
Whether the same is true of our basic beliefs about the world, it is not yet possible to say. However, there are parallels. Each of us begins life with no knowledge or experience, and we spend our formative years learning from our elders. We learn cultural norms and mores. We learn what is good to eat, and what is bad -- including such details as methods of preparation. We come to think of these things as "the way the world is." These are the fundamental truths of life, and they work in the specific confines of the culture and locale in which we learned them.
Among the things we accept as "the way the world is" is our basic religious worldview. Not only do our elders act in certain ways that are consistent with their religious beliefs, they actively teach us in churches, synagogues, mosques, hogans, or wherever it is our tradition to learn "our history." As a result, much of our worldview is so deeply ingrained that it is often difficult or impossible to question its validity.
For many of us, coming from relatively homogeneous neighborhoods or towns, the first time we encounter people of different faiths is in college. It often takes some time to become comfortable with the fact that other people may have different beliefs, yet hold those beliefs as firmly as we hold our own. The resultant search for understanding often leads to the recognition that faith, and questions of the afterlife, may have no single right answer, and different opinions are valid.
But not everyone goes to college. In addition, many people do not travel very widely, and may live their whole lives in the culture and locale in which they were raised. Consequently, there is a significant proportion of students -- and their parents -- who may be immersed in a fairly homogeneous religious culture lifelong. Without the opportunity to live closely with people of different beliefs, they may come to feel that their own beliefs really are the way the world is.
It is tremendously important to recognize that the beliefs our students have as they enter our classes are, to them, as logical and sensible and, by definition, true as any beliefs that we may hold ourselves. They came to hold those beliefs in a perfectly valid way. If we come into the classroom, and directly contradict those beliefs, there is the very real possibility that our students will simply conclude that we are nuts. This is as true for a fundamentalist Christian being taught evolution as it is for a non-theistic student being taught the fundamental tenets of Baptist theology.
This is much more significant than a mere "misconception," like the idea that the earth is closer to the sun in the summer, and that's why it's warm. A creationist worldview is a different conception than the scientific explanation, certainly, but it is so deeply ingrained, and so fundamental to one's basic core values, that reconciling it with a contradictory worldview is exceptionally complex, if it is even possible.
Where we, as a nation, have fallen down in our task to resolve this issue is in approaching it as a yes vs no choice in a black-and-white world. No one profits by being told dogmatically, "I am right and you are wrong." Here, we need an open dialog that includes all of the shades of gray.
Evolution or Religion? back to top
The most politically active creationists typically belong to fundamentalist denominations that consider that their particular interpretation of the Bible is the only one that is correct. Many even go so far as define themselves as "True" Christians, as opposed to Pretenders who have stepped on the slippery slope to the abandonment of faith. These denominations commonly include a strong missionary component dedicated to spreading their views, a belief in Absolute Morality, and a belief that their view of morality must be encoded in law. (One might note that these three features are shared among various fundamentalist extremes of otherwise-more-inclusive faiths, including Christian, Islamic, and Hindu.)
One of the statements that is made by Christian fundamentalists is that it is impossible to accept evolution and maintain religious faith. The choice is presented as a very clear, black-and-white decision: Evolution or religion. This view is presented so often, and so loudly, yet countered softly if at all, that many citizens have come to think that it is true. It is not.
In fact, the majority of Christian denominations, and the denominations with the most members, accept evolution. Indeed, it is instructive to read the statements of religious organizations concerning evolution and the teaching of creation in the schools. How do these faiths reconcile evolution and creation? Perhaps this was expressed most succinctly by Pope Pius XII, as long ago as 1939, when he said,
"Man learns from two books: the universe for the human study of things created by God; and the Bible, for the study of God's superior will and truth. One belongs to reason, and the other to faith. Between them, there is no clash."
The key is to recognize that God's Creation cannot contradict God's Word. Rather than deny the evidence from Creation (the world itself, and thus the scientific data), we should recognize that God's Word is profound; its deepest messages may not be on the surface. There is much in the Bible that is metaphorical. Interestingly, most biblical inerrantists also seem to accept some portions to be metaphorical; it is otherwise impossible to reconcile the inconsistencies. It is much more reasonable to accept scripture as speaking to us on many levels at once, than to deny the veracity of those observations that any and all of us can make by looking at the world itself.
In thinking about evolution and religion, it is tremendously important to make it clear that there are a great many people who are deeply religious, yet accept evolution as a part of the natural world. The fundamentalist claim that they are incompatible is, apparently, not true.
The Different Flavors of Creationism back to top
Even within Christian theology, there are many interpretations of scripture, leading to different degrees to which scripture and scientific findings can be reconciled. At one extreme are those who accept Biblical text as absolute, even to the extent of retaining geocentrism in their philosophy. To them, the earth is flat, and evidence to the contrary is fictitious.
A less extreme version of Biblical literalism accepts that the images of a flat, immobile earth and the celestial motion around a stationary earth are metaphorical, but Genesis is still literal. In general, this version of creationism accepts that the King James Version of the Bible, and not earlier or later translations, is God's word. In this view, the Hebrew term yom is interpreted to mean a 24-hour day, as opposed to its alternative meaning, age or eon. Thus, creation occurred in six 24-hour days, not over an unknowable span of six ages.
This version of creationism accepts Bishop Ussher's chronology, based upon the lineage of descent described in the Bible. Bishop Ussher calculated that creation occurred on October 26th, 4004 BC. The Flood occurred in 2350 BC. There have been some revisions of these dates, based on some uncertainties, but the Biblical chronology is surely taken to mean that the earth is 6000 years old, and (with the uncertainties) certainly no more than 10,000. Therefore, these are the Young Earth Creationists.
Old Earth Creationists accept that Genesis is metaphorical, and therefore, Biblical creation is consistent with the earth being several billion years old. It becomes somewhat difficult to reconcile the chronology of the events of creation as described in Genesis with the events preserved in the fossil record, so there are many (probably most) Christians who are best described as Theistic Evolutionists. They accept evolution, based on the overwhelming evidence, with the theological premise that it has been guided by God, or that God established the natural world so that evolution would occur.
Biblical creationists are not, of course, the only anti-evolutionists. A literal reading of Hindu tradition also conflicts with evolution. Many anti-evolution arguments have been put forth by people of this faith. Similarly, the Unification Church of the Rev. Sun Myung Moon denies evolution. Indeed, Rev. Moon assigned one of his acolytes, John Corrigan Wells, to earn a PhD in Biology at the University of California at Berkeley, so that he would have scientific credentials when he later published anti-evolution books. He has since authored Icons of Evolution, but now under the legal name of Jonathan Wells. It is also noteworthy that L. Ron Hubbard, in establishing the Church of Scientology, declared evolution to be absurd.
One consequence of the wide variation in creationist doctrine is that a discussion of creationism often leads to heated theological arguments about Biblical interpretation. Is Genesis metaphorical or not? Isn't anything short of absolute Biblical literalism somewhere on that slippery slope that leads from True Christianity to apostasy? These arguments can be as intense as creation vs evolution--but even then, as noted above, the issue is not the science. It's the theological implications of accepting the science that cause the controversy.
The Establishment Clause back to top
Earlier attempts to require equal time for creation and evolution have been ruled unconstitutional. We generally interpret this as "the teaching of creationism violates the constitutional separation of church and state." It is now common, however, in creation/evolution debates, to find statements that the constitution says nothing about the separation of church and state! In fact, the constitution specifies that the government may not establish a state religion. Many creationists argue that this was meant to prevent the government from specifying which denomination of Christianity would be the state religion. After all, the logic goes, the founding fathers were Christians, so obviously they assumed that everyone else would be, too.
As the nation has grown, and as we have diversified with the immigration of new citizens from other countries and other religions, the establishment clause has, in fact, gained a broader definition than this limited one that has been suggested. In practice, it has also been interpreted to mean freedom from the imposition of religious views upon those who do not want them. This makes sense; those of us who are Christians, even Creationists, would be very upset to have the government impose upon us the rules of Wicca. Freedom to worship as you wish must also include the freedom not to worship as someone else insists that you must.
Like Genesis, the Establishment Clause is phrased in such a way as to encompass a variety of interpretations. That is, the Constitution is not so specific in its phrasing as to become "quaint" and clearly outdated. Rather, it has thus far been able to guide us, even as the world has become much, much different than it was when the Constitution was written.
Intelligent Design back to top
The express purpose of the Intelligent Design (ID) movement is "to reverse the stifling dominance of the materialist worldview, and to replace it with a science consonant with Christian and theistic convictions… that nature and human beings are created by God ," as stated in the Wedge Document that outlines the 20-year plan of the ID movement. While this is certainly fundamentalist Christian doctrine, ID professes to be non-religious, because the "science" behind it does not specify any particular intelligent designer. In essence, ID is an effort by the fundamentalist creationist organizations to introduce creationism into the science classroom. ID is described as "the thin end of the wedge" that bypasses the Establishment Clause of the Constitution by being "purely science."
But just how scientific is it? Much more has been written elsewhere (e.g. Talkdesign.org). Here, we will discuss only two issues. The first is the scientific test for design: the principle of "irreducible complexity." Michael Behe, in Darwin's Black Box: The Biochemical Challenge to Evolution, describes it this way:
"By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional. An irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution." (p. 39)
That is, an irreducibly complex structure cannot be produced "by slight, successive modifications of a precursor system."
In practice, this definition has led to the description of complex structures, and the simple application of the term "irreducibly complex" because the writer cannot imagine how evolution might have developed that structure. If the writer does not know the entire history of a particular structure, then the writer concludes that it is inherently unknowable, so the structure cannot have arisen evolutionarily. Therefore, for any structure for which we do not have a complete evolutionary description, the only possible explanation, in ID philosophy, is that it was created by God (i.e. produced by an intelligent designer).
Not only does this logic deny the possibility that we may learn more in the future, it also reveals the second important issue that we will discuss here: the failure to examine alternative hypotheses. In science, it is a fundamental part of data interpretation to examine alternative hypotheses and tentatively choose the one that best fits the data. The central tenet of ID is that only one pre-defined hypothesis is possible: an intelligent designer. For virtually every one of the examples that has been described as "irreducibly complex," there is considerable information (not mentioned by the proponents of ID) that leads directly to alternative hypotheses that do not involve supernatural intervention. It is the failure to consider alternate hypotheses, and the failure to examine the existing evidence, and instead to base the conclusion on the lack of imagination of the investigator, that renders ID non-scientific.
The logic is, basically, "I don't know how this works, so God must have done it."
There are additional considerations that should be considered fully by creationists, before they seek to have ID established in local school systems. For example, in its efforts to define the Designer without reference to a particular religion, and to cast specific structures as designed entities, ID reduces the Designer's creative activity to one-time events for each structure, spread out across evolutionary time -- and all of them prior to the evolution of humans from simian ancestors.
Teach the Controversy? back to top
Since there is a controversy, isn't it only fair that students be taught both sides? There are similar controversies in many fields, but we don't teach those. We do not teach holocaust denial simply because there are people who choose to say that it never happened. We do not teach that the earth is flat, simply because there are people who maintain that it is, and who insist that pictures of earth from space are a government plot. Nor do we teach that gravity is "just a theory" because we do not have a precise physical and chemical description of how it works. Instead, we teach what is known, and describe the current best explanations for the evidence we have.
The evolution/creation controversy is a controversy only between the scientific explanations and the religious views of a minority of religious denominations. There is no controversy among scientists who actively study the history of life on earth.
But, it might be instructive to do a thought-experiment. What would happen if we did teach creation from a scientific perspective? We can divide the biblical creation story into two primary parts: creation itself, and the Flood. We can accept each of these as a valid hypothesis to describe certain observations we can make in the world. To be scientific, we must test these hypotheses by determining what predictions each of them makes, and then seeking data to assess whether those predictions are met.
Creation itself is very difficult to examine. It predicts that what we see is what was created. In terms of what exists in the world, this model appears to be untestable. The only testable aspect is the time of creation--the age of the world. As noted above, Bishop Ussher calculated that creation occurred some 6000 years ago. Therefore, we predict that geological dating methods should provide data consistent with this calculation. Instead, the data indicate that the earth is considerably older. It is for this reason that most Christian denominations consider Genesis to be metaphorical, and evolution to be a reasonable mechanism by which creation might have occurred.
The Flood hypothesis makes a great many geological predictions and numerous biological ones. It is quite straightforward to enumerate these predictions, then go out into the world and look. Are these predictions met? Alas, they are not.
It is evident that a direct discussion of these hypotheses in science classes would be destined to reveal data that do not support them. To my mind, it seems preferable not to bring them into the classroom. To do so may cause more harm than good.
Similarly, a scientific examination of Intelligent Design seems destined to reveal its weaknesses as well.
Arguments Against Evolution back to top
Because of the difficulties inherent in supporting theological models in the science classroom, the main political tactic has been to insist upon raising doubts about evolution. The infamous Critical Analysis of Evolution lesson plan is one such example. As a perusal of the lesson plan reveals, the approach is to provide incomplete information about various topics, working from common misconceptions about the mechanism of evolution. The goal is to imply that the evidence for evolution is shaky or non-existent, and to imply that scientists have grossly misinterpreted their findings or, in some cases, perpetuated known frauds. Some brief examples may be in order, after such a scathing indictment.
A classic, and well-known example of natural selection is the "industrial melanization" of peppered moths in England. As soot from industrial centers killed lichens that live on nearby tree trunks, the tree trunks shifted from light (lichen) to dark (tree bark). Correspondingly, peppered moths that alight on the trees also switched from light to dark. When cleaner technologies were developed, and the lichens came back, the moths switched back to light as well. To test the idea that natural selection might account for this, the test was done: place light and dark moths on dark and light tree trunks, and determine how many of each were eaten by birds. In support of the hypothesis, light moths were preferentially eaten on dark trees, and dark moths were preferentially eaten on light trees.
This is said to be fraud, for two reasons. First, peppered moths don't alight on tree trunks, so the experiment is a fake. Second, no net evolution occurred, because (a) the moths were light-colored both before and after the whole series of events, and (b) they did not turn into new kinds of animals. Let us examine the validity of these criticisms.
Do peppered moths alight on tree trunks, in the locations where they were placed in the experiment? Not precisely; the experimenter placed them randomly on tree trunks, when normally the moths prefer to alight on tree trunks where branches join the trunks. As it turns out, this is exactly where birds look for them. In this specific location, as with moths placed in random locations, dark moths are harder to see on dark trunks, and light moths are harder to see on light trunks. There is no reason to invalidate the test (or conclude that it is fraud) on the basis of this subtlety.
What about the criticism that "no net evolution" occurred? The observed phenomonon is that light-colored moths were replaced by dark-colored moths during the industrial era (evolutionary event #1), and then dark-colored moths were replaced by light-colored moths as industrial pollution was subsequently cleaned up (evolutionary event #2). Thus, there were two rounds of selection, first selecting against the light-colored moths, and second selecting for them. The logic of claiming that no evolution occurred is similar to saying that taking a round-trip flight to Australia does not get you to Australia because you end up at home when it's over.
Third, this argument plays on the misconception that "evolution" must be a "change in kind" of organism. This is tied up in the controversy over microevolution vs macroevolution, outlined below.
When Ernst Haeckel reported his famous inference, that "ontogeny recapitulates phylogeny," he provided drawings of embryos in support of his hypothesis. However, it was subsequently shown -- rather later -- that his drawings were overly optimistic. That is, he had borrowed liberally from his imagination. Although Haeckel's contemporaries confronted him with this, and he admitted it, the forgery and the admission were not well enough known to avoid having the drawings enter biology textbooks. When the errors were re-discovered, the drawings were removed, and replaced with accurate information.
Interestingly, many anti-evolutionists claim that biologists continue to perpetuate the fraud of Haeckel, in a vain attempt to find some shred of evidence for evolution. Is this so? While Haeckel's recapitulation idea was wrong, and his drawings unsupportable, there are significant similarities in vertebrate embryo development that warrant discussion in textbooks. Facial development and embryology among vertebrates are remarkably similar, and justify including drawings or photographs in textbooks.
Replacing an erroneous figure and discussion with a correct figure and discussion is not one's usual definition of fraud. But, to a casual observer who does not examin the text or the drawings closely, the mere presence of embryo photographs may be misinterpreted as the perpetuation of Haeckel's idea of recapitulation, especially if they have been primed to see it as such.
A favorite criticism of evolutionary theory is the claim that "there are no transitional fossils." Indeed, Darwin himself puzzled over this apparent problem (which leads to a quote of Darwin's that is frequently used as evidence that evolution cannot be true). What makes this criticism so popular is that the common misconception of evolution is that individual animals change form while alive, which is obviously contradicted by common sense. Presumably, a "transitional fossil" would be a fossil of an animal caught in the act of some kind of species-to-species transformation.
Of course, this kind of magical transmogrification is not possible. What is possible is that there is genetic variation in populations of organisms, due to genetic mutation. Within this variation, some individuals are better suited to their particular environment and have large numbers of offspring. Other individuals are less-well suited to that environment, and have fewer offspring. As one generation gives way to another, and then to another, and so on, the genetic variations that are most helpful become common. Those genetic varations that are least helpful become rare. Because there are so very many characteristics of organisms, and because they tend to show genetic variation independently of one another, a coordinated change of several characteristics is extremely rare. Given that this is the actual mechanism of evolution, a "transitional" fossil is any fossil that exhibits some characteristics common to its ancestors, and some characteristics common to its descendents. In general, this is true of all fossils.
Darwin recognized that populations of plants and animals exhibit considerable variation from individual to individual. Without Mendelian genetics, however, he was unable to ascertain where the variation might come from. He tended to favor Lamarck's notion that acquired characteristics are heritable. Indeed, the inheritance of acquired characteristics is commonly assumed to be true even today, despite educational efforts to the contrary. If acquired characteristics could be inherited, then, logically, evolution should proceed by means of animals acquiring new characteristics as needed. The common assumption that this is possible leads to the serious misconception that evolution is supposed to be some kind of magical process in which organisms evolve in response to an internal drive to become better.
Although the mechanisms of genetics make this kind of "drive for betterment" impossible, opponents of evolution frequently assume that biologists think evolution does work this way. They incorporate this "drive" and Lamarckian inheritance to conjure up the image of individuals evolving from one species to another, such as the patent absurdity of a monkey spontaneously turning into a human. They never mention what transitional fossils are really like.
What if These Issues are Raised in the Classroom? back to top
It is surprisingly easy to raise an anti-evolution argument, and to describe it in simple enough terms that it is intuitively obvious to everyone. It is surprisingly difficult and time-consuming to provide the scientific understanding that illustrates why the argument is not valid. Yet, it is insufficient to say, simply, "that's wrong." Dogmatic statements do not lead to learning.
Nor, in my opinion, is it adequate to say that supernatural explanations are not a part of science. This approach leads inexorably to the conception that God is formally excluded from science and from classrooms through an atheistic/scientific conspiracy. Rather, it is far more appropriate and far more accurate to remind the audience what science is and how it works. The fundamental Nature of Science is to begin with observations -- data that are reproducible and can be verified by others. The next step is to make sense of the observations. Any explanatory model, hypothesis, or theory, that makes sense of the observations is potentially valid if it accounts for all of the observations, is not ruled out by other sets of observations, and does not invoke phenomena for which there are no data. Often, there are multiple alternative explanations for data, in which case additional data are needed to distinguish among them. Other times, there are such a great many observations, so much data, that the explanatory model earns the coveted title of "theory."
As a general rule, arguments over evolution vs religion (or vs anti-evolution) become less argumentative and more amicable when we refocus our attention. Rather than argue about who is "right," let's look at the data. What do we find when we go out into the world and look around? Once we have the data, how can we interpret it? When we have refocused this way, we're all on the same page: trying to figure out what could have happened to give rise to what we have observed.
We have provided a number of links to sites that have addressed each of the main misconceptions and anti-evolution arguments (more here and here). These can serve as useful resources when questions arise. In general, if you are uncertain how to address a particular issue, say that you'll have to think about it, and provide your answer in the next class period.
In my experience, limited though it may be, people who accept the anti-evolution arguments as valid are either primarily concerned about the theological implications of treating Genesis as metaphorical (see above), or are genuinely mystified due to pre-existing conceptions of what they think evolution is. In the former situation, it is essential to respect the faith of the questioner, and offer evidence that compromise positions are valid. Consider, for example, the statements from religious organizations supporting evolution. Not only is it not true that religion and evolution are incompatible, in fact, most religious denominations accept evolution without any problem. That is, we are teaching evolutionary theory not to undermine faith, but to provide additional understanding of the natural world, and of scientists' conceptions of how it works. If a student goes home thinking "these are scientists' conceptions, and don't really impact my faith, " they may be able to learn it perfectly well, without an immediate theological crisis.
In the event that a student bases his understanding on incorrect perceptions of what evolution is supposed to be -- such as a dog morphing into a bear -- the most important thing may be to enter into a longer-term discussion with them about the things that seem implausible. Usually, it is possible to identify one or more aspects of evolution for which the student has rather a fuzzy understanding. Those of which I am aware, I have listed among the misconceptions pertaining either to essential underpinnings of evolution, or to the process itself.
Once it is possible to identify these "rough spots" in understanding, it is sometimes possible to provide examples of what we understand really happens. Most commonly (which may explain why I have mentioned it so often in these pages), it is the idea that animals mutate by transmogrifying into something else, usually with some kind of planning or pre-meditation on their part. Often, the issue is the seeming conundrum that mutation is random, but natural selection is not. Both of these are complex issues to understand fully, and easy to misunderstand.
In short, there is no such thing as a dumb question, and, when faced with student concern about the teaching of evolutionary principles that contradict their worldview, respect is essential.
My personal view is that it is best to orient these discussions around data, not theory; fact, not supposition. We know that DNA is the genetic material; we know how it determines the characteristics of plants and animals; we know that it is subject to mutation. We can easily build the case, step by step, for the inescapable conclusion that evolution happens. The "recommended sequence of presentation" is designed to do just this--perhaps to forestall some of the questions.
Microevolution and Macroevolution back to top
There was a time when biologists did not understand genetics as well as we do now. Nor did we understand the molecular control of embryology. As a consequence, evolutionary biologists coined the terms Microevolution and Macroevolution. Microevolution was meant to refer to small changes -- things we could easily understand, based upon changes in allele frequencies in populations. Macroevolution was meant to refer to Big Changes -- things that seemed to occur, but for which mechanisms and even the definition were uncertain. A big change might be a dramatic change in morphology. Among many evolutionary biologists, this is what the term means today. Alternatively, a big change might be a speciation event, with the ensuing reproductive isolation that has a significant impact on evolution.
In its current usage among Creationists, and some biologists, the term "macroevolution" has come to mean to the overall pattern of relationships among living things. It refers to the theory of common descent from a single ancestor. Usually, it is applied to the Tree of Life (simpler version here), which links all species according to their similarities and differences. Needless to say, a theory that suggests humans and corn are more similar than yeast and bacteria is hard to accept if you have been raised in a faith tradition in which humans were independently created and superior to all other forms of life.
Some years ago, neither microevolution nor macroevolution (by whatever definition) were accepted by creationists. Nor was speciation. It was held steadfastly that the different kinds of plants and animals were created as they are now, and that "each reproduces according to its kind." For quite some time, "kind" was synonymous with "species."
More recently, however, as more and more data have become available, it has become necessary to accept microevolution. There are simply too many documented examples. many Creationists have even accepted speciation. Acceptance of microevolution is what allows the anti-evolution argument that the peppered moth story outlined above is not an example of evolution. It is "just microevolution", which is a natural process, and therefore "doesn't count." Similarly, the development of antibiotic resistance in bacteria is also "just microevolution." In no case did the organism actually evolve, and become a different kind of organism.
As more and more examples of speciation have been documented, it has similarly been necessary to accept speciation as a natural phenomenon "not related to evolution." The discussion now centers around the definition of Genesis kinds as families, orders, or higher taxa. It seems that the current consensus favors families. Within families (within "kinds"), there is a great deal of genetic variation, so of course microevolution will lead to speciation. But, never to "real" evolution.
It is interesting to consider current evolutionary theory as a counterpoint to this notion of "variation within kind." Virtually every possible evolutionary mechanism is able to occur during the formation of multiple species within a genus or family. DNA is passed from parent to offspring (that is, organisms reproduce according to their kind even in evolutionary theory!). Sometimes, DNA mutates, providing the raw material for genetic variation. Some genetic variants are more successful, some are less successful, so natural selection chooses among them to change allele frequencies in populations (this being the classic definition of "microevolution"). Physical isolation of sub-populations can enable sufficient change to occur that the two sub-populations may become separate species, particularly if mutations occur in genes involved in mating rituals or sperm/egg fusion. Even morphological change is allowed (the evolutionary biologist's "macroevolution"), as we see with the wide variety of sizes and shapes of dogs.
In a real sense, the only difference between evolutionary theory and the creationists' microevolution-only view is the time frame. A single "round" of microevolution, in which a new gene appears in the population and then becomes the norm generations later, can occur in a relatively short time frame. Several such "rounds" may give rise to a speciation event. But if we allow a great many such "rounds," over the course of millions of years, then we may see differences that are large enough to justify family-level distinctions. If we allow even more such "rounds" over a couple of billion years, of course, then we have the current Tree of Life as we know it.
Hyper-microevolution After the Flood back to top
The acceptance of microevolution outlined above solves an otherwise sticky issue. Noah is said, by biblical account, to have taken 8000 species aboard the Ark with him. After debarking some 4000 years ago, these 8000 species gave rise to the million or more species that we now observe. How did this occur?
I have yet to receive a detailed mechanistic answer to this question from my Creationist friends, though it is they who brought this interesting puzzle to my attention. It seems that the general answer is that there was a period of hyper-evolution during the first thousand or so years after the flood. The genetic variation inherent in each "kind" of animal was acted upon by microevolution, to produce the array of variations within each kind that now exist. This supposition raises an interesting question or two.
Where did the genetic variation come from? It has been suggested that the genetic variation was inherent in each kind -- that is, somehow contained within the pair of animals that Noah took aboard. Sufficient variation to create a vast number of species among several different genera, while at the same time being merely diploid, with no more than two alleles at each locus, seems insufficient to account for the diversification. Mutation must also have occurred, and mutations must have accumulated. The only difference between this model of hyper-evolution and traditional evolutionary theory is the time frame. Evolutionary biologists propose millions of years for such diversification; this Creationist model proposes a mere thousand.
Where are the transitional fossils? If there was a period of rapid expansion of populations just after the flood, and if these populations underwent hyperevolution, shouldn't there be evidence in the fossil or archeological records?
These questions notwithstanding, the expansion of animal life after the flood is currently considered by some creationists to have followed this type of trajectory.
Useful Links back to top
Talk.Origins Archive-- The primary reason for this archive's existence is to provide mainstream scientific responses to the many frequently asked questions (FAQs) that appear in the talk.origins newsgroup and the frequently rebutted assertions of those advocating intelligent design or other creationist pseudosciences.
Statements Supporting Evolution, from Various Religious Organizations at the National Center for Science Education
The Panda's Thumb -- the virtual pub of the University of Ediacara. The patrons gather to discuss evolutionary theory, critique the claims of the antievolution movement, defend the integrity of both science and science education, and share good conversation.
Includes: "The fact is that every scientific theory presented as orthodoxy in science classes began in exactly the place ID finds itself now: A heresy believed by a handful of people dissatisfied with the orthodox view. In no case, however, did the adherents of the heresy earn their place in the curriculum by appealing directly to schools boards and state legislatures. In every case the heresy won out by producing evidence adequate to convince a large majority of scientists." From Jason, posted on Evolutionblog
Scientific, Legal, and Moral Issues -- from the National Center for Science Education
Evolution, Creation, and Design -- a long list of links from Butler University
Lots More Links at Yahoo
last updated: Jan. 16, 2009