Evolution vs. Intelligent Design in Public Schools: Is Randomness Scientific?
December 30, 2009
In a recent exchange with a scientist, I came upon an argument that intelligent design should not be taught in public schools because it is not science and is not falsifiable. I am not a scientist, but this argument led me to a question: what would falsify the theory of evolution by means of natural selection? I decided to get some of the basics of the theory of evolution from a hostile source. Here are some quotes from Douglas Futuyma, professor of evolutionary biology at the State University of New York at Stony Brook, president of the Society for the Study of Evolution and the American Society of Naturalists, that I find relevant to my thoughts:
The reason that natural selection is important is that it’s the central idea, stemming from Charles Darwin and Alfred Russel Wallace, that explains design in nature. It is the one process that is responsible for the evolution of adaptations of organisms to their environment.
Darwin’s book On the Origin of Species by Means of Natural Selection caused quite a stir when it appeared in 1859. Evidence to support evolution and natural selection, of course, has accumulated over time, and now science accepts that evolution is a fact and that natural selection explains very well how adaptive evolution takes place.
You can’t have any evolutionary change whatever without mutation, and perhaps recombination, giving rise to genetic variation. But once you have genetic variation, there are basically two major possibilities:
- First, there is simply no difference between the different genotypes or different genes in their impact on survival or reproduction, and in that case, you can have random changes of one versus the other type in a population or a species until eventually one replaces the other. That is an evolutionary change. It happens entirely by chance, by random fluctuations. That is what we call the process of genetic drift.
- Genetic drift is very different from possibility number two, natural selection, which is a much more consistent, predictable, dependable change in the proportion of one gene vs. another, one genotype vs. another. Why? Simply because there is some consistent superiority, shall we way, of one genotype vs. another in some feature that affects its survival or some feature affecting its reproductive capabilities.
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Evolution certainly does involve randomness; it does involve unpredictable chance. For example, the origin of new genetic variation by mutation is a process that involves a great deal of chance. Genetic drift, the process I referred to earlier, is a matter of chance.
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[N]atural selection is not like Mother Nature watching over us. Since natural selection is totally an impersonal process that is nothing more than a difference, generation by generation, in the reproductive success of one genome over another, there’s no way that it can look forward to the future or guard against the possibility of extinction. What individuals have right now that gives them superior adaptation may lead to disaster tomorrow.
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[F]irst of all, random processes are involved in the evolutionary process. For example, the origin of new mutations: a lot of evolution is dependent on particular mutational changes in genes that were very, very rare or unlikely, but that just happened at the right time, in the right species, in the right environment, but it need not happen that way. So, there’s this unpredictability. In addition, the particular sequence of environmental changes that the Earth underwent and that organisms were exposed to over billions of years has left a long-term imprint on species as they are today. If the sequence of environmental changes were different, you would have a different evolutionary history, leading to entirely different organisms over time.
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The philosopher Daniel Dennett called natural selection “Darwin’s dangerous idea” for a good reason: it is a very simple natural mechanism that explains the appearance of design in living things. Before Darwin, the adaptations and exquisite complexity of organisms were ascribed to creation by an omnipotent, beneficent designer, namely God, and indeed were among the major arguments for the existence of such a designer. Darwin’s (and Wallace’s) concept of natural selection made this “argument from design” completely superfluous. It accomplished for biology what Newton and his successors had accomplished in physics: it provided a purely natural explanation for order and the appearance of design. It made the features of organisms explicable by processes that can be studied by science instead of ascribing them to miracles. The contemporary “intelligent design” movement is simply a repetition of the predarwinian argument, and of course it cannot be taken seriously as a scientific explanation of the properties of living things.
So what I take from the above is that evolution involves a process of random and unpredictable mutation, combined with a predictable process of natural selection whereby certain mutations win out over others, but all mutations in all species began in a single common ancestor. [Another more succinct summary is available here.]
Professor Futuyma admits that there is an “appearance of design in living things.” He claims that the theory of evolution by means of natural selection—which is to say, one way of interpreting the evidence—explains that appearance of design based on random occurrences. The intelligent design (ID) crowd claims that the theory of evolution by means of natural selection is not the best explanation of the appearance of design. The ID people claim that life appears designed because it is designed; it is not random. Now, keep in mind, the ID scientists make no claim for the source of this designer—it could be aliens; they can’t (and won’t) say (“Unlike creationism, the scientific theory of intelligent design does not claim that modern biology can identify whether the intelligent cause detected through science is supernatural”). But ID scientists claim that life was designed by some intelligent source. I’ll allow some of the ID people to speak for themselves:
The theory of intelligent design holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection. . . .
If [evolution] simply means “change over time,” or even that living things are related by common ancestry, then there is no inherent conflict between evolutionary theory and intelligent design theory. However, the dominant theory of evolution today is neo-Darwinism, which contends that evolution is driven by natural selection acting on random mutations, an unpredictable and purposeless process that “has no discernable direction or goal, including survival of a species.” (NABT Statement on Teaching Evolution). It is this specific claim made by neo-Darwinism that intelligent design theory directly challenges.
Now, as to the claim that the theory of evolution by means of natural selection is scientific and ID is not because ID is not falsifiable: how is the concept of randomness possibly falsifiable in any way that ID is not? Is the question of whether some certain pattern is random or designed not a proper subject of scientific inquiry? If not, then scientists have no business saying anything is random (and thus Professor Futuyma’s brilliant explanation above is not scientific; the concept of randomness is all over the place). But if that question is a subject of science, then ID certainly belongs in the scientific discussion. ID is merely an interpretation of the evidence which, as Professor Futuyma admitted, establishes the appearance of design in nature.
Thus, the ID proponents claim that what they are doing is science:
Is intelligent design a scientific theory?
Yes. The scientific method is commonly described as a four-step process involving observations, hypothesis, experiments, and conclusion. Intelligent design begins with the observation that intelligent agents produce complex and specified information (CSI). Design theorists hypothesize that if a natural object was designed, it will contain high levels of CSI. Scientists then perform experimental tests upon natural objects to determine if they contain complex and specified information. One easily testable form of CSI is irreducible complexity, which can be discovered by experimentally reverse-engineering biological structures to see if they require all of their parts to function. When ID researchers find irreducible complexity in biology, they conclude that such structures were designed.
So, if we’re going to teach the evolutionary process in public schools, either we include arguments for randomness and arguments for intended design, or we exclude both. I do not buy Professor Futuyma’s conclusory dismissal of ID on the ground that the design argument is “pre-darwinian” and therefore wrong or unscientific. Darwinian evolutionary theory is pre-Naturallawyer (Darwin died long before I was born); so is it wrong if I disagree with it? The age of an argument is a remarkably bad reason for discarding an argument. Equally suspect is the argument that ID is wrong because the “scientific consensus” says that it’s wrong. The consensus of the scientific community is constantly changing. If scientific consensus is a reason to abandon a controversial argument, the emperor is wearing some mighty fine new clothes on his way to public schools these days.