Without a definition, there can be no reasoned discussion. Disagreements deteriorate to name calling. Agreements based on false definitions are misunderstood. I once observed a panel discussion between Japanese and American educators. One issue they heartily agreed on was the importance of equal education. The trouble was the Japanese meant "equal
delivery of education" (all students receive the same education regardless of individual differences), while the Americans meant "equal
opportunity of education" (all students have an equal chance to be educated to their potential). These differing definitions have resulted in very different educational policies in the two countries, yet both groups believed they were talking about the same thing. So we will begin with definitions of evolution.
Summarizing several scientifically credible definitions of evolution,
Laurence Moran says,,
When biologists say that they have observed evolution, they mean that they have detected a change in the frequency of genes in a population...When biologists say that humans and chimps have evolved from a common ancestor they mean that there have been successive heritable changes in the two separated populations since they became isolated.
The two mechanisms for these changes are
natural selection and genetic drift. Laurence Moran laments the hodge-podge of popular definitions such as these:
"evolution: The gradual process by which the present diversity of plant and animal life arose from the earliest and most primitive organisms, which is believed to have been continuing for the past 3000 million years."-Oxford Concise Science Dictionary
"evolution: ...the doctrine according to which higher forms of life have gradually arisen out of lower.." - Chambers
"evolution: ...the development of a species, organism, or organ from its original or primitive state to its present or specialized state; phylogeny or ontogeny" - Webster's
As Laurence Moran points out, discussing evolution without a common, agree-upon definition leads to "fruitless debate." Furthermore,
once we realize that evolution is simply "a process that results in heritable changes in a population spread over many generations" it seems a little silly to pretend that this excludes religion!
Definition of Intelligent Design
According to [Intelligent Design Network www.intelligentdesignnetwork.org/],
The theory of intelligent design (ID) holds that certain features of the universe and of living things are best explained by an intelligent cause rather than an undirected process such as natural selection. ID is thus a scientific disagreement with the core claim of evolutionary theory that the apparent design of living systems is an illusion.
In a broader sense, Intelligent Design is simply the science of design detection -- how to recognize patterns arranged by an intelligent cause for a purpose. Design detection is used in a number of scientific fields, including anthropology, forensic sciences that seek to explain the cause of events such as a death or fire, cryptanalysis and the search for extraterrestrial intelligence (SETI). An inference that certain biological information may be the product of an intelligent cause can be tested or evaluated in the same manner as scientists daily test for design in other sciences.
ID is controversial because of the implications of its evidence, rather than the significant weight of its evidence. ID proponents believe science should be conducted objectively, without regard to the implications of its findings. This is particularly necessary in origins science because of its historical (and thus very subjective) nature, and because it is a science that unavoidably impacts religion.
Several Kossians have observed that evolution is not airtight; it is full of holes. If there were no problems there would be no need for investigation. In this essay, I am going to list a few of the problems with a common rebuttal. One ground rule is that I am going to examine the data as it lies without injecting an assumption of God or Biblical interpretations. It is well to remember that the phrase, "Many scientists think..." introduces any number of topics in a typical textbook. Obviously some scientists think something else. The pros and cons of evolution have frequently been formally debated. There has been no clear winner. Debate results flip one way or another based more on the preparedness of the participants than the merits of the position.
Problems and Rebuttals
1. Irreducible Complexity
A favorite example of irreducible complexity is the eye. If any one part is missing, the eye does not function. Incremental mutations would not favor the organism. One rebuttal is that each part of a complex system might have had an independent function before being combined into a unique, functioning system. See here. A "might" produces a hypothesis.
A hypothesis must be testable, measurable, observable and falsifiable. If a complex system is found to be made up of crucial parts with independent functions, the hypothesis is supported. If a number of such systems are identified, the hypothesis may become a theory. Every new example raises confidence in the theory, however theories are not proven. But theories are fragile. If even one complex system is found to be irreducible, the theory must be discarded. Theories also remain tentative. Even now, physicists are reevaluating gravity (also here).
2. Law of Entropy
The Law of Entropy states that within the closed system of the universe, complexity tends to decrease. The common rebuttal is that earth systems are not closed, i.e., there is a constant infusion of new energy from the sun. Others will object that Einstein's conservation of energy and matter contradict the claim that earth's systems are not closed. Physicists engaged in the search for the "Theory of Everything" assume that earth's systems are integrated within a closed universe.
3. Abiogenesis
Abiogenesis means "life arising from non-life." In an earlier time it was called the "Theory of Spontaneous Generation" and thoroughly discredited. The rebuttal is that the original theory posited the appearance of known life forms. Abiogenesis is a reformulation of the earlier theory as "previously unknown life arising from non-life." There is no problem with reformulating a hypothesis. Scientists are engaged in testing the reformulation now.
4. Deleterious mutations
Nearly all mutations are neutral, conferring neither benefit nor harm to the organism. Of the remaining mutations, deleterious mutations (harmful or fatal) far outnumber beneficial mutations. So some incredible probabilities come into play. The rebuttal is that whatever the probability, it happened, as in the example of being dealt any particular poker hand. In spite of the statistical improbability, the hand was dealt. Even granting the poker hand example, ID proponents question being held to a standard higher than the 0.01 or 0.05 confidence acceptable for most hypotheses.
5. Artificial selection
If natural selection is the mechanism whereby rare beneficial mutations eventually produce divergent species, then artificial selection (purposeful breeding) ought to speed up the process. Yet thousands of years of dog breeding has produced nothing but dogs. Purebred animals are generally weaker than mutts who draw from a more random gene pool. A rebuttal is that dog breeders never tried to produce something besides a dog. Breeders work with phenotypical dog traits, not random mutations. Furthermore, given enough time, it is possible that artificial selection could produce divergent species. Again, this is a hypothesis that needs to be tested. According to Laurence Moran,
It is important to remember that most species consist of numerous smaller inbreeding populations called "demes". It is these demes that evolve.
Yet the deleterious effects of inbreeding are well known.
I have listed just a few of the areas where fruitful hypothesis testing can be undertaken regardless of any belief in God. Nor is it necessary to pick sides. People can believe in God and allow science to carry on. There is no fraud in that and there is no problem with science teachers pointing out the holes in evolution. The problem is the leap to philosophy, or belief systems. The debate is not really about science at all; often it is about the existence of God. Nearly all rebuttals involve falsifiable hypotheses that need to be tested. ID "hypothesizes" a supernatural cause which cannot be falsified. This cause is supernatural because it is outside observed nature. It is not necessarily God, although that's as good an untestable supernatural cause as any.
Another problem I see is that too many K-12 science teachers do not know anymore than what the textbook says. Textbooks tend to be well behind the eight ball in terms of current knowledge. Textbooks also often contain a bias that starts out as "Many scientists think..." but ends up as "proven" fact on the final examination. As long as there are holes, one hypothesis is as good as another. Instead of a holy war on science, a workable approach would be to encourage a more honest education that frankly admits what we know and what we do not know. It has been said that dogmatists study science as well as theology. Kossians have rightly pointed out that philosophy is sadly neglected in American K-12 education. A classical education has its advantages.
We should not paint all critics of evolution with the same brush as the "wedge" people, anymore than we would consider Jerry Falwell the spokesman for all Christians. In the long run, practically speaking, it doesn't make much difference. Whether in a church-run school or a public school, essentially the same material is taught: the parts of the cell, the classification system, the human body, whatever. In a typical textbook, evolution is one chapter out of maybe twenty; the other nineteen chapters rarely mention it. Lay parents would probably be satisfied if textbooks avoided the unwarranted drift from hypothesis to fact that occurs so often.
A well-tested theory has predictive power. When Mendeleev created his table of the elements, prestigious scientists of the Royal Academy laughed him to scorn because of the gaps. Nonplussed, he said those gaps represented yet-to-be-discovered elements. Time has vindicated Mendeleev. The elements were discovered with the chemical properties he predicted. It remains to be seen whether evolution has the predictive power to fill in the gaps. Nevertheless, filling the gaps with God is not productive.
The official Position Statement of the National Association of Biology Teachers states,
The diversity of life on earth is the outcome of biological evolution--an unpredictable and natural process of descent with modification that is affected by natural selection, mutation, genetic drift, migration and other natural biological and geological forces.
It used to say "unsupervised, impersonal, unpredictable." If evolution is unpredictable, it risks losing credibility as a theory. It is possible that this is just another one of those popular definitions, but with this kind of confusion, doubters have plenty of wiggle room.
When some people take criticism of evolution so personally, it is fair to wonder if evolution is a matter of faith, even religion for those people. It is not necessary to assume that a critique of the weaknesses in evolution is automatically an endorsement of something else.
