Intelligent design
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Intelligent design (ID) encompasses a number of theories arguing that life and living things show signs of having been designed with purpose and design, rather than coming into being purely by the force of naturalistic law. There is considerable dispute over whether Intelligent Design qualifies as being "scientific" or merits consideration as a "hypothesis".
Adherents to intelligent design view it as a valid challenge to the prevailing theory of strictly naturalistic evolution. Some of its proponents have described it as a "wedge" to gain entry into mainstream scientific discourse, as it purports to point out the weakness of the mainstream theories. Supporters of evolution frequently and loudly denounce it as mere metaphysics and thus dismiss at as pseudoscience. However, not all believers in intelligent design are creationists or even theists.
It is generally agreed that if life was created by an intelligent agent, the naturalistic abiogenesis hypothesis must be false.
Intelligent design theories
At the heart of Intelligent Design lies the belief that the universe in general and life in particular show signs of having been designed by an intelligent agent. Examples of intelligent design theories include:
- Abiogenesis. The origin of the first self-replicating cell remains a mystery to science. Despite the demonstration that many of the organic ingredients of life may arise naturally, and several hypothetical models including "genes-first," "metabolism-first," and "hybrid" models, there has been no demonstration of any mechanism by which organic compounds came to be arranged into a self-replicating, "living" organism. Proponents of intelligent design argue that the existence of life itself is most reasonably explained by the act of an intelligent designer.
- Mendelian inheritance and speciation. Gregor Mendel, the "father of modern genetics," identified the mechanism of genetic variation. Through his research, he concluded that although natural variation and natural selection could explain the development of minor traits, it could not explain speciation. In a lecture on March 8, 1865, Mendel noted that his research described the mechanism of microevolution, but gave no grounds for belief in macroevolution, saying "No one will seriously maintain that in the open country the development of plants is ruled by other laws than in the garden bed. Here, as there, changes of type must take place if the conditions of life be altered, and the species possesses the capacity of fitting itself to its new environment. [However,] nothing justifies the assumption that the tendency to form varieties increases so extraordinarily that the species speedily lose all stability, and their offspring diverge into an endless series of extremely variable forms." To the contrary, he said, the tendency is toward stability, with variation being the exception, not the rule. Henig, "The Monk in the Garden: The Lost and Found Genius of Gregor Mendel, the Father of Genetics," p. Boston: Houghton Mifflin Company, 2000, p. 141.
Advocates of intelligent design note that the Modern evolutionary synthesis has yet to demonstrate any mechanism for macroevolution, or to show some of the transitional forms in the fossil record that the theory predicts. Intelligent design asserts that species differentiation is most reasonably explained as the act of an intelligent designer.
- Irreducible complexity. Irreducible complexity is defined as "a single system which is composed of several interacting parts that contribute to the basic function, and where the removal of any one of the parts causes the system to effectively cease functioning" (Michael Behe, Molecular Machines: Experimental Support for the Design Inference). Proponents argue that many aspects of life are composed of an enormous number of interdependent parts, which could not function alone, such as the eye, sexual reproduction, the four chambered heart, cilia, and mammary glands. They note that naturalistic evolution holds that life evolves new characteristics one mutation at a time. They conclude that naturalistic evolution fails to explain instances of irreducible complexity, because irreducibly complex systems could not have evolved gradually, but, in order to function, must have been created at once, as a single system, by an intelligent designer.
Opposing arguments
Opponents of ID, who include the overwhelming majority of the scientific community, claim that this argument is deceptive and has no standing as a scientific hypothesis, i.e. it is considered pseudoscience. They say that ID does not present falsifiable hypotheses, and violates the principle of naturalism within scientific philosophy. They also point to examples of seemingly poor design within biology.
The evolutionary argument against biogenesis being wrought by an outside entity is that the leading evolutionary theory of life's creation, the RNA world hypothesis, notes the near omnipresence of catalytic RNA molecules (ribozymes) in life. Evolutionists indicate that, despite the fact that there are no RNA molecules at present time capable of reproduction, RNA has the pairing ability that gives rise to the DNA "double helix" and is capable of many functions once thought to be restricted to proteins, a stumbling block for many years in the "abiogenesis" theory that would have made cocreation of RNA/DNA and proteinaceous building blocks of life necessary. This makes the "abiogenesis" theory somewhat more plausible because a random assembly of self-reproducing nucleotides (the building blocks of RNA/DNA) many orders of magnitude more likely than a random, coeval assembly of amino acids (protein building blocks) and nucleotides leading to life. Since the entire debate of life's origins, at least, is admittedly a historic rather than expressly scientific debate, the analogy of the ribozyme discovery to human history is finding pottery at the correct strata for one's proposed civilization; not proof of the entire civilization per se but definitely bolstering evidence.
Evolutionists further propose that science has demonstrated several mechanisms for macroevolution, including crossing-over, imprinting/methylation or polyploidy, which can result in Down's syndrome and speciation (as defined by evolutionists) in plants. The evolutionary argument against "irreducible complexity" is taken up later in the article.
Advocacy and controversy
Advocates of ID believe there is empirical evidence that an "intelligent designer" (or designers) has been at work in the history of life, and many do not think that macroevolution of life, particularly the evolution of humans, is credible. Members of the "intelligent design movement" are typically theists (Christians, Jews, or members of other faiths that believe in a powerful deity) though ID itself does not specify the identity of the designer.
The intelligent design movement is mostly based in the United States, and is centered around part of a conservative Christian thinktank, the Discovery Institute's Center for Science and Culture (CSC), formerly known as the Center for Renewal of Science and Culture. The CSC was founded in 1996 and has a number of fellows. The program director is Stephen C Meyer, Associated Director is John G West. The father of the movement however and perhaps the most important is Phillip E. Johnson.
ID and Creationism
ID is similar to Creationism in that it asserts that the life was created, rather than developing purely naturalistically. It is different from creationism, however, in that while Creationists assert that God created life as described in the Biblical book of Genesis, ID makes no explicitly religious claims, relying simply on evidence that life was created by an "Intelligent Designer," which could be the God of any religion or no religion, or some other intelligent being that is not God.
The wedge
In their effort to gain entrance into mainstream scientific discourse, some advocates of intelligent design have devised the "Wedge strategy." Evolutionary theory is analogised as a log, and ID as a wedge. The wedge may be put into cracks into the log (perceived discrepancies within evolutionary theory) and after some hammering, the log will shatter due to its inherent weaknesses. Because advocates of intelligent design believe that the evidence for intelligent design of one form of another is overwhelming, they believe that the movement should initially focus on advocating more clear-cut issues, such as irreducible complexity, rather than on more questionable issues, such as Noah's flood and the age of the Earth. The godfather of the ID movement, University of California, Berkeley law professor Phillip E. Johnson (now emeritus), is quoted as saying that issues such as the age of the Earth can be taken up once the common enemy of evolution has been done away with. Opponents of ID say that this shows is that ID is a tactical device.
The Wedge Strategy document was a document produced in 1998 by the Center for Renewal of Science and Culture but later leaked 1999 and published on the Internet. [1].
Intelligent Design in Public Education
Main article: Creation and evolution in public education
The legal status of intelligent design and evolution in public education has been the subject of a great deal of debate and litigation over the course of the past 80 years in America. By the establishment clause of the Constitution's first amendment, "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof." Under current constitutional law, states may not pass laws which ban the teaching of evolution, or require the teaching of creation whenever evolution is taught. Most recently, the Supreme Court has held in their ruling of Edwards_v._Aguillard that a variety of theories of origins may be taught in public schools, as long as they are taught with the secular intent of enhancing a scientific education, and not motivated by religious conviction or agenda.
Rejection by the scientific community
Much of the controversy over ID stems from its advocates' desire to get the concept accepted as a scientific theory, and specifically for it to be taught as such in schools. Opponents argue that ID does not fit into the framework of scientific philosophy and call it pseudoscience. Opponents claim ID is a religious philosophy, and the common usage of ID is, in its most basic essence, no different from deism.
The National Center for Science Education seeks to fight what it calles antievolutionism, and various organisations such as the American Association for the Advancement of Science have spoken out against intelligent design.
The basic ID argument is similar to the argument from design for the existence of God presented by William Paley in his book Natural Theology, published in 1800. Charles Darwin reported being deeply influenced by Paley's book—required reading in his time—which he later rejected based on the evidence at hand. Today the global scientific community overwhelmingly accepts and applies the theory of evolution (see also natural selection) originated by Charles Darwin and updated by many. To date, intelligent design has been able to publish one single peer-reviewed article in a scientific journal, Proceedings of the Biological Society of Washington. The author is Stephen C. Meyer, Program Director of the Discovery Institute’s Center for Science and Culture, the major organization promoting ID. This article is not available on-line from this journal, but a copy is on the Discovery Institute site:
A review of it is available on the Panda's Thumb website:
The paper has subsequently been disowned by the journal, which has stated that it did not go through the journal's approved peer review process. The journal's statement explains that the Meyer paper does not meet the scientific standards of the journal.
Metaphysical objections
A key objection to ID is that it does not explain the source of the designer. Opponents of ID say that instead of explaining the complexity of life, it merely transfers the problem to an unknown domain where it cannot be directly analyzed, since now explanations have to cover a newly-introduced alien or supernatural entity while evolution does not need to. However, although those are good questions, they do not invalidate the basic premise of ID. Rather it is tantamount to saying, "because I do not know who made my watch, it was not made."
Biological complexity
Since the ID viewpoint does not prescribe the identity of the designer nor the mechanism by which the design was instantiated, ID is potentially compatible with a large number of different philosophies. The following views are all supportable within the narrow meaning of ID as an identifier of a past design action:
- ID only applies to life as investigated to date, on Earth, and is not an indication that life cannot originate through abiogenesis. This allows ID as a component of hypotheses that life on Earth was introduced by aliens, or as a result of panspermia.
- ID states that there has not been sufficient time for evolution to produce the complexity of life as observed even within the timespan available since the Big Bang, and thus the only available mechanism for the creation of life is one that is supernatural.
- ID states that the present knowledge of physics at the quantum level still allows that there are realms outside the well investigated space/time dimensions such that all natural explanations are not excluded.
Similarly, the observation of signs of design does not restrict the point of intervention, and the following possibilities exist:
- de novo creation of life
- intervention in existing organisms to introduce observed complexity
- on-going or intermittent intervention.
Further, there is no restriction on the number of designers responsible for observed life, so the number and character of intelligent design scenarios is potentially large.
Evolutionary vs. ID views
According to the theory of evolution, genetic variations occur randomly, and environmental stress selects against those variations that are not as advantageous as others. From the intelligent design viewpoint, these random variations exist but are not the explanation for the appearance of new "kinds". The definition of a "kind" is vague, usually something like a genus rather than a species. New kinds arise when the designer steps in and causes significant variation to occur. Actually, ID is not closely tied to "kinds", but to complex changes whenever they occur.
Adherents of intelligent design call the idea that God causes new species to come into being a viable scientific hypothesis (see scientific creationism). Nearly all scientists consider it pseudo-scientific, on the grounds that it is an amalgam of false or unsupported claims within the realm of science, and of philosophical or religious claims outside the realm of science. (See methodological naturalism for a discussion of supernatural explanations in science.)
To underscore the pseudo-scientific nature of ID, in the mid-1990s George W. Gilchrist of the University of Washington looked through thousands of scientific journals searching for any articles on intelligent design or creation science—he didn't find any. Other more recent surveys have also failed to find articles on these subjects in the primary scientific literature (not to mention that only a handful of these articles were even submitted). Some ID proponents claim this is due to a global conspiracy, career requirements, etc. In response, opponents can point out that tenured professors are pretty safe, and anyone presenting convincing evidence of design would be lavishly rewarded and published in the popular press. In contrast, many articles have been published in highly-ranked journals which specifically deny the claims of ID (for example, Lenski et al. 2003 The evolutionary origin of complex features. Nature 423:139-44.)
Advocates of intelligent design argue that the biological evidence presents serious problems for macroevolution. For example, they claim that all the major types of animals appeared at the same time in the fossil record with no evidence of common ancestry (a claim that is not supported by subject experts)—a pattern they say is inconsistent with Darwin's theory of evolution. Modern evolutionary biologists' concept of evolution goes beyond the gradualism proposed by Darwin in the nineteenth century. Better evidence gathered since the time of Darwin has shown that evolution occurs at a steady Darwinian rate until a large environmental change occurs (such as an ice age, asteroid impact, or very large volcanic eruption). Evolution then occurs at a greatly accelerated rate. Those who adhere to the concept of intelligent design seem to ignore the modern concept of evolution, say many scientists.
They also argue that complex organs that cannot function without all their parts provide evidence for a cause having intelligence. Usually, this intelligence is attributed to God. This is one aspect of the idea that some biological developments are too complex to have come about without having been designed. This idea is particularly pressed by Michael Behe under the rubric irreducible complexity in his Darwin's Black Box (1996; see reference above). See also: argument from design and especially argument by lack of imagination. This is also called a "God in the gaps" argument. All of Behe's examples have been explained without the need for design (for example, [2]).
Proponents of intelligent design point to complex biological structures such as the eye, birds' wings, the existence of mitochondria, bacterial flagella, etc., arguing that such structures could not possibly have developed due purely to random mutations, even with the aid of natural selection. Symbiotic relationships, such as plants which can only be pollinated by a specific species of insect, which in turn can only reproduce by using the plant, could not have arisen, they argue—a typical chicken and egg problem. It is argued that these kinds of biological features are by their very nature too interdependent to come into existence independently through a natural process and then become so intricately intertwined. Opponents say these examples have been adequately explained.
Criticism of intelligent design
The strategy of ID critics takes two main forms:
- Looking at certain examples, often the same ones as ID proponents use.
- Refuting the logic of the arguments invoked to support ID.
These critics assert that most of intelligent design's examples of things that cannot be explained by evolution have since been explained by new advances in genetics and biotechnology. For example, the development of mitochondria was once puzzling, but Lynn Margulis's theory of their evolution from endosymbiotic bacteria, once rejected even by biologists, has amassed enough evidence that it is now widely accepted.
Critics of ID say that evolutionary development of such structures as eyes and wings has been simulated in computers. Studies of fig wasps have revealed how symbiotic species can evolve.
The watch argument
A particularly famous example of an argument for ID is the "watch argument".
In 1802 theologian William Paley wrote that if a pocket watch is found on a field, it is most reasonable to assume that someone dropped it and that it was made by a watchmaker and not by natural forces. Paley went on to argue that complex structures of living things must be the work of an intelligent designer because they are too complex to work half-evolved.
Many have attempted to refute Paley's argument, mainly by showing that highly complex systems can be produced by a series of very small randomly-generated steps. Richard Dawkins' book The Blind Watchmaker is one of the best known works following this idea.
The debate over this is closely related to irreducible complexity, the idea that certain structures in biology can function only if all their substructures are present. It is argued that each substructure confers no benefit on its own, and therefore would not have been selected by an evolutionary mechanism. The probability of all the substructures being created in a single mutation is too low to be considered possible.
The eye argument
Many early creationists cited the human eye as their prime example of this principle; "What use is half an eye?", they asked. Evolutionists would provide a detailed explanation for this and would state that creationists were simply falling into the logical fallacy called lack of imagination. A modern explanation for the evolution of the eye is given here.
The apparent "miracle" of the human eye, along with other body parts and organs, has often been used as proof by both creationists and intelligent design proponents that a higher power must be responsible for creating such a complex organ. Scientists, however, have devised working hypotheses on how certain body parts and organs have evolved.
For example, many biological cells not associated with the senses respond to the presence of light. Most notable of this group are photosynthetic proteins of algae and photosynthetic cells of plants. Other very primitive organisms, such as sponges, have very rudimentary photoreceptive cells that can only tell the difference between light and dark. These organisms use this primitive sense to orient themselves correctly toward light. In other words, much less than half an eye is actually quite useful. Yet other organisms have clusters of these photoreceptive cells that can distinguish crude shapes. Increasing the complexity, number, and arrangement of these cells will then yield rudimentary eyes that can recognize certain objects by shape and so on until an eye capable of seeing in color and three dimensions is produced (this has happened at least twice in evolution with the advent of the cephalopod eye and is currently under way with many other animal groups). Each of these steps in the development of a fully functioning eye has modern analogues in the animal kingdom, and each step need only develop through nothing more than natural selection: those animals with a better ability to sense their environment with photoreceptive cells will survive to produce more young than those that don't have this ability, and so on. Scientists thus conclude there is no need for divine intervention of intelligent design.
Richard Dawkins in particular has vigorously challenged ID arguments similar to Paley's. Furthermore, he points out that a hypothetical evolutionary path such as that given above for the eye need not even be correct; in order to refute the argument from design it need only be plausible, thus demonstrating that there are other ways in which such an organ could have come about. The title of Dawkins' book The Blind Watchmaker is a reference to Paley's example of the pocket watch. Dawkins's book, River out of Eden (1995) gives an example of a computer simulation where multiple independent organisms all showed a steady progression from a light-sensitive spot to a complex eye with a lens focus.
Additional arguments
Further, say scientists, a body part or organ that has a modern function did not necessarily have the same function in the past. Evolution works on chance and opportunity, with gill bones of mouth-less fishes evolving into jaws, fish air bladders becoming vertebrate lungs, and fin support structures becoming fingers and toes. Scientists have also argued that arguments like the watch argument actually damage the case for the ID theory. Specifically, some of them claim that life is often "poorly designed" on the macroscopic, cellular, and genetic levels. Others just say that we simply don't have enough knowledge about the processes in living systems to draw this type of conclusion.
Related examples are given under the topic Irreducible complexity.
Broader view of "intelligent design"
Some people use the term "intelligent design" in a broader sense than that given in intelligent design theory. It can refer simply to the belief that God designed the universe, without any specific claim as to how or when he did so. Many people consider this belief entirely compatible with standard Darwinian evolution, with no divine intervention—life could be produced by a purely natural process, evolution, designed by God. God might merely have written the laws of physics, or chosen the fundamental constants, and left the universe to run like clockwork afterwards. This would be a form of deism. A more theologically robust view is theistic evolution (see e.g., Kenneth R. Miller's Finding Darwin's God cited above), which is too nuanced to explain here. Not all people who believe God was involved in the design of the Universe also adhere to the specifics of the intelligent design belief, as proposed by creationists.
Public discourse
Intelligent design has lately been a controversial subject, particularly in American schools. After years of judicial rejection of creationist teaching—on the grounds that creationism is a religious theory, not a scientific theory—many creationists have begun to promote intelligent design as a non-religious, scientifically acceptable alternative to the theory of Evolution. However, this attempt has met with strong opposition from some theologians. In order to be non-religious, one must argue that the intelligent being who designed the universe is not necessarily the same as the religious God. This view has been criticized as allowing for the existence of a demiurge and for being perilously close to gnosticism, which is considered heretical by most Christian groups.