 |
|
| ||||||||||||||||||||||||||
|
|
| ||||||||||||||||||||||||||
|
|
|
|
|
| ||||||||
Intelligent design (ID) is the claim that empirical evidence points to the conclusion that life on earth was deliberately designed by one or more intelligent agents, or that an intelligent designer is necessary to fully account for the adaptive complexity and diversity of life, because naturalistic causes are inherently insufficient.
The phrase "Intelligent Design," was first widely publicized by legal scholar Phillip E. Johnson in his 1991 book Darwin on Trial, though earlier references can be found in creationist literature. Johnson's argument, and a key tenet of the ID movement, is that philosophical naturalism is false.
The claims of the Intelligent design movement are regarded as pseudoscience by the vast majority of practicing biologists, and the scientific community asserts that ID has been repeatedly debunked.
| Contents |
ID supporters claim to present a scientific case for "reasonable doubt" about the standard scientific model of evolution by natural selection. ID includes arguments that abiogenesis is impossible, that evolution cannot account for the complexity of life (see "irreducible complexity") and that the universe is "fine tuned" for living things in a manner that must have been by design. ID makes no explicit claims about the identity, motives, or methods of the intelligent designer(s). ID proponents argue that it is reasonable to infer intelligent causes when natural laws and causes provide no satisfactory explanation for how things have come about.
The Intelligent Design movement is an organized campaign to promote ID arguments in the public sphere, primarily in the United States. The hub of the movement is the Center for Science and Culture, a subsidiary of the Discovery Institute, a politically conservative think tank.
Though explicitly secular in its arguments, the ID movement is largely associated with Conservative Christians, and in this connection ID is sometimes described as a revision of the argument from design made famous by William Paley in the early 19th century.
The overwhelming majority of professional scientists reject the ID arguments; organizations such as the National Academy of Sciences and the National Center for Science Education characterize ID as pseudoscience. Practicing scientists uses phrases such as their "arguments are deeply flawed and have little to contribute to science or mathematics" and "muddled thinking, fallacious arguments, errors, equivocation and misleading use of technical jargon." In short, unworthy of scientific examination, and important because of what is an "unconcealed" desire for an "unembodied" designer. (Not a Free Lunch But a Box of Chocolates Richard Wein 2002).
Arguments for intelligent design can be broadly split into four categories:
In addition, proponets of ID argue:
Principal criticisms of intelligent design (from agencies like the National Center for Science Education [2] (http://www.natcenscied.org/) ) include:
The term "irreducible complexity" was coined by biochemist Michael Behe in his 1996 book Darwin's Black Box. The irreducible complexity argument holds that evolutionary mechanisms cannot account for the emergence of complex cellular systems. ID advocates argue that cellular machines must therefore have been deliberately engineered by some form of intelligence.
"Irreducible Complexity" is defined by Behe 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" (Behe, Molecular Machines: Experimental Support for the Design Inference). According to the theory of evolution, genetic variations occur without specific design or intent, and the environment selects variants that have the highest fitness, which are then passed on to the next generation of organisms. Change occurs by the operation of natural forces over time, perhaps gradually, perhaps more quickly (See Punctuated equilibrium) and is able to create complex structures from simpler beginnings, or convert complex structures from one function to another (see spandrel). Most ID advocates accept that evolution through mutation and natural selection occurs, but assert that it cannot account for irreducible complexity, because none of the parts of an irreducible system would be functional or advantageous until the entire system is in place.
Behe uses the example of a mousetrap to illustrate this concept. A mousetrap consists of several interacting pieces -- the base, the catch, the spring, the hammer -- all of which must be in place for the mousetrap to work. The removal of any one piece destroys the function of the mousetrap. Likewise, biological systems require multiple parts working together in order to function. Natural selection could therefore not create them from scratch by successive, slight modifications, because the selectable function is only present when all parts are assembled. Behe's original examples of irreducibly complex mechanisms included the bacterial flagellum of E. coli, the blood clotting cascade, cilia, and the adaptive immune system.
The ID argument of specified complexity was developed by mathematician, philosopher, and theologian William Dembski. Dembski uses specified complexity to denote a property that makes living things unique. He claims that specified complexity is present when there exists a large amount of specified information. The following examples demonstrate the concept of specified information:.
Dembski defines complex specified information (CSI) as something containing a large amount of specified information, which has a low probability of occurring by chance. He defines this probability as 1 in 10150, which he calls the universal probability bound. Anything below this bound has CSI. The terms "specified complexity" and "complex specified information" are used interchangably.
Dembski and other proponents of ID assert that specified complexity cannot come about by natural means, and is therefore a reliable indicator of design.
ID proponents use the argument that we live in a "finely-tuned universe." They propose that the natural emergence of a universe with all the features necessary for life is wildly improbable. Thus, an intelligent designer of life was needed to ensure that the requisite features were present to achieve that particular outcome. Opinion within the scientific community is still divided on the "finely-tuned universe" issue, but this particular explanation and assessment of probabilities is rejected by most scientists and statisticians - see Fine-tuned universe for a more detailed discussion.
Within mainstream physics this is related to the question of the Anthropic principle: whose weak form is based on the observation that the laws of physics must allow for life, since we observe there is life. The strong form however is the assertion that the laws of the physics must have made it possible for life to arise. The strong form is a distinctly minority position and is highly controversial. (See Anthropic principle, Cosmology).
Critics of ID attack the definition of irreducible complexity, showing numerous inconsistencies in Behe's work, its lack of mathematical precision, and the application of an assertion that one can count a number of irreducible steps as Behe claims. They also point out that Behe has backed off of examples of irreducible complexity. They argue that Behe does not accurately calculate the odds of particular changes in the genome occuring. Further they argue that ID has promulgated no theory or method which would allow them to detect possible examples of cases of human modification of the genome, which would seem to be indistinguishable from the process of interfering with the genome that Intelligent Design asserts occured.
Critics of ID also argue that the IC argument assumes that the present function of a system must have been the one that it was selected for. But the concept of cooption, in which existing features become adapted for new functions, has long been a mainstay of biology. Many purported IC structures have functional subsystems that are used elsewhere. ID advocates have often reacted to this by trying to define an "IC core", or by changing the number of parts required for an IC system. Critics have claimed that these instances of "moving the goal posts" show that IC is not a clear concept that can be objectively applied.
The IC argument assumes that a necessary part of a system has always been necessary. But something which is at first merely advantageous can later become necessary. For example, one of the clotting factors that Behe listed as a part of the IC clotting cascade was later found to be absent in whales[3] (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9678675), demonstrating that it isn't essential for a clotting system. Evolutionary pathways have been elucidated for IC systems such as cilia, the immune system[4] (http://www.talkdesign.org/faqs/Evolving_Immunity.html) and the flagellum[5] (http://www.talkdesign.org/faqs/flagellum_background.html). If IC is a reliable barrier to evolution, it should not be possible to construct such pathways. Computer simulations of evolution also demonstrate that IC can evolve. [6] (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12736677&dopt=Abstract)[7] (http://www.embl.org/aboutus/news/press/2004/press28oct04.html)
Critics also reject the ID movement's assertion that design is recognizable, namely that if it looks designed, it must be designed.
ID advocates respond by saying that proposed models for the evolution of IC structures are not detailed enough, or cannot be tested. They also dismiss computer simulations as biologically unrealistic.
The conceptual soundness of Dembski's SC/CSI argument is strongly disputed by critics of ID. First, specified complexity, as originally defined by Leslie Orgel, is precisely what Darwinian evolution is proposed to create. It is not enough for Dembski to take a property of living things and arbitrarily declare it to be a reliable indicator of design; he must also provide compelling reasons why no natural processes could create such a property.
Additionally, Dembski confuses the issue by using "complex" as most people would use "improbable". He defines CSI as anything with a less than 1 in 10150 chance of occurring naturally. But this renders the argument a tautology. CSI cannot occur naturally because Dembski has defined it thus, so the real question becomes whether or not CSI actually exists in nature. To demonstrate this, Dembski would need to show that a biological feature really did have an extremely low probability of occurring naturally by any means, an enormously difficult (perhaps impossible) task that would require definitively ruling out all potential theories, including those that may not have been thought of yet. In general, Dembski does not attempt to do this, but instead simply takes the existence of CSI as a given, and then proceeds to argue that it is a reliable indicator of design.
Scientists point out that this is "argument from ignorance", namely the fallacy that because we do not know how something occured, it must be the sign of intelligence.
Further, mathematicians have pointed out that Dembski's information theory is flawed, that many of his examples that he claims cannot be compressed further, in fact can be.
Main Article: Center for Science and Culture
The intelligent design movement is centered around the Center for Science and Culture (CSC), formerly known as the Center for Renewal of Science and Culture, which was founded in 1996. The CSC is affiliated with the conservative Christian thinktank, the Discovery Institute.
In their effort to gain widespread acceptance of their views, the CSC fellows devised the "wedge strategy", and produced an internal memo now known as the Wedge Document (http://www.antievolution.org/features/wedge.html), which was inadvertently leaked to the public. The Wedge Document serves as the unofficial manifesto of the ID movement; it outlines the movement's goal to exploit perceived discrepancies within evolutionary theory in order to discredit evolution and scientific materialism in general. Much of the strategy is directed toward the broader public, as opposed to the professional scientific community. The stated "governing goals" of the CSC's wedge strategy are "1. To defeat scientific materialism and its destructive moral, cultural and political legacies" and "2. To replace materialistic explanations with the theistic understanding that nature and human beings are created by God." Critics of ID argue that the wedge strategy demonstrates that the ID movement is motivated by religion and political ideology.
George W. Gilchrist of the University of Washington looked through thousands of scientific journals in the mid-1990s, searching for any articles on intelligent design or creation science—he found none. More recent surveys have also failed to find articles on these subjects in the primary scientific literature. By contrast, many articles have been published in peer reviewed science journals that specifically deny the claims of ID (for example, Lenski et al. 2003 The evolutionary origin of complex features. Nature 423:139-44 (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12736677&dopt=Abstract).)
One of the scientific community's justifications for its vociferous opposition to ID, is the perception that ID proponents are attempting to "end run" the scientific process by either not submitting to peer reviewed journals, or by setting up "peer review" that consists entirely of ID supporters.
One of ID's explanations for its absence from peer-reviewed literature is that papers explaining the findings and concepts in support of ID are consistently excluded from the mainstream scientific discourse by definition, because ID arguments challenge the principles of naturalism and uniformitarianism that are accepted as fundamental by the mainstream scientific community. Thus, they claim, research that points toward an intelligent designer is often rejected simply because it deviates from these dogmatically held beliefs, without regard to the merits of their specific claims.
To date, the intelligent design movement has succeeded at publishing one article in a peer-reviewed scientific journal, Proceedings of the Biological Society of Washington, although that journal has subsequently disowned the paper. The author is Stephen C. Meyer, Program Director of the Discovery Institute’s Center for Science and Culture, the major organization promoting ID. The journal issued a public statement (http://www.biolsocwash.org/id_statement.html) explaining that the Meyer paper did not go through the journal's approved peer review process and does not meet the scientific standards of the journal.
This article is not available on-line from this journal, but a copy is on the Discovery Institute site:
A critical review of it is available on the Panda's Thumb website:
[8] (http://www.pandasthumb.org/pt-archives/000430.html)
Although the Intelligent Design movement is often portrayed as a variant of Bible-based Creationism, ID arguments are formulated in secular terms; they do not cite Biblical evidence of creation, nor do they require that their adherents accept the Bible’s accounts or even the existence of a creator god. ID avoids claims about the identity of the designer or the mechanism of the design process, though proponents do make claims about the moment or moments in history at which the designer’s intervention occurred, usually assuming the designer to be available and capable at every place and time.
The key arguments in favor of the different variants of ID are so broad that they can be adopted by any number of communities that seek an alternative to evolutionary thought, including those that support non-theistic models of creation although the designers might be different. For example, the notion of an “intelligent designer” is compatible with the materialistic hypotheses that life on Earth was introduced by an alien species, or that it emerged as a result of panspermia, but would not be with the designer(s) of the "fine-tuned" universe.
Likewise, ID claims can support a variety of theisitic notions. Some proponents of creationism and intelligent design reject the hellenic Christian concept of omnipotence and omniscience on the part of the creator, and ascribe to Open Theism or Process theology. ID researchers that hold to the proposition of an omniscient, omnipotent and benevolent God as the designer may face an additional burden of proof beyond the claims of the ID movement, by having to additionally demonstrate that the designs themselves are flawless and anticipate all eventualities. Existing evidence poses many difficult challenges for the advocates of omniscient, omnipotent design, for example:
Some of these ID researchers would instead argue that when compared to that of an all-knowing God, our own knowledge is insignificant, and so features that may appear flawed to us, are more rightly considered perfect.
|
||||
| View Live Article | This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License | |
||
