Intelligent design: Difference between revisions
imported>Nancy Sculerati (the longer this stays in Biology the more clear it is that it is not a wanted part of the Biology workgroup by the Biology workgroup, as a member of the biology workgroup,I am removing it) |
imported>Will Nesbitt (→Irreducible Complexity: moving and sorting) |
||
Line 38: | Line 38: | ||
Both Dembski and Behe are senior fellows of the Discovery Institute's Center for Science and Culture in Seattle. The Discovery Institute is a Christian educational foundation established to promote creationist thought, founded by Stephen C. Meyer, Bruce Chapman and George Gilder. Meyer gained a Ph.D in [[history of science|history]] and [[philosophy of science]] from Cambridge University for a dissertation entitled "Of clues and causes : a methodological interpretation of origin of life studies." | Both Dembski and Behe are senior fellows of the Discovery Institute's Center for Science and Culture in Seattle. The Discovery Institute is a Christian educational foundation established to promote creationist thought, founded by Stephen C. Meyer, Bruce Chapman and George Gilder. Meyer gained a Ph.D in [[history of science|history]] and [[philosophy of science]] from Cambridge University for a dissertation entitled "Of clues and causes : a methodological interpretation of origin of life studies." | ||
==Distinct from creationism== | ==Distinct from creationism== |
Revision as of 17:46, 26 May 2007
Intelligent design (ID) is the designation for a claim that certain fundamental features of the universe and living things are best explained by purposeful causation—a "higher intelligence."
Proponents of ID point to examples in the natural world, such as living organisms, whose origins, in their view, are the result of the intervention of a higher intelligence, rather than by chance interactions. For mainstream biologists, such claims are not supported by evidence in the scientific literature and when intelligent design claims have been put to a rigorous test an evolutionary explanation provides an adequate explanation for the diversity of related structures.[1]
See intelligent design movement for an account of the efforts to employ ID to rebut evolution to better promote education about intelligent design within schools.
An Argument for Intelligent Design
The classic design argument for the existence of an intelligent creator may be traced from ancient philosophy, through the works of medieval scholastics such as the philosopher-theologian Saint Thomas Aquinas(1225-1274), who argued that the existence of God could be deduced by reason.
In the 19th century, William Paley (1743-1805) introduced the "watchmaker analogy", one of the best known metaphors in the philosophy of science, as an argument for the existence of God.[2] The argument is, in essence, as follows: Imagine walking on a pebbled beach, where the pebbles may be wonderfully shaped, beautiful in different ways, interesting and varied one from another. However interesting and beautiful you find them, you will not doubt that they are the products of purely natural causes. However, if amongst the pebbles you find a watch, even if you have never seen a watch before, you will immediately recognise it as qualitatively different from the pebbles. Inspecting it, from the intricacy of its design, and the clear purpose of that design, you will inevitably and correctly conclude that the watch is not a 'natural' object but an artifact, something designed by a powerful and intelligent agent.
Casual observation might similarly lead to the conclusion that, compared to a watch, even the simplest living form is incredibly complex, giving it the appearance of being designed for a purpose. There must be a designer, said Paley, and that designer is God.
The currently accepted account of the origin of living things is known as the "Modern Evolutionary Synthesis", a theoretical framework which expresses the theory of evolution by natural selection in a form consistent with molecular biology and population genetics. By this theory all extant living things are the products of descent with modification from common ancestors that lived 3-4 billion years ago. This theory explains all evolution as resulting from processes of natural selection among populations that vary in a random way (as a result of spontaneous genetic mutations, and of random shuffling of genes in the offspring of sexually reproducing species). Natural selection is a creative process because, as favorable mutations accumulate over generations and combine in different ways, this produces a huge diversity of organisms - more than 10 million living species.
There are important features that distinguish the 'design' achieved by natural selection from the kind produced by an intelligent designer. Natural selection is undirected in that it has no preordained plan, but is simply a result of the differential survival and reproduction of living beings. Natural selection has no foresight, and so environmental changes may threaten the survival of organisms that werethriving. As a result, species extinction is common: it is estimated that "more than 99% of all species that have ever lived on Earth are now extinct." [3]
Modern proponents of intelligent design argue that evolution by an 'undirected' process like natural selection cannot adequately account for the complexity of life. [4]They argue that essential features of even the simplest extant living things are 'irreducibly complex', in that such features arise only in highly complex systems and do not appear in even a rudimentary form in simple systems. They argue that an irreducibly complex system is very unlikely to be produced by successive, slight modifications of a previously existing system, because any precursor that was missing a crucial part would be unable to function at all.
It has not been possible to reconstruct in reliable detail the events that gave rise to the simplest form of life; there is too much that remains unknown. Accordingly, intelligent design theory argues that it is just as appropriate to postulate an intelligent agent to explain the mysteries of life as it is to postulate an intelligent watchmaker to explain the watch found on a beach.
Some ID proponents consider that alternative explanations (including Darwinian evolution) are not feasible, as they argue that the well-documented natural selection mechanisms that have been used to explain the "apparent design" of numerous components and interactions of living organisms cannot explain all features of organism complexity. They see evolution as an "undirected, chance-based process"; ID does not emphasise that selection for reproductive success intrinsically directs evolutionary change towards functional design solutions, or that numerous genetic mechanisms exist to provide a vast array of genetic diversity from which well designed components can be selected. [5]
Proponents of intelligent design
Prominent ID proponent William Dembski has a PhD in mathematics from the University of Chicago, and is research professor in philosophy at Southwestern Baptist Theological Seminary in Fort Worth, Texas. In 1998, Cambridge University Press published Dembski's first book, a philosophical monograph entitled The Design Inference: Eliminating Chance through Small Probabilities. Dembski has published several books since, but has published no papers on intelligent design in the peer-reviewed scientific literature. Dembski is particularly associated with the concept of 'specified complexity'.
Another prominent proponent, and one particularly associated with arguments related to the concept of 'irreducible complexity', is Michael J. Behe. Behe is professor of biochemistry at Lehigh University in Pennsylvania. Behe holds that some biological structures are too biochemically complex to be plausibly explained as a result of evolution by natural selection. Unlike many in the intelligent design movement, Behe accepts the evidence for the common descent of species, including the conclusion that humans descended from other primates; however, he claims that common descent alone cannot fully explain the differences between species.
Both Dembski and Behe are senior fellows of the Discovery Institute's Center for Science and Culture in Seattle. The Discovery Institute is a Christian educational foundation established to promote creationist thought, founded by Stephen C. Meyer, Bruce Chapman and George Gilder. Meyer gained a Ph.D in history and philosophy of science from Cambridge University for a dissertation entitled "Of clues and causes : a methodological interpretation of origin of life studies."
Distinct from creationism
Most proponents of the intelligent design hypothesis are also creationists, meaning they believe the universe was created by a deity or some other power beyond the comprehension of mortal man. The hypothesis, however, is not the same as young earth creationism, which is a belief that the account of the creation of the universe and of life as given by the Bible is literally true. Intelligent design does not try to identify the designer as supernatural, nor does it try to establish the veracity of a particular narrative, although some leading proponents of intelligent design have stated that they believe the designer to be the Christian God.
As intelligent design avoids identifying the designer, its focus is different to that of arguments in natural theology, such as the teleological argument. William Dembski argues that intelligent design can be formulated as a scientific theory of information that has empirical consequences and which is devoid of any religious commitments.[1] By this view, intelligent design asks whether design can be detected in nature from purely scientific and mathematical considerations.
Other proponents of intelligent design see no conflict between intelligent design and evolution, and indeed see evolution as evidence of intelligent design.
Peer reviewed ID publications
Many books on ID have been written [6] but very few ID research papers or monographs have been published in peer-reviewed scientific journals. Many prominent proponents of ID are qualified, practising scientists and it is a weakness of the theory that so little has appeared in the journal literature. This leads some proponents of the theory to suppose that there is some conspiracy or other effort to supress intelligent design discussion in an academic environment.
On 4 August 2004, an article by Stephen Meyer, an intelligent design proponent, appeared in the peer-reviewed Proceedings of the Biological Society of Washington, questioning conventional evolutionary explanations for the Cambrian Explosion and proposing intelligent design as an alternative. Later, however, the Council of the Biological Society of Washington retracted the article. The managing editor for the journal at the time, the process structuralist Richard Sternberg, stated that the article had been properly peer reviewed by three well qualified referees. His decision to publish the paper nevertheless resulted in protests, and colleagues at the Smithsonian Institute, where he was employed, sought to discredit him and created what the The U.S. Office of Special Council (which is authorized to investigate allegations of prohibited personnel practices and activities prohibited by civil service law) called "a hostile working environment".[7][8]
The lack of peer reviewed articles is cited by ID opponents as proof that ID is unscientific. ID supporters point to the Proceedings incident as showing just the opposite: that the scientific climate is so prejudiced against ID that not even peer review is enough to overcome publication bias.
Criticisms of intelligent design
Both philosophical and scientific proponents of intelligent design argue that it is a scientific theory rather than a matter of religious belief[9], but many scientists reject this assertion. Mainstream scientists consider that for a theory to be 'scientific' it must generate predictions by which it can be tested; in other words it must be open to attempted disproof. For example, the philosopher of science Karl Popper argued that a theory that has no testable components "has no connection with the real world." As ID is not open to test, it is not a scientific theory in this sense (see Scientific method).
Scientists critical of intelligent design also dismiss the claim that only the intervention of a higher intelligence can adequately explain certain poorly understood phenomena; they do not regard such a lack of understanding as good evidence for any scientific conclusions. Intelligent design proponents respond, to the contrary, by claiming that the phenomena they take as evidence of intelligent design cannot be understood except by reference to a higher intelligence. Mainstream scientists, being concerned with understanding those phenomena in natural terms, naturally disagree.
Herein, we will detail some of the most common elements of the intelligent design narrative, but this criticism is by no means exhaustive or complete. So long as the basis of intelligent design remains an explanation for that which is not fully understood, then the refutation intelligent design will remain expansive but incomplete.
Critics hold that the postulate of an intelligent designer is not an explanation for life at all, but an evasion of attempted explanation. By this view, intelligent design has no content, and makes no predictions by which it can be tested.[10] Some argue that the theory of evolution by natural selection, is also not really a testable scientific theory. For example, there is a detailed and coherent argument that accepts that "Darwinism" is scientifically invaluable, but also asserts that it is untestable, and should be regarded as a metaphysical platform for a research programme rather than a theory.[11]
Opponents of intelligent design who are scientists consider that the evidence of complexity in biological systems can be explained by conventional biological theory. There are also many opponents of intelligent design who are religious, and who believe that the role of science is to seek natural, physical explanations of the world; although they believe that there is a God who created the world and life in it, for them this is a matter of faith not of science. Opponents of intelligent design doubt the intellectual honesty of intelligent design theory, in that they do not consider it to be a viable alternative to the theory of evolution by natural selection, and hence consider that the only reason for promoting it is for the religious message that it is said to contain, not for the intrinsic intellectual merits of the arguments.
The basic thesis of intelligent design that 'natural selection is undirected' is open to logical challenge. Natural selection of organism survival is indirectly specific on organism subcomponents, because many features of the subcomponents are determined by genes whose retention is determined by their importance for reproductive success of the organism. Organism survival selects for effective function of the organism sub-components as part of a coherently functioning whole. In any organism, survival places specific and subtle requirements and restrictions on particular components such as enzymes, sensors, organs and systems that interact to generate behavior of living things.
While proponents of intelligent design see evidence of design in how well complex structures fit their purpose, molecular biologists see something very different in the fine details of those structures. So far from seeing genetic information being perfectly and economically fashioned to suit a given purpose, they see wastefulness, duplication, errors, the detritus of now redundant genes in gene sequences - in other words, things they would expect to see as the residue of evolution by natural selection. In short, despite the appearance of efficient design at a high level, at a molecular level the design shows little sign of purposeful intelligence but extensive signs of chance processes. [12]
Could the flagellum have evolved by natural selection?
Critics of intelligent design argue that the idea that every piece of any biological machine must be assembled in its final form before anything useful can emerge is wrong. Evolution produces complex biochemical machines by copying, modifying, and combining proteins that were previously used for other functions. For example, Michael Behe argues that if you remove almost any of its parts, the bacterial flagellum does not work. However, it is argued by evolutionary theorists that many features of organisms evolved to fit one function and were then adapted through natural selection to fulfil a different function. By this view, natural selection is not a single path, but a multiply branching path with many dead ends, with many branching points where genes were duplicated, and with many changes of direction where the 'destination' changed. In other words, critics argue that the proponents of intelligent design misrepresent or misunderstand the processes involved in natural selection.
In particular, the flagellum is a structure that allows bacteria to move: 30 to 40 different proteins are required in a particular arrangement for the flagellum to work, and as it is argued that a flagellum is useless if it won't move, and needs all its parts to function, and that it is difficult to conceive that it arose by successive gradual mutations. This interpretation needs to account for the importance other genetic mechanisms in addition to mutation, and the evidence available from reconstruction of protein evolution by sequence comparisons. When the similarities among the different flagellum protein components are examined using this approach, it becomes clear that the modern day flagellum proteins evolved from just two precursors (a proto-flagellin and a proto-rod/hook protein) by multiple rounds of gene duplication and diversification. Relatives of some flagellum proteins are used in other bacterial structures. A protein that is similar to flagellum component FlgA is used in assembly of Type IV pili. Flagellum protein FlgJ contains region that digests the cell wall during flagellum insertion through the wall, and there are many bacterial proteins that are similar to it doing other tasks. [13]
Thus some of the proteins from the flagellum are used by many bacteria for other functions as well, such as as a device for injecting poisons into other cells. Accordingly, biologists believe it is likely that different elements of the flagellum evolved separately to fulfil other functions in precursor organisms, and that motility arose relatively late in evolution, once many of the elements used in the flagellum were already in place for other reasons.
See also
- Intelligent Design? A special report reprinted from Natural History magazine. Three proponents of intelligent design present their views. Each view is followed by a response from a proponent of evolution. [2]
- Intelligent design movement
Notes
- ↑ Pallen MJ, Matzke NJ. From The Origin of Species to the origin of bacterial flagella. Nat Rev Microbiol. 2006 Oct;4(10):784-90. Epub 2006 Sep 5.
- ↑ *Works by William Paley at Project Gutenberg
- William Paley - the watchmaker analogy
- text of David Hume, Dialogues concerning Natural Religion; see especially Parts II-VIII for Hume's classic refutation of the design argument
- text of Charles Darwin, Natural Theology; or, Evidences of the Existence and Attributes of the Deity
- An Animated Presentation of the Watchmaker Analogy
- Dawkins, Richard [1986] (1996). The Blind Watchmaker. New York: W. W. Norton & Company, Inc.. ISBN 0-393-31570-3.
- ↑ Ayala FJ (2007) Colloquium Papers: Darwin's greatest discovery: Design without designer. Proc Natl Acad Sci U S A. 104 Suppl 1:8567-73. PMID 17494753
- ↑ Intelligent Design? a special report reprinted from Natural History magazine
- ↑ Intelligent Design Intelligent Design network.
- ↑ Books by Intelligent Design proponents
- Michael J. Behe (2006) Darwin's Black Box: The Biochemical Challenge to Evolution Free Press ISBN 0743290313
- Behe MJ, Dembski WA, Meyer SC (Eds) (2000)Science and Evidence for Design in the Universe (Proceedings of the Wethersfield Institute) Ignatius Press ISBN 0898708095
- William A. Dembski (2004) The Design Revolution: Answering the Toughest Questions About Intelligent Design InterVarsity Press, ISBN 0830823751
- William A. Dembski (1998) The Design Inference: Eliminating Chance through Small Probabilities (Cambridge Studies in Probability, Induction and Decision Theory) Cambridge University Press ISBN 0521623871
- William A. Dembski (2002) Intelligent Design: The Bridge Between Science & Theology InterVarsity Press ISBN 083082314X
- Percival Davis and Dean H. Kenyon (1989) Of Pandas and People: The Central Question of Biological Origins (2nd edition 1993) a school-level textbook published by the Foundation for Thought and Ethics ISBN 0-914513-40-0 See a review by paleontologist Kevin Padian of the National Center for Science Education
- ↑ The homepage of Richard Sternberg
- ↑ Decision of the Office of Special Council regarding Richard Sternberg's allegations
- ↑ Primer: Intelligent Design Theory in a Nutshell Intelligent Design and Evolution Awareness (IDEA)
- ↑ Sober E (2007) What is wrong with intelligent design? Q Rev Biol. 2007 Mar;82(1):3-8 PMID 17354991
- ↑ Popper, Karl (1974) Unended Quest Fontana
- ↑ Zuckerkandl E (2006) Intelligent design and biological complexity. Gene 30;385:2-18.
- ↑ Pallen MJ, Matzke NJ. (2006)
From The Origin of Species to the origin of bacterial flagella.
Nat Rev Microbiol. 4:784-90. PMID 16953248
- Soscia C et al.' (2007) Cross talk between type III secretion and flagellar assembly systems in Pseudomonas aeruginosa. J Bacteriol 189:3124-32