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. For creationists, it should allow room on Noah’s Ark for a pair of each kind. 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 (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12736677&dopt=Abstract).)
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] (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12736677&dopt=Abstract)).
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.