Just as the meaning of a sentence depends upon the specific arrangement of the letters in a sentence, so too does the function of a gene sequence depend upon the specific arrangement of the nucleotide bases in a gene. Thus, molecular biologists beginning with Crick equated information not only with complexity but also with specificity, where specificity or specified has meant necessary to function (Crick 1958:144, 153; Sarkar, 1996:191)...
...Molecular biologists have recently estimated that a minimally complex single-celled organism would require between 318 and 562 kilobase pairs of DNA to produce the proteins necessary to maintain life (Koonin 2000). More complex single cells might require upward of a million base pairs. Yet to build the proteins necessary to sustain a complex arthropod such as a trilobite would require orders of magnitude more coding instructions. The genome size of a modern arthropod, the fruitfly Drosophila melanogaster, is approximately 180 million base pairs (Gerhart & Kirschner 1997:121, Adams et al. 2000). Transitions from a single cell to colonies of cells to complex animals represent significant (and, in principle, measurable) increases in CSI.Intelligent Design:
The Origin of Biological Information and the Higher Taxonomic Categories Stephen C. Meyer
Actually, Meyer disproves his own points in his latest book
Signature in the Cell. He first notes (his own distinction, not mine) that there are two kinds of CSI: a popular, engrossing forensics show on national television, and a sterile, nebulous concept about genetic information that has never been quantifiably measured by ID practitioners (who nevertheless say it has "increased") and is never used outside their isolated little enclave.
No, actually, he says that CSI can be either "functional" or "meaningful". (Those with the book, see page 359.) That is, the information can be specified either by virtue of the physical and chemical properties of the system conveying the information, or it can be specified because of some layer of abstraction imposed on top of the concrete physical and chemical properties.
So, for example, a photograph of the Statue of Liberty and a photograph of the Eiffel tower both carry information. However, the information they carry is not based on the physical and chemical differences between the two photographs: they have the same shape, size, and weight, and if you took them to a chemical lab for analysis their chemical compositions would be almost identical. Rather, they carry abstract information which transcends their physical realities as colored sheets of paper. Indeed, a culture which does not build tall buildings or does not photograph them will not be able to derive any CSI from these photographs, even though the physical composition of the photographs presented to them is the same.
Now, Meyer explicitly states that DNA's CSI is functional:
Although DNA does not convey information that is received, understood, or used by a conscious mind, it does have information that is received and used by the cells machinery to build the structures critical to the maintenance of life. DNA displays a propertyfunctional specificitythat transcends the merely mathematical formalism of Shannons theory.
(
Signature in the Cell, p109). But immediately his attempts at a syllogism collapse like a house of cards. Which intelligent designer has ever tried to create information that is not received, understood, or used by a conscious mind? I have never tried to write an essay which could not be read, compose a song which could not be sung, or filmed a video which could not be watched - yet that is precisely the kind of information Meyer
himself calls DNA.
And since no example Meyer cites anywhere has ever shown intelligent designers creating purely functional CSI, he cannot claim that there is an inductive argument that the purely functional CSI of DNA was produced by an intelligent designer. Indeed, here is a direct example of CSI being produced by natural processes:
In the bigger picture, this example [antibody production] shows how a homogeneous population of pre-B cells is transformed to a dynamically diverse population of B cells, with a tremendous increase in information content. This complex information then becomes highly specified by fine-tuning to match the antigens to which they are presented. The result is a high degree of specificity and complexity with no involvement of an intelligent designer as an immediate cause. This does not, of course, preclude the sustaining involvement of an Intelligent Designer at a metaphysical level.
... The random process of gene rearrangement is necessary to ensure a sufficiently broad range of binding specificities, such that some of them are almost sure to bind to one part of each pathogen. His example also illustrates clearly how highly complex and highly specified information is derived directly from a population of relatively low-information cells. Hence, the argument that Meyer makes that all complex specified information comes from an intelligent source does not withstand scrutiny.
The full explanation of antibody production is
here, and the full argument against
Signature of the Cell here. Both pages are maintained under the ASA Book Discussion forum/blog.