Can information theory help us understand the Cambrian explosion?
|February 26, 2014||Posted by News under Cambrian explosion, Informatics, Intelligent Design, News|
The starting point is the search for ways of measuring biological information representing different body plans. Shannon’s theory of information (when applied to the animal genome) has the merit of mathematical rigour, but Meyer shows that this approach gives insight only into a sequence’s capacity to carry information. Whether the sequence is functional is undetermined ? so discussion of biological information must extend far beyond quantitative measures. Meyer discusses the number of cell types as an indicator of complexity of embedded information. With reference to the genome, which uses digital codes, he uses the term “specified information”, meaning that a genetic sequence can only be functional if the codons have a specific arrangement. Is the neo-Darwinian mechanism adequate to explain the origins of novel specified information associated with the Cambrian Explosion? Meyer describes this as a challenging question for Darwinists and claims that the necessity of “vast amounts” of specificity makes their explanations implausible.
To show that this argument is real, and not an argument from ignorance, Meyer devotes the next chapter to unpacking the issues surrounding specificity. In the early 1960s, Murray Eden (a professor of engineering and computer science at MIT) realised that there was a problem with neo-Darwinian theory and organised a conference to explore the issues at the Wistar Institute in Philadelphia. The theme was: “Mathematical challenges to the neo-Darwinian interpretation of evolution”. The participants came from many disciplines and included Ernst Mayr (one of the architects of neo-Darwinism) and Richard Lewontin (Professor of genetics and evolutionary biology). Chairing the meeting was the Nobel laureate Sir Peter Medawar. The discussion provided by Meyer is extremely helpful in clarifying the nature of the problems and summarising some of the suggestions for resolving the dilemmas. The most favoured possible solution is explained in the quotation below, and is significant for stimulating a design-based research programme discussed in the subsequent chapter.
“The solution was this: even though the size of the combinatorial space that mutations needed to search was enormous, the ratio of functional to non-functional base or amino-acid sequence in their relevant combinatorial spaces might turn out to be much higher than Eden and others had assumed. If that ratio turned out to be high enough, then the mutation and selection mechanism would frequently stumble onto novel genes and proteins and could easily leapfrog from one functional protein island to the next, with natural selection discarding the non-functional outcomes and seizing upon the rare (but not too rare) functional sequences.” (page 178) More.
See also: “Software mogul calls technology growth a “Cambrian explosion” (“What’s interesting in the context is simply that he assumes that readers will know what he means by the term. Culturally, that’s important.”)
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