2018/09/06

Multiple overlapping and poly-functional DNA reduce the probability of beneficial mutation

DNA is already optimized - Beneficial mutations are extremely rare - However, mutations happen and they result in genetic degradation

http://www.cs.cmu.edu/~gmontane/pdfs/montanez-binps-2013.pdf

Excerpt from abstract: "There is growing evidence that much of the DNA in higher genomes is poly-functional, with the same nucleotide contributing to more than one type of code. Such poly-functional DNA should logically be multiply-constrained in terms of the probability of sequence improvement via random mutation. We describe a model of this relationship, which relates the degree of poly-functionality and the degree of constraint on mutational improvement. We show that: a) the probability of beneficial mutation is inversely related to the degree that a sequence is already optimized for a given code; b) the probability of beneficial mutation drastically diminishes as the number of overlapping codes increases.

The growing evidence for a high degree of optimization in biological systems, and the growing evidence for multiple levels of poly-functionality within DNA, both suggest that mutations that are unambiguously beneficial must be especially rare. The theoretical scarcity of beneficial mutations is compounded by the fact that most of the beneficial mutations that do arise should confer extremely small increments of improvement in terms of total biological function. This makes such mutations invisible to natural selection. Beneficial mutations that are below a population’s selection threshold are effectively neutral in terms of selection, and so should be entirely unproductive from an evolutionary perspective. We conclude that beneficial mutations that are unambiguous (not deleterious at any level), and useful (subject to natural selection), should be extremely rare."
 
A model nucleotide sequence of 100 bases that encodes 12 partially overlapping codes. Each sub-section represents the positions of the Genome Section that participate in that particular code. For example, only the first 10 positions of the Genome Section participate in Code 1 whereas all except the last 5 positions of the Genome Section participate in Code 12. Nucleotide positions of the Genome Section that do not fall into any code are considered entirely neutral with respect to those codes, since they play no part in what the function of those codes may be. In that regard, these neutral positions are not part of the functional genome (at least with respect to those specific codes). (G. Montañez, R. J. Marks II, J. Fernandez and J. C. Sanford)
Excerpt 2: "Each biological specification is encoded by strings of characters (nucleotides or amino acids) that are very specific (and hence very unlikely), with each character having meaning only in the context of many other characters — like letters in a book or like the binary bits comprising a computer code. Any random change in such a set of specifications causes some loss of useful information — with a very high degree of probability. The more that each character is contextually interactive with other characters, the less feasible it becomes to improve a set of specifications via random character changes, because each character is multiply constrained by its many contextual relationships.

The discovery of ubiquitous poly-functional DNA is profound, and forces us to reassess our understanding of the degree of genetic specificity and the probability of beneficial mutation."

My comment: Evolutionists need beneficial mutations to be able to scientifically prove their theory. But as we know, the number of known random beneficial mutations is extremely rare, that it is not possible for evolution to happen. This is because neutral (critical) and harmful mutations are so common. For example, there are 224,642 disease-causing genetic mutations in human genome at population level. This same genetic degradation, genetic entropy, is a phenomenon occurring rapidly all over nature. You can read about it more from here:

http://sciencerefutesevolution.blogspot.com/2018/04/mutation-rate-and-lack-of-beneficial.html
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