Science Literature

Digital codes can be protected against failure. A variety of options have been explored by computer programmers because it is important to catch malfunctions early and alert the user to a problem.

"In digital codes, the bits are usually packed into sets of eight bits called bytes. Normally, seven bits are used to record information and one bit - called the 'parity bit' - is used for mutation protection, usually denoted as error protection. The seven-bit string 1000001, for example, codes the letter A and 0110011 codes the number 3. If the number of 1's in the seven-bit string is even, the parity bit is given the value 1, else the value 0. If one of the seven information bits changes, for instance, by radiation, heat, or mechanical influences, they no longer correspond with the parity bit value; this is detected, an error message is generated, and the program stops, is aborted, or a switch is made towards a back-up."

The word that comes most readily to mind when considering DNA repair mechanisms is sophisticated (source here)

DNA codes are far more sophisticated than their human counterparts, and they also have a variety of repair mechanisms. A recent report of a microbe's "extraordinary maintenance and repair system" drew attention to the striking similarities between the DNA repair systems of bacteria and humans.

"Like council crews repairing damaged roads these DNA repair mechanisms employ individuals with different specialities: sometimes all that is needed is a small patch on the DNA, like filling in a pothole, other times large sections of the DNA need to be removed entirely and replaced. The repair systems need molecular machines that can detect the DNA damage in the first place, machines that can cut away the damaged DNA, and machines that can finish the repair by building new undamaged DNA. All of these molecular machines must work together in an organised fashion to carry out these very intricate repairs, and so they also require machines that take the part of foreman and co-ordinate the work of the others. When DNA is heavily damaged, cells from humans to bacteria ensure the sections that are being read at that moment (in a process called transcription) are repaired before sections that aren't being read. (Source here)"

In a new paper, William DeJong and Hans Degens discuss the implications of DNA repair mechanisms for evolutionary theory. They accompany the discussion with a simulation of a population of digital amoebae experiencing mutation and repair.

"To illustrate the difference between random change of digital and nucleotide codes within the boundaries of mutation protection and unbounded random change, we present a computer simulation of the evolutionary dynamics of a population of digital amoebae."

The findings are of considerable interest. They show that any evolutionary theory which ignores mutation protection is missing out a factor of great importance. The consequence of protection is that limitations of the evolutionary dynamics of digital and nucleotide codes are highly probable.

"Our mutation protection perspective advances the understanding of the evolutionary dynamics of both digital and nucleotide codes. It reveals that random change of digital codes is limited to the variation, recombination, and selection of predefined parameters, operators, or program modules, as a consequence of the normal mutation protection of digital codes that is present at the bit-level and the higher levels of a digital code."

They identify an ambiguity between 'mutational robustness' - that is the persistence of an organismal trait under genetic perturbations - and evolvability. The mutational robustness characteristic is often given the name 'microevolution' whereas evolvability is known as 'macroevolution'. These terms have received attention in the literature of evolutionary biology, but DeYong and Degens have brought the distinction to prominence by showing that only 'mutational robustness' scenarios are consistent with repair mechanisms.

"Unbounded random change of nucleotide codes through the accumulation of irreparable, advantageous, code-expanding, inheritable mutations at the level of individual nucleotides, as proposed by evolutionary theory, requires the mutation protection at the level of the individual nucleotides and at the higher levels of the code to be switched off or at least to dysfunction. Dysfunctioning mutation protection, however, is the origin of cancer and hereditary diseases, which reduce the capacity to live and to reproduce. Our mutation protection perspective of the evolutionary dynamics of digital and nucleotide codes thus reveals the presence of a paradox in evolutionary theory between the necessity and the disadvantage of dysfunctioning mutation protection. This mutation protection paradox, which is closely related with the paradox between evolvability and mutational robustness, needs further investigation."

A video presentation of the article can be found here. The authors have made a significant contribution to thinking about origins. The novelty of the argument is the way they have used simulation to illustrate cogent differences between evolvability and mutational robustness, something that appears to have been lacking in other models of evolutionary processes. Simulation depends, of course, on the validity of the underlying logic and associated parameters. Without the link with the empirical world, simulation models are just games to entertain. The paper shows that all the empirical evidences for evolutionary processes (Darwin's finches, lizard legs, etc) fit into the mutational robustness type of change. We do not have empirical data for evolvability. This is why Darwinists insist that the present is the key to the past and that the small scale changes can be extrapolated to produce novel life forms. The DNA repair argument needs to be answered before they can be allowed to continue with such wishful thinking.

A note to educators and policy makers: is this information that students should consider in their education? Should the Darwinists have the freedom to promote their dogmas without being challenged?

The Evolutionary Dynamics of Digital and Nucleotide Codes: A Mutation Protection Perspective
William DeJong and Hans Degens
Open Evolution Journal, February 2011, 5(1), 1-4 | DOI: 10.2174/1874404401105010001

Abstract: Both digital codes in computers and nucleotide codes in cells are protected against mutations. Here we explore how mutation protection affects the random change and selection of digital and nucleotide codes. We illustrate our findings with a computer simulation of the evolution of a population of self replicating digital amoebae. We show that evolutionary programming of digital codes is a valid model for the evolution of nucleotide codes by random change within the boundaries of mutation protection, not for evolution by unbounded random change. Our mutation protection perspective enhances the understanding of the evolutionary dynamics of digital and nucleotide codes and its limitations, and reveals a paradox between the necessity of dysfunctioning mutation protection for evolution and its disadvantage for survival. Our mutation protection perspective suggests new directions for research into mutational robustness.

See also:

Contradiction in evolutionary theory [video], by INIResearch (19 Apr 2011)