The Theory of Devolution Part 2

Shubee · Posted: Fri Sep 04, 2009 2:33 pm Post subject:

Formally, the new theory of descent with modification (devolution) is based on two postulates, in addition to my preferred definition of a scientific theory and a minor adjustment in the modern evolutionary synthesis.

1. All life forms are molecular machines. I don't believe that any scientist doubts this scientific hypothesis. [1][2][3].

2. The second postulate, the devolution hypothesis, stipulates that all molecular machines are becoming less robust over time. As genetic code in all life forms continues to get corrupted and degrades through copying errors and other mutations, successive generations of machines, in all series, must plod along with increasing inefficiency and sometimes features are entirely lost.

Experimental support for the theory of devolution is just beginning to be noticed. Consider the article, Evolution of Penicillin-Binding Protein 2 Concentration and Cell Shape during a Long-Term Experiment with Escherichia coli, in the Journal of Bacteriology, 2009 February; 191(3): 909–921. The Abstract states: "In a long-term experiment, 12 populations of Escherichia coli having a common ancestor were allowed to evolve for more than 40,000 generations in a defined environment." The abstract specifies the "physiological trade-offs and ecological specialization during experimental evolution" and identifies them precisely. The trade-offs were that "both mutations that evolved were beneficial in the environment used for the long-term experiment and that … both mutations decreased cellular resistance to osmotic stress."

That's a very precise confirmation of the theory of descent with modification (devolution). Yes, the mutant Escherichia coli that survived were better adapted to the new environment and could outcompete the more robust ancestral strains in that new environment. However, the more robust ancestral strains were more robust in their preferred environment than the mutant Escherichia coli were in their specialized environment. That's exactly what the theory of devolution predicts. As the theory of devolution affirms, along with evolution (change), which is due to accumulated mutation, there is devolution (the decrease in robustness).

Obviously, in the background, there is a rather unsurprising principle. Escherichia coli and their descendants can adapt to eating junk food but it's not good for them. It accelerates their mutation rate. They would have been better off in their original environment.