Life: Designed to not evolve
Semi Technical
A mutation is simply an inheritable error that occurs when DNA is copied. A long-standing assumption of biological evolution was that mutations are completely random. This is what most evolutionists believed, and this is what most students have been taught. This randomness is important for evolution theory because it allows for any and all possible mutational changes to happen. A series of discoveries have proven that assumption to be false.
DNA repair system
A recent study found something previously unknown in the plant Arabidopsis thaliana. Also known as thale cress, A. thaliana is one of the ‘workhorses’ of modern molecular genetics. We know more about it than just about any other plant, so this new discovery came as quite a surprise.
Associated with the DNA in chromosomes is a group of proteins known as histones. Their usual role is to provide structural support to the coiled DNA that makes up the chromosome. By wrapping around and around histone proteins, DNA is also able to attain an incredibly compact conformation. The researchers discovered that certain portions of the plant’s genome are surrounded by specialized histones that have chemical markers which detect mutations and release chemical signals to bring in DNA repair proteins.1
Lead author of the paper, plant genomicist Grey Monroe of the University of California Davis, said, “Based on the result of our study, we found that gene regions, especially for the most biologically essential genes, are wrapped around histones with particular chemical marks.”1 Monroe believes that the chemical marks are used as molecular signals to promote DNA repair in vital portions of the genome.
Monroe stated, “Previous studies into mutations in cancer patients have also found that these chemical markers can affect whether DNA repair proteins fix mutations properly … . However, this is the first time these chemical markers have been shown to influence genome-wide mutation patterns and, as a result, evolution by natural selection.”2
Copying errors (‘typos’ in the DNA, as it were) take place regularly in the complex process of DNA replication. But they will often be repaired by the cell’s machinery. As a result, the error is not passed on to succeeding generations as an inherited mutation. This study indicates that certain parts of the genome, particularly in areas essential to the organism’s functioning, are more likely to be repaired, and thus less likely to suffer mutational change, than other parts.
Evolution shock
Monroe said he was shocked to find this indication of non-randomness in the process of mutation, as he had been taught the opposite as far back as high school. While it is not yet known if this mechanism (or something that serves a similar role) is present in animals, it would hardly be surprising. If it is widespread in living things, the problems this poses for evolution become very noticeable.
The article, however, was quick to perform damage control for evolution with this throw-away line: “The new finding does not disprove or discredit the theory of evolution, and the researchers said randomness still plays a big role in mutations.”2 However, there was no attempt to explain why this was not a problem for evolution, just a fact-free assurance that boils down to nothing more than: ‘Don’t worry, don’t doubt’.
The revelation that mutations are not random is not news to CMI. We already knew that the chemical makeup of DNA causes mutations to happen most often in specific regions of the DNA double helix.3 In fact, we wrote about the non-randomness of mutations in our article series Species Were Designed to Change.4,5,6 This new study just shows that mutations are even less random than previously thought.7
The less random mutations are, the less freedom natural selection has to produce biological change. This is because it has a more limited range of DNA changes to choose from.
The genes in question play a role in reproduction and sexual maturation in this plant. On one level, having an extra way to protect against mutations in these regions makes sense. On another level, this makes little sense … for the evolutionist. This is because there are extreme differences between categories of living things in the ways they reproduce and develop. If living things protect these processes, how could such differences arise by evolution via mutations?
Those processes would need to have morphed from one strategy to another over time, but the mutations required would affect reproduction, and successful reproduction is required for the supposed evolutionary process.
It seems that the changes that are most needed for the evolutionary tale to have occurred are also the changes that life can least tolerate. And (at least in some cases) the organism contains specialized structures to prevent such changes from occurring in the first place.
Dr Monroe acknowledges that mutations in genes that code for things essential to survival and reproduction are usually harmful. And he goes on to say, “Our results show that genes, and essential genes in particular, experience a lower mutation rate than non-gene regions in Arabidopsis. The result is that offspring have a lower chance of inheriting a harmful mutation.”2
Of course, this is not because these histones analyze the mutation to determine if it will improve survival odds, hinder reproduction, or have no effect. They merely detect a copying error and send out chemical signals to bring in repair machinery. This applies for all mutations in these portions of the genome. So, this reduces the occurrence of harmful mutations in those essential gene regions by reducing the frequency of mutations in general. There is nothing here that determines the impact of the mutation before removing it.
Evolution-blocking mechanisms
If mechanisms like that found in Arabidopsis turn out to be widespread in living things, this issue will become a wider-ranging problem for evolution. For example: the process of metamorphosis is extremely complex and delicate. In caterpillars, the larva is melted down into a protein soup (its body dissolves into liquid) and is rearranged into a butterfly.8 The intricacy here is extreme. How could such a developmental system evolve? Starting from a worm-like ancestor, most steps toward metamorphosis would be completely lethal. (Consider a mutational change that headed in the direction of dissolving your body—before the ‘reassembly’ plan had evolved!) They would provide nothing but massive barriers to reproductive success long before evolution could make it work.
And the genes that control this process, the very ones that would have needed to be changed by mutation in the evolutionary scenario, are exactly the kind that these special histones would prevent from mutating.
Such an evolutionary development should have never occurred, since the hypothetical, caterpillar-like ancestors of the modern butterfly would already have a completely functional life cycle that didn’t involve metamorphosis. Since the ancestor would be perfectly well able to reproduce, no massive overhauls to the reproductive system would be needed. Plus, the process of transitioning from one mode of reproduction to the other would be heavily resisted, both by natural selection and by this mutation-prevention system.
It will be interesting to see if this ends up being a common feature in living creatures. According to Dr Monroe, research has already been done on other plant species that suggests this non-random mutation system is not unique to Arabidopsis thaliana.
The genome appears to be designed to resist the major evolutionary changes that are needed to create the extreme diversity seen among living things. These specialized histones are another example of this design. Has life ‘evolved to not evolve’, or has a Master Designer knowingly created life to be able to adapt in little ways while remaining stable over the long term?
References and notes
- Monroe, J. et al., Mutation bias reflects natural selection in Arabidopsis thaliana, Nature 602:101–105, 2022. Return to text.
- Baker, H., New study provides first evidence of non-random mutations in DNA, livescience.com, 14 Jan 2022. Return to text.
- Price, P., Evolution’s well-kept secret: Mutations are not random! creation.com/mutations-not-random, 7 Jul 2020. Return to text.
- Carter, R., Species were designed to change, part 1, creation.com/species-designed-change-1, 1 Jul 2021. Return to text.
- Carter, R., Species were designed to change, part 2 creation.com/species-designed-change-2, 22 Jul 2021. Return to text.
- Carter, R., Species were designed to change, part 3, creation.com/species-designed-change-3, 12 Aug 2021. Return to text.
- Monroe, J. et al., Mutation bias reflects natural selection in Arabidopsis thaliana, Nature 602:101–105, 2022. Return to text.
- Devine, D., Inexplicable insect metamorphosis, Creation 29(3):31–33,2007; creation.com/metamorphosis. Return to text.
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