Does Darwinian Evolution claim that DNA mutations are random?

"If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case."
[Charles Darwin, Wikiquote]

This post forms part of a series on Mr Marshall's Random Mutator. You can find all the posts here:

1. The Random Mutator of Perry Marshall.


2. Is DNA Analogous to Human Language?


3. How Random is Random Mutation in DNA?


4. Does Darwinian Evolution Claim that DNA Mutations are Random?

Evolution vs Genetics

Darwinian Evolution came about in 1859 with the publishing of Charles Darwin's On the Origin of Species. The roots of genetics could be traced back to 1865 with the publishing of Gregor Mendel's Experiments on Plant Hybridisation. However, the importance of Mendel's work was not fully realised until the 20th century, with the modern evolutionary synthesis.

It is thus apparent that Charles Darwin made no claims about genetics. Charles Darwin tried to explain how species came about and how some traits become more widespread while others become extinct.


Mu, a Japanese word which roughly translates as 'no thing'. Kind of what Mr Marshall's Random Mutation Generator has to do with Darwinian Evolution, or evolution in general.

What is Darwinian Evolution?

As already noted, Darwinian Evolution and the modern theory of evolution are not the same thing at all. Darwinian Evolution claims the following:

1. "If all the individuals of a species reproduced successfully, the population of that species would increase uncontrollably.


2. Populations tend to remain about the same size from year to year.


3. Environmental resources are limited.


4. No two individuals in a given species are exactly alike.


5. Much of this variation in a population can be passed on to offspring."

[Introduction to Evolution, Wikipedia]

Since resources are limited, there is a struggle among individuals of a species for survival. Darwin precisely claims that it is not chance alone which determines survival, but that survival depends on the traits of an individual which enable that individual to survive. In other words, survival of the fittest.

The modern theory of evolution thus bases its principles of natural selection and speciation on Darwinian Evolution, but Darwinian Evolution entirely lacks some of the other modern mechanisms of evolution. This is because the mechanisms of gene flow and genetic drift in particular are based on genetics, with which Darwin was unfamiliar.

What does Darwinian Evolution claim about DNA mutations?

Nothing. Absolutely nothing.

What does Mr Marshall's Random Mutation Generator have to do with Darwinian Evolution?

Nothing. Absolutely nothing.

How Random is Random Mutation on DNA?

"If we want to postulate a deity capable of engineering all the organized complexity in the world, either instantaneously or by guiding evolution, that deity must have been vastly complex in the first place.

The creationist, whether a naive Bible-thumper or an educated bishop, simply postulates an already existing being of prodigious intelligence and complexity."
Richard Dawkins


This post forms part of a series on Mr Marshall's Random Mutator. You can find all the posts here:

1. The Random Mutator of Perry Marshall.


2. Is DNA Analogous to Human Language?


3. How Random is Random Mutation in DNA?


4. Does Darwinian Evolution Claim that DNA Mutations are Random?

What is mutation?

Simply put, a mutation is a change in the nucleotide sequence of the genetic material of an organism. This genetic mutation could cause changes in the phenotype of your species. For example, you could have a mommy and a daddy with blue eyes who give birth to a child with brown eyes.

What causes mutation?

"Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can be induced by the organism, itself, by cellular processes such as hypermutation."
[Mutation, Wikipedia]

Copying errors, you say? One would think that a system intelligently designed by an omniscient, omnipotent deity would not be prone to copying errors. It surely wouldn't be sensitive to ultraviolet radiation either, given that an omniscient deity would've seen that one coming.

Similarly, if mutations were not random, but predicted and designed by a perfect designer, one would expect that these errors would not be copied over to the next generations, but that some error-correcting mechanism would be in place. This would ensure that if you exercised your free will too leniently and you ended up next to a UV light for too long that your children and your children's children are at least protected from your inability to practice sound discrimination towards malignant types of light sources.

Do mutations in DNA occur randomly and indiscriminately?

This is exactly what Mr Marshall's random mutator suggests. However, in DNA, you don't have one string, like you do in Mr Marshall's random mutator. You have two strands. Both strands consist entirely of the letters A, C, G and T. An A on the one string mostly (but not necessarily) corresponds to a T on the other strand, and vice versa. A C on one strand mostly (but not necessarily) corresponds to a G on the other strand, and vice versa. More significantly, any possible combination of A, C, G and T is a proverbial word in the language of DNA.

This is important, because not all combinations of letters in Plain English are words. Mr Marshall would do well to model his random mutator so that it bewares of the Jabberwocky. At least this would resemble the working of one strand of DNA somewhat. Since any combination of letters in the DNA alphabet form meaningful words in the genetic code, there is no possibility that a random mutation would prevent your genetic information from being transferred. It follows that the randomness of mutation in DNA is immaterial, because no mutation would cause your organism to necessarily become extinct.


A Cro-magnon skull. Mr Marshall's random mutator reasons that natural selection implies that we can revert our current human population back to Cro-magnons, and if we can't evolve to our current level of humanity, humanity would necessarily become extinct.

Mutation does occur randomly, but not indiscriminately thanks to natural selection. A mutation in some of your DNA is not necessarily a mutation in all of your DNA, or in all of the DNA of a particular species, as only the mutations which get passed on to your offspring are relevant. Mr Marshall's mutator does not model this scenario at all, but his model implies that any random mutation in the DNA of a particular organism automatically occurs species wide.

Mr Marshall's random mutator does not model natural selection

Mr Marshall reasons that since you can mutate randomly and then revert back to your selected text, his mutator does model natural selection. I fail to see how taking modern day humans and reverting us back to archaic homo sapiens has anything to do with natural selection. Besides, his 'Revert To Selected Text' button does not in fact revert back to selected text. It entirely clears the text. As an information scientist, Mr Marshall should surely be aware of Nielsen's heuristics. Poor user interface design does nothing to bring your point across more clearly.

Natural selection is not a carefully designed, directed process. Nor is it capable of being completely ignored in a model of mutation. Sticking with Darwin's definition:

"One general law, leading to the advancement of all organic beings, namely, multiply, vary, let the strongest live and the weakest die".
[Wikiquote, Charles Darwin]

There is nothing in this mutator that models selecting the strongest letters, words or sentences, and letting the weakest letters, words or sentences die. Note that this mechanism does not imply a designer. This mechanism could be brought about by an outbreak of Aids in your population.

Surely, if your DNA were designed by a perfect, omniscient deity, she would've seen that one coming too? Why then are some people immune to Aids while others are not? Why then are some more immune to malaria, while others are not? Natural selection seems to explain that, without the need for a designer. Mr Marshall's random mutator does not.

By the way, I haven't mentioned Cthulhu in this post. I just thought I'd randomly mention that.

Is DNA analogous to human language?

"It all starts with random mutation, from which natural selection can choose winners. Since DNA is a language based on a four-letter alphabet (A, C, T, G); since letters form words (Codons) and words form instructions (Genes) we can test the concept in Plain English."
Mr Perry Marshall


This post forms part of a series on Mr Marshall's Random Mutator. You can find all the posts here:

1. The Random Mutator of Perry Marshall.


2. Is DNA Analogous to Human Language?


3. How Random is Random Mutation in DNA?


4. Does Darwinian Evolution Claim that DNA Mutations are Random?

The analogy that DNA is a language like Plain English is just a metaphor. It's a very convenient metaphor to explain the mechanisms of DNA, but as a metaphor, it should not be taken too literally. Operations on a string of text in English do not represent operations on DNA. Here is why:

DNA is a language based on a four letter alphabet (A, C, T, G)

This seems pretty valid and it does clarify the workings of DNA a little. However, letters in Plain English do not work like this:

"Each nucleotide sub-unit consists of a phosphate, deoxyribose sugar and one of the 4 nitrogenous nucleotide bases. The purine bases adenine (A) and guanine (G) are larger and consist of two aromatic rings. The pyrimidine bases cytosine (C) and thymine (T) are smaller and consist of only one aromatic ring.

In the double-helix configuration, two strands of DNA are joined to each other by hydrogen bonds in an arrangement known as base pairing. These bonds almost always form between an adenine base on one strand and a thymine on the other strand and between a cytosine base on one strand and a guanine base on the other."
[Transfer of information via the genetic code, Wikipedia]

The letters A, C, T and G represent nucleotides. While these letters are the basic building blocks of DNA, just like letters are the basic building blocks of words, nucleotides are further divisible into more basic building blocks.


A nucleotide is composed of a ring of nitrogen, carbon and oxygen atoms, a five carbon sugar (together referred to as a nucleoside) and one phosphate group.
[Nucleotide, Wikipedia]

While you could argue that letters are formed by ascenders, descenders, markers and serifs, these do not represent the basic building blocks of letters in the same way that a ring of nitrogen, carbon and oxygen atoms, a five carbon sugar and one phosphate group represent the basic building blocks of nucleotides.


The Gypsy Curse font from sinisterfonts.com. Does it look like nucleotides? Didn't think so.

Letters are not further divisible into functional parts in Plain English, but the nucleotides which make up DNA are further divisible into functional, stand-alone, chemical parts.

Furthermore, in any language there are rules which stipulate which letters can go next to which other letters. You'd mostly have a vowel next to a consonant, for instance.These rules are not determined by the message encoded in the text, but have to do with the conventions of the language.

This is different from DNA because DNA is not a language. DNA mostly forms as two strands: an adenine base on one strand and a thymine on the other strand and between a cytosine base on one strand and a guanine base on the other. This arrangement is not determined by convention, nor by the genetic code contained in the DNA, but the chemical properties of nucleotides and the resulting Hydrogen bonds.

Random mutations on a single string of Plain English text do not take the double helix structure of DNA into account.

This means the claim that we can test DNA concepts with Plain English is fundamentally flawed. The analogy that DNA is similar to Plain English is entirely inappropriate, as random operations on an entire string of text do not equate to any kind of operations on DNA at all.

The Random Mutator of Perry Marshall

"Oh no! He's a creationist proving his point with a spam generator."
http://ave-imperator.blogspot.com/


This post forms part of a series on Mr Marshall's Random Mutator. You can find all the posts here:

1. The Random Mutator of Perry Marshall.


2. Is DNA Analogous to Human Language?


3. How Random is Random Mutation in DNA?


4. Does Darwinian Evolution Claim that DNA Mutations are Random?

This random mutator is an attempt by Mr Marshall to debunk Darwinian Evolution. Note that Darwinian Evolution is merely the origin of our current Theory of Evolution. No biologist currently believes in Darwinian Evolution in its strict sense, as the Theory of Evolution itself has gone through the processes of adaptation, genetic drift, gene flow, mutation, natural selection and speciation.


A mutation. It might be pretty damn ugly, but it's not extinct.

It is thus clear from the outset that this random mutator is a straw man argument. Nevertheless, information scientist to information scientist, yet biological layman to biological layman, let's scrutinise this random mutator of Mr Marshall.

How Mr Marshall Imagines Random Mutation Works

• the genetic code of DNA is analogous to a high-level human language. Letters map to amino acids, words map to codons and sentences (or the meaning of sentences) map to instructions in the genetic code


• random mutations in the letters of words are similar to mutations in the genetic code of DNA


• random mutation occurs among the entire portion of code without keeping certain portions intact


• Darwinian Evolution claims that these mutations are completely random and are not subjected to any kind of selection process


• a selection process implies a designer of that process. Hello, Cthulhu!


• if you apply random mutation to a sentence and you don't get a new meaningful sentence immediately, your mutated organisms immediately go extinct

In the following posts, I shall take each of these points to task as patiently as I can while listening to Slayer. I've already dealt with Mr Marshall's spurious claims that DNA proves the existence of god. Hopefully, these posts would also lead to a healthy debate. All comments, hate mail and bottles of single malt whiskey are welcome, however I shall only take intellectually honest comments seriously.