Does DNA Contain Digital Information?

In a recent interaction with a skeptic, I brought up that DNA contains digital information. The response I received was no short of something like "You're lying, DNA doesn't contain digital code! You're a pseudo-scientist!" My response was simply to research the discovery of DNA and the Sequence Hypothesis. I believe that person had a firm misunderstanding (from clues later in the dialogue) of what I was saying, mainly because I reacted similarly to that claim when I was an Atheist. Whether the person was under the same misunderstanding as I do not know, but I think this article will still yield good information.

Before I was saved, and this memory is a little vague, I remember someone saying something along the lines of "At the core of all life is digital code," and I remember thinking to myself "That's some matrix, simulation crap that conspiracy theorists believe in." I think the person I interacted with was under the same interpretation, so in this article, I will cover what we mean when we say that DNA contains Digital information. To get us on a track of thought, I want to explain the differences between an Analog Signal and a Digital Signal.

Analog vs. Digital Signals

When speaking about signals and how they represent information, there are two categories the signal can fall under. An Analog Signal means that the signal can represent a value within a set or determined range, and this signal will be a continuous, fluctuating signal. Displayed below is a wave diagram that represents an analog signal that is continuous and fluctuating within a given range of values (See Below). Notice how the waves vary in height over a given timeframe. The signal is always continuous, changing values, but never being isolated to one specific value.

The Y Axis represents the range of values, and the X Axis represents the time of measurement of an Analog Signal.

The Digital Signal is a bit different. Digital refers to the fact that the values will be discrete, or "in digit format." The signal will never represent information in between the given values, it will be either or. A good example of digital information is Binary Code, where there are only two discrete values that can be represented, a one or a zero, but it will never smudge in between. Provided below is a diagram of a digital signal (See Below). There is no continuous wave displayed, but instead isolated bars that represent either a whole value of one or zero. The signal is never between the values given. Another good example of digital information is writing, where various values are separated and may be represented in the form of characters or letters. This is important later. Digital information is discrete, single, sequenced/patterned information.

The Axis labeled X represents the values that can be represented, and the Horizontal Axis represents the time of the measurement of the Digital Signal.

The Discovery of DNA

In times before modern technological advancements in biology were made. Men observing the heavens were filled with awe and wonder at the design and beauty of the stars, the movements of planets, the purpose of the moon, and the mechanisms of our sun. Turning their heads away from above, and when Men began to look down, did they recognize the amazing complexity and appearance of design in living systems. The elegant and irreducible structures, the interdependent parts of the mammalian eye (even the trilobite eye); the interlocking bone structure of bird feathers, and the complexity of their respiratory systems; the hydraulic machinery of insects, etc.

On February 28th, 1953, James Watson (1928 - 1968), an American molecular biologist and geneticist, and Francis Crick (1916 - 2004), a British molecular biologist and biophysicist, discovered the double-helix structure of the DNA Molecule. DNA (deoxyribonucleic acid) is the long chain-like molecule that every single cell in your body contains, which stores the genetic information of your development and function. Watson and Crick realized that DNA could store information in the form of a four-character digital code (represented by four isolated, discrete characters, (A)denine & (T)hymine, and (C)ytosine & (G)uanine). The double helix structure of DNA displayed that precisely sequenced chemical sub-units called Nucleotide Bases were fixed along the interior backbone of the DNA molecule. These four bases represented letters, A, T, C, and G, in the genetic code. In 1958, Crick further developed this idea into the Sequence Hypothesis. See below for a picture of the chemical structure of DNA, and a simplified drawing created by yours truly.

The backbone of the DNA Molecule is made of Phosphates that are hooked to pentasugars, also hooked to another phosphate. The sugars are bonded to the Nucleotide Bases that align the interior of the double helix structure. https://commons.wikimedia.org/wiki/File:DNA_chemical_structure_2.svg

The Phosphate (P) is bonded to a Carbon Pentasugar (C), which is bonded to the Nucleotide Bases (A, T, C, and G)

According to the Sequence Hypothesis, the Nucleotide bases function as letters in a written text or digital characters in Binary code written in computers (where I believe this person had their misunderstanding, thinking I was referring to electronic code only). Just like how different arrangements of letters in a code can convey specific information, so too can a specific arrangement of Nucleotide Bases along the backbone of the DNA molecule. Crick also knew that proteins were responsible for performing a lot of key life-sustaining reactions and functions in cells; they process genetic information and perform the structural parts of molecular machines within cells. In the mid-1960s, experiments were conducted that confirmed the Sequence Hypothesis. By the late 1960's biologists and geneticists knew that information is stored in the DNA molecule, and how the information was translated and used for building the cell. (Return of the God Hypothesis has a good summary of this discovery, Pages 164 -168).

Final Remarks

As we have seen in this article, the DNA molecule does store digital, discrete information; the history of the discovery of the structure of DNA, and the revelation of the vast information processing system stored within it. When I say that the information in DNA is Digital, I do not mean that there are electronic resistors in DNA, or that cells are circuit boards. I am referring to the nature of the information in DNA, that being of a four-digit, letter-based specified information system.