Information is central to life.
It’s a sentence that feels almost self-evident today, yet its full meaning is still unfolding. In 1958, Francis Crick condensed this idea into what became known as the Central Dogma of molecular biology:
DNA → RNA → Protein
A sequence of events as deceptively simple as a row of dominoes. DNA stores the instructions. RNA carries them. Proteins — the machinery of the living world — execute them. But reality, as always, resists simplicity. Proteins themselves are required to interpret and enact the instructions coded in DNA. The neat arrow begins to loop and bend, and the story becomes more intricate.
The Long Road to the Code
For most of human history, biology was the art of observing life’s outward forms — the curve of a leaf, the stripes of a tiger, the mating dance of a bird. The 18th century brought Linnaeus’ grand taxonomy; the 19th, Mendel’s invisible particles of heredity.
Then, in the mid-20th century, the curtain lifted. Watson and Crick revealed DNA’s double helix, and suddenly life was not just shapes and behaviors, but a text — written in an alphabet of four bases, carrying instructions billions of years old.
Crick’s Leap into Information
Why did Crick describe his discovery in the language of “information”? According to Ramsden (2023), part of the answer lies in the intellectual climate of the time. Just a few years before the discovery of the double helix, Claude Shannon had published his seminal Mathematical Theory of Communication.
In such a context, thinking of DNA as a message — copied, transmitted, translated — seemed natural. The subsequent cracking of the genetic code only deepened the analogy. Life was no longer just chemistry; it was communication.
What We Mean by “Biological Information”
But the metaphor requires care. As John Maynard Smith observed in 2000, the information in biology is not mere poetry borrowed from telegraphs and radio waves. It is embedded in the structure of molecules, in the constraints they impose and the possibilities they allow.
A DNA sequence “means” nothing in isolation. Only in the molecular theatre of a cell — with its enzymes, ribosomes, and membranes — does it become instruction, command, destiny. Without context, the message is a string of nonsense syllables.
The Silence in the Textbooks
Given this, it is curious that “information” has so often been a ghost in biology textbooks. Energy gets entire chapters; information, if mentioned at all, is a passing guest. The likely reasons are practical: for decades, biology lacked the two essentials that could make information theory truly useful — vast datasets and the computational power to analyze them.
Today, both are in abundance.
A Revival
In the age of high-throughput sequencing, neural network models, and petabytes of genomic data, the conversation between information science and biology is resuming with urgency. Researchers now measure the “information content” of genomes, model cellular signaling as communication networks, and trace the flow of messages across ecosystems.
Two Ways to Think About Life’s Messages
Philosophers, as ever, bring precision to our terms. The Stanford Encyclopedia of Philosophy distinguishes between two visions:
- Shannon (Correlational) Information — symmetrical, statistical, about reducing uncertainty.
- Teleological (Biological) Information — asymmetrical, functional, about what a sequence is for.
Crick’s “information” fits the second sense: the precise ordering of DNA bases whose function is to produce a particular protein, in a particular place, at a particular time.
The Old Question, Revisited
Biology has long sought to answer the question What is life? Physics and chemistry have explained the material and energetic foundations of living systems. Information could be the missing third element — the factor that organizes matter and energy into functioning biological processes.
As our knowledge of molecules grows, we increasingly encounter something that goes beyond their physical properties: the patterns, codes, and instructions they embody. When physics, chemistry, and information are integrated, we may finally gain a clearer understanding not only of life’s components, but also of the principles that govern them.
References
- Crick, F. H. C. (1958). On Protein Synthesis. Symposium of the Society for Experimental Biology, 12, 138–163.
- Ramsden, J. (2023). Bioinformatics: An Introduction. Springer International Publishing.
- Smith, J. M. (2000). The concept of information in biology. Philosophy of Science, 67(2), 177–194.
- Artiga, M. (2024). Biological Information. In E. N. Zalta & U. Nodelman (eds.), The Stanford Encyclopedia of Philosophy (Fall 2024 Edition). Retrieved from https://plato.stanford.edu/archives/fall2024/entries/information-biological/