How Information Theory is Rewriting Biology
From the genetic code in every cell to the alarm calls of monkeys in the forest, life is built on information. Scientists are now discovering that to truly understand biology, we must first learn to read its messages.
Imagine if we could listen to the conversations happening inside our own cells. The DNA in every cell isn't just a chemical; it's a vast library of digital information. A monkey's alarm call isn't just a sound; it's a targeted message with meaning. A hormone isn't just a molecule; it's a signal triggering a cascade of commands.
This isn't metaphorical—scientists are increasingly finding that the very essence of life can be understood through the flow, processing, and interpretation of information. This revolutionary perspective is bridging the gap between biology and technology, revealing that the same fundamental principles that govern computer networks and communication systems also operate in the living world.
Living systems aren't just complex chemical machines—they are dynamic information-processing networks that are perpetually "in formation," constantly interpreting and responding to internal and external signals 1 .
At its core, biological information is about meaning and instruction. While a rock carries no intrinsic message, a single gene provides a detailed recipe for building a specific protein. This "aboutness"—the quality of being about something else—is a hallmark of biological information 4 .
A segment of DNA carries information about the protein it will help create, but the protein does not carry the same information back to the DNA.
It can be "right" or "wrong." A genetic mutation represents incorrect information that can lead to malfunction.
Not every biological element carries information in this specific sense. While your DNA is packed with information, your bones primarily provide structural support.
This understanding represents a fundamental break from purely reductionist, mechanical views of biology. Living systems aren't just complex chemical machines—they are dynamic information-processing networks that are perpetually "in formation," constantly interpreting and responding to internal and external signals 1 .
The journey to understanding biological information began unexpectedly with the work of Claude Shannon, a mathematician at Bell Laboratories. In 1948, Shannon published "A Mathematical Theory of Communication," tackling a practical problem: how to optimize telephone communication by minimizing errors in message transmission 4 .
Shannon's revolutionary insight was to quantify information itself, defining it mathematically as a reduction in uncertainty. His concept of "mutual information" measured how much knowing the state of one system (like a transmitted signal) could reduce uncertainty about another system (like the received message) 4 .
Initially, Shannon's framework seemed ill-suited for biology. His mathematical information was symmetric (if A carries information about B, then B carries information about A), non-normative (it couldn't be true or false), and ubiquitous (nearly everything carries some correlational information about everything else) 4 . These properties didn't align with the directional, meaningful, and specific nature of biological information.
Scientists have since built upon Shannon's foundation, developing richer concepts that capture the unique aspects of living systems. These include teleosemantic approaches that link information to biological function and evolutionary history, and game-theoretic models that show how communication systems can spontaneously evolve even in simple organisms 4 .
Several foundational biological theories implicitly recognize the informational nature of life, even if they don't always use the language of information theory.
| Theory | Core Principle | Informational Interpretation |
|---|---|---|
| Central Dogma of Molecular Biology | Genetic information flows from DNA to RNA to protein 3 . | The foundational information pathway in biology; describes how stored genetic data (DNA) is transcribed into a transportable format (RNA) and translated into functional effectors (proteins). |
| Theory of Evolution by Natural Selection | Organisms with advantageous traits survive and reproduce more successfully 3 . | A process of information gain through natural selection, where successful genetic "strategies" are retained and accumulated in populations over generations. |
| Cell Theory | All living organisms are composed of cells, the basic unit of life 3 . | Establishes the cell as the fundamental information-processing unit in biology, where genetic, proteomic, and signaling information integrates. |
| Gene Theory | Traits are inherited through genes passed from parents to offspring 3 . | Identifies genes as the primary storage medium for heritable biological information. |
These theories collectively paint a picture of life as a multi-layered informational phenomenon, operating at scales from molecules to ecosystems.
While molecular biology reveals information processing within cells, animal communication shows how information structures complex social behaviors. A groundbreaking study published in the journal Science demonstrated that marmoset monkeys use specific calls to vocally label each other—essentially using names 6 .
The findings were striking. Marmosets consistently used distinct call variations when addressing different individuals. More importantly, the monkeys responded more quickly and appropriately when they heard calls that were specifically directed at them 6 .
| Experimental Measure | Finding | Significance |
|---|---|---|
| Call Variation | Distinct acoustic patterns for different individuals | Marmosets use vocal labels analogous to names |
| Response Consistency | Stronger responses to self-directed calls | Monkeys recognize when they are being "addressed" |
| Communication System | First evidence of naming in non-human primates | Expands known examples of complex animal communication |
This discovery revealed several important aspects of biological information:
This type of referential communication—using specific signals to denote particular entities—had previously been documented only in humans, elephants, and dolphins 6 . The finding challenges us to reconsider how we define communication and intelligence in the animal kingdom and provides a fascinating window into the evolution of our own linguistic capabilities.
Understanding biological information requires specialized tools that allow researchers to detect, measure, and manipulate informational molecules and signals.
| Reagent/Tool | Function | Role in Information Processing |
|---|---|---|
| Reverse Transcriptase | Converts RNA into complementary DNA (cDNA) | Allows "reading" of RNA messages by converting them into more stable DNA format for analysis |
| Restriction Enzymes | Cut DNA at specific sequence patterns | Molecular "scissors" that allow precise editing of genetic information |
| Green Fluorescent Protein (GFP) | Visualizes protein location and movement in cells | Tracks the "output" of genetic information—where proteins go and what they do |
| CRISPR-Cas9 | Precisely edits specific DNA sequences | Allows rewriting of genetic information with unprecedented precision |
| RNA Interference Molecules | Silences specific gene expression | Selectively blocks the "reading" of particular genetic messages |
These tools have transformed biology from an observational science to an informational engineering discipline, allowing researchers not just to read but to rewrite the code of life.
The informational perspective continues to yield dramatic insights across biology. Recent discoveries include:
Scientists have successfully transformed giant panda skin cells into stem cells, creating a potentially inexhaustible source of material for conserving endangered species 6 .
Researchers have developed mRNA vaccines that train the immune system to recognize and attack pancreatic cancer cells by presenting them with informational signatures of the tumor 6 .
In lupus patients, scientists discovered a critical breakdown in immune cell communication—specifically an imbalance between attacking and repairing T-cells—pointing to novel treatment strategies 6 .
"Once we look at biology in the light of information, it is hard not to see the fundamental importance of this concept to biology. Indeed, everything in biology starts to make sense when viewed from this perspective" 8 .
Each discovery reinforces that information isn't just a metaphor in biology—it's a fundamental physical property of living systems that can be measured, manipulated, and understood.
The challenge now is to develop what Pedro Marijuán calls a "new communication theory of non-conservative nature" that can fully capture the dynamic, creative, and meaning-generating capacity of living information systems 1 . As we rise to this challenge, we're not just learning about biology—we're learning a new language, the native tongue of life itself.