The Origin and Nature of Consciousness: From the Genetic Code to Subjective Experience

1. Introduction

There are two mainstream theories of the origin of consciousness: integrated information theory, or IIT, which argues that consciousness arises from the capacity to integrate information [1] and global neuronal workspace theory, or GNWT [2], that assumes consciousness is a result of long-distance neural connectivity, which provides a global network for sharing information between multiple specialized brain areas.

Despite their prominence, it is quite obvious to a biologist outside this highly specialized field that both theories are more abstract and metaphysical than they are empirical and evolutionarily viable models. It is likely because the nature of consciousness was and is often associated with philosophical, mathematical, psychological and spiritual nuances rather than with purely biological inquiries.

What was the “light bulb” that suddenly illuminated the darkness of small brains of Australopithecus anamensis or Australopithecus afarensis making them to eventually transform into larger “cognitive devices”? What was the starting point of this breathtaking evolution that initiated the origin of consciousness in an “evolutionary correct”, Darwinian, way? Natural selection is the main driver of evolution. At the molecular level, natural selection relies on genetic variations created by random changes in DNA sequences. It is thus theoretically possible that consciousness may have emerged when the genetic code bearing a handful of beneficial mutations yielded novel, functionally advantageous protein(s) critical to neural processing and brain development.

This process sequentially paved the way to rudimentary neural frameworks intended for a particular cognitive experience, for instance, a more sophisticated stress response. Put simply, the basic mechanisms of molecular biology that govern all essential processes of life in multicellular organisms - genetic coding, transcription, and translation - determined how consciousness originated, how it evolved, and what it actually is. Driven by the unique genomic signatures within neurons, consciousness makes electrochemical wiring a mere tool for its expansion rather than the cause of cognitive experience.

2. Main Text

The DNA molecule is composed of billions of carbon, oxygen, nitrogen, phosphorus and hydrogen atoms structured into monomers, then polymers and then inexplicably into ordered sequence that carries information and constitutes the genetic code of life. Similarly, the roughly 86 billion neurons of the human brain assemble into dynamic and sequential neural circuits working in unison to generate consciousness as an ultimate result. If basic biochemistry and natural selection can largely explain the origin of the genetic code - arguably biology’s most complex problem - then consciousness, as a product of the genetic code, must be explainable by the same fundamental mechanisms or at least follow a parallel pattern.

Previous proposals argued that the evolution of the genetic code was driven by the need to secure early RNA molecules within protective shells, a process that sequentially fostered specific amino acid-RNA interactions and enabled primitive coding instructions to produce multiple copies of a single protein [3]. Much like the emergence of the genetic code, the origin of consciousness should have required a similar evolutionary force that would offer specific advantages to ensure survival of early hominids in harsh environments.

The initial adaptations must have originated from underlying genetic mutations favored by natural selection due to their contribution to survival and fitness. Just as O, H, N, C , and P atoms during the Early Earth and RNA World [4] organized into RNA rather than other chemical compounds, primitive consciousness likely began when the genetic code bearing these specific mutation(s) led to a rudimentary neural network intended for a particular cognitive experience, for instance, a more sophisticated stress response.

Analogous to the code triplets, individual neurons within this minimum neural assemble would coordinate and rearrange their synaptic plasticity to produce and transmit a unique message to neighboring networks, eventually building a goal-oriented circuit architecture indirectly comparable with translation of the genetic code into functional proteins. Gradually, multiple purpose-built organized patterns of synaptic connectivity would allow brain to multitask, simultaneously processing different information and achieving survival-driven goals by integrating primitive reflexes into learned, pre-cognitive actions. These behaviors will be refined by scrutinizing pressure of natural selection evolving into rudimentary forms of mental processes and proto-cognition, in the end maturing into primitive thinking and full cognitive ability (Figure 1).

This mechanism closely resembles the formation of protein-protein interaction networks essential to organ development and function. Indeed, as Nature frequently repurposes universal ‘machinery’ to perform diverse functions, it is plausible that the origin, evolution, and the very essence of consciousness might be rooted in the same foremost principles as the genetic coding and translation.

What novel perspective does this assumption offer on the extensively researched problem of consciousness, a field already saturated with theories? While the evolutionary origin of consciousness as a mechanism for survival and social coordination is evident, the nature of this brain activity is unknown. Comparing consciousness with the origin and significance of the genetic code from which it unequivocally emerged, provides a clear answer to this fundamental question: the nature of consciousness is determined by the same molecular mechanisms that govern all essential life processes in multicellular organisms –the genetic code, gene expression, transcriptional regulation, epigenetic remodeling, post-transcriptional controls, and protein translation.

In other words, whether consciousness is a product of information sharing [2]; an integrated information itself [5]; a result of sensory input [6]; a process rooted in quantum mechanics and “brain microtubules” [7]; a generative model constantly updating a mental status of the world [8]; or else [9,10], it ultimately stems from the genetic coding, transcriptional variations, and production of distinct proteins.

This is why the mechanisms of consciousness should be studied at the levels of molecular biology, genetics and functional genomics rather than through philosophy, mathematics, physics, or psychology. Regrettably, this approach remains largely, if not entirely, unexplored as none of the current theories focuses on these aspects of consciousness’s nature and origin, arguing instead about “excitable membranes”, “consciousness in single cell”, “biocivilisations”, or importance of vague “molecular perspectives” [11,12,13,14,15].

Evolution is powered by natural selection. At the molecular scale, it relies on random changes in DNA sequences. Accordingly, the genesis of consciousness can undoubtedly be linked to advantageous mutations responsible for unique proteins facilitating critical neural processes. It is theoretically possible that the evolution of consciousness in primates began with just one genetic mutation that radically transformed their behavior and physiology.

For instance, a single C-to-G point mutation that happened between 1.5 and 0.5 mya in the duplicated ARHGAP11B gene, encoding Rho GTPase-activating protein 11B and present in modern humans, Neanderthals, and Denisovans, but not in chimpanzees (Florio et a. 2015), triggered a 55-nucleotide deletion, altering the protein’s C-terminal sequence. These changes enabled the protein to move from the nucleus to the mitochondria, allowing it to drive increased basal progenitor proliferation crucial for neocortex expansion and a larger brain [16,17,18,19]. High expression of this gene in radial glial cells caused evolutionary expansion of human neocortex, the primary site for consciousness [20].

If basic processes of molecular biology originating in the RNA World, a predecessor of the “Central Dogma” [4], catalyzed the emergence of consciousness, what mechanisms, beyond physically shaping brain’s structure, enabled them to facilitate information processing? Key processes responsible for conscious sensations - the synaptic neurotransmission and high-frequency action potentials – depend entirely on the gene expression, although in obviously different ways. Differential gene expression leads to structural and functional changes in neurons and resulting neural activity translates through a series of signals into coordinated pattern that brain interprets as a cognitive event.

In other words, consciousness arises from the unique genomic/transcriptomic signatures within neurons and electrochemical “wiring” is the subsequent process rather than a starting point. Unlikely being associated with an elusive state of “DNA consciousness” or a sci-fi-like condition of “cellular consciousness” [13,21], it is most probably a sustained product of selective activation or repression of specific genes to perform distinct tasks, although doubtfully related to “meditation techniques” [22]. It is no wonder, then, that a control hub of three miRNAs and three protein-coding genes was recently discovered to orchestrate a network of over 4,000 genes linked to human personality and self-awareness, solidifying the role of gene expression in these core experiences of consciousness [23].

Recent data suggested that conscious processing speed is ~ 10 bits per second, much slower than that of sensory data ~ 10⁹ bits/s [24]. The speed of eukaryotic genetic processing such as transcription and translation on individual and molecular scale is approximately 36–84 bits/s and ~12–120 bits/s, respectively [25,26], and the dynamic speed of the whole cell, or global, genetic processing is likely much faster since a human cell doesn’t just run one gene at a time and is a parallel processor.

Therefore, the conscious experience (~ 10 bits/s) aligns more closely with the slower timescale of cellular and molecular kinetics (~ 10¹-10² bits/s) rather than with the rapid neuronal spikes (~10³ bits/s) or a massive human sensory input (~ 10⁹ bits/s [24], (Figure 2).

That is to say, the aggregate genetic activity of the cell not merely builds biological machinery required for information to be integrated, but also actively generates thoughts as the direct output of millions of synchronized molecular events. Afterall, if universal transcriptomic signatures can modulate aging, lifespan, health and mortality [27], why would not they also control our cognitive processes and intellectual functions? Perhaps this is a path that future consciousness research can look into more closely.

3. Conclusions

In summary, both the “hard” and the “easy” problems of consciousness [28] are comparable with the enigma of the genetic code. If laws of chemistry and evolution can explain the origin of the genetic code, then consciousness, as a byproduct of the code, likely operates under the same biological principles or follows a parallel logical pattern.

Is this perspective strictly mechanistic and dismissing all philosophico-spiritual attempts to explain consciousness as a pure expression of mind detached from any biological processes? Yet the whole human organism operates as a finely tuned biological entity, a complex infrastructure and a continuum sustained by billions of interconnected cellular and molecular events - from the genetic coding, transcription and translation to protein networks and cell signaling. Mental processes cannot possibly be excluded from this rule. Therefore, the “easy” problems of consciousness explainable by science may actually unlock the answer to the “hard” problem—the true origin of conscious experience [28]. Within this concept, neural nets and their dynamic communication systems is a “hardware”, or a physical scaffold of the conscious brain, while the genetic code, genomic architecture, gene expression and protein interaction networks is the software that brings the process of consciousness to life.