Do Cells Have Sentience? New Framework For Understanding Life And Consciousness

The Sentient Cell. Arthur Reber, Frantisek Baluska, and William Miller. OUP Oxford. Pages 274. Rs 997.

Microbiologist Lynn Margulis (1938-2011) famously wrote that not only animals but ‘every autopoietic cell’ is conscious. That was in 1995.

The concept that remained a fringe in biology has been making significant strides and has today emerged as an important position.

Cognitive psychologist Arthur Reber, plant biologist Frantisek Baluska and evolutionary biologist William Miller have come together to author this book.

Each of them has been a pioneer in exploring uncharted paths, challenging conventional notions in their domains.

Do cells have sentience?

The theory that has been proposed is called CBC — cellular basis of consciousness.

The authors propose that at the cellular level consciousness emanates from ‘the coordination of multiple internal structures and processes including the macromolecular assemblies at and around excitable plasma membranes and cytoskeletal polymers.’

The book points out that the plasma membrane only once formed in evolution and since then for four billion years of biological evolution has remained the same. It never appeared de nova in the evolution. This means that the cells are sentient at their very origin.

This means that a form of cellular consciousness has been accompanying the evolution of life from the very beginning.

The foundational thesis of CBC is that ‘the emergence of the very first living cells, enclosed with an ancient version of the plasma membrane, is coterminous with the origin of life and consciousness.’

The authors also emphasise a principle called 'evolutionary creativity.'

This principle posits that no trait, form, or function that once had Darwinian survival value ever gets entirely lost in evolution but becomes the basis for new traits, forms, and functions.

Sentience is an implicit aspect of cellular cognition and memory, and essential for cell survival via contextual decision-making from the very early evolution of cells. This cellular sentience then becomes an important component in evolution, coterminous with life.

Another principle the book introduces is the concept of ‘homeorhesis,’ ‘a dynamic system that returns to a prior trajectory’ as against the more familiar term, ‘homeostasis,' which is a system that returns to a particular state.’ Then there is cooperation at the level of cells.

The book is a rich feast of concepts that challenge some of the basic assumptions of biology. Does consciousness then arise with the plasma membranes and the interaction that happens there? For the authors, as already noted, life and consciousness are coterminous. So the question of minimal life is also the question of minimal consciousness.

To this question, the authors speculate quite boldly that even some biomolecules might possess ‘a mind.’ They give the instance of the mammalian protein mTOR which accomplishes a range of functions in human organisms at the cellular level. The authors ask:

Apart from such single molecules, the authors favour the view that almost every intracellular component — from plasma membrane to cytoskeletal microtubules has a minute nano brain or ‘mind.’

In this view of life, consciousness ‘galvanises’ evolution through sentient problem-solving against changing environmental constraints as ‘life is cognition, embodied in the perpetual cellular form.’

The authors visualise ‘a minimal version of proto-consciousness that was sufficient to respond sensitively and effectively to diverse environmental insults and challenges that were extremely violent on ancient earth.’ They also associate cellular circadian clocks evolving with this early sentience. And when it comes to endosymbiosis and the emergence of eukaryotic cells, consciousness becomes a very important catalysing force for biological evolution.

One of the authors William B Miller, the evolutionary biologist, has even authored a book titled ‘Cognition-Based Evolution’ (2023) where he amends the famous statement of the great evolutionist Ernst Mayer — ‘The theory of evolution is quite rightly called the greatest unifying theory in biology’ — by the statement ‘cellular cognition is the great unifying force in biology.’

The book also looks into the ethical implications of CBC. Often a rhetorical question is asked when one becomes a vegetarian for ethical reasons — Are not plants sentient? The authors give quite a tantalising answer here:

A footnote points out that the ethical implications resonate with the non-violence model of Jainism. One would extend that to the entire Sanatana Dharma though.

Overall, this book is rich with data and insights that challenge fundamental tenets of biology.

This trend has been evident as complex networks are uncovered at every level of biology, from molecular pathways to tropical rainforests. While reductionism remains an effective tool, it does not capture the entire reality.

Cellular Basis of Consciousness (CBC) to Cognition-based Evolution (CBE) provide quite interesting and transforming views of the field of biology itself. If further validated and developed into powerful schools, they can have a very serious impact on how we approach biology.

If one is to go through the history of the notion of cellular consciousness, then one always arrives at Lynn Margulis (1938-2011).

As every study progresses into the complexity and richness of processes that shape evolution, one realises that Margulis should be considered as perhaps the greatest biologist since Darwin.

At the start of the review, the writer has referred to her view of the consciousness of the autopoietic cell. In the same book, she also said: