‘Shift Towards Ecological Context Of Organism To Understand Its Cognitive Abilities’: Harvard Systems Biologist Jeremy Gunawardena Tells Swarajya

More than a century ago, biologist Herbert Spencer Jennings had observed that single-celled organisms are capable of making decisions.

A century later, work by three system biologists, two from Harvard and one from India, shows that single-celled organisms do seem to have a capacity that is quite remarkable.

(Read: New Paper Suggests That Single-Celled Organisms Can Make Decisions)

Dr. Jeremy Gunawardena, one of the three systems biologists, shares with Swarajya his views, vision and framework of doing science:

On Paradigm Change And Resurrection Of Marginalised Experiments

Gunawardena: I would say, broadly following Kuhn, that scientific practice yields paradigms which determine ‘normal science’. The paradigm defines what is, and what is not considered ‘good’ science by the majority of scientists.

What is outside the paradigm tends to be regarded as ‘marginal’. Behaviourism was one such paradigm and, in that context, it was easy to ignore Jennings' work because that was what scientists at the time had persuaded themselves to believe was reasonable.

Paradigms change, as happened when cognitive science replaced behaviourism, but it can take a long time to rescue what was previously marginalised.

The lesson I would take is the importance of historical context in evaluating any piece of science, especially in biology.

On The Understanding Of Cognition Of Aneural Organism Redefining Boundaries

Gunawardena: I would hope that our work will contribute to an ongoing debate about cognition. Opinions on this differ widely.

I personally feel that cognitive capabilities have to be set in the ecological context of each organism and that those organisms without nervous systems, such as plants or ciliates, have to solve similar problems of information processing to animals with brains.

Arguing about whether this constitutes "cognition" or not is, I think, just semantics. The more important question is what information processing problems are being solved and by what mechanisms.

I think it is plausible that evolution has found similar solutions to the same problem, even though they are implemented in widely different ways, perhaps by neurons at one level and by molecules at another.

On The Need To Rethink 'Perceptron' - Computational Neuron Model And Rework It Taking Into Account The Ability Of Aneural Organisms To Make Complex Decisions

Gunawardena: Yes. And I think that is already happening at some level. Biology has many examples of "computation" besides neuronal networks — ecosystems, immune systems, gene regulatory networks, post-translational modification systems can all implement more or less complex forms of information processing at different biological scales.

However, these have not (yet) been explored with the same combination of theoretical depth and experimental power as neuronal networks.

In that respect, I have always felt that neuroscience offers important analogies for those of us who work primarily at a molecular level.

On Reductionism: Perhaps Incomplete But It Works For Integrative Questions With Reductionist Frameworks

Gunawardena: There has been a long-standing uneasiness on the part of some scientists that the reductionist approach is incomplete.

I certainly agree with that — in fact, I think it is obvious that it is incomplete. The problem is that we do not have an adequate framework to replace it.

Some people have tried — Robert Rosen, for instance, to incorporate autopoiesis into mathematics in his book Life Itself (1991) — and the idea that a ‘relational’ framework of some kind would be better suited to describe living phenomena, as you suggest, has been made by others.

However, none of these approaches have been successful at providing working scientists with something they could actually use to do science, meaning to develop an understanding of phenomena, formulate experiments and interpret data.

In the absence of an alternative, we fall back on reductionist approaches and, indeed, they have been very successful at accomplishing the things they are very successful at accomplishing.

So, how this tends to play out in our own work is that I am always conscious of the need to ask integrative questions — about ‘function’ and ‘evolution’ — but, for the most part, we try to answer these questions within a molecular reductionist framework.

On The Return of Lamarckism And Its Impact On The ‘Central Dogma’

Gunawardena: Indeed, Lamarck is no longer a prohibited name in biological discourse (see, for instance, ‘Transformations of Lamarckism’). And the central dogma has been so modified that it is barely recognisable.

We now know that there are several mechanisms of non-genetic hereditary, such as imprinting and, indeed, RNA (Miska & Ferguson-Smith, 'Transgenerational inheritance: Models and mechanisms of non-DNA sequence-based inheritance', Science. 2016).

Where it remains very controversial is whether these mechanisms have an evolutionary impact. Here, there is a wide difference of opinion but I would say the evidence is rather slender, certainly for animal evolution. Plants may be another matter.

Implications On The Larger Questions Regarding The Phenomena We Call Mind And Consciousness

Gunawardena: Again, this touches on issues which are hotly debated. We do not have a definition of mind or of consciousness, so these debates often reveal more about personal inclinations and domain knowledge — neuroscientists tend to believe different things from philosophers or cognitive scientists and different kinds of neuroscientists believe different things amongst themselves.

There are at least two major challenges in the way of scientific progress here. First, we do not understand well enough, and sometimes not at all, the ecological context of each organism. Hence, we tend either to overestimate their capabilities or underestimate them.

Second, consciousness as we understand it seems to involve many different features, such as "attention", "feelings", "identity", "agency", "learning", "decision making", "internal representations", "memory", "language", etc.

And it seems that many of these are separable, as we often observe in cases of humans with pathologies or injuries.

It seems plausible that these features are also distributed differently across organisms, depending on their evolutionary history and ecological context and that some features may have been lost as well as gained in particular lineages.

We are starting to formulate definitions for some of these features — aspects of "learning", for instance, have been well characterised — and showing by experiments that they exist in many different kinds of organisms.

This, perhaps, offers some hope that we can acquire a better evolutionary understanding of how these features arose and diversified and this gives us a scientific approach to "mind".

I hope Jennings' work on S roeseli will be seen as fitting into that. I feel this approach is more informative than attempts to argue for correlates of "mind", which tends to be restricted to organisms with nervous systems.

Of course, I am sure that some philosophers will continue to insist that the "qualia" gap cannot be bridged and that human minds are distinctive for possessing consciousness.

I do not personally subscribe to that view but acknowledge that subjective experience is especially challenging to address scientifically.