Crossing the Complexity Barrier

January 11, 2010 at 4:33 pm (Book reviews, Complexity Theory)
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Darwinism Evolving: Systems Dynamics and the Genealogy of Natural Selection

Depew, D. J., and Weber, B. H. ,

Cambridge, Mass.: The MIT Press. (1996).

The study of complexity and self-organization in living organisms offers a powerful, new way to understand the natural world.  It provides a profound and serious alternative to the reductionist program which has dominated biology since the early part of the 20th century.  But what does it imply for Darwin’s theory of natural selection, the bulwark of modern biological thought?  Over the past two decades, a number of researchers have shown how natural selection and complexity theory, far from being rivals, are in fact “marriage partners.”[1]

Of these studies, the one that I’ve found most rewarding is Darwinism Evolving by Depew & Weber, which gives an in-depth narrative of the thought currents around Darwin’s theory, from before Darwin all the way to the present day, using the narrative to establish and support their own approach.

They begin with an interesting take on Darwinian theory, describing how it developed in the context of both the political and scientific framework of the mid-19th century.  Politically, Depew and Weber show how Adam Smith’s view of the “invisible hand” could be powerfully translated from economics to biology.  In both cases, individuals struggle to do what’s best for them, and by doing so, blindly become agents in the natural laws of capitalism and evolution.  Similarly, the “gradualist” approach that Darwin favored in describing the process of natural selection, fit well with the prevailing political ethos of Victorian England.  They describe a chemist named W.R. Grove addressing a scientific meeting in 1866, telling his compatriots how: “Happily in this country practical experience has taught us to improve rather than remodel; we follow the law of nature and avoid cataclysms.”

Depew & Weber are not the first to note this political context (in fact they tell us how Karl Marx picked up on it as early as 1862.)  But they probably break some new ground in their linkage of Darwin’s ideas to developing theories in physics, arguing that:

… the Darwinian research tradition, while successfully resisting reduction to or incorporation within physics, has from the beginning used explanatory models taken from physics to articulate its core idea of natural selection.

They show how Newton’s laws formed a “generalized model for describing and explaining phenomena in fields beyond physics, even social systems” in the nineteenth century, and they offer a fascinating analysis of how the laws of statistical mechanics developed by Maxwell and Boltzmann had a profound effect on later, post-Darwinian evolutionary thinking.

This thesis really hits its stride when Depew & Weber follow the interactions between evolutionary thought and the second law of thermodynamics, which states that processes in a system will tend towards entropy.  They give an account of the strange life of Ronald Fisher, the first person to formally link evolution with the second law, with his view that “just as the world moves downhill by the exploitation of energetic gradients, so it moves uphill by the exploitation of fitness gradients.”  With a clear distaste for how evolutionary theories can be manipulated to support ethical idiosyncrasies, they note how “as his classmates went off to the slaughter of World War I, Fisher was writing in the Eugenical Review that although morality and aesthetics are both grounded in sexual selection, those who rightly rule in a society know that beauty is a higher value than morality.”

The linkage of evolution with the second law of thermodynamics becomes more rigorous and powerful as the story continues.  We’re introduced to Alfred Lotka’s thermodynamic theory of evolution which can be summarized as:

Evolution proceeds in such direction as to make the total energy flux through the system a maximum compatible with the constraints… In accord with this observation is the principle that, in the struggle for existence, the advantage must go to those organisms whose energy-capturing devices are most efficient in directing available energy into channels favorable to the preservation of the species.

Depew & Weber tell us how “with his vision of the unity of physics, chemistry, and biology, Lotka proposed this as a fourth law of thermodynamics.”

Perhaps the most important milestone in this narrative is the “seminal little book that appeared in 1944”, by quantum physicist Erwin Schrödinger called What is Life?, which threw “considerable sweetness, as well as light” on the subject.  Schrödinger’s breakthrough was to contrast an organic or open system with the universe as a whole, arguing that “the second law requires only that the universe as a whole must show an increase in entropy.  Eddies of order, or what Schrödinger called ‘negentropy’, could be sustained in the great flow of ever-increasing entropy.”

So life can be seen as a continual struggle against entropy, whereby cells, organisms or ecosystems take energy from the broader universe, organize it in ways that assist them (i.e. metabolism), and dissipate the waste back out.  This is why Ilya Prigogine, the next great thinker on this subject, refers to organisms as “dissipative structures.”

This narrative enables one to see current theories of complexity and self-organization within a full historical context.  Those who are “marrying” self-organization to evolution are, in fact, working on the fourth or fifth generation of matchmaking.  The difference now, as Weber and Depew point out, is that the new science of complexity has developed theoretical tools and data-driven applications that fundamentally change the project.  As they put it:

The first lesson to be learned from the new dynamics is that the world contains more novelty, diversity, and complexity than we had assumed…  Crossing the complexity barrier, accordingly, calls for … radical revisions in how scientific theories are to be analyzed and in how they explain when they are applied to problems… [I]t is not just physics and biology that must change to accommodate this fact but philosophies of science, too.

The implications of “crossing the complexity barrier” are far-reaching, and Depew & Weber explore some of these directions.  For example, a thermodynamically-based view of evolution leads to an understanding of evolution as occurring on multiple levels rather than solely on the individual organism (or as espoused in recent decades, the individual gene.)  It also supersedes the “competition” metaphor in traditional evolutionary narrative, as Depew and Weber explain:

Organisms will, on this account, be construed as informed patterns of thermodynamic flow.  Those populations will be fittest that best enhance the autocatalytic behavior of the reward loops in which they participate.  One advantage of this notion is that it makes it possible to contextualize natural selection to the wider array of processes in which it occurs, and to project a vision of ecological communities in which cooperation becomes as characteristic as competition, or indeed inseparably linked to it…

Not surprisingly, Depew & Weber come out strongly against reductionist thinking in general, and even more fiercely against Richard Dawkins’ particular style of that thinking, describing how he “invests his metaphors with disturbing semantic reverberations that harken back to Enlightenment themes”, giving the choice between being pawns of our genes” or “of a tyrannical Calvinist God.”  As I’ve described elsewhere, I’m in strong agreement with their view of Dawkins’ “false choice,” and the inherent limitations of thought offered by reductionism, which they describe as follows:

The problem has been that when everything is antecedently considered to be ‘nothing but’ atoms in the void, many real, important, and interesting phenomena tend to get explained away, brushed aside, eliminated, or, worse, crammed into the wrong explanatory box… Indeed… the reducing impulse undermines fairly huge tracts of experience.

The dynamical systems perspective is far from universally accepted, even by those who challenge conventional gene-centered evolutionary approaches.  Here is a critique from David Sloan Wilson, known for championing multi-level selection theory:

Embedded in the thermodynamics talk is the naive assumption that adaptation at level x … automatically leads to adaptation at level x + 1… It is… discouraging that ‘‘the emerging sciences of complexity’’ are so isolated from evolutionary biology that the mistakes of the 1940s and 1950s are being repeated.[2]

I disagree with Wilson about the “automatic” assumption.  I think the “complexity” part of modern systems thought leads to the understanding that there’s nothing “automatic” about the dynamics leading to evolution, or for that matter, leading to the life of any given organism.  But this type of dismissal, even from advanced thinkers such as Wilson, shows how far the scientific community still has to go in crossing the complexity barrier, and participating in that “marriage” of natural selection and complexity theory.

[1] See Kosse, K. (2001). “Some Regularities in Human Group Formation and the Evolution of Societal Complexity.” Complexity, 6(1 (2001)), 60-64, who calls for a “marriage between Darwinian theory and the emerging science of complexity.”

[2] Wilson, D. S. (1997). “Biological Communities as Functionally Organized Units.” Ecology, 78(7), 2018-2024.

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Carry It On

December 8, 2009 at 4:58 pm (Book reviews)
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Mind in Life: Biology, Phenomenology, and the Sciences of Mind

By Evan Thompson

Cambridge: Harvard University Press

In a couple of recent blog posts[1], I’ve talked about how life-science needs to expand its reductionist agenda to approach the mysteries of life, enabling us to bridge the chasm between science and spirituality.  After recently completing Evan Thompson’s Mind in Life, I believe that he could be one of the leading thinkers in getting us there.

Thompson was one of the co-authors, along with Francisco Varela, of a ground-breaking book published in 1993 called The Embodied Mind: Cognitive Science and Human Experience, which explored some of the areas of overlap between cognitive science and Buddhist psychology.  Varela, who introduced (with Humberto Maturana) the idea of autopoiesis[2], was viewed by many as a thought-leader in this area, until he tragically died in mid-career in 2001.  In his current book, Thompson is carrying on the thought-processes he began with Varela[3], and taking them into expansive new areas.

At the core of the book is the idea that life is a self-organized, self-creating system.  This central theme is then applied to different aspects of life, such as consciousness, evolution and cellular dynamics, to provide a coherent view of how these seemingly disparate areas are in fact all integrated.

A key phrase Thompson has coined to describe his particular view of life’s self-organized nature is “dynamic co-emergence.”  This is crucially important for contrasting living systems with other complex, self-organized non-living processes, such as a candle flame or a whirlpool.  Here’s how Thompson explains it:

An autonomous system, such as a cell or multicellular organism, is not merely self-maintaining, like a candle flame; it is also self-producing… In the single-cell, autopoietic form of autonomy, a membrane-bounded, metabolic network produces the metabolites that constitute both the network itself and the membrane that permits the network’s bounded dynamics.  Other autonomous systems have different sorts of self-constructing processes…  Whether the system is a cell, immune network, nervous system, insect colony, or animal society, what emerges is a unity with its own self-producing identity.

The reason why Thompson calls this “dynamic co-emergence” is that:

… the whole is constituted by the relations of the parts, and the parts are constituted by the relations they bear to one another in the whole.  Hence, the parts do not exist in advance, prior to the whole, as independent entities that retain their identity in the whole.  Rather, part and whole co-emerge and mutually specify each other.

Thompson traces a tradition of Western thought, going back to Aristotle, which entertained this approach to understanding life.  I call it the “moonlight tradition”, because its illumination was so overwhelmed by the bright glare of Platonic dualism, that it’s just about invisible to most conventional examinations of Western thought; but when you look at the world by its light, you see things in a new and beautiful way, in the same way that a plain, familiar landscape becomes entrancing by moonlight.

Following this line of thought, Thompson shows how Kant arrived at a view of “natural purpose” for living organisms which is only now being re-discovered by scientists applying the mathematical tools of complexity theory that were not available to Kant.

These tools are, however, available to Thompson, and he makes excellent use of them in exploring the implications of “dynamic co-emergence” to central aspects of our lives.  A key concept from complexity theory is that of an “attractor”: a relatively stable, dynamic state to which a complex system converges over time.  Every time you turn on the water in a sink and see the pattern it makes as it circles the drain, you’re seeing an attractor.  It’s both stable and dynamic.  It keeps changing, but only within certain parameters.  Open the faucet more, and after a few chaotic moments, the water will settle into a new attractor.[4] Attractors can describe the changes in state taken by the kinds of self-organizing, dynamically co-emergent systems that comprise life as we know it.

When you apply the concept of attractors to the most complex systems of all, such as our minds, this leads to another concept known as “metastability”, where things appear relatively stable even as they keep fluctuating from one area to another within an attractor.  This dynamic, Thompson explains, “permits a flexible repertoire of global states without the system becoming trapped in any one particular state”.  Increasingly, leading neuroscientists are applying this analysis to understand how complex patterns of neuronal firings can lead in our brains to the state of consciousness.

Thompson follows this logic on inexorably, exploring how the cellular complexities of dynamics such as metabolism lead to a sense of purpose in even a single-celled organism.  As this microcosm of value is then traced up the ladder of complexity all the way to human cognition, we see how intentionality turns into what is known as “valence” (attraction/repulsion, like/dislike, etc.) and ultimately into what we define as values.

Similarly, we can trace how the short-term dynamics of the attractor of our consciousness lead to feelings, then to moods, and ultimately personality.  From this perspective, we can begin to see personality as a kind of metastable phase-state within which our emotions and moods play out.  But always, the emphasis is on the dynamic co-emergence of the parts and the whole.  So, in this example, your feelings and moods are continually re-forming your personality at the margin, which then impacts those very feelings.  You, therefore, are a self-created and self-creating entity!

Thompson champions a fundamentally different, and potentially liberating, view of ourselves and the world around us, in stark contrast to the reductionist, deterministic view espoused by the life-science mainstream.  In a powerful invective, Thompson witheringly critiques Richard Dawkins’ metaphor of the “selfish gene,” arguing that “it is little more than a metaphor that masquerades as a theoretical concept and… leads to a misleading picture of the nature of possible explanations in molecular biology.” I found this section very convincing, and feel it should be required reading for anyone who remains committed to the “genocentric” view of life.

But what metaphor could we use to replace the current “genetic program” view of the natural world?  Thompson proposes a metaphor that he calls “laying down a path,” implying that “there is no separation between plan and executed action.”  This is one area where I think there’s a lot more to be done.  Personally, I believe that the “music” metaphor may be the most powerful candidate to replace “genetic programming.”  Later in the book, Thompson does describe evolution in term of dance:

Like two partners in a dance who bring forth each other’s movements, organism and environment enact each other through their structural coupling.

However, I think there’s a lot more play in the metaphor than that.  One writer who has embraced this as a central metaphor is Denis Noble, author of The Music of Life: Biology Beyond Genes, a book that I’d recommend as a great complement to Thompson.  The power of the music metaphor is that it incorporates all the complexities of dynamic co-emergence, and at the same time it plays havoc with the traditional “competition” metaphor so prevalent among genetic determinists.  Imagine a biologist from another planet watching an orchestra play and observing that “the violins must pursue the most successful adaptive strategy because there are so many of them.”

After centuries of its concealment in the twilight of the “moonlight tradition,” the application of mathematical rigor to a more holistic view of life has the potential to revolutionize the life sciences in the 21st century and beyond.  Thompson’s book does a great job of applying Varela’s insights further afield, and in doing so he’s “laying down” an important path for others to follow.

[1] Re-weaving the Rainbow and A False Choice: Reductionism or Dualism.

[2] Autopoiesis can be loosely defined as a definition of life as a system with a semi-permeable boundary produced by reactions within that boundary that simultaneously regenerate the components of the system: thus, it’s self-organizing and dynamically self-creating.

[3] Thompson writes in the Preface that the book was originally intended to be co-authored with Varela.

[4] Technically, this describes what’s called a chaotic or strange attractor, as opposed to a more predictable point attractor or limited cycle attractor.

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