“Since Darwin, we turn to a single, singular force, Natural Selection, which we might as well capitalize as though it were the new deity.” (Kauffman 1995, page 8).

Stuart Kauffman tackled the question of the origin of life and mounted a major challenge to the accepted belief that Natural Selection is the only source of complexity in biology in 1995 in his book, At Home in the Universe: the Search for the Laws of Complexity.  His research into mathematical models and computer programs showed that in serial computer programs almost any random change produces garbage.  Almost all small changes in structure lead to catastrophic changes in behaviour, and only redundancy allows some changes to be tolerated.  Taking the lessons learned in computer programming to understand the emergence of life, Kauffman concluded that the NeoDarwinist concept concerning the role of Natural Selection in this area is almost certainly wrong. 

Kauffman states that there are two fundamental limits to selection: firstly, in some complex systems, any minor change causes catastrophic changes in the behaviour of the system; in these cases gradualism does not help and selection cannot assemble complex systems.  Secondly, “Selection runs headlong into an ‘error catastrophe’ where all accumulated useful traits melt away.” (Kauffman 1995, page 183).  Thus, Darwin’s thesis concerning gradualism is wrong – that minor useful variations can be accumulated bit by bit over time to construct organisms that are able to adapt by mutation and selection (Kauffman 1995, page 152).

Natural Selection occurs, but it has always had a ‘handmaid’ that Kauffman believes is spontaneous order.  Thus, Kauffman ’s solution is self-organization as a precondition to evolvability.  There are limits to what selection can achieve.

“Were cells and organisms not inherently the kinds of entities such that selection could work, how could selection gain a foothold?  After all, how could evolution itself bring evolvability into existence, pulling itself up by its own bootstraps?”  (Kauffman 1995, page 188).

“Most biologists have believed for over a century that selection is the sole source of order in biology, that selection alone is the “tinkerer” that crafts the forms.  But if the forms selection chooses among were generated by laws of complexity, then selection has always had a handmaiden.  It is not, after all, the sole source of order, and organisms are not just tinkered-together contraptions, but expressions of deeper natural laws.” (Kauffman 1995, page 8).

So what is this natural law?

Kauffman introduces the concept of Emergent Properties; if you keep adding ingredients, at a certain threshold, a new level of complexity emerges.  The origin of life is a collective emergent property of “complex systems of chemicals” he states (page 19).  He believes that Emergent Order underlies not only the origin of life, but also much of the order seen in organisms.

Thus, for Kauffman the concept of Emergent Properties:

• Is really the recognition that Natural Selection cannot explain the coming into being of everything concerning life.
• Recognizes discontinuities in levels of complexity that demand a different explanation.
• Is a rejection of Reductionism in biology i.e. the idea that the living organism as a whole can be explained by a description of the parts of which it is composed; the ‘nothing but’ explanations.

Concerning the origin of life, Kauffman believes that as the molecular diversity of a prebiotic chemical system increases beyond a certain threshold of complexity, an autocatalytic set of chemicals will arise that sustains itself and reproduces.  This would be a living metabolism.  Life is the collective property of systems of interacting molecules.  Whenever a collection of chemicals contains enough different kinds of molecules, a metabolism will crystallize from the broth. 

“If this argument is correct, metabolic networks need not be built one component at a time; they can spring full-grown from a primordial soup.  Order for free, I call it.”  (Kauffman 1995, page 45).

Kauffman, in his upbeat style, expected life to be synthesized within one or two decades.  He describes a model consisting of buttons and threads to illustrate the idea of connections between elements (buttons or dots) and a phase transition in which the whole becomes interconnected.

Kauffman proposes, concerning the origin of life, that as the diversity of molecules in our system increases, the ratio of reactions to chemicals becomes higher.  When the number of catalysed reactions is about equal to the number of chemical dots, a giant catalysed reaction web forms, and a collectively autocatalytic system snaps into existence.  A living metabolism crystallizes.  Life emerges as a phase transition (Kauffman 1995, page 62).

These autocatalytic sets apparently did not have DNA or RNA, and no genetic code (Kauffman 1995, pages 72-73, 275).  Kauffman attempts a scenario explaining how they can evolve without a genome. 

He writes, if we are to believe that life began when molecules spontaneously joined to form autocatalytic metabolisms, we will have to find a source of molecular order, a source of the fundamental internal homeostasis that buffers cells against perturbations, a compromise that would allow the protocell networks to undergo slight fluctuations without collapsing.  He concludes that it must be another case of order for free.

Kauffman rightly observes that one way to get such a network to behave in an orderly manner would be to design it.  But he proposes that autocatalytic metabolisms arose in primeval waters spontaneously, built from a random conglomeration of whatever happened to be around (Kauffman 1995, page 75).  Thus, a natural law must be found.

He investigates the behaviour of a dynamical system using light bulbs wired together randomly and blinking on and off.  The range of possible behaviours is the state space in which the system is free to roam.  When the system is supplied with an attractor, no matter what initial state it starts from, the system will run through a sequence of states, and settle into a same state cycle producing a repeating pattern of blinking lights.

In a large dynamical system, tiny attractors will trap the system into tiny subregions of its state space.  Among the vast range of possible behaviours, the system settles into an orderly few.  The attractors, if small, create order.  He states that tiny attractors are a prerequisite for the Order for Free that we are seeking (page 79).

According to the laws for orderly dynamics, a sparsely connected network K = 2 in which each light bulb receives two inputs and is assigned a Boolean function, will settle down into 317 states.  On the other hand, K = 4 or K = 5 networks exhibit chaotic behaviour.  Kauffman proclaims that this is Order for Free; such systems do not show sensitivity to initial conditions and they are not chaotic.  Once such a network is on an attractor, it will return to the same attractor with very high probability if it is perturbed.  This, he claims, is homeostasis (page 83).

In searching for a universal law of self-organization, Kauffman defines dynamical order as springing from a phase transition between stability and chaos; the most complex behaviours occurring at the edge of chaos.  Spontaneous order happens when a system “squeezes” itself onto tiny attractors (page 92).

Subcritical (orderliness) and supracritical (explosive diversity) regimes, and a phase transition drive the creation of molecular diversity in the biosphere, he concludes.  Kauffman proclaims that cells evolve to the subcritical-supracritical boundary. There is a supracritical biosphere and subcritical cells – and this is a new universal biological law!  (Kauffman 1995, pages 128-129). 

Kauffman suggests that most of the order of ontogeny[1] is spontaneous, a natural expression of self-organization that abounds in very complex regulatory networks.  Thus, biological evolution would not be the result of selection alone.

The real examples cited by Kauffman of “Order for Free” as opposed to the mathematical models he uses are as follows:

• Crystals – a crystalline seed chooses and orientates the molecules that spontaneously link themselves to it causing the crystal to grow in a defined manner.
• Snowflakes exhibit six-fold symmetry.
• An oil droplet in water forms a sphere.  Lipids spontaneously form a bilipid vesicle in water. 
• After viruses have been liquidized (broken up), they will self-assemble again as viruses because this gives them a lower energy state.
• The patterns in pinecones and other plants known as phyllotaxis are generated by growth processes in the growing tips (the Fibonacci series).  (See footnote[2]).

Comment

I entirely agree with Kauffman that Natural Selection cannot put together organisms as the starting point for evolution.  Order is the condition for the occurrence of evolution; it cannot be imposed by evolution in terms of the origins of biological systems.

Kauffman writes that the living world is graced with a bounty of order.  I agree, but I do not believe it is ‘order for free’.

Kauffman combines poetry with science, he writes: the life around us must somehow be the natural consequence of the coupling of free energy in the universe to forms of matter.  How?  No one knows.  ………. Here is a mystical longing, a sacred core……..  “If we are, in ways we do not yet see, natural expressions of matter and energy coupled together in nonequilibrium systems, if life in its abundance were bound to arise, not as an incalculably improbable accident, but as an expected fulfilment of the natural order, then we truly are at home in the universe.”  (Kauffman 1995, page 20).  – I can see how this would have appeal for some people.

Kauffman puts forward the view of holism – that life emerged whole.  This is not mysticism he says, as if answering a critic.  However, it seems to me that this so-called universal law of self-organization goes with a type of new age belief in the earth as god: a type of pantheistic view.  I have gone into Spontaneous Order in depth because of the current popularity of this idea. 

John Maynard Smith[3] has accused Kauffman of practicing “fact-free science”.  Kauffman’s mathematical theories have a total lack of chemical details.

My opinion is that when Kauffman writes about order in the context of systems treated mathematically, order means featurelessness.  Its opposite is total randomness or chaos.  The use of Boolean canalizing functions produces pattern with order.  For example, an F = 2 system with Boolean functions applied as attractors will cycle through 317 states.  In my opinion this is not interesting order, it is sclerotic order characterized by simple repeating patterns.  It does not carry meaning.

The examples Kauffman gives of ‘Order for Free’ are simple, repeating patterns found in nature.  They all have an explanation.  They are due to the different types of bonds that may be formed between the elements that compose the molecules.  The last example of the pattern found in pinecones may be due to homochirality (left or right symmetry) in the carbon-based organic molecules of life.

Patterns have their own fascination, but these are simple patterns, not complex patterns.  I do not deny that patterns can be generated spontaneously, but they are only a relatively simple facet of reality; they do not carry complex meaning.  On the contrary, life is complex and carries meaning.

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[1] Ontogeny is the development of an organism from the fertilized egg to its mature form.  Developmental biology studies ontogeny.

[2] One of the first people to recognize the patterns in nature was Alan Turing.  He presented the Turing Hypothesis of Pattern Formation, an example of which is Fibonacci phyllotaxis in a paper in 1952.  The paper consists of a decoding of nature in mathematical equations.  During the Second World War Turing worked as a code-breaker at Bletchley Park for the Allies.

Turing, Alan (1952) The Chemical Basis of Morphogenesis  Philosophical Transactions of the Royal Society of London  Series B 237 (641): 37-72.

[3] Smith J. M. (1995)  Life at the edge of chaos?  New York ReviewMarch 2, pages 28-30.