Biology Reference
In-Depth Information
The scientific question we are then left with (and this is the question in which
I am interested) is twofold: how did these early machines first come about,
and by what processes (or dynamics) did they come together, combine, and,
ultimately, constitute a primitive cell? We take it for granted that all this came
about through evolution, but by what kind of evolution? Clearly, not through
evolution by natural selection as natural selection itself is a product of this early
evolution. What, then, are the alternatives? What other than natural selection,
or intelligent design, can provide directionality or sheer accumulation to the
random processes of change to which entities in the physical world are subject?
In other words, is it possible to account for the emergence of natural design,
of a 'self' that can be said to organize - indeed, for the emergence of natural
selection itself - from purely physical and chemical principles?
The main scientific alternative that has been promoted in recent years - and
for many people, the only possible scientific alternative to evolution by natural
selection - is the spontaneous emergence of order associated with the third
meaning of self-organization I discussed earlier, i.e., the kind of self-organization
seen in nonlinear dynamical systems that can 'mold itself,' as Davies put it, 'into
thunderstorms, people and umbrellas'. Or as Stuart Kauffman writes, '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.' (1993, p. 45). Kauffman
is correct. Many complex structures - including networks - can and do arise
spontaneously. Indeed, we can find examples of order-for-free all around us.
The problem is that such structures do not yet have function, agency, or purpose.
They are not yet alive. Self-organization, as mathematicians use the term, may
be necessary for the emergence of organized complexity, but as I have already
emphasized, and as Stuart Kauffman now acknowledges,
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it is not sufficient.
Something else, something engineers have been struggling to characterize ever
since the 1940s, is also required.
Cybernetics, and its emphasis on the relation between feedback and function
characteristic of homeostatic devices, offered one clue; I believe that Herbert
Simon offered us another. In fact, it is sobering to go back and read Simon's 1962
essay on 'The Architecture of Complexity'. Here Simon introduces a crucial
if much neglected argument for a form of evolution that is alternative both to
natural selection and to emergent self-organization: evolution by composition.
The idea is this: If stable heterogeneous systems, initially quite simple, merge
into composite systems that are themselves (mechanically, thermodynamically,
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In his more recent work, Kauffman concludes that 'We have no theory of organization', and asks: 'What
must a physical system be to constitute an autonomous agent?' (2003: 1089). His answer is that it must
couple a motor with self-reproduction/autocatalysis in a nonequilibrium energy flow, and offers as a primitive
example a DNA hexamer that can catalyze the linking of two trimers into a hexamer that is a copy of the
initial hexamer, provided it is coupled with a PP (pyrophosphate) motor, in a system, far from equilibrium,
with an excess of trimers and photons.
