- Kauffman, Stuart A.
Investigations.
New York: Oxford University Press, 2000.
ISBN 0-19-512105-8.
-
Few people have thought as long and as hard about the origin
of life and the emergence of complexity in a biosphere as
Stuart Kauffman. Medical doctor, geneticist, professor of
biochemistry and biophysics, MacArthur Fellow, and member of
the faculty of the Santa Fe Institute for a decade, he has
sought to discover the principles which might underlie
a “general biology”—the laws which
would govern any biosphere, whether terrestrial, extraterrestrial, or
simulated within a computer, regardless of its physical
substrate.
This book, which he describes on occasion as “protoscience”,
provides an overview of the principles he suspects, but cannot
prove, may underlie all forms of life, and beyond that systems
in general which are far from equilibrium such as a modern
technological economy and the universe itself. Most of science
before the middle of the twentieth century studied complex
systems at or near equilibrium; only at such states could the
simplifying assumptions of statistical mechanics be applied to
render the problem tractable. With computers, however, we can now
begin to explore open systems (albeit far smaller than those in nature)
which are far from equilibrium, have dynamic flows of energy and
material, and do not necessarily evolve toward a state of maximum
entropy.
Kauffman believes there may be what amounts to a fourth law of
thermodynamics which applies to such systems and, although we don't
know enough to state it precisely, he suspects it may be that these
open, extremely nonergodic, systems evolve as rapidly as possible to
expand and fill their state space and that unlike, say, a gas in a
closed volume or the stars in a galaxy, where the complete state space
can be specified in advance (that is, the dimensionality of the space,
not the precise position and momentum values of every object within
it), the state space of a non-equilibrium system cannot be prestated
because its very evolution expands the state space. The presence of
autonomous agents introduces another level of complexity and
creativity, as evolution drives the agents to greater and greater
diversity and complexity to better adapt to the ever-shifting fitness
landscape.
These are complicated and deep issues, and this is a very difficult
book, although appearing, at first glance, to be written for a popular
audience. I seriously doubt whether somebody who was not previously
acquainted with these topics and thought about them at some length
will make it to the end and, even if they do, take much away from the
book. Those who are comfortable with the laws of thermodynamics,
the genetic code, protein chemistry, catalysis, autocatalytic
networks, Carnot cycles, fitness landscapes, hill-climbing strategies,
the no-go theorem, error catastrophes, self-organisation, percolation
phase transitions in graphs, and other technical issues raised in the
arguments must still confront the author's prose style. It seems
like Kauffman aspires to be a prose stylist conveying a sense of
wonder to his readers along the lines of Carl Sagan and
Stephen Jay Gould. Unfortunately, he doesn't pull it off as well,
and the reader must wade through numerous paragraphs like the following
from pp. 97–98:
Does it always take work to construct constraints? No, as we will soon
see. Does it often take work to construct constraints? Yes. In
those cases, the work done to construct constraints is, in fact,
another coupling of spontaneous and nonspontaneous processes. But
this is just what we are suggesting must occur in autonomous
agents. In the universe as a whole, exploding from the big bang into
this vast diversity, are many of the constraints on the release
of energy that have formed due to a linking of spontaneous and
nonspontaneous processes? Yes. What might this be about? I'll say
it again. The universe is full of sources of energy. Nonequilibrium
processes and structures of increasing diversity and complexity arise
that constitute sources of energy that measure, detect, and capture those
sources of energy, build new structures that constitute constraints on
the release of energy, and hence drive nonspontaneous processes to
create more such diversifying and novel processes, structures, and
energy sources.
I have not cherry-picked this passage; there are hundreds of others
like it. Given the complexity of the technical material and the
difficulty of the concepts being explained, it seems to me that the
straightforward, unaffected Point A to Point B style of explanation
which Isaac Asimov employed would work much better. Pardon my
audacity, but allow me to rewrite the above paragraph.
Autonomous agents require energy, and the universe is full
of sources of energy. But in order to do work, they require
energy to be released under constraints. Some constraints
are natural, but others are constructed by autonomous agents
which must do work to build novel constraints. A new constraint,
once built, provides access to new sources of energy, which
can be exploited by new agents, contributing to an ever
growing diversity and complexity of agents, constraints, and
sources of energy.
Which is better? I rewrite; you decide. The tone of the prose is
all over the place. In one paragraph he's talking about
Tomasina the trilobite (p. 129) and Gertrude the ugly squirrel
(p. 131), then the next thing you know it's “Here, the
hexamer is simplified to 3'CCCGGG5', and the two complementary
trimers are 5'GGG3' + 5'CCC3'. Left to its own devices,
this reaction is exergonic and, in the presence of excess trimers
compared to the equilibrium ratio of hexamer to trimers, will flow
exergonically toward equilibrium by synthesizing the hexamer.”
(p. 64). This flipping back and forth between colloquial
and scholarly voices leads to a kind of comprehensional
kinetosis. There are a few typographical errors, none serious, but
I have to share this delightful one-sentence paragraph from
p. 254 (ellipsis in the original):
By iteration, we can construct a graph connecting the founder
spin network with its 1-Pachner move “descendants,”
2-Pachner move descendints…N-Pachner move
descendents.
Good grief—is Oxford University Press outsourcing their
copy editing to Slashdot?
For the reasons given above, I found this a difficult read. But it is an
important book, bristling with ideas which will get you looking at the
big questions in a different way, and speculating, along with the
author, that there may be some profound scientific insights which
science has overlooked to date sitting right before our eyes—in
the biosphere, the economy, and this fantastically complicated
universe which seems to have emerged somehow from a near-thermalised
big bang. While Kauffman is the first to admit that these are
hypotheses and speculations, not science, they are eminently testable
by straightforward scientific investigation, and there is every reason
to believe that if there are, indeed, general laws that govern these
phenomena, we will begin to glimpse them in the next few decades. If
you're interested in these matters, this is a book you shouldn't miss,
but be aware what you're getting into when you undertake to read it.
February 2007