Some ideas are reeled into our mind wrapped up in facts; and some
ideas burst upon us naked without the slightest evidence they could be
true but with all the conviction they are. The ideas of the latter sort
are the more difficult to displace.
The idea of antichaos -- order for free -- came in a vision of the
unverifiable sort.
The idea was dealt to Stuart Kauffman, an undergraduate medical student
at Dartmouth College some thirty years ago. As Kauffman remembers it, he
was standing in front of a bookstore window daydreaming about the design
of a chromosome. Kauffman was a sturdy guy with curly hair, easy smile,
and no time to read. As he stared in the window, he imagined a book, a
book with his name on it in the author's slot, a book that he would
write in the future.
In his vision the pages of the book were filled with a web of arrows
connecting other arrows, weaving in and out of a living tangle. It was
the icon of the Net. But the mess was not without order. The tangle
sparked mysterious, almost cabalistic, "currents of meanings" along the
threads. Kauffman discerned an image emerging out of the links in a
"subterranean way," just as recognition of a face springs from the crazy
disjointed surfaces in a cubist painting.
As a medical student studying cell development, Kauffman saw the
intertwined lines in his fantasy as the interconnections between genes.
Out of that random mess, Kauffman suddenly felt sure, would come
inadvertent order -- the architecture of an organism. Out of chaos would
come order for no reason: order for free. The complexity of points and
arrows seemed to be generating a spontaneous order. To Kauffman the
depiction was intimately familiar; it felt like home. His task would be
to explain and prove it. "I don't know why this question, this ill-lit
path," he says, but it has become a "deeply felt, deeply held image."
Kauffman pursued his vision by taking up academic research in cell
development. As many other developmental biologists had, he studied
Drosophila, the famous fruit fly, as it progressed from fertilized egg
to adult. How did the original lone egg cell of any creature manage to
divide and specialize first into two, then four, then eight new kinds of
cells? In a mammal the original egg cell would propagate an intestinal
cell line, a brain cell line, a hair cell line; yet each substantially
specialized line of cells presumably ran the same operating software.
After a relatively few generations of division, one cell type could
split into all the variety and bulk of an elephant or oak. A human
embryo egg needed to divide only 50 times to produce the trillions of
cells that form a baby.
What invisible hand controlled the fate of each cell, as it traveled
along a career path forking 50 times, guiding it from general egg to
hundreds of kinds of specialized cells? Since each cell was supposedly
driven by identical genes (or were they actually different?), how could
cells possibly become different? What controlled the genes?
Françoise Jacob and Jacques Monod discovered a major clue in 1961
when they encountered and described the regulatory gene. The regulatory
gene's function was stunning: to turn other genes on. In one breath it
blew away all hopes of immediately understanding DNA and life. The
regulatory gene set into motion the quintessential cybernetic dialogue:
What controls genes? Other genes! And what controls those genes? Other
genes! And what...
That spiraling, darkly modern duet reminded Kauffman of his home image.
Some genes controlling other genes which in turn might control still
others was the same tangled web of arrows of influence pointing in every
direction in his vision book.
Jacob and Monod's regulatory genes reflected a spaghetti-like vision of
governance -- a decentralized network of genes steering the cellular
network to its own destiny. Kauffman was excited. His picture of "order
for free" suggested to him a fairly far-out idea: that some of the
differentiation (order) each egg underwent was inevitable, no matter
what genes you started out with!
He could think of a test for this notion. Replace all the genes in the
fruitfly with random genes. His bet: you would not get Drosophila, but
you would get the same order of monsters and freak mutations Drosophila
produced in the natural course of things. "The question I asked myself,"
Kauffman recalls, "was the following. If you just hooked up genes at
random, would you get anything that looked useful?" His intuitive hunch
was that simply because of distributed bottom-up control and
everything-is-connected-to-everything type of cell management, certain
classes of patterns would be inevitable. Inevitable! Now here was a germ
of heresy. Something to devote one's years to!
"I had a hard time in medical school," he continues, "because instead of
studying anatomy I was scribbling all these notebooks with little model
genomes." The way to prove this heresy, Kauffman cleverly decided, was
not to fight nature in the lab, but to model it mathematically. Use
computers as they became accessible. Unfortunately there was no body of
math with the ability to track the horizontal causality of massive
swarms. Kauffman began to invent his own. At the same time (about 1970)
in about a half-dozen other fields of research, the mathematically
inclined (such as John Holland) were coming up with procedures that
allowed them to simulate the effects of a mob of interdependent nodes
whose values simultaneously depend on each other.
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