Darwin's Dangerous Idea - Evolution and the Meaning of Life

226 BIOLOGY IS ENGINEERING Stuart Kauffman as MetaEngineer 227
Darwinism that Monod and Jacob concentrate on are chance on the one hand
and, on the other, the utter directionlessness and myopia (or blindness ) of the
watchmaker. But, says Kauffman, "Evolution is not just 'chance caught on the
wing.' It is not iust a tinkering of the ad hoc, of bricolage, of contraption. It is
emergent order honored and honed by selection" (Kauff-man 1993, p. 644).
Is he saying the watchmaker isn't blind? Of course not. But then what is he
saying? He is saying that there are principles of order that govern the design
process, and that force the tinker's hand. Fine. Even a blind tinker will find
the forced moves; it doesn't take a rocket scientist, as one says. A tinker who
can't find the forced moves is not worth a tinker's damn, and won't design a
thing. Kauffman and his colleagues have made an interesting set of
discoveries, but the attack on the image of the tinker is to a large extent, I
think, misplaced. The tinker, says Levi-Strauss, is willing to be guided by the
nature of the material, whereas the engineer wants the material to be perfectly
malleable—like the concrete so beloved by the Bau-haus architects. So the
tinker is a deep thinker after all, complying with constraints, not fighting
them. The truly wise engineer works not contra naturam but secundum
naturam.
One of the virtues in Kauffman's attack is that it draws attention to an
underappreciated possibility, one that we can make vivid with the help of an
imaginary example from human engineering. Suppose that the Acme Hammer
Company discovers that the new hammers made by its rival, Bulldog
Hammer, Inc., have plastic handles with exactly the same intricate pattern of
colored whorls on them as is sported by the new Acme Model Zeta. "Theft!"
scream their legal representatives. "You copied our design!" Maybe, but then
again, maybe not. It just might be that there is only one way of making plastic
handles with any strength, and that is to stir up the plastic somehow as it sets.
The result is inevitably a distinctive pattern of whorls. It would be almost
impossible to make a serviceable plastic hammer handle that didn't have
those whorls in it, and the discovery of this fact might be one that would be
eventually imposed on just about anybody who tried to make a plastic
hammer-handle. This could explain the otherwise suspicious similarity
without any hypothesis of "descent" or copying. Now, maybe the Bulldog
people did copy Acme's design, but they would have found it in any case,
sooner or later. Kauffman points out that biologists tend to overlook this sort
of possibility when they draw their inferences about descent, and he draws
attention to many compelling cases in the biological world in which similarity
of pattern has nothing to do with descent. (The most striking cases he
discusses are illuminated by Turing's 1952 work on the mathematical analysis
of the creation of spatial patterning in morphogenesis. )
In a world with no discoverable principles of design, all similarities are
suspicious—likely to be due to copying (plagiarism or descent).
We have come to think of selection as essentially the only source of order
in the biological world. If 'only' is an overstatement, then surely it is
accurate to state that selection is viewed as the overwhelming source of
order in the biological world. It follows that, in our current view, organisms
are largely ad hoc solutions to design problems cobbled together by
selection. It follows that most properties which are widespread in organisms
are widespread by virtue of common descent from a tinkered-together
ancestor, with selective maintenance of the useful tinkerings. It follows
that we see organisms as overwhelmingly contingent historical accidents,
abetted by design. [Kauffman 1993, p. 26.]
Kauffman wants to stress that the biological world is much more a world
of Newtonian discoveries (such as Turing's) than Shakespearean creations,
and he has certainly found some excellent demonstrations to back up his
claim. But I fear that his attack on the metaphor of the tinker feeds the
yearning of those who don't appreciate Darwin's dangerous idea; it gives
them a false hope that they are seeing not the forced hand of the tinker but
the divine hand of God in the workings of nature.
Kauffman himself has called what he is doing the quest for "the physics of
biology" (Lewin 1992, p. 43), and that is not really in conflict with what I am
calling it: meta-engineering. It is the investigation of the most general
constraints on the processes that can lead to the creation and reproduction of
designed things. But when he declares this a quest for "laws," he feeds the
antiengineering prejudice (or you might call it "physics envy") that distorts so
much philosophical thinking about biology.
Does anyone suppose that there are laws of nutrition? Laws of locomotion?
There are all sorts of highly imperturbable boundary conditions on nutrition
and locomotion, owing to fundamental laws of physics, and there are plenty
of regularities, rules of thumb, trade-offs, and the like that are encountered by
any nutritional or locomotive mechanisms. But these are not laws. They are
like the highly robust regularities of automotive engineering. Consider the
regularity that {ceteris paribus) ignition is accomplished only by or after the
use of a key. There is a reason for this, of course, and it has to do with the
perceived value of automobiles, their susceptibility to theft, the cost-effective
(but not foolproof) options provided by preexisting locksmith technology, and
so forth. When one understands the myriad cost-benefit trade-offs of the
design decisions that go into creating automobiles, one appreciates this
regularity. It is not any kind of law; it is a regularity that tends to settle out of
a complex set of competing desiderata (otherwise known as norms). These
highly reliable, norm-tracking generalizations are not laws of automotive
engineering, nor are their biological counterparts laws of locomotion or
nutrition. The location of the mouth at the bow rather than the stern end of the
locomoting organism ( ceteris paribus— there are exceptions!) is a deep
regularity, but why call it a law? We under-