Darwin's Dangerous Idea (14 page)

process—the features that make sex a magnificent crane—is as nothing to the Consider a population of a species in which there is considerable variation myopic, local competitions that must determine which organisms get favored at birth in the way their brains are wired up. Just one of the ways, we may in the very next generation. Some other, short-term, benefit must have suppose, endows its possessor with a Good Trick—a behavioral talent that maintained the positive selection pressure required to make sexual protects it or enhances its chances dramatically. The standard way of reproduction an offer few species could refuse. There are a variety of representing such differences in fitness between individual members of a compelling—and competing—hypotheses that might solve this puzzle, which population is known as an "adaptive landscape" or a "fitness landscape" (S.

was first forcefully posed for biologists by John Maynard Smith ( 1978). For Wright 1931). The altitude in such a diagram stands for fitness (higher is a lucid introduction to the current state of play, see Matt Ridley 1993- (More better), and the longitude and latitude stand for some factors of individual on this later.)

design—in this case, features of brain-wiring. Each different way a brain What we learn from the example of sex is that a crane of great power may might be wired is represented by one of the rods that compose the land-exist that was not created
in order to exploit
that power, but for other reasons, scape—each rod is a different
genotype.
The fact that just one of the com-although its power as a crane may help explain why it has been maintained binations of features is any good—that is, any better than run-of-the-mill—is ever since. A crane that was obviously created to be a crane is
genetic
illustrated by the way it stands out like a telephone pole in the desert.

engineering.
Genetic engineers—human beings who engage in recombinant-As figure 3.1 makes clear, only one wiring is favored; the others, no matter DNA tinkering—can now unquestionably take huge leaps through Design how "close" to being the good wiring, are about equal in fitness. So such an Space, creating organisms that would never have evolved by "ordinary"

isolated peak is indeed a needle in the haystack: it will be practically invis-means. This is no miracle—
provided that genetic engineers (and the artifacts
ible to natural selection. Those few individuals in the population that are
they use in their trade) are themselves wholly the products of
lucky enough to have the Good Trick genotype will typically have difficulty

78 UNIVERSAL ACID

The Tools for R and D: Skyhooks or Cranes?
79

FIGURE 3.1

FIGURE 3.2

a minimum, if not altogether out of the picture; all it requires is some brute, passing it on to their offspring, since under most circumstances their chances mechanical capacity to stop a random walk when a Good Thing comes of finding a mate who also has the Good Trick genotype are remote, and a along, a minimal capacity to "recognize" a tiny bit of progress, to "learn"

miss is as good as a mile.

something by blind trial and error. In fact, I have put it in
behavioristic
But now we introduce just one "minor" change: suppose that although the terms. What Baldwin discovered was that creatures capable of "reinforce-individual organisms
start out
with different wirings (whichever wiring was ment learning" not only do better individually than creatures that are entirely ordered by their particular genotype or genetic recipe)—as shown by their

"hard-wired"; their species will
evolve faster
because of its greater capacity scatter on the fitness landscape—they have some capacity to adjust or revise to discover design improvements in the neighborhood.6 This is not how their wiring, depending on what they encounter during their lifetimes. (In the Baldwin described the effect he proposed. His temperament was the farthest language of evolutionary theory, there is some "plasticity" in their thing from behaviorism. As Richards notes:

phenotypes.
The phenotype is the eventual body design created by the genotype in interaction with environment. Identical twins raised in different The mechanism conformed to ultra-Darwinian assumptions, but nonethe-environments would share a genotype but might be dramatically different in less allowed consciousness and intelligence a role in directing evolution.

phenotype.) Suppose, then, that these organisms can end up, after explo-By philosophic disposition and conviction, Baldwin was a spiritualistic ration, with a design different from the one they were born with. We may metaphysician. He felt the beat of consciousness in the universe; it pulsed suppose their explorations are random, but they have an innate capacity to through all the levels of organic life. Yet he understood the power of recognize (and stay with) a Good Trick when they stumble upon it. Then mechanistic explanations of evolution. [R.J. Richards 1987, p. 480. ]7

those individuals who begin life with a genotype that is closer to the Good Trick genotype—fewer redesign steps away from it—are more likely to come The Baldwin Effect, under several different names, has been variously across it, and stick with it, than those that are born with a faraway design.

described, defended, and disallowed over the years, and recently indepen-This head start in the race to redesign themselves can give them the edge dently rediscovered several more times (e.g., Hinton and Nowland 1987).

in the Malthusian crunch—if the Good Trick is so good that those who never learn it, or who learn it "too late," are at a severe disadvantage. In populations with this sort of phenotypic plasticity, a near-miss is
better
than a mile. For such a population, the telephone pole in the desert becomes the 6. Schull (1990), is responsible for the perspective that allows us to see species as summit of a gradual hill, as in figure 32; those perched near the summit, variably capable of "seeing" design improvements, thanks to their variable capacities for phenotypic exploration (for commentary, see Dennett 1990a).

although they start out with a design that serves them no better than others, will tend to discover the summit design in short order.

7. Robert Richards' account of the history of the Baldwin Effect (1987, especially pp.

In the long run, natural selection—redesign at the genotype level—will 480-503 and discussion later in that book) has been one of the major provocations and guides to my thinking in this book. What I found particularly valuable (see my review, tend
to follow the lead
o/and
confirm
the directions taken by the individual Dennett 1989a) was that Richards not only shares with Baldwin and many other Dar-organisms' successful explorations—redesign at the individual or phenotype winians a submerged yearning for skyhooks—or at least a visceral dissatisfaction with level.

theories that insist on cranes—but also has the intellectual honesty and courage to The way I have just described the Baldwin Effect certainly keeps Mind to expose and examine his own discomfort with what he is obliged to call "ultra-Darwinism."

Richards' heart is clearly with Baldwin, but his mind won't let him bluster, or try to paper

°ver the cracks he sees in the dikes that others have tried to erect against universal acid.

80 UNIVERSAL ACID

Who's Afraid of Reductionism?
81

Although it has been regularly described and acknowledged in biology chemistry reduces to physics, that biology reduces to chemistry, that the textbooks, it has typically been shunned by overcautious thinkers, because social sciences reduce to biology, for instance. The problem is that there are they thought it smacked of the Lamarckian heresy (the presumed possibility both bland readings and preposterous readings of any such claim. According of inheritance of acquired characteristics—see chapter 11 for a detailed to the bland readings, it is possible (and desirable ) to
unify
chemistry and discussion). This rejection is particularly ironic, since, as Richards notes, it physics, biology and chemistry, and, yes, even the social sciences and biol-was intended by Baldwin to be—and truly is—an acceptable
substitute
for ogy. After all, societies are composed of human beings, who, as mammals, Lamarckian mechanisms.

must fall under the principles of biology that cover all mammals. Mammals, in turn, are composed of molecules, which must obey the laws of chemistry, The principle certainly seemed to dispatch Lamarckism, while supplying which in turn must answer to the regularities of the underlying physics. No that positive factor in evolution for which even staunch Darwinists like sane scientist disputes this bland reading; the assembled Justices of the Lloyd Morgan longed. And to those of metaphysical appetite, it revealed Supreme Court are as bound by the law of gravity as is any avalanche, that under the clanking, mechanical vesture of Darwinian nature, mind because they are, in the end, also a collection of physical objects. According could be found. [R. J. Richards 1987, p. 487]

to the preposterous readings, reductionists want to abandon the principles, Well, not Mind—if by that we mean a full-fledged, intrinsic, original, theories, vocabulary, laws of the higher-level sciences, in favor of the lower-skyhook-type Mind—but only a nifty mechanistic, behavioristic, crane-style level terms. A reductionist dream, on such a preposterous reading, might be mind. That is not nothing, however; Baldwin discovered an effect that gen-to write "A Comparison of Keats and Shelley from the Molecular Point of uinely increases the power—locally—of the underlying process of natural View" or "The Role of Oxygen Atoms in Supply-Side Economics," or "Ex-selection wherever it operates. It shows how the "blind" process of the basic plaining the Decisions of the Rehnquist Court in Terms of Entropy Fluctu-phenomenon of natural selection can be abetted by a limited amount of ations." Probably nobody is a reductionist in the preposterous sense, and

"look-ahead" in the activities of individual organisms, which create fitness everybody should be a reductionist in the bland sense, so the "charge" of differences that natural selection can then act upon. This is a welcome reductionism is too vague to merit a response. If somebody says to you, "But complication, a wrinkle in evolutionary theory that removes one reasonable that's so reductionistic!" you would do well to respond, "That's such a quaint, and compelling source of doubt, and enhances our vision of the power of old-fashioned complaint! What on Earth did you have in mind?"

Darwin's idea, especially when it is cascaded in multiple, nested applications.

I am happy to say that in recent years, some of the thinkers I most admire And it is typical of the outcome of other searches and controversies we will have come out in defense of one or another version of reductionism, care-explore: the motivation, the passion that drove the research, was the hope of fully circumscribed. The cognitive scientist Douglas Hofstadter, in
Godel
finding a skyhook; the triumph was finding how the same work could be
Escher Bach,
composed a "Prelude ... Ant Fugue" (Hofstadter 1979, pp. 275-done with a crane.

336) that is an analytical hymn to the virtues of reductionism in its proper place. George C. Williams, one of the pre-eminent evolutionists of the day, published "A Defense of Reductionism in Evolutionary Biology" (1985).

The zoologist Richard Dawkins has distinguished what he calls hierarchical 5. WHO'S AFRAID OF REDUCTIONISM?

or gradual reductionism from precipice reductionism; he rejects only the precipice version (Dawkins 1986b, p. 74 ).8 More recently the physicist
Reductionism is a dirty word, and a kind of 'holistier than thou' self-Steven Weinberg, in
Dreams of a Final Theory
(1992), has written a chapter
righteousness has become fashionable.

entitled "Two Cheers for Reductionism," in which he distinguishes between

—RICHARD DAWKINS 1982, p. 113

uncompromising reductionism (a bad thing) and compromising reductionism (which he ringingly endorses). Here is my own version. We must distinguish The term that is most often bandied about in these conflicts, typically as a reductionism, which is in general a good