Darwin's Dangerous Idea (45 page)

ticularly to name "the old Panglossian fallacy that natural selection favours Adaptationist reasoning is not optional; it is the heart and soul of evolu-adaptations that are good for the species as a whole, rather than acting at the tionary biology. Although it may be supplemented, and its flaws repaired, to level of the individual." As he later commented, "It is ironic that the phrase think of
displacing
it from central position in biology is to imagine not just

'Pangloss's theorem' was first used in the debate about evolution (in print, I the downfall of Darwinism but the collapse of modern biochemistry and all think, by myself, but borrowed from a remark of Haldane's), not as a the life sciences and medicine. So it is a bit surprising to discover that this is criticism of adaptive explanations, but specifically as a criticism of 'group-precisely the interpretation that many readers have placed on the most selectionist', mean-fitness-maximising arguments" (Maynard Smith 1988, p.

famous and influential critique of adaptationism, Stephen Jay Gould and 88). But Maynard Smith is wrong, apparently. Gould has recently drawn Richard Lewontin's oft-cited, oft-reprinted, but massively misread classic, attention to a still earlier use of the term by a biologist, William Bateson

"The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme" (1979).

(1909), of which he, Gould, had been unaware when he chose to use the term.

As Gould (1993a, p. 312) says, "The convergence is hardly surprising, as Dr.

Pangloss is a standard synecdoche for this form of ridicule." As we saw in 2. T

chapter 6, the more apt or fitting a brainchild is, the more likely it is to be HE LEIBNIZIAN PARADIGM

born (or borrowed) independently in more than one brain.

Voltaire created Pangloss as a parody of Leibniz, and it is exaggerated and
If, among all the possible worlds, none had been better than the rest, then
unfair to Leibniz—as all good parody is. Gould and Lewontin similarly car-God would never have created one.

icatured adaptationism in their article attacking it, so parity of reasoning

—GOTTFRIED WILHELM LEIBNIZ 1710

suggests that, if we wanted to undo the damage of that caricature, and
The study of adaptation is not an optional preoccupation with fascinating
describe adaptationism in an accurate and constructive way, we would have a
fragments of natural history, it is the core of biological study.

title ready-made: we could call adaptationism, fairly considered, the "Leibnizian Paradigm."

—COLIN PITTENDRIGH 1958, p. 395

The Gould and Lewontin article has had a curious effect on the academic Leibniz, notoriously, said that this was the best of all possible worlds, a world. It is widely regarded by philosophers and other humanists who have striking suggestion that might seem preposterous from a distance, but turns heard of it or even read it as some sort of
refutation of adaptationism.
Indeed, out, as we have seen, to throw an interesting light on the deep questions of I first learned of it from the philosopher/psychologist Jerry Fodor, a lifelong critic of my account of the intentional stance, who pointed out that 240 SEARCHING FOR QUALITY

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what I was saying was pure adaptationism (he was right about that), and went But in fact the role of optimality assumptions in Fisher's work—beyond the on to let me in on what the
cognoscenti
all knew: Gould and Lewontin's explicit role that Eldredge conceded—is so "vital" and indeed omnipresent article had shown adaptationism "to be completely bankrupt." (For an that Eldredge entirely overlooked it. For instance, Fisher's inference that the instance of Fodor's view in print, see Fodor 1990, p. 70.) When I looked into Jurassic crabs swam at 15-20 cm/sec has as a tacit premise that those crabs it, I found out otherwise. In 1983, I published a paper in
Behavioral and
swam at the optimal speed for their design.
( How does he know they swam
Brain Sciences,
"Intentional Systems in Cognitive Ethology," and since it at all? Perhaps they just lay there, oblivious of the excess functionality of was unabashedly adaptationist in its reasoning, I included a coda, "The their body shapes.) Without this tacit (and, of course, dead obvious) premise,

'Panglossian Paradigm' Defended," which criticized both Gould and no conclusion at all could be drawn about what the
actual
swimming speed of Lewontin's paper and—more particularly—the bizarre myth that had grown the Jurassic variety was.

up around it.

Michael Ghiselin (1983, p. 363 ) was even more forthright in denying this The results were fascinating. Every article that appears in
BBS
is accom-unobvious obvious dependence:

panied by several dozen commentaries by experts in the relevant fields, and my piece drew fire from evolutionary biologists, psychologists, ethologists, Panglossianism is bad because it asks the wrong question, namely, What is and philosophers, most of it friendly but some remarkably hostile. One thing good?... The alternative is to reject such teleology altogether. Instead of was clear: it was not just some philosophers and psychologists who were asking, What is good? we ask, What has happened? The new question does uncomfortable with adaptationist reasoning. In addition to the evolutionary everything we could expect the old one to do, and a lot more besides.

theorists who weighed in enthusiastically on my side (Dawkins 1983b, Maynard Smith 1983), and those who fought back (Lewontin 1983), there He was fooling himself. There is hardly a single answer to the question were those who, though they agreed with me that Gould and Lewontin had

"What has happened (in the biosphere)?" that doesn't depend crucially on not refuted adaptationism, were eager to downplay the standard use of assumptions about what is good.4 As we just noted, you can't even avail optimality assumptions that I claimed to be an essential ingredient in all yourself of the concept of a homology without taking on adaptationism, evolutionary thinking.

without taking the intentional stance.

Niles Eldredge (1983, p. 361) discussed the reverse engineering of func-So now what is the problem? It is the problem of how to tell good—

tional morphologists: "You will find sober analyses of fulcra, force vectors irreplaceable—adaptationism from bad adaptationism, how to tell Leibniz and so forth: the understanding of anatomy as a living machine. Some of this from Pangloss.5 Surely one reason for the extraordinary influence of Gould stuff is very good. Some of it is absolutely dreadful." He went on to cite, as an example of good reverse engineering, the work of Dan Fisher (1975) comparing modern horseshoe crabs with their Jurassic ancestors: 4. Doesn't my assertion fly in the face of the claims of those cladists who purport to deduce Assuming only that Jurassic horseshoe crabs also swam on their backs, history from a statistical analysis of shared and unshared "characters"? ( For a philosophical Fisher showed they must have swum at an angle of 0-10 degrees (flat on survey and discussion, see Sober 1988.) Yes, 1 guess it does, and my review of their ar-their backs) and at the somewhat greater speed of 15-20 cm/sec. Thus the guments (largely via Sober's analyses ) shows me that the difficulties they create for them-

'adaptive significance' of the slight differences in anatomy between modern selves are largely if not entirely due to their trying so hard to find non-adaptationist ways horseshoe crabs and their 150-million-year-old relatives is translated into of drawing the sound inferences that are dead obvious to adaptationists. For instance, those an understanding of their slightly different swimming capabilities. (In all cladists who abstain from adaptation talk cannot just help themselves to the obvious fact honesty, I must also report that Fisher does use optimality in his argu-that haying webbed feet is a pretty good "character" and having dirty feet (when examined) is not. Like the behaviorists who pretended to be able to explain and predict "be-ments: He sees the differences between the two species as a sort of trade-havior" defined in the starkly uninterpreted language of geographical trajectory of body off, where the slightly more efficient Jurassic swimmers appear to have parts, instead of using the richly functionalistic language of searching, eating, hiding, chas-used the same pieces of anatomy to burrow somewhat less efficiently than ing, and so forth, the abstemious cladists create majestic edifices of intricate theory, which their modern-day relatives). In any case, Fisher's work stands as a really is amazing, considering they do it with one hand tied behind their backs, but strange, con-good example of functional morphological analysis. The notion of adapta-sidering that they wouldn't have to do it at all if they didn't insist on tying one hand behind tion is naught but conceptual filigree—one that may have played a role in their backs. (See also Dawkins 1986a, ch. 10, and Mark Ridley 1985, ch. 6.) motivating the research, but one that was not vital to the research itself.

5. The myth that the point of the Gould and Lewontin paper was to destroy adaptation-

[Eldredge 1983, p. 362.]

ism, not correct its excesses, was fostered by the paper's rhetoric, but in some quarters it backfired on Gould and Lewontin, since adaptationists themselves tended to pay more

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Calvin
and
Hobbes

by Bill Watterson

me" call. They follow as the bird darts ahead and waits for them to catch up, always making sure they can see where it's heading. When the bird reaches the hive, it changes its tune, giving the "here-we-are" call. When the Boran locate the beehive in the tree and break into it, they take the honey, leaving wax and larvae for the honey guide. Now, don't you ache to believe that this wonderful partnership actually exists, and has the clever functional properties described? Don't you want to believe that such a marvel could have evolved under some imagined series of selection pressures and opportunities? I certainly do. And, happily, in this case, the follow-up research is confirming the story, and even adding nifty touches as it does so. Recent controlled tests, CALVIN AND HOBBES copyright 1993 Watterson. Reprinted with permission of UNIVERSAL PRESS

for instance, showed that the Boran honey-hunters took much longer to find SYNDICATE. All rights reserved.

hives without the help of the birds, and 96 percent of the 186 hives found FIGURE 9.3

during the study were encased in trees in ways that would have made them inaccessible to the birds without human assistance (Isack and Reyer 1989).

and Lewontin's paper (among nonevolutionists) is that it expressed, with Another fascinating story, which strikes closer to home, is the hypothesis many fine rhetorical flourishes, what Eldredge called the "backlash" against that our species,
Homo sapiens,
descended from earlier primates via an the concept of adaptationism among biologists. What were they reacting intermediate species that was aquatic (Hardy I960, Morgan 1982, 1990)!

against? In the main, they were reacting against a certain sort of laziness: the These aquatic apes purportedly lived on the shores of an island formed by the adaptationist who hits upon a truly nifty explanation for why a particular flooding of the area that is now in Ethiopia, during the late Miocene, about circumstance should prevail, and then never bothers to test it—because it is seven million years ago. Cut off by the flooding from their cousins on the too good a story, presumably, not to be true. Adopting another literary label, African continent, and challenged by a relatively sudden change in their this time from Rudyard Kipling (1912), Gould and Lewontin call such climate and food sources, they developed a taste for shellfish, and over a explanations "Just So Stories." It is an enticing historical curiosity that period of a million years or so they began the evolutionary process of Kipling wrote
his Just So Stories
at a time when this objection to Darwinian returning to the sea that we know was undergone earlier by whales, dolphins, explanation had already been swirling around for decades;6 forms of it were seals, and otters, for instance. The process was well under way, leading to the raised by some of Darwin's earliest critics (Kitcher 1985a, p. 156). Was fixation of many curious characteristics that are otherwise found
only
in Kipling inspired by the controversy? In any case, calling the adaptationists'

aquatic mammals—not in any other primate, for example— when flights of imagination "Just So Stories" hardly does them credit; as delightful circumstances changed once again, and these semi-seagoing apes returned to as I have always found Kipling's fantasies about how the elephant got its a life on the land (but typically on the shore of sea, lake, or river ). There, trunk, and the leopard got its spots, they are quite simple and unsurprising they found that many of the adaptations they had developed for good reasons tales compared with the amazing hypotheses that have been concocted by in their shell-diving days were not only not valuable but a positive hindrance.