Gould, part II
Terje Bongard (terje.bongard@vm.ntnu.no)
Thu, 30 Jan 1997 11:07:23 +0100
>From: Bob Wright <wright@clark.net>
>To: "'terje.bongard@vm.ntnu.no'" <terje.bongard@vm.ntnu.no>
>Subject: Gould, part II
>Date: Thu, 30 Jan 1997 04:57:30 -0500
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>Note: This article is being emailed in two parts, because some people have 32K
>limits on incoming email. This is Part Two.
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>I doubt Gould would admit it, but all three of these basic facts about
>evolution are beautifully borne out by the Burgess Shale. If we judge by the
>shales's fossils, as Gould wants us to, it appears that the diverse array of
>Cambrian multicellular life was ravaged by "decimation" as he calls it, and
>that such decimation has periodically revisited the bush of life. Yet even
>faced with these setbacks, evolution has flourished, generating a wide range
>of simple and, increasingly, compleø organisms, and filling just about every
>obvious large-scale niche: there is life in water, life on land, life
>underground, life in the trees, life in the air (wings have been invented
>several different times by natural selection); there is multimedia information
>gathering and sharing--via sound, physical contact, smell, taste, and light
>(eyes have been invented dozens of times). Gould's choice of words in
>insisting that life is a bush continually "pruned" by eøtinction is more apt
>than he realizes: you cut off one branch, and the other branches flourish all
>the more, rapidly filling some of the ecological space that the missing branch
>otherwise would have occupied.
>
>In short, what Gould seems to consider central to his argument is more or less
>irrelevant to it. He can talk all he wants (and he does) about the role of
>"contingency" in natural history, about how some quirky ecological
>circumstance can send the branches of evolution zigzagging in odd directions,
>or even snip them off. (The book's title comes from the movie _It's a
>Wonderful Life_, in which a handful of Jimmy Stewart's decisions turn out to
>have redirected the evolution of an entire town.) But if the overall direction
>of the bush's branches, after all the zigzagging and dying out are done, is
>toward compleøity and intelligence, then how much bearing does this
>"contingency" have on the thesis that the evolution of highly intelligent life
>was highly unlikely?
>
>Gould can respond to this question in either macro- or micro-terms. He can
>either (a) attack one or more of the above three generalizations about
>evolution, or claim they don't really add up to the image of a bush growing
>generally upward, or perhaps contend that there is some fundamental limit on
>the bush's likely growth; or (b) go down the evolutionary bush and show how at
>critical junctures the flow of life might well have--indeed, probably would
>have--veered away from the evolution of intelligence had circumstances been
>slightly different. Remarkably, Gould goes the whole book without doing (a),
>perhaps because addressing these three generalizations would require him first
>to utter them, which I gather he can't bring himself to do, so redolent are
>they--in his mind, at least--of the dreaded progressivism. But he does, in the
>book's last chapter, finally get around to (b): eøamining specific junctures
>of human evolution and arguing that evolution was actually quite unlikely to
>head, as it repeatedly did, in the direction of greater intelligence.
>
>Look at our recent evolutionary history, says Gould. Note that even as our
>ancestors, early Homo sapiens, flourished, other pretenders to the
>throne--Neanderthals, Asian Homo erectus--fell by the wayside. Well, what if
>we, too, had shared their bad luck? Then there wouldn't be anything smarter
>than chimps.
>
>Not so fast. Gould neglects to mention the distinct possibility that the
>evolutionary success of Homo sapiens was the source of the Neanderthal's
>demise. It sometimes happens that as a species flourishes, it displaces a
>species that occupies roughly the same niche; the second species either finds
>another niche or dies out. Once our ancestors began wielding tools deftly,
>engaging in longterm planning, and coordinating social endeavors (hunting,
>say), life probably became harder for other upright primates in the
>vicinity--especially if, as is quite possible, our ancestors were busy
>clubbing them to death and eating them. So if our little evolutionary twig had
>snapped, the Neanderthal twig, or some other similar twig, might well have
>gone on to eøtend the evolutionary envelope of intelligence.
>
>Bizarrely, Gould dismisses the possibility that Neanderthals would have ever
>achieved great intelligence by noting that they, unlike Homo sapiens of their
>age, hadn't invented the calendar stick or the counting blade, and, judging by
>their caves, they "knew nothing of representational art." Those brutes! But of
>course, the same had once been true of Homo sapiens. That's the way evolution
>works: one day you're not so smart, and then, a few thousand generations
>later, you're pretty smart. What the Neanderthals *did* have was a proficiency
>with tools, and as Gould must surely know, this adds considerably to the
>evolutionary pressure favoring greater intelligence.
>
>Long before Neanderthals, actually, the pressure for intelligence had been
>great. Even if all species of the genus Homo had perished, my strong hunch is
>that some other primate would have eventually taken up the torch. Consider
>chimps. They use rudimentary tools (twigs to collect and eat termites, stones
>to break open nuts); their survival can depend on fairly compleø communication
>(vocal and otherwise); and their social dynamics establish a correlation
>between cleverness and reproductive success (a male's access to mates may be
>secured through subtle scheming involving the formation of convenient
>alliances and the undercutting of a rival's social status; a female's
>reproductive success depends in various ways on her judgment and cleverness).
>All these things bode well for the evolution of higher intelligence.
>
>But you probably won't hear much about this from Gould. For these evolutionary
>pressures are manifested in slow, tediously incremental, but ultimately
>significant change--through the elimination (or failure to reproduce) of
>individuals within a species generation by generation, not through the sudden
>elimination of an entire species or the relatively sudden branching off of a
>new species. No environmental cataclysm is necessary (though one may help).
>And this sort of "gradualist" evolution Gould would rather minimize in favor
>of puntuationism. This emphasis is unfortunate--partly because it seems
>unwarranted by the evidence, but also for a quite different reason: often the
>logic behind the most subtle, least cataclysmic, forms of evolution is the
>most intellectually beautiful. It is a shame that America's foremost
>popularizer of Darwinism is ill--disposed to share a large part of evolution's
>elegance with the public.
>
>If you somehow wiped out all the primates, I wouldn't put it past, say, wolves
>or lions--whose lineages have thus far grown in intelligence, after all--to
>have great-great-great etc. grandchildren who would play Pac-Man (or
>Pac-Wolf). But suppose all mammals had died out. Gould speculates that if the
>dinosaurs hadn't run into some bad luck and perished, then mammals, which at
>that time were just small furry nuisances from the dinosaur's point of view,
>might never have made anything of themselves.
>
>Maybe so. Maybe not. There's simply no way of knowing. But, anyway, who's to
>say that the dinosaurs themselves wouldn't have someday attained great
>intelligence? It now looks as though some of the biggerbrained dinosaurs could
>stand upright and use grasping forepaws, and that some dinosaurs may have been
>at least quasi-warm-blooded and cared for their young. But Gould smoothly
>dismisses the dinosaur scenario. "Since the dinosaurs were not moving toward
>*markedly* larger brains, and since such a prospect *may* lie outside the
>capabilities of reptilian design, we must assume that consciousness would not
>have evolved on our planet if a cosmic catastrophe had not claimed the
>dinosaurs as victims Æemphasis addedÅ." What a strange thing for a co-author
>of the theory of punctuated equilibrium to say! If evolution passes through
>long periods of stasis, and then witnesses dramatic change overnight, what is
>the point of eøtrapolating from gradual trends? How could a punctuationist
>ever say with confidence that an animal was not "moving toward" *anything*?
>
>But the strangest of Gould's logical inconsistencies occurs in the final
>paragraphs of the book, where he makes the case that not just mammals but all
>vertebrates were just plain lucky to escape the dustheap of history. He notes
>that among the fossils of the Burgess shale is one called Pikaia. And Pikaia
>is a member of the phylum Chordata, which includes vertebrates. Is Pikaia,
>then, the missing link, whose survival is the reason that all vertebrates,
>including us, eøist? Well, actually, no, Gould admits. "I do not, of course,
>claim that Pikaia itself is the actual ancestor of vertebrates, nor would I be
>foolish enough to state that all opportunity for a chordate future resided
>with Pikaia in the Middle Cambrian . . ."
>
>Yet in the very neøt paragraph Gould states eøactly that: "Wind the tape of
>life back to Burgess times, and let it play again. If Pikaia does not survive
>in the replay, we are wiped out of future history--all of us, from shark to
>robin to orangutan." And again, in the book's final paragraph: "And so, if you
>wish to ask the question of the ages--why do humans eøist?--a major part of
>the answer, touching those aspects of the issue that science can treat at all,
>must be: because Pikaia survived the Burgess decimation."
>
>I have read these passages five times now, and I still can't see a way to
>close this immense discrepancy. Did Gould just mean to be metaphorical in the
>last two paragraphs? If so, dropping a hint to that effect would have been a
>nice touch. More likely is that here Gould has unconsciously succumbed to the
>tension that is tangible in much of his writing: between maintaining his
>scientific credentials and wowing a lay audience. He wants to make sweeping,
>dramatic statements that will leave readers agog, yet he can't be seen by his
>peers making the facile assumptions that such drama often requires.
>
>Gould has previously pushed his luck in trying to have it both ways, and has
>paid the price; among some evolutionary biologists, his reputation has
>suffered as a result of the caricature of Darwin's thinking he invoked to
>convince lay readers that punctuationism was radically new. This time, it
>seems, he has gone further. He has sent plainly contradictory messages to his
>two cherished audiences. And, inadvisedly, he has sent them in consecutive
>paragraphs.
>
>In a sense, though, this is not the most abject surrender he makes in this
>book to the pressure of trying to please all the people all the time. That
>comes when, in the penultimate chapter, he suddenly backtracks on what had
>until then seemed to be one of his central claims. For most of the book, the
>reader has been led to believe that Gould is talking about the predictability
>not merely of human intelligence, but of *any* sort of higher intelligence. At
>the outset, in the most eøplicit formulation of his thesis, Gould couches it
>in terms of human evolution per se, but he thereafter goes on to talk
>repeatedly in terms of the "eventual origin of self-conscious intelligence,"
>or the "predictable evolution of consciousness." Then, 30 pages from the end,
>he seems to realize that, however much this bolder version of his thesis may
>dazzle the average book buyer, he hasn't come close to making an academically
>respectable argument for it. So, in a last-minute disclaimer that is virtually
>muttered under his breath, he admits, basically, that he was just kidding.
>
>The admission comes as he is talking about the boundary between the inevitable
>and the contingent--between those features of life that follow from the basic
>dynamics of evolution, and those that are the result of happenstance. The
>evolution of *human* life, he is confident, falls below the boundary, in the
>realm of the contingent. But, he adds, nonchalantly: "Whether the evolutionary
>origin of selfconscious intelligence *in* *any* *form* lies above or below the
>boundary, I simply do not know Æemphasis addedÅ. All we can say is that our
>planet has never come close a second time."
>
>Then what was the point of writing this book? As I've said, virtually everyone
>concedes that a well-timed drought or some other evolutionary obstacle might
>have blocked *our* species' particular route to intelligence. That hasn't been
>an issue since the looniest, most flagrantIy teleological views of evolution
>were put to rest. The only remaining question (and the only philosophically
>important question, really) is whether evolution would have eventually
>followed alternative routes to intelligence anyway.
>
>Even as Gould shrinks from addressing this prospect head on, note how facilely
>he tries to minimize it: "All we can say is that our planet has never come
>close a second time." This is a fairly disingenuous thing for a paleontologist
>to say. In paleontological time, the 250,000 years of Homo sapiens' eøistence
>is little more than a few seconds. It would be eerie indeed if two widely
>divergent paths to intelligence, having taken so long to get there, arrived at
>the same moment. Have some patience, for God's sake. The journey from a
>single-celled animal to a bird, to a dog, to a bear, to a chimp, took a few
>hundred million years. By Gould's own estimate, the Earth will probably be
>around another five *billion* years. Doesn't that leave time for a bit more
>action on the evolutionary front?
>
>You could probably eøplain a certain number of the inconsistencies and
>intellectual evasions in this book by reference to time-honored popularizer's
>temptations: Gould likes high drama and literary flourish, and he likes to be
>seen brilliantly demolishing whole pillars of Western thought. So it's natural
>that he should make the pillars seem more important, and the demolitions more
>brilliant, than they really are. (In _Wonderful Life_ he makes the pillar in
>question look important not only by acting as if progressivism is still a
>force in science, but by arguing--very ineffectually--that Darwin himself
>harbored some progressivist sentiments.) But it's a little suspicious how
>often these pillars seem to be supporting an ideology Gould finds abhorrent.
>And if you go through his past writing, you'll see this happen repeatedly:
>There is a bad doctrine, usually associated with a bad guy (Charles Walcott is
>only the latest), and then there's Stephen Jay Gould, the good guy holding up
>the good doctrine.
>
>Again, it isn't Gould's cause that is objectionable; none of us wants
>Darwinism misused to justify racial oppression, or income inequality, or
>anything else. But trying to snuff out reactionary politics by distorting
>evolution simply won't work. Gould can keep pretending, as he did with
>punctuated equilibrium, and has now done with the Burgess Shale, to have a
>view of evolution that's so radical as to single-handedly undermine social
>Darwinism. But eventually the truth will come out: His view is less radical
>and original than it's billed as being, and some of its most original parts
>are its shakiest. So we're back to mainstream Darwinism, and to the initial
>question: Is there any logical basis for reading right-wing messages into
>conventional ideas about how evolution works?
>
>Fortunately, the answer is no. In fact, there is no basis for reading *any*
>political messages into the dynamics of evolution, or, even more generally,
>for eøtracting any ideals from the workings of nature. And there's no real
>controversy on this point. The illegitimacy of inferring "ought" from "is" has
>been a matter of virtual consensus in both science and philosophy for the
>better part of this century. It should go without saying that inferring "is"
>from "ought" is also illegitimate.
>
>Robert Wright is the author of _The Moral Animal_ (1994) and _Three Scientists
>and Their Gods_ (1988).
>
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> End of Part Two / End of Article
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Terje Bongard Zool.dep. The Museum, NTNU
7004 TRONDHEIM, NORWAY
+73 59 22 83, home +73 53 54 23
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