-------------------------------------------------------------------------------
COPYRIGHT 2000 American Museum of Natural History
in association with The Gale Group and LookSmart. COPYRIGHT 2000 Gale Group
-------------------------------------------------------------------------------
David Gergen, editor-at-large of U.S. News & World Report, engages Stephen Jay Gould, Professor of Zoology and Geology at Harvard University, author of Full House: The Spread of Excellence from Plato to Darwin.
DAVID GERGEN, U.S. News & World Report: Steve, you’ve written this very challenging book about evolution, challenging the notions that are in our heads. Maybe we ought to start with what the conventional notion is about evolution.
STEPHEN JAY GOULD, Author, Full House: The conventional view is more a result of what western culture makes us want to think and what actually happened in the history of life. Darwin’s theory in natural selection doesn’t make any reference to any notion of progress, or development or increasing complexity. It’s only a theory about adaptation to changing environments. There are as many ways to adapt to local environments by becoming less complex is by getting more complex, but for reasons of our history and our biases and our preferences, we very much want to spin doctor that theory and make it appear as though the history of life is a predictable rise to increasing complexity and progress I think so that we can validate ourselves as the crown of creation.
After all, humans have only been here for a geological eye blink in the three and a half million year history of life, and that leads to the frightening thought that we might be an insignificant little twig that was never meant to be and is here only by accident, which I think is right, but if we spin doctor the process and make evolution appear like a predictably progressive sequence, then our late evolution makes sense. I think that’s why we do it.
DAVID GERGEN: That’s right. Sort of there’s human error against the notion that there’s a ladder, that cells are at the bottom of the ladder, and we’re at the top of the ladder.
STEPHEN JAY GOULD: That’s how we always draw the history of evolution, from amoeba to human, or from crouch chimpanzee to upright white male in a business suit, thereby encoding other biases of that culture into the process, but evolution isn’t that. Evolution is--
DAVID GERGEN: Okay. Now what is it?
STEPHEN JAY GOULD: Evolution is a process of constant branching and expansion. Life began three and a half billion years ago, necessarily about as simple as it could be, because life arose spontaneously from the organic compounds in the primeval oceans. You couldn’t begin by precipitating a giraffe out of this primordial soup, so he began the history of life with the simplest possible form of cellular life, namely bacteria. And since there’s no way of getting any simpler as life expanded every once in a while you get something more complex because that’s the only direction open, but if you look at the full range, rather than falsely, and myopically concentrating on the history of the most complex thing through time.
What you see is that the most outstanding feature of life’s history is a constant domination by bacteria. In fact, this is not the age of man as the old textbooks used to say, or the age of mammals, or even the age of insects, which is more correct, if you want to honor multicellular animals. This is the age of bacteria. Bacteria have always been dominant. The bacterial mode, the mode being the most common form of life, is never altered in 3 1/2 billion years. We don’t see it that way because bacteria are tiny and they live beneath us, but bacteria live in a wider range of environments. There are more, just E-coli cells, that’s only one species in the gut of every human being than there have ever been people on earth, and if this report on Martian life is true, then the bacterial mode is universal. It’s not only planetary, and there’s no universality for little green men. So this is a bacterial planet. You can’t nuke them into oblivion. They’ve always dominated life on this planet.
As far as they’re concerned, we’re just little islands of mobile resources which they can exploit for a while. They’re happy to let us strut this little hour on the stage because they’ll still be here when we’re gone. But, you see, you don’t see that unless you’re willing to look at the history of life as the full range of its variation through time. I mean, it is true the most complex thing has gotten more complex. Once there were only bacteria. Now there are humans, but that’s not the result of an intrinsic defining central drive. It’s just a kind of random movement away from a necessary beginning at maximal bacterial simplicity. That’s all it is.
DAVID GERGEN: You used an analogy, which I found quite helpful to me, in thinking about the randomness of it all. You talked about the drunk coming out of a bar and staggering. Could you--
STEPHEN JAY GOULD: Yeah. It’s an old statistical paradigm called the drunkard’s walk, which is a wonderful way of illustrating how you can get directional and predictable motion within a totally random system. All right. Here’s the story. A drunk staggers out of a bar. Here’s the bar, and he’s leaning right against the wall of the bar. Now, he’s staggering completely at random, back and forth. There’s a gutter 30 feet away. He staggers five feet every time he staggers, completely at random, goes towards the bar as often as he goes away, except if he hits the bar wall, he can’t go through it, so he just stands there until he staggers away. Now, where does he end up every time? Of course, he ends up in the gutter. He falls down in the gutter, the thing’s over. We understand that very easily.
DAVID GERGEN: Right.
STEPHEN JAY GOULD: He’s going to lend up in the gutter every time.
DAVID GERGEN: Right.
STEPHEN JAY GOULD: It’s like flipping six heads in a row because he staggers five feet, but his movement is entirely random. The only reason he ends up in the gutter is that he’s beginning next to this wall that he can’t go through. The history of life did the same thing. The history of life began with a bacteria next to the left wall of maximal simplicity.
DAVID GERGEN: Right.
STEPHEN JAY GOULD: So in its random motion back and forth occasionally a species staggers over towards greater complexity, but it arises within an effectively random system.
DAVID GERGEN: But the complexity is over here toward the gutter.
STEPHEN JAY GOULD: Yes. The complexity is toward the gutter in that analogy. And the bar wall is home.
DAVID GERGEN: Now, what’s interesting about that is that that--the bar, in effect, is the left wall. It’s the simplicity. You can’t get any simpler than that left wall is, itself.
STEPHEN JAY GOULD: You can’t get simpler than a bacterium, so as life expands, there is a real trend. The real trend is the success in expansion of life.
DAVID GERGEN: Right.
STEPHEN JAY GOULD: If you begin at maximal simplicity, there’s no room to get any simpler, so what happens is this position of maximal simplicity. The bacterial mode just gets higher and higher.
DAVID GERGEN: Right.
STEPHEN JAY GOULD: Through the history of life. It’s never moved. We just ignore it. We tend to look only at the most complex thing as it moves away from the wall.
DAVID GERGEN: And your other part of your argument was, though, that culturally or in some fields or baseball or say musical composition, there’s not a left wall but there’s a right wall, in effect, how fine you can become, how terrific you can become. That was interesting too. We haven’t had a 400 hitter in baseball since--
STEPHEN JAY GOULD: In 55 years.
DAVID GERGEN: In 55 years.
STEPHEN JAY GOULD: Since Ted Williams in 1941.
DAVID GERGEN: What ever happened to the 400 hitter?
STEPHEN JAY GOULD: That used to happen. Between 1900 and 1930, seven different plays, did it in nine of those years. No one’s done it in 55 years. To understand that, you have to use the same perspective of considering the full range of variation, rather than our usual false way of just looking at a single thing moving through time. That’s why I call
my book "Full House." It’s not only the poker hand in life’s randomness, it’s a plea for looking at the full range of variation. Everybody assumes that 400 hitting disappeared because hitting has gotten worse. After all, it was good. It used to exist in abundance. Nobody’s done it for 55 years. What you have to do is reconceptualize the whole problem in terms of variation, that is the full house, the full range of variation.
When you do that, you realize the following: The average batting average has never changed. It’s always been around 260. It fluctuates back and forth, but it stays around 260. And that’s not an absolute measure like running a mile or throwing a javelin; 260 is a balance between hitting and pitching. The fact that it’s stayed 260 only shows that the balance has been maintained. I say it’s been maintained as everyone has gotten better. Hitting’s gotten better. Pitching’s gotten better. Everything’s gotten better. The balance remains the same. Now as everything gets better, the variation shrinks. That’s all that happens. There’s a right wall of human limits based on how tall we are and our musculature. Nobody’s ever going to hit a ball a mile or pitch it 200 miles an hour.
Ty Cobb was standing right next to the right wall in 1910, but the average level of play was so much worse, he was so much better than the average that his hitting could be measured as 420. Today, everybody’s gotten enormously better. Wade Boggs a few years ago, Tony Gwyn today. They’re standing in the same place Ty Cobb was, an inch from the wall. The best players are always there, but everyone is so much better now that the average has moved right next to them. So their performance, which is equal to Cobb’s, is now measured as three forty or three fifty. So, in other words, the disappearance of 400 hitting paradoxically is measuring the general improvement of play and not as we always thought the exact opposite of the disappearance of batting skills. But you’ve got to have that full house perspective.
DAVID GERGEN: I understand that. Let me ask you this. You also write about German composers. You had this period from the late 1600's until the early 1800's, a very short period, when you had Bach and Beethoven and Mozart and Hayden, you know, these wonderful German composers.
STEPHEN JAY GOULD: Their full life span is between 1685 and the 1820's. Where are they today? And I speculated in there that if this concept of right walls has any validity, it’s conceivable, I’m not sure that this is so, that you can run out of accessible styles; since the arts demand innovation as a criterion of genius, it’s possible in certain fields that you can run out of accessible styles. The arts loves to say, well, the avant garde isn’t understood; the next generation will. And maybe that’s often true, but it need not always be true. Maybe you can really run out of styles that intelligent people can comprehend, and perhaps that’s happened with the classical music tradition. I’m not sure that’s the explanation.
DAVID GERGEN: Do you think the same paradox holds, that you may not have the Bachs and the Beethovens but the general level of musical composition has improved, or do you think--
STEPHEN JAY GOULD: I think there have to be Bachs and Beethovens. We may have--there are so many more people. Musical training is available to so many more, but it may be that we’ve hit a right wall in terms of accessible styles and since we demand innovation as a criterion of genius, there may not be more innovative styles to be found.
DAVID GERGEN: Final question. When Darwin completed his book on evolution in 1859, the final paragraph was, "There is a grandeur in this view of life." Is there a grandeur in your view of life?
STEPHEN JAY GOULD: Oh, yes, and I’ve shared Darwin’s position, because Darwin’s very explicit that grandeur is in the spreading of the diversification, the constant surprise, the constant novelty, and he compares it to the planet, which cycles around the Sun year after year after year, and he s ays, while this planet has gone on endlessly cycling from so simple a beginning, endless forms most beautiful and most wonderful have been and are being evolved. That’s his closing line.
DAVID GERGEN: And that’s your closing line as well. Thank you very much.
STEPHEN JAY GOULD: Thank you very much for having me.
DAVID GERGEN: Thank you.
I Have Landed
In the final essay of this twenty-seven-year series, the author reflects on continuity—from family history to the branching lineage of terrestrial life.
By Stephen Jay Gould
As a young child, thinking as big as big can be and getting absolutely nowhere for the effort, I would often lie awake at night, pondering the mysteries of infinity and eternity and feeling pure awe (in an inchoate, but intense, boyish way) at my utter inability to comprehend. How could time begin? For even if a God created matter at a definite moment, then who made God? An eternity of spirit seemed just as incomprehensible as a temporal sequence of matter with no beginning. And how could space end? For even if a group of intrepid astronauts encountered a brick wall at the end of the universe, what lay beyond the wall? An infinity of wall seemed just as inconceivable as a never-ending expanse of stars and galaxies.
I will not defend these naive formulations today, but I doubt that I have come one iota closer to a personal solution since these boyhood ruminations so long ago. In my philosophical moments—and not only as an excuse for personal failure, for I see no sign that others have succeeded—I rather suspect that the evolved powers of the human mind may not include the wherewithal for posing such questions in answerable ways (not that we ever would, should, or could halt our inquiries into these ultimates).
Irene and Joseph Rosenberg (Grammy and Papa Joe), the author's maternal grandparents, circa 1950.
All photographs and illustrations
courtesy of Stephen Jay Gould.
However, I confess that in my mature years, I have embraced the Dorothean dictum: yea, though I might roam through the pleasures of eternity and the palaces of infinity (not to mention the valley of the shadow of death), when a body craves contact with the brass tacks of a potentially comprehensible reality, I guess there's no place like home. And within the smaller, but still tolerably ample, compass of our planetary real estate, I would nominate as most worthy of pure awe—a metaphorical miracle, if you will—an aspect of life that most people have never considered but that strikes me as equal in majesty to our most spiritual projections of infinity and eternity, while falling entirely within the domain of our conceptual understanding and empirical grasp: the continuity of etz chayim, the tree of earthly life, for at least 3.5 billion years, without a single microsecond of disruption.
Consider the improbability of such continuity in the conventional terms of ordinary probability: take any phenomenon that begins with a positive value at its inception 3.5 billion years ago, and let the process regulating its existence proceed through time. A line marked zero runs along below the current value. The probability of the phenomenon's descent to zero may be almost incalculably low, but throw the dice of the relevant process billions of times and the phenomenon just has to hit the zero line eventually.
For most processes, the prospect of such an improbable crossing bodes no permanent ill, because an unlikely crash (a year, for example, when a healthy Mark McGwire hits no home runs at all) will quickly be reversed, and ordinary residence well above the zero line reestablished. But life represents a different kind of ultimately fragile system, utterly dependent upon unbroken continuity. For life, the zero line designates a permanent end, not a temporary embarrassment. If life had ever touched that line for one fleeting moment at any time during 3.5 billion years of sustained history, neither we nor a million species of beetles would grace this planet today. A single handshake with voracious zero dooms all that might have been, forever after.
When we consider the magnitude and complexity of the circumstances required to sustain this continuity for so long—and without exception or forgiveness in each of so many components—well, I may be a rationalist at heart, but if anything in the natural world merits designation as "awesome," I nominate the continuity of the tree of life for 3.5 billion year
s. Earth experienced severe ice ages but never froze completely, not for a single day. Life fluctuated through episodes of global extinction but never crossed the zero line, not for one millisecond. DNA has been working all this time, without an hour of vacation or even a moment of pause to remember the extinct brethren of a billion dead branches shed from an ever growing tree of life.
When Protagoras, speaking inclusively despite the standard translation, defined "man" as "the measure of all things," he captured the ambivalence of our feelings and intellect in his implied contrast of diametrically opposite interpretations: the expansion of humanism versus the parochialism of limitation. Eternity and infinity lie too far from the unavoidable standard of our own bodies to secure our comprehension, but life's continuity stands right at the outer border of ultimate fascination: just close enough for intelligibility by the measure of our bodily size and earthly time but sufficiently far away to inspire maximal awe.
I would nominate as most worthy of pure awe the continuity of the tree of earthly life for 3.5 billion years, without a single microsecond of disruption.
Moreover, we can bring this largest knowable scale further into the circle of our comprehension by comparing the macrocosm of life's tree to the microcosm of our family's genealogy. Our affinity for evolution must originate from the same internal chords of emotion and fascination that drive so many people to trace their bloodlines with such diligence and detail. I do not pretend to know why the documentation of unbroken heredity through generations of forebears brings us so swiftly to tears and to such a secure sense of rightness, definition, membership, and meaning. I simply accept the primal emotional power we feel when we manage to embed ourselves into something so much larger.