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*Contents*
A Modest Proposal 1
PART ONE
* * *
How Shall We Read and Spot a Trend?
1. Huxley's Chessboard 7
2. Darwin Amidst the Spin Doctors 17
Biting the Fourth Freudian Bullet 17
Can We Finally Complete Darwin's Revolution? 21
3. Different Parsings, Different Images of Trends 30
Fallacies in the Reading and Identification of Trends 30
Variation as Universal Reality 38
PART TWO
* * *
Death and Horses: Two Cases for the Primacy of Variation
4. Case One: A Personal Story 45
5. Case Two: Life's Little Joke 57
PART THREE
* * *
The Model Batter: Extinction of 0.400 Hitting and the Improvement of Baseball
6. Stating the Problem 77
7. Conventional Explanations 80
8. A Plausibility Argument for General Improvement 89
9. 0.400 Hitting Dies as the Right Tail Shrinks 98
10. Why the Death of 0.400 Hitting Records Improvement of Play 111
11. A Philosophical Conclusion 129
PART FOUR
* * *
The Modal Bacter: Why Progress Does Not Rule the History of Life
12. The Bare Bones of Natural Selection 135
13. A Preliminary Example at Smallest Scale, with Some Generalities on the Evolution of Body Size 147
14. The Power of the Modal Bacter, or Why the Tail Can't Wag the Dog 167
An Epitome of the Argument 167
The Multifariousness of the Modal Bacter 175
No Driving to the Right Tail 195
A Note on the Fatal Weakness of the Last Straw 213
15. An Epilog on Human Culture 217
Bibliography 231
Index 238 [not scanned]
FULL HOUSE
A Modest Proposal
In an old literary theme, from Jesus' parable of the prodigal son to Tennessee Williams's _Cat on a Hot Tin Roof_, our most beloved child is often the most problematic and misunderstood among our offspring. I worry for _Full House_, my adored and wayward boy. I have nurtured this short book for fifteen years through three distinctly different roots (and routes): (1) an insight about the nature of evolutionary trends that popped into my head one day, revised my personal thinking about the history of life, and emerged in technical form as a presidential address for the Paleontological Society in 1988; (2) a statistical eureka that brought me much hope and comfort during a life-threatening illness (see chapter 4); and (3) an explanation that, once conceptualized, struck me as self-evident and necessarily correct, but also diametrically opposed to all traditional accounts, for a major puzzle of American popular culture—the disappearance of 0.400 hitting in baseball.
All three roots arose from a common insight in the form most personally exciting to intellectuals—the eureka or a-ha! moment that inverts an old way of seeing and renders both clear and coordinated something that had been muddy, inchoate, or unformulated before. (I speak of a deeply personal experience, not a claim full of hubris about absolutes. Such eurekas only remove scales from one's own eyes and break idiosyncratic impediments. The rest of the world may always have known what you just discovered. But then, some eurekas are more generally novel.) My insight made me view trends in an entirely different way: as changes in variation within complete systems, rather than as "a thing moving either up or down" (hence the subtitle of this book, The _Spread_ of Excellence).
With insight came fear—and for two reasons. First, the theme may seem small and offbeat at first. Why should a different explanation of trends become a subject of general interest? Moreover, and second, the key reformulation (thinking of whole systems expanding or contracting, rather than entities on the move) is fundamentally statistical and must be presented in graphical terms. I did not fear for incomprehensibility. The key idea is as simple as could be (a conceptual inversion, not an arcane mathematical expression), and I knew that I could present the argument entirely in pictorial (not algebraic) terms. But I also knew that I would have to lay out the argument carefully, first making the general point and then developing some simple and preliminary examples before taking on the two main subjects: 0.400 hitting and a resolution of the problem of progress in the history of life.
But would people read the book? Would readers persist through the necessary preliminaries to reach the key reformulations? Would they maintain interest through a graphical development, given our cultural disinclination toward anything that smacks of mathematical style? Yet, I remain convinced that this book presents a novel argument of broad applicability—and that persistent readers may emerge with satisfaction, and in agreement with the father as he pardoned his prodigal son (and justified mercy to his other, persistently obedient child): "it was meet that we should make merry and be glad."
So let me make a deal with you. As a man who has spent many enlightening, if unenriching, hours playing poker (hence the book's title), I want to propose a bet. Persist through to the end, and I wager that you will be rewarded (perhaps even with a royal flush to beat my full house). In return, I have made the book short (remarkably so compared with my other effusions), hopefully clear and entertaining (if methodical in building up to the two main examples), and imbued with a promise that two truly puzzling, important, and apparently unrelated phenomena can be explained by the conceptual apparatus here developed.
The rewards of persistence should be twofold. First, I think that my approach of studying variation in complete systems does provide genuine resolution for two widely discussed issues that can only remain confusing and incoherent when studied in the traditional, persistently Platonic mode of representing full systems by a single essence or exemplar—and then studying how this entity moves through time. I find both resolutions particularly satisfying because they are not so radical that they lie outside easy conceivability. Rather, both solutions make eminent good sense and resolve true paradoxes of the conventional view, once you imbibe the revised perspective based on variation. How can we believe, as the traditional approach requires, that 0.400 hitting has disappeared because batters have gotten worse, when record performances have improved in almost any athletic activity? My approach shows that the disappearance of 0.400 hitting actually records the increasing excellence of play in baseball—and this makes satisfying sense (but cannot be coherently grasped at all under traditional modes of thought about the problem).
Similarly, although I can marshal an impressive array of arguments, both theoretical (the nature of the Darwinian mechanism) and factual (the overwhelming predominance of bacteria among living creatures), for denying that progress characterizes the history of life as a whole, or even represents an orienting force in evolution at all—still, and if only for legitimate parochial reasons, we rightly embrace the idea that humans are uniquely complex, and we properly insist that this fact requires some acknowledgment of a trend. But the explanatory apparatus of _Full House_ permits us to retain this commonsensical view about human status, while understanding that progress truly does not pervade or even meaningfully mark the history of life.
Second—and I don't quite know how to say this without sounding more immodest than I truly intend to be—this book does have broader ambitions, for the central argument of _Full House_ does make a claim about the nature of reality. I say nothing that has not been stated before by other folks in other ways, but I do try to explicate a broad range of cases not usually gathered together, and I am making my plea by gentle example, rather than by tendentious frontal assault in the empyrean realm of philosophical abstraction (the usual way to attack the nature of reality, and to guarantee limited attention for want of anchoring). I am asking my readers finally and truly to cash out the deepest meaning of the Darwinian revolution and to view natural reality as composed of varying individuals in populations—that is, to understand variation itself as irre
ducible, as "real" in the sense of "what the world is made of." To do this, we must abandon a habit of thought as old as Plato and recognize the central fallacy in our tendency to depict populations either as average values (usually conceived as "typical" and therefore representing the abstract essence or type of the system) or as extreme examples (singled out for special worthiness, like 0.400 hitting or human complexity). The subtitle of this book—The Spread of Excellence from Plato to Darwin—epitomizes the two approaches, and the importance of owning Darwin's solution.
_Full House_ is a companion volume of sorts to my earlier book _Wonderful Life_ (1989). Together, they present an integrated and unconventional view of life's history and meaning—one that forces us to reconceptualize our notion of human status within this history. _Wonderful Life_ asserts the unpredictability and contingency of any particular event in evolution—and emphasizes that the origin of _Homo sapiens_ must be viewed as such an unrepeatable particular, not an expected consequence. _Full House_ presents the general argument for denying that progress defines the history of life or even exists as a general trend at all. Within such a view of life-as-a-whole, humans can occupy no preferred status as a pinnacle or culmination. Life has always been dominated by its bacterial mode.
Both volumes present their basic arguments through particular examples (of an arresting sort), rather than by tendentious generalities—the full range of the Cambrian explosion as revealed in the fauna of the Burgess Shale in _Wonderful Life_: the disappearance of 0.400 hitting in baseball, and the constant bacterial mode of life's bell curve in _Full House_. These cases suggest that we trade the traditional source of human solace in separation for a more interesting view of life in union with other creatures as one contingent element of a much larger history. We must give up a conventional notion of human dominion, but we learn to cherish particulars, of which we are but one (_Wonderful Life_), and to revel in complete ranges, to which we contribute one precious point (_Full House_)—a good swap, I would argue, of stale (and false) comfort for broader understanding. It is, indeed, a wonderful life within the full house of our planet's history of organic diversity.
So you have my modest proposal. Please read this book. Then let's talk, and have a whale of an argument about all manner of deepest things—and of cabbages, and kings.
PART ONE
* * *
How Shall We Read and Spot a Trend?
1
Huxley's Chessboard
We reveal ourselves in the metaphors we choose for depicting the cosmos in miniature. Shakespeare, unsurprisingly, saw the world as "a stage, and all the men and women merely players." Francis Bacon, in bitter old age, referred to external reality as a bubble. We can make the world really small for various purposes, ranging from religious awe before the even grander realm of God ("but a small parenthesis in eternity" according to Sir Thomas Browne in the mid-seventeenth century), to simple zest for life as stated so memorably in a conversation between the paragons for such a position, Pistol and Falstaff: "the world's mine oyster, which I with sword will open").
We should therefore not be surprised that Thomas Henry Huxley, the arch rationalist and master of combat, should have chosen a chessboard for his image of natural reality:
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The chess board is the world, the pieces are the phenomena of the universe, the rules of the game are what we call the laws of Nature. The player on the other side is hidden from us. We know that his play is always fair, just, and patient. But also we know, to our cost, that he never overlooks a mistake, or makes the smallest allowance for ignorance. (From _A Liberal Education_, 1868.)
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This image of nature as a tough but fair adversary, beatable by the two great weapons of observation and logic, underlies Huxley's most famous pronouncement that "science is simply common sense at its best; that is, rigidly accurate in observation and merciless to fallacy in logic." (From his great popular work _The Crayfish_, 1880.)
Huxley's metaphor fails—and our task in revealing nature becomes correspondingly harder—because we cannot depict the enterprise of science as Us against Them. The adversary at the other side of the board is some complex combination of nature's genuine intractability and our hidebound social and mental habits. We are, in large part, playing against ourselves. Nature is objective, and nature is knowable, but we can only view her through a glass darkly—and many clouds upon our vision are of our own making: social and cultural biases, psychological preferences, and mental limitations (in universal modes of thought, not just individualized stupidity).
The human contribution to this equation of difficulty becomes ever greater as the subject under investigation comes closer to the heart of our practical and philosophical concerns. We may be able to apply maximal objectivity to taxonomic decisions about species of pogonophorans in the Atlantic Ocean, but we stumble in considering the taxonomy of fossil human species or, even worse, the racial classification of _Homo sapiens_.
Thus, when we tackle the greatest of all evolutionary questions about human existence—how, when, and why did we emerge on the tree of life; and were we meant to arise, or are we only lucky to be here—our prejudices often overwhelm our limited information. Some of these biased descriptions are so venerable, so reflexive, so much a part of our second nature, that we never stop to recognize their status as social decisions with radical alternatives—and we view them instead as given and obvious truths.
My favorite example of unrecognized bias in depicting the history of life resides quite literally in the pictures we paint. The first adequate reconstructions of fossil vertebrates date only from Cuvier's time, in the early nineteenth century. Thus the iconographic tradition of drawing successive scenes to illustrate the pageant of life through time is not even two centuries old. We all know these series of paintings—from a first scene of trilobites in the Cambrian sea, through lots of dinosaurs in the middle, to a last picture of Cro-Magnon ancestors busy decorating a cave in France. We have viewed these sequences on the walls of natural history museums, and in coffee-table books about the history of life. Now what could be wrong, or even strongly biased, about such a series? Trilobites did dominate the first faunas of multicellular organisms; humans did arise only yesterday; and dinosaurs did flourish in between.
Consider three pairs of scenes spanning a century of this genre, and including the three most famous practitioners of all time. Each shows a Paleozoic and a Mesozoic marine scene. In each, the Paleozoic tableau features invertebrates, while the Mesozoic scene shows only marine reptiles that have descended from terrestrial forms. The first pair comes from a work that established the genre in the early 1860s—Louis Figuier's _La terre avant le déluge_ (_The World Before the Deluge_; see Rudwick's fascinating book, _Scenes from Deep Time_, for a survey of this genre's foundation in the nineteenth century). The second is the canonical American version, painted by Charles R. Knight, greatest artist of prehistoric life, for an article in _National Geographic Magazine_ (February 1942), and titled _Parade of Life Through the Ages_, The last pair represents the equally canonical European work of the Czech artist Z. Burian in his 1956 work written with paleontologist J. Augusta and entitled _Prehistoric Animals_.
So why am I complaining? No vertebrates yet lived in the early Paleozoic, and marine reptiles did return to the sea during dinosaur days in the Mesozoic. The paintings are "right" in this narrow sense. But nothing can be more misleading than formally correct but limited information drastically yanked out of context. (Remember the old story about the captain who disliked his first mate and recorded in the ship's log, after a unique episode, First mate was drunk today." The mate begged the captain to remove the passage, stating correctly that this had never happened before and that his employment would be jeopardized. The captain refused. The mate kept the next day's log, and he recorded, "Captain was sober today.")
As for this nautical tale, so for the history of life. What can be more misleading than the representation of something small as everything typical?
All prominent series of paintings in this genre of prehistoric art—there are no exceptions, hence the example's power—claim to be portraying the nub or essence of life's history through time. They all begin with a scene or two of Paleozoic invertebrates. We note our first bias even here, for the prevertebrate seas span nearly half the history of multicellular animal life, yet never commandeer more than 10 percent of the pictures. As soon as fishes begin to prosper in the Devonian period, underwater scenes switch to these first vertebrates—and we never see another invertebrate again for all the rest of the pageant (unless a bit-playing ammonite squeezes into the periphery of a Mesozoic scene). Even the fishes get short shrift (literally), for not a single one ever appears again (except as fleeing prey for an ichthyosaur or a mosasaur) after the emergence of terrestrial vertebrate life toward the end of the Paleozoic era.
Now, how many people have ever stopped to consider the exceedingly curious and unrepresentative nature of such limited pageantry? Invertebrates didn't die or stop evolving after fishes appeared; much of their most important history unrolls in contemporaneous partnership with marine vertebrates. (For example, the most fascinating and portentous episodes of life's history—the five largest mass extinctions—are all best recorded by changes in invertebrate faunas.) Similarly, fishes didn't die out or stop evolving just because one lineage of peripheral brethren managed to colonize the land. To this day, more than half of all vertebrates are fishes (more than 20,000 living species). Isn't it absurd to eliminate a vertebrate majority from all further pictorial representation just because one small lineage changed its abode to land?