|A book by|
William H. Calvin
UNIVERSITY OF WASHINGTON
SEATTLE, WASHINGTON 98195-1800 USA
The Throwing Madonna|
Essays on the Brain
Copyright 1983, 1991 by William H. Calvin.
You may download this for personal reading but may not redistribute or archive without permission (exception: teachers should feel free to print out a chapter and photocopy it for students).
Scanned, OCR'ed, and webbed -- but NOT proofread (14 Jan 97)
For my mother,
AGNES LEEBRICK CALVIN
FIRST THINGSThere is a vast untapped popular interest in the deepest scientific questions. For many people, the shoddily thought out doctrines of borderline science [parapsychology, astrology, ancient astronauts] are the closest approximation to comprehensible science readily available. The popularity of borderline science is a rebuke to the schools, the press, and commercial television for their sparse, unimaginative and ineffective efforts at science education, and to us scientists, for doing so little to popularize our subject.
CARL SAGAN, Broca's Brain
. . . aversion to science is [surely] an unnatural state of mind. Science is the natural searching within ourselves and in our surrounds for explanations. It is the process of making comprehensible, by discovering and explaining with simple laws, that which had been dark--and often frightening--mystery. Science is curiosity in harness, and curiosity is surely one of the most elemental human motivating forces.
MAHLON B. HOAGLAND, The Roots of Life
New knowledge should ennoble not merely those who seek and find it, nor their immediate colleagues; it should add to the civility and wonder and the nobility of the common life.J. ROBERT OPPENHEIMER. The Need for New Knowledge
Sometimes, an indirect approach is better. When you are stuck trying to remember something with a head-on approach ("Now, what is her name . . . ?"), it is often best to think instead about other, related things (perhaps the last time and place you met) --and hope that everything will fall into place. Tackling the mind-brain-intelligence troika in a head-on manner with verbal tools has been done traditionally by many philosophically inclined writers, such as Hofstadter and Dennett in recent years.
Neurobiologists are not uninterested in the big questions, but tend to feel that they too require a more indirect approach: thoroughly familiarizing oneself with the biological bases of animal and human behavior (ethology), with evolutionary processes and how they create stable hierarchies, with the bottom-up approaches to brain organization which start with membranes and neurons and circuits. And the top-down approaches which look at linguistics, instinct, hemispheric specializations, cortical maps, selective attention mechanisms, language physiology, and characteristic malfunctions.
Neurobiologists also have a broad practical knowledge about what works and what doesn't, ranging from the neurosurgeon trying to prevent a patient with epilepsy from hearing strange voices to the zoologist who learns to manipulate the caterpillar's nervous system as it changes over at metamorphosis from controlling crawling to controlling flying. And their tools are not merely verbal and mathematical: neurobiologists are always driving the medical instrument makers crazy with requests for tiny scissors smaller than the eye surgeons use, always chiding the computer manufacturers for making it hard to interface computers to animal brains.
But the head-on approaches from philosophy and artificial intelligence seldom raise my blood pressure. There are, however, some approaches from the direction of the physical sciences which I consider insidious due to their superficial reductionism. It's not merely that I've heard too many physicists and molecular biologists talking about decoding the brain as their next frontier, proposing to bring order to that computer like with their well-known mathematical reasoning. It's not merely that they, rather than the neurobiologists themselves, have been writing most of the popular books on neurobiology (a major exception, highly recommended, is Programs of theBrain by one of the most eloquent of all neurobiologists, J. Z. Young). Contrary to the grating tendency of some historians of science to treat biology as an imperfect stepchild of physics, many biologists originally trained in physics (the plop-plop sound and the oily smell of a vacuum pump, which characterize the corridors of physics departments, still stir fond memories for me) come to consider the methods of physics as simply inadequate for many aspects of biological hierarchies, especially evolution itself.
The reductionistic approach is, of course, a very important part of neurobiology (chapters 8, 9, and 16 show some classic examples), and a steep descent through a few layers of the hierarchy can indeed be exhilarating. But while digging deeper is all very well, there are too few people who attempt to understand the breadth of a particular level, such as comparing the various styles that neurons exhibit in making decisions. There seem to be several reasons. First, there is the competitiveness of researchers: we scientists like to see our names in print, and synthesizing never produces as many publications per year as tending a well-oiled digging machine. The second reason is more insidious because it is a form of self-definition growing out of the work ethic: just as narrow-minded economists define "work" so as to exclude what housewives do, many scientists define scientific productivity so as to exclude anything that isn't excavation labor. Depth counts, not breadth. And young researchers quickly learn that this narrow concept of productivity is what counts in getting promotions and grant money; they ignore it at their peril. (For example, writing a review article synthesizing several fields often doesn't count, but the tenth variation on a familiar excavation theme always counts. Of course, since most science tesearchers work for the "public sector," we all--by the economists' definition -- exhibit zero productivity!)
This abused prestige of reductionism has had especially serious effects upon whole fields, such as our investigations into the origins of biological systems. People working in paleontology, developmental biology, neurobiology, and ethology have been essentially told to just report the facts and leave it to the population geneticists to explain how it all came about. As if discovering the evolutionary history within a particular level wouldn't be as interesting as the gene-jumping some layers below. Alas. That's like ignoring the development of sophisticated computer software in favor of reducing everything to quantum mechanical tunneling in the semiconductors from which the computers are constructed.
People have been driven to writing books themselves with even less provocation than provided by all of the bad examples. But the last straw was when a Reader's Digest editor phoned me, asking was it really true that, if a computer was built the size of the 10-billion-element human brain, it would consume more power than a New York skyscraper? As it happens, this is a figure extrapolated from those cited by the famous mathematician John von Neumann in his little book from the mid-fifties, The Computer and The Brain, still seemingly the major reference source for some physicists on matters neurological.
A few things have happened in the last quarter-century to both computers and neurobiology (my little word processor idles along at 150 watts, six times the basal metabolic rate of the poor brain which it assists, but the computer figure would have been another thousandfold higher back in von Neumann's time; as for neurobiology's progress, that just happens to be the topic of this book). Which left me trying to persuade Reader's Digest that there really were more interesting aspects to the human brain--if its power consumption of 25 watts is more efficient than a big computer, so what else is new . . . ? And repeating to Reader's Digest my standard refrain about the numbers game--that of those famous 10 billion neurons comprising the brain, 100 billion o f them are located in just one section of the brain (the granule cell neurons of the cerebellum). Everyone's always underestimating the brain.
I did try tracking down that 10 billion rumor to its source, since even neurobiologists have been known to repeat it: 10 billion is really the estimate made by some quantitative Russian anatomists for the number of neurons in only the cerebral cortex of one hemisphere. Along the rumor mill, someone confused one hemisphere with two, then someone else confused the cerebral cortex with the whole brain. So there are 20 billion neurons total in the cerebral cortex. But the cerebral cortex, important as it seems to be in the brain of modern hominids,is only--to use a singularly appropriate metaphor--the frosting on the cake. The cake's neuronal numbers will have to be estimated by someone more brave than I. Besides, I have enough trouble just trying to count the cake's layers. Numbers, though of importance (see Chapter 4), do not do it justice.
What evolutionary process created that frosting? It is indeed ironic that the term evolution (which literally means unfolding) is applied to the origins and development of the human cerebral cortex, which is noted for its extensive convolutions (deep folds in its surface which increase its surface area manyfold). Evolution by convolution--unfolding by infolding. Like an Escher print of a Mobius strip twisting around upon itself? Or perhaps a more appropriate image would be the deep folds revealed as a Georgia O'Keeffe flower opens up.
And it seems likely that science will need such artistic images if we are to succinctly summarize our understanding of the brain's evolution: just as the artist pares away the inessential detail and rearranges things so as to strike the viewer's eye with special impact, so the scientist tries to reduce things to essentials and present a representation so that the human mind can readily comprehend it. But the essentials, for science as well as art, are not elementary particles but rather principles of organization, of composition. Georges Braque said it well: "I do not believe in things, I believe only in their relationships." Our attempts to describe human brains are still the fledgling efforts of the child with watercolors, but we look forward to the various schools of brain art which may emerge.
Many thanks to my friends, relatives, editors, and colleagues who took the trouble to criticize the writing and the science. Simplification is a double-edged sword. It is, in many ways, the essence of science rather than (as some would have it) the imprecise refuge of popularizers. As Karl Popper recently said, "Science may be described as the art of systematic oversimplification--the art of discerning what we may with advantage omit." But I am also writing about neurobiology as the community endeavor of many people, so I am reminded of the other side of simplification, noted by a historian of molecular biology:
Confronted with this living fabric unrolled abundantly upon his worktable, the historian picks up his shears, hesitates, and puts them down again. Whatever he does, he will be like the damned eighteenth-century Dutchman who made Rembrandt's Night Watch smaller to fit a smaller room.
HORACE FREELAND JUDSON, The Eighth Day of Creation, 1979
Though not a history of neurobiology, this book shares the same dilemma in selecting topics. While it touches on a spectrum from behavior to membranes, they are chosen because I can write easily about them, not because I have attempted to distill and evaluate in the manner of the historian.
I hope to persuade the reader that there is a new picture of human origins emerging from neurobiology and sociobiology which complements the more traditional methods of anthropology and linguistics. Some of what I present is new data, some is informed speculation, much is just bringing together traditional data from scattered sources.
It gives a picture of where science may be headed in its quest for human origins--but it is just one picture, mine, though shaped by many influences such as my colleagues' wide interests. This picture is likely flawed in some significant way--that's the (fortunately self-correcting) history of science, after all. I hope that the book whets appetites rather than satisfying them (to this end, I have provided many leads for further reading) and that some of the readers will become the thinkers and doers who will shape the future versions of the story.
Preface to the 1991 Bantam editionAfter a lecture in which I mentioned that none of the seventeen essays in this book were originally published in periodicals (that's the case with nearly all the essay books available on the science-for-general-readers bookshelves), a reader came up to see me afterwards, asking how I came to write so many of them without the prod of the columnist's monthly deadline. In particular, she was puzzled about "Last Year in Jerusalem," as it seemed longer and more experimental than the other essays, what with its travelogue style. I was delighted to tell her that the answer to her style query would soon appear in print as The River that Flows Uphill: A Journey from the Big Bang to the Big Brain. The answer to the many-essays question is that I didn't write them for the usual reasons.
Shortly after my first book, Inside the Brain, was published in 1980, I set out to write about evolution on a broad scale, utilizing the float trip down the Colorado River through the bottom of the Grand Canyon as a thread. I took a second river trip, scribbled lots of notes along the way, and began writing. But my initial attempts quickly convinced me that -- despite much youthful journalism, several decades of writing up my research for other scientists, and co-authoring one book for general readers -- my writing skills were still not sufficient for such a long narrative adventure, especially considering the challenges posed by the grand scope of evolution and the spectacle of the Canyon itself. And so I set those attempts aside and tried to teach myself how to write. The essay format's self-contained brevity lent itself to focused efforts at rewriting for style, and I picked topics that I already knew a lot about, mostly from my own scientific research endeavors but also from teaching, so that I could concentrate on the writing itself. Especially rewriting (some of the earlier essays went through several dozen versions, as I brought them up to the standard of later ones).
And so this book is, in a sense, the product of my self-education in writing during 1981-1982; it owes a lot to the examples set by Annie Dillard and Lewis Thomas (curiously, and inexplicably, I didn't begin reading Loren Eiseley or Oliver Sacks extensively until after this book was finished). In 1983, I returned to the challenges of evolution and the Grand Canyon, taking the travelogue experiment of "Last Year in Jerusalem" and developing it into the style that I used in The River That Flows Uphill, and subsequently in The Cerebral Symphony, in The Ascent of Mind, and in my "scientific hobby" book,How the Shaman Stole the Moon.
In this new Bantam edition, I have refrained from tampering with the essays (except to correct errors and provide a few updated leads for further reading); I was pleased to see, when rereading them, that they represent something close to my modern writing style, without the awkwardness that one might expect from developmental exercises. I do sometimes wish that I could change the book's title, as it has been a source of confusion to people who have not read the book but know about my "throwing theory" for language origins from other sources (it was published in the Journal of Theoretical Biology about the same time as this book first appeared). The Throwing Madonna is, in the tradition of essay books, simply the title of one of the included essays -- but it is not the one about my throwing theory.
In my opening essay, I parody the "Man the Hunter" theories for right-handedness by developing an equally-plausible explanation involving women hunters (and have some fun with the capricious nature of "explaining" things in an evolutionary sense). Neither the male or the female version, however, is likely much more than a sideshow to the main event: Evolving a brain that can do a lot of novel sequencing tasks (versatile throwing, but also language, scenario-spinning, music, dance, and our many serial-order games). The truth about right-handedness surely involves a lot of things not mentioned in my parody, many of which happened long before projectile predation began to influence hominid evolution and open up a new niche in the temperate zone.
The throwing theory proper was further developed in The River that Flows Uphill in 1986, extended as "The brain as a Darwin Machine" in Nature in 1987 and elaborated in the final chapters of The Cerebral Symphony in 1989,. It then evolved into the "cortical consensus" in chapter 9 of The Ascent of Mind in 1990. Had I known in 1983 how much the throwing theory would subsequently develop, I would have avoided confusing the issue by using the word "throwing" in the title of an unrelated parody. But, as parents and teachers come to realize, you never can tell what your efforts will develop into.
That's also true of styles. In the more conventional essay book format, the reader understands that individual essays can be skipped over if too difficult or insufficiently interesting: essays are presumed to be capable of standing alone, however connected they may also be to the adjacent essays. But readers may not apply this reasoning to other kinds of books about science ("If you can't understand chapter two," so the textbook-based reasoning goes, "You'll never understand chapter four.") with the result that the author loses the reader somewhere, the book laid aside and never resumed. Like the book of collected essays, the travelogue-assisted book provides some reassurance to the reader, implied permission to skip over certain sections. Because of the thread provided by the journey itself, the author may be thereby emboldened to ignore "prerequisites" and rely on shortcuts, reasoning by analogy to get across a more advanced concept. Were the author to simplify to a common denominator in the typical textbook strategy, many interesting topics would have to be omitted.
Were I to retitle this book to use the most important (to me as a writer) essay as the title, it would probably be Last Year in Jerusalem. But for me as a scientist, the most important chapters were those final ones on language and evolution, as they helped to lead me into that interesting zone of overlap between neurobiology, developmental biology, linguistics, anthropology, and evolutionary biology that has characterized my subsequent research.
W. H. C.
The Throwing Madonna:|
Essays on the Brain (McGraw-Hill 1983, Bantam 1991) is a group of 17 essays: The Throwing Madonna; The Lovable Cat: Mimicry Strikes Again; Woman the Toolmaker? Did Throwing Stones Lead to Bigger Brains? The Ratchets of Social Evolution; The Computer as Metaphor in Neurobiology; Last Year in Jerusalem; Computing Without Nerve Impulses; Aplysia, the Hare of the Ocean; Left Brain, Right Brain: Science or the New Phrenology? What to Do About Tic Douloureux; Linguistics and the Brain's Buffer; The Woodrow Wilson Story; Thinking Clearly About Schizophrenia; Of Cancer Pain, Magic Bullets, and Humor; Linguistics and the Brain's Buffer; Probing Language Cortex: The Second Wave; and The Creation Myth, Updated: A Scenario for Humankind. The preface for the revised edition (1991) is available as is the Lovable Cat chapter. Note that my throwing theory for language origins (last 3 essays) has nothing to do with the title essay: THE THROWING MADONNA is a parody (involving maternal heartbeat sounds!) on the typically-male theories of handedness.
|AVAILABILITY poor. |
Many libraries have it (try the OCLC on-line listing, which cryptically shows the libraries that own a copy), and used bookstores may have either the 1983 or the 1991 edition.