Thirteen years after the legendary confrontation over the theory of evolution between Bishop Samuel Wilberforce (“Soapy Sam”) and Thomas Henry Huxley (“Darwin’s bulldog”), Wilberforce died in 1873 in an equestrian fall. Huxley quipped to the physicist John Tyndall, “For once, reality and his brain came into contact and the result was fatal.”

When it comes to such basic forces as gravity and such fundamental phenomena as falling, our intuitive sense of how the physical world works — our folk physics — is reasonably sound. Thus, we appreciate Huxley’s wry comment and note that even children get the humor of cartoon physics, where, for example, a character running off a cliff does not fall until he realizes that he has left terra firma.

But much of physics is counterintuitive, as is the case in many other disciplines, and before the rise of modern science we had only our folk intuitions to guide us. Folk astronomy, for example, told us that the world is flat, celestial bodies revolve around the earth and the planets are wandering gods who determine our future. Folk biology intuited an élan vital flowing through all living things, which in their functional design, were believed to have been created ex nihilo by an intelligent designer. Folk psychology compelled us to search for the homunculus in the brain — a ghost in the machine — a mind somehow disconnected from the brain. Folk economics caused us to disdain excessive wealth, label usury a sin and mistrust the invisible hand of the market.

The reason folk science so often gets it wrong is that we evolved in an environment radically different from the one in which we now live. Our senses are geared for perceiving objects of middling size — between, say, ants and mountains — not bacteria, molecules and atoms on one end of the scale and stars and galaxies on the other end. We live a scant three score and 10 years, far too short a time to witness evolution, continental drift or long-term environmental changes.

Causal inference in folk science is equally untrustworthy. We correctly surmise designed objects, such as stone tools, to be the product of an intelligent designer and thus naturally assume that all functional objects, such as eyes, must have also been intelligently designed. Lacking a cogent theory of how neural activity gives rise to consciousness, we imagine mental spirits floating within our heads. We lived in small bands of roaming hunter-gatherers that accumulated little wealth and had no experience of free markets and economic growth.

Folk science leads us to trust anecdotes as data, such as illnesses being cured by assorted nostrums based solely on single-case examples. Equally powerful are anecdotes involving preternatural beings, compelling us to make causal inferences linking these non-material entities to all manner of material events, illness being the most personal. Because people often recover from sickness naturally, whatever was done just before recovery receives the credit, prayer being the most common.

In this latter case, we have a recent scientific analysis of this ancient folk science supposition. The April issue of the American Heart Journal published a comprehensive study directed by Harvard Medical School cardiologist Herbert Benson on the effects of intercessory prayer on the health and recovery of patients undergoing coronary bypass surgery. The 1,802 patients were divided into three groups, two of which were prayed for by members of three religious congregations. Prayers began the night before the surgery and continued daily for two weeks after. Half the prayer recipients were told that they were being prayed for, whereas the other half were told that they might or might not receive prayers. Results showed no statistically significant differences between any of the groups. Case closed.

Of course, people will continue praying for their ailing loved ones, and by chance some of them will recover, and our folk science brains will find meaning in these random patterns. But for us to discriminate true causal inferences from false, real science trumps folk science.

At a February 12, 2002, news briefing, Secretary of Defense Donald Rumsfeld explained the limitations of intelligence reports: “There are known knowns. There are things we know we know. We also know there are known unknowns. That is to say, we know there are some things we do not know. But there are also unknown unknowns, the ones we don’t know we don’t know.”

Rumsfeld’s logic may be tongue-twisting, but his epistemology was sound enough that he was quoted twice at the World Summit on Evolution. The June conference, hosted by San Francisco University of Quito, was held on the Galápagos island of San Cristóbal, where Charles Darwin began his explorations. Rumsfeld’s wisdom was first invoked by University of California at Los Angeles paleobiologist William Schopf, who, in a commentary on a lecture on the origins of life, asked: “What do we know? What are the unsolved problems? What have we failed to consider?”

Creationists and outsiders often mistake the latter two categories for signs that evolution is in trouble, or that contentious debate between what we know and do not know means that the theory is false. Wrong. The summit revealed a scientific discipline rich in data and theory as well as controversy and disputation over the known and unknown.

For example, Schopf began with the known: “We know the overall sequence of life’s origin, from CHONSP [carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus], to monomers, to polymers, to cells; we know that the origin of life was early, microbial and unicellular; and we know that an RNA world preceded today’s DNA-protein world. We do not know the precise environments of the early earth in which these events occurred; we do not know the exact chemistry of some of the important chemical reactions that led to life; and we do not have any knowledge of life in a pre-RNA world.” As for what we have failed to consider, Schopf noted a problem with what he called “the pull of the present” — it is extremely difficult to model the early earth’s atmosphere and the biochemistry of early life because we are so accustomed to conditions today.

Rumsfeld’s heuristic was summoned again at the end of the conference by University of Georgia evolutionary biologist Patricia Gowaty, in response to Stanford University biologist Joan Roughgarden, who declared that Darwin’s theory of sexual selection is wrong in its claim that females choose mates who are the most attractive. “People are surprised to learn how much sex animals have for purely social reasons and how many species have sex-role reversal in which the males are drab and the females are colorfully ornamented and compete for the attention of males,” Roughgarden said. Gowaty agreed that exceptions to Darwin’s theory exist and that there are many unknowns. But, she added, since Darwin much has been learned about mate selection and competition.

Between these Rumsfeldian bookends, scientific skepticism was rampant. University of Massachusetts Amherst biologist Lynn Margulis said that “neo-Darwinism is dead,” because “random changes in DNA alone do not lead to speciation. Symbiogenesis — the appearance of new behaviors, tissues, organs, organ systems, physiologies or species as a result of symbiont interaction — is the major source of evolutionary novelty in eukaryotes: animals, plants and fungi.” University of California at Berkeley paleoanthropologist Timothy White suggested that his colleagues have engaged in far too much species splitting in classifying fossil hominids. American Museum of Natural History paleontologist Niles Eldredge explained how punctuated equilibrium — the idea that long periods of species stability are punctuated by rapid bursts of speciation — better accounts for the fossil record than the theory of slow and steady gradualism.

During the conference, I had a nightmarish thought: creationists could have a field day yanking quotes out of context while listening to a room full of evolutionary biologists arguing over specific issues. In point of fact, such debates are all within evolutionary theory, not between evolutionary theory and something else. And this boundary between the known and the unknown is where science flourishes.

Evolutionary biologist Jared Diamond of the University of California at Los Angeles once classified humans as the “third chimpanzee” (the second being the bonobo). Genetically, we are very similar, and when it comes to high levels of aggression between members of two different groups, as I noted in last month’s column on “The Ignoble Savage,” we also resemble chimpanzees. Although humans have a brutal history, there’s hope that the pessimists who forecast our eventual demise are wrong: recent evidence indicates that, like bonobos, we may be evolving in a more peaceful direction.

One of the most striking features in artificially selecting for docility among wild animals is that, along with far less aggression, you also get a suite of other changes, including a reduction in skull, jaw and tooth size. In genetics, this is called pleiotropy. Selecting for one trait may generate additional, unintended changes.

The most famous study on selective breeding for passivity began in 1959 by Russian geneticist Dmitri Belyaev of the Institute of Cytology and Genetics in Siberia. It continues today under the direction of Lyudmila N. Trut. Silver foxes were bred for friendliness toward humans, defined by a graduating series of criteria, from the animal allowing itself to be approached, to being hand fed, to being petted, to proactively seeking human contact. In only 35 generations the researchers produced tail-wagging, hand-licking, peaceful foxes. What they also created were foxes with smaller skulls, jaws and teeth than their wild ancestors.

The Russian scientists believe that in selecting for docility, they inadvertently selected for paedomorphism — the retention of juvenile features into adulthood — such as curly tails and floppy ears found in wild pups but not in wild adults, a delayed onset of the fear response to unknown stimuli, and lower levels of aggression. The selection process led to a significant decrease in levels of stress-related hormones such as corticosteroids, which
are produced by the adrenal glands during the fight-or-flight response, as well as a significant increase in levels of serotonin thought to play a leading role in the inhibition of aggression. The Russian scientists were also able to accomplish what no breeder had ever achieved before — a lengthened breeding season.

Like the foxes, humans have become more agreeable as we’ve become more domesticated. Whereas humans are like chimpanzees when it comes to between-group aggression, when it comes to levels of aggression among members of the same social group, we are much more like peaceful, highly sexual bonobos. Harvard University anthropologist Richard W. Wrangham proffers a plausible theory: as a result of selection pressures for greater within-group peacefulness and sexuality, humans and bonobos have gone down a different behavioral evolutionary path than chimps have.

Wrangham suggests that over the past 20,000 years, as humans became more sedentary and their populations grew, selection pressures acted to reduce within-group aggression. This effect can be seen in such features as smaller jaws and teeth than our immediate hominid ancestors, as well as our year-round breeding season and prodigious sexuality; bonobos were once called the “pygmy chimpanzee” because of their paedomorphic features. (Emory University psychologist Frans B. M. de Waal has documented how bonobos in particular use sexual contact as an important form of conflict resolution and social bonding.) Wrangham also shows how Area 13 in the human limbic frontal cortex, believed to mediate aggression, more closely resembles in size the equivalent area in bonobo brains than it does that same area in chimpanzees.

A plausible evolutionary hypothesis suggests itself: limited resources led to the selection for within-group cooperation and between-group competition in humans, resulting in within-group amity and between-group enmity. This evolutionary scenario bodes well for our species — if we can continue to expand the circle of whom we consider to be members of our in-group. Recent conflicts are not encouraging, but in the long run there is a trend toward including more people (such as women and minorities) within the in-group deserving of human rights.

The world lost the creators of two of its most celebrated biohoaxes recently: Douglas Herrick, father of the risibly ridiculous jackalope (half jackrabbit, half antelope), and Ray L. Wallace, paternal guardian of the less absurd Bigfoot.

The jackalope enjoins laughter in response to such peripheral hokum as hunting licenses sold only to those whose IQs range between 50 and 72, bottles of the rare but rich jackalope milk, and additional evolutionary hybrids such as the jackapanda. Bigfoot, on the other hand, while occasionally eliciting an acerbic snicker, enjoys greater plausibility for a simple evolutionary reason: large hirsute apes currently roam the forests of Africa, and at least one species of a giant ape — Gigantopithecus — flourished some hundreds of thousands of years ago alongside our ancestors.

Is it possible that a real Bigfoot lives despite the posthumous confession by the Wallace family that it was just a practical joke? Certainly. After all, although Bigfoot proponents do not dispute the Wallace hoax, they correctly note that tales of the giant Yeti living in the Himalayas and Native American lore about Sasquatch wandering around the Pacific Northwest emerged long before Wallace pulled his prank in 1958.

In point of fact, throughout much of the 20th century it was entirely reasonable to speculate about and search for Bigfoot, as it was for the creatures of Loch Ness, Lake Champlain and Lake Okanagan (Scotland’s Nessie, the northeastern U.S.’s Champ and British Columbia’s Ogopogo, respectively). Science traffics in the soluble, so for a time these other chimeras warranted our limited exploratory resources. Why don’t they now? The study of animals whose existence has yet to be proved is known as cryptozoology, a term coined in the late 1950s by Belgian zoologist Bernard Heuvelmans. Cryptids, or “hidden animals,” begin life as blurry photographs, grainy videos and countless stories about strange things that go bump in the night. Cryptids come in many forms, including the aforementioned giant pongid and lake monsters, as well as sea serpents, giant octopuses, snakes, birds and even living dinosaurs.

The reason cryptids merit our attention is that enough successful discoveries have been made by scientists based on local anecdotes and folklore that we cannot dismiss all claims a priori. The most famous examples include the gorilla in 1847 (andthe mountain gorilla in 1902), the giant panda in 1869, the okapi (a short-necked relative of the giraffe) in 1901, the Komodo dragon in 1912, the bonobo (or pygmy chimpanzee) in 1929, the megamouth shark in 1976 and the giant gecko in 1984. Cryptozoologists are especially proud of the catch in 1938 of a coelacanth, an archaic-looking species of fish that had been thought to have gone extinct in the Cretaceous. Although discoveries of previously unrecorded species of bugs and bacteria are routinely published in the annals of biology, these instances are startling because of their recency, size, and similarity to cryptid cousins Bigfoot, Nessie, et al. They also have in common — a body! In order to name a new species, one must have a type specimen — a holotype — from which a detailed description can be made, photographs taken, models cast and a professional scientific analysis prepared.

If such cryptids still survived in the hinterlands of North America and Asia, surely by now one would have turned up. So far all we have are the accounts. Anecdotes are a good place to begin an investigation — which by themselves cannot verify a new species. In fact, in the words of social scientist Frank J. Sulloway of the University of California at Berkeley—words that should be elevated to a maxim: “Anecdotes do not make a science. Ten anecdotes are no better than one, and a hundred anecdotes are no better than ten.”

I employ Sulloway’s maxim every time I encounter Bigfoot hunters and Nessie seekers. Their tales make for gripping narratives, but they do not make sound science. A century has been spent searching for these chimerical creatures. Until a body is produced, skepticism is the appropriate response.

In his 1950 science-fiction novel I, Robot, Isaac Asimov presented the Three Laws of Robotics: “1. A robot may not injure a human being, or, through inaction, allow a human being to come to harm. 2. A robot must obey the orders given it by human beings except where such orders would conflict with the First Law. 3. A robot must protect its own existence as long as such protection does not conflict with the First or Second Law.”

The irrational fears people express today about cloning parallel those surrounding robotics half a century ago. So I would like to propose Three Laws of Cloning that also clarify three misunderstandings: 1. A human clone is a human being no less unique in his or her personhood than an identical twin. 2. A human clone has all the rights and privileges that accompany this legal and moral status. 3. A human clone is to be accorded the dignity and respect due any member of our species.

Although such simplifications risk erasing the rich nuances found in ethical debates over pioneering research, they do aid in attenuating risible fears often associated with such advances. It appears that the Raelians have not succeeded in Xeroxing themselves, but it is clear that someone, somewhere, sometime soon is going to generate a human clone. And once one team has succeeded, it will be Katy bar the door for others to bring on the clones.

If cloning produces genetic monstrosities that render it impractical as another form of fertility enhancement, then it will not be necessary to ban it, because no one will use it. If cloning does work, however, there is no reason to forbid it, because the three common reasons given for implementing restrictions are myths. I call them the Identical Personhood Myth, the Playing God Myth, and the Human Rights and Dignity Myth.

The Identical Personhood Myth is well represented by activist Jeremy Rifkin: “It’s a horrendous crime to make a Xerox of someone. You’re putting a human into a genetic straitjacket. Baloney. He and fellow cloning critics have the argument bass ackward. As environmental determinists, they should be arguing: “Clone all you like — you’ll never produce another you, because environment matters as much as heredity.” The best scientific evidence to date indicates that roughly half the variance among us is accounted for by genetics and the rest by environment. It is impossible to duplicate the near-infinite number of permutations that come into play during the development of each individual, so cloning is no threat to unique personhood.

The Playing God Myth has numerous promoters, among the latest being Stanley M. Hauerwas, a professor of theological ethics at Duke University: “The very attempt to clone a human being is evil. The assumption that we must do what we can do is fueled by the Promethean desire to be our own creators.” In support of this myth, he is not alone. A 1997 Time/CNN poll revealed that 74 percent of 1,005 Americans answered “yes” to the question “Is it against God’s will to clone human beings?” Balderdash. Cloning may seem to be “playing God” only because it is unfamiliar. Consider earlier examples of once “God-like” fertility technologies that are now cheerfully embraced because we have become accustomed to them, such as in vitro fertilization and embryo transfer.

The Human Rights and Dignity Myth is embodied in the Roman Catholic Church’s official statement against cloning, based on the belief that it denies “the dignity of human procreation and of the conjugal union,” as well as in a Sunni Muslim cleric’s demand that “science must be regulated by firm laws to preserve humanity and its dignity.” Bunkum. Clones will be no more alike than twins raised in separate environments, and no one is suggesting that twins do not have rights or dignity or that they should be banned.

Instead of restricting or preventing the technology, I propose that we adopt the Three Laws of Cloning, the principles of which are already incorporated in the laws and language of the U.S. Constitution, and allow science to run its course. The soul of science is found in courageous thought and creative experiment, not in restrictive fear and prohibitions. For science to progress, it must be given the opportunity to succeed or fail. Let’s run the cloning experiment and see what happens.

In 1959 astronomers were polled for their opinion on the then undecided debate between two competing cosmological theories. “Did the universe begin with a Big Bang several thousand million years ago?” A third answered yes. “Is matter continuously created in space?” Almost half answered yes. Most telling, to the question “Is a poll of this kind helpful to scientific progress?” all answered no.

The reason for this unanimity is that scientific questions are not settled by consensus opinion. Unfortunately, in complex human and social issues, separating fact from opinion is not so easy, and for no issue is this more apparent than abortion. Setting aside the emotionally charged moral and political aspects of abortion for a moment, how can science inform this debate?

At the core of the moral and political question of whether or not aborting a fetus constitutes murder is the scientific question of when a fetus becomes a human being. Supreme Court Justice Harry A. Blackmun, writing for the 7-2 majority ruling in the 1973 Roe v. Wade decision, concluded: “When those trained in the respective disciplines of medicine, philosophy and theology are unable to arrive at any consensus, the judiciary, at this point in the development of man’s knowledge, is not in a position to speculate as to the answer.”

The problem is one of logic, not knowledge. Legal and political decisions are grounded in binary logic in which unambiguous yeses and noes determine final Truths. The law must make a determination on a case, a hard and fast ruling by which we are to abide. And political issues are settled by a consensus process called democracy. By contrast, science is grounded in fuzzy logic in which ambiguous probabilities determine provisional truths. Error bars accompany data graphs, p (probability) values are designated in decimal percentages indicating the likelihood of chance accounting for the finding, and caveats and cautions are sprinkled throughout conclusions.

In the abortion debate here is how the difference between binary and fuzzy logic plays out. Most Pro-Lifers believe that human life begins at conception — before conception not-life, after conception, life. Binary logic. Binary life. With fuzzy logic we can assign a probability to human life — before conception 0, the moment of conception, .1, multi-cellular blastocyst, .2, one-month old embryo, .3, two-month old fetus, .4, and so on until birth, when the fetus becomes a 1.0 human life form. Fuzzy logic. Fuzzy life.

The process does not sound very romantic, but from a scientific perspective human life is a fuzzy continuum. Neither egg nor sperm is a human individual, nor is the zygote or blastocyst because they might split to become twins, or stop developing and naturally abort. The eight-week old fetus has recognizable human features such as face, hands, and feet, but neuronal synaptic connections are still being made so thought is not possible. Only after eight weeks do embryos begin to show primitive response movements, but not until seven months does the fetus develop sufficient neocortical complexity to exhibit some of the cognitive capacities typically found in full-term newborns (in between, the fetus may respond reflexively to stimuli but this in no way can be construed as sentience). Fetus EEG recordings with the characteristics of an adult EEG appear at approximately 30 weeks. In other words, the capacity for human thought does not exist until just six weeks before birth.

Autonomy is also an issue. Between two and six months the fetus could not exist on its own because such critical organs as the lungs and kidneys do not mature before that time. For example, air sac development sufficient for gas exchange does not occur until at least 23 weeks after gestation, and often later. Since virtually no abortions are performed after the second trimester, and before then there is no scientific evidence that the fetus is an autonomous thinking human individual (most scientists agree that of all the characteristics used to define what it means to be human, the capacity to think is the most important), the case for abortion as murder cannot be based on scientific grounds.

Unfortunately, fuzzy thinking often prevails over fuzzy logic, where morality, politics, and science are confoundedly conflated. Moral issues are personal. Political issues are social. Scientific issues are factual. Pro-Choicers believe that whether a woman decides to abort a fetus or not is a personal moral issue. Pro-Lifers want to make it a political issue in which society makes that choice. The fuzzy logic of science reveals that there is no consensus on when a human life begins because it unfolds along a quantitative scale. Therefore, although one may oppose abortion for personal reasons, there is no scientific justification to shift the abortion issue from the personal to the political.

This article was first published here.

A review of Stephen Jay Gould’s The Structure of Evolutionary Theory.

We live in the Age of Science. Scientism is our worldview, our mythic story about who we are, where we came from, and where we are going. As such, scientists are our preeminent storytellers, the mythmakers of our epoch. Prominent among them are such cosmologists and evolutionary theorists as Stephen Hawking and Carl Sagan, Edward O. Wilson and Richard Dawkins, whose books are read by professionals and the public alike, with spectacular advances and (hopefully) matching sales that reflect the rise of a scientistic literati, where it is now chic to have read (or at least to have on your coffee table) their works.

Stephen Jay Gould has been a highly successful product and producer of this salubrious arrangement between scientists, agents, publishers, and readers. Stretching to 1,433 pages and weighing in at 5.5 pounds, Gould’s magisterial The Structure of Evolutionary Theory is destined to go down in the annals of this genre alongside the works of Galileo, Darwin, Huxley, Freud, Mayr, and others who write for the ages, as changing forever both colleagues and cultures. His critics — and there are plenty — may weep and gnash their teeth at such an assessment, but they ignore Gould at their — and our — peril. This man has something important to say about the preeminent origin myth of our age — evolutionary theory — and he has said it in this magnificent work.

The Structure of Evolutionary Theory is an elegant blend of science and history that revises both Darwin’s original 19th-century theory and the neo-Darwinian synthesis of the mid-20th century. Over the past four decades — during which he penned over 500 scientific papers, 300 essays, and 21 other books — Gould has systematically built upon Darwin’s cathedral, an apt metaphor as his tome begins with an architectural analysis of the Duomo (Cathedral) of Milan, showing how the original 14th century foundational structure was appended over the centuries with spires and pinnacles, such that we can legitimately say a core structure remains intact while the finished building represents a far richer compendium of historical additions. Gould’s mission is not to raze the Darwinian Gothic structure, or to tear down the neo-Darwinian Baroque facades, but to revise, refine, reinforce, and reconstruct those portions of Darwin’s Duomo that have begun to crumble under the weathering effects of a century and a half of scientific research.

The foundation of Darwin’s Duomo rests upon three theoretical pillars (or, in the visual metaphor that graces the cover of this handsomely-produced volume, a three-pronged fossil coral, whose foundational trunk gives rise to three branches). All three pillars are needed to prevent the theory from toppling over, which it might do, says Gould, unless necessary retrofittings and revisions are implemented. There are three theoretical pillars.

Agency, or the level at which evolutionary change occurs. For Darwin, it is individual organisms alone that are being selected for or against. Gould proposes a multi-tiered theory of evolution where change (and selection) occurs at a number of different levels — genes, cell-lineages, organisms, demes, species, and clades.

Efficacy, or the mechanism of evolutionary change. For Darwin it was natural selection (and its handmaiden sexual selection) alone that drives organisms to evolve. Gould does not deny the power of natural selection, but wishes to emphasize that in the three billion-year history of the earth’s rich panoply of life, there is so much more to the story. On top of the substratum of microevolution Gould adds macroevolution — long-term changes caused by mass extinctions and other large-scale forces of change. To the bottom floor of adaptationism Gould attaches exaptationism — structures subsumed for later uses and whose original adaptive purposes are now lost to history.

Scope, or the range of effects wrought by natural selection. For Darwin, gradual and systematic change extrapolated over geological expanses of time is all that is needed to account for life’s diversity. For Gould, slow and steady sometimes wins the race, but more often than not life is punctuated with catastrophic contingencies that fall in the realm of unique historical narratives rather than predictable natural laws. History, not physics, should be evolutionary theory’s model of science.

Revisions to these three branches (while the main Darwinian trunk retains its theoretical power), says Gould, produces a “distinct theoretical architecture, offering renewed pride in Darwin’s vision and in the power of persistent critiques — a reconstitution and an improvement.” Some of those critiques, however, have been aimed not at Darwin’s Duomo, but at Gould’s Pinnacles. To his credit, Gould unhesitatingly allows his critics to speak, but the price they pay is facing the buzz saw of his rhetorical brilliance (and literary erudition), as in this maximally insulting cut of one critic when he quotes Schiller: “Mit Dummheit kämpfen die Götter selbst vergebens” (“even the gods cannot fight with stupidity”).

One persistent misunderstanding about Gould’s remodeling of Darwin’ Duomo stems from what I call (in my book The Borderlands of Science) the “paradigm paradox.” How can the paradigms of Darwinism, neo-Darwinism, and Gouldian Darwinism co-exist peacefully? Doesn’t one paradigm displace another in a way that makes them incompatable? No. Paradigms can build upon one another and cohabit the same scientific niche. Just as the Newtonian paradigm has been reconstituted to include the paradigms of relativity and quantum mechanics, the overarching Darwinian paradigm has been improved by, for example, the subsidiary punctuated equilibrium paradigm, that constitutes an improved reading of the herky-jerky fossil record whose numerous gaps so embarrassed Darwin. (The gaps, say Gould and his co-theorist Niles Eldredge, represent data of a speciational process that happens so rapidly that few “transitional” fossils are left in the historical record.) Both Darwinian gradualism and Gouldian punctuationism constitute paradigm shifts, with each filling a theoretical ecosystem that allows disperate forms of data to be properly interpreted.

Think of species not as billiard balls being knocked about the table of nature willy nilly, but as polyhedrons, or multi-faceted structures (think of an eight-sided die) that sit on a side until nudged by a potent force, and whose internal properties, Gould writes, “‘push back’ against external selection, thereby rendering evolution as a dialectic of inside and outside.” Without discounting the outside, Gould wants us to look again inward (as so many evolutionary theorists did in Darwin’s own day), where the restricting channels of both nature and history direct the selective forces in particular directions. Copious examples and eye-blurring data from numerous fields flesh out the scientific portions of this book, which critics and students alike will have to address if they want to take Gould seriously, either for or against.

Most of the theoretical themata that Gould presents (theory–data, time’s arrow — time’s cycle, adaptationism–nonadaptationism, punctuationism–gradualism, contingency–necessity) have been played out on the historical stage before, and therefore much of The Structure of Evolutionary Theory resurrects the thoughts and ideas of the great evolutionary theorists of the past two centuries. Gould may have an ego to match the Brobdingnagian proportions of this book, but he generously offers credit to the founding fathers of the field and lovingly brings their ideas back to life. Here we see Gould the humanistic historian, living up to the assessment made by the eminent science historian Ronald Numbers when he remarked to me: “I can’t say much about Gould’s strengths as a scientist, but for a long time I’ve regarded him as the second most influential historian of science (next to Thomas Kuhn).”

So, even if you disagree with Gould’s science, his historiography is stellar, although a modicum of effort will be required of readers as Gould does have a tendency to lard his narrative with 19th-century style paragraph-length sentences (analogous, he likes to say, to the “riffing” of Jazz musicians). But for those who enjoy the music — professionals and public alike — The Structure of Evolutionary Theory will leave a lasting imprint (literally and figuratively) on all who dare to take the challenge.

(Harvard University Press, 2002, ISBN 0674006135)
This review was originally published in Washington Post Book World.

A review of Matt Ridley’s Genome: the Autobiography of a Species in 23 Chapters.

We are at a unique confluence of science and publishing where the results of the former are being dispersed by the latter at such a rate that even the most ardent reader of popular science books can hardly keep up. This is good news for science, of course, since its products are outstripping even Moore’s law of doubling every eighteen months, so updates and revisions are called for just as frequently. Lucky for publishers that readers are willing and able to plunk down a quarter of a hundred bucks to discover the secrets of the cosmos and life, and literary agents specializing in science tomes are demanding — and getting — five- and six-figure advances for their clients. And by most counts publishers are earning out those advances in a matter of months, thereby closing indefinitely the gap between C.P. Snow’s two cultures.

British science writer Matt Ridley is a participant in and beneficiary of this pleasant conjuncture, and he has rewarded his readers admirably with such bio-bestsellers as The Red Queen: Sex and the Evolution of Human Nature and The Origins of Virtue: Human Instincts and the Evolution of Cooperation, the latter, in my opinion, the most readable book to date on evolutionary ethics. In Genome Ridley continues with his expansion into larger themes, as he takes us on a roller coaster ride through the very foundation of life: DNA. The carnival-ride metaphor is apt because in Genome Ridley hits many highs and lows (depending on the complexity of the subject and his knowledge of it), and leaves the reader feeling a little dizzy at the end. The fault, on one level, is not Ridley’s, as he has taken on a subject vastly deeper and more complicated than can possibly be covered in a single volume — any one of the 23 chapters could have been a book in itself. But for readers with little to no knowledge of the subject Ridley provides a highly readable and informative encapsulation of the science that promises to do for the 21st century what nuclear physics did for the 20th. Revolution is in the air and Ridley has his finger on its pulse.

Ridley’s technique is at once clever and delimiting: Each chapter represents a chromosome, for which he has chosen a single entity supposedly determined or influenced by that chromosome. To wit: Chromosome 6: Intelligence; Chromosome 7: Instinct; Chromosome 8: Self-Interest. It is a facile literary device to help readers get their minds around this illimitable subject, but I fear that it gives the wrong impression, disclaimers notwithstanding, that such things as intelligence, instinct, or self-interest are wholly located on that chromosome (and, therefore, genetically programmed and biologically determined). I have the same concerns about books with such titles as The Math Gene or Mean Genes that, again, disclaimers notwithstanding, propagate the myth these same authors claim to be debunking that mathematics or meanness (or whatever) is wholly or even predominantly determined by our genes.

Only half in jest I sometimes wonder if there isn’t a metagene gene — a gene that causes people to think that everything is in our genes. Evolutionary psychologists could have a field day with the metagene gene concept: people tend to view behavior as genetically caused because back in the paleolithic those individuals who were more inclined to view behavior as genetically determined won more copulations and thus passed on their metagene genes through more offspring. Of course, paleolithic cave persons knew nothing about genes, so we must postulate that they tended to view the actions of others as either largely capricious or largely determined. The latter would be high in metagene genes, and they, of course, would be better adapted and more successful because living in a deterministic world better allows one to determine cause and effect relationships, and that is what leads to enhanced survival and the propagation of one’s genes, including one’s metagenes.

Okay, I’m being rather facetious (and wondering if this too is in my genes), and I do think evolutionary psychology has much value to add to the social sciences (indeed, I did some of it myself in my book How We Believe, in an attempt to explain the evolutionary origins of religion). But the glut of metagene books, I fear, is doing more harm than good in the public understanding of how science and nature really work. Fortunately, in most cases Ridley does an admirable job of clarifying the enormous complexities involved in gene-environment interactions, demonstrating in numerous cases that it is next to impossible to say that any complex human trait (such as intelligence or athletic ability) is, say, 60% genetic and 40% environment.

In Chromosome 11: Personality, for example, Ridley describes a gene called D4DR located on the short arm of the 11th chromosome. D4DR codes for dopamine, a neurotransmitter released by neurons that, when received by other neurons receptive to its chemical make-up, sets up dopamine pathways throughout the brain that stimulates the organism to be active (or not, if a shortage exists). A complete lack of dopamine, for example, causes patients (or rats), to slip into a virtual catatonic state. High levels of dopamine turn humans schizophrenic and rats frenetic. Dopamine stimulation, in fact, is the basis of the famous experiment where rats pressed a bar to stimulate their so-called “pleasure center,” which they did until collapsing in exhaustion. Humans have been known to do the same thing, but they don’t need scientists to hook them up.

Here Ridley is summarizing the fascinating work of Dean Hamer who, in his quest to find genes for smoking and homosexuality, discovered the gene (or, more precisely, the gene-complex) for thrill-seeking personality. It turns out that the D4DR gene sequence is repeated on chromosome 11. Most of us have four to seven copies, but some people have two or three, while others have eight, nine, ten, or eleven copies. More copies of D4DR means lower levels of dopamine, which translates into higher novelty seeking behavior to artificially produce more dopamine (jumping off buildings and out of planes will do that for you). Hamer took 124 people who scored high on a survey measuring their desire to seek novelty and thrills (bungee-jumpers and sky-divers knock the roof off these tests), then looked at their DNA — specifically, chromosome 11. He found that people who like to jump off buildings and out of planes had fewer copies of D4DR than those who prefer knitting and watching grass grow. (Presumably those who like to watch sky-divers go splat are higher in the mean gene category.)

When Hamer’s research was picked up in the media headlines declared that scientists had discovered the novelty-seeking gene, implying that perhaps all of our personality traits are so genetically coded. Alas, if only it were that simple — whenever you get that urge to jump off the top of Yosemite’s half dome, just take a dopamine tablet and you’ll prefer to stay on the marked trails. Fortunately for his readers, Ridley is honest enough to report the other side to this story. When you actually read the original research it turns out that Hamer is claiming to explain no more than four percent of novelty seeking behavior by D4DR sequences. That is, if we say that humans vary by 100 percent in their novelty seeking behavior — catatonics on one end and X-Game skateboarders careening down hills at 50 mph two inches off the ground on the other — only four percent of that variance can be accounted for by D4DR. That’s it! That’s nothing, as Ridley concludes:

This is the reality of genes for behaviour. Do you see now how unthreatening it is to talk of genetic influences over behaviour? How ridiculous to get carried away by one “personality gene” among 500? How absurd to think that, even in a future brave new world, somebody might abort a foetus because one of its personality genes is not up to scratch — and take the risk that on the next conception she would produce a foetus in which two or three other genes were a kind she does not desire? Do you see now how futile it would be to practise eugenic selection for certain genetic personalties, even if somebody had the power to do so? You would have to check each of 500 genes one by one, deciding in each case to reject those with the “wrong” gene. At the end you would be left with nobody, not even if you started with a million candidates. We are all of us mutants. The best defence against designer babies is to find more genes and swamp people in too much knowledge.

Well said. But is this the general conclusion about genes that readers will come away with in this book? I hope so, but fear not.

One quibble I had with Genome comes about in the final chapter, Chromosome 22: Free Will. Granted one cannot cover in one book the fine nuances of all positions in every debate in this vast field, but in one area that I do know something about — personality development — Ridley leans far too heavily on the work of psychologist Judith Rich Harris, whose book, The Nurture Assumption, generated much heat (and, thankfully, some light) for its attack on psychology’s long love affair with nurture arguments. Ridley writes: “Rich Harris has systematically demolished the dogma that has lain, unchallenged, beneath twentieth-century social science: the assumption that parents shape the personality and culture of their children.” It turns out, Harris argues, that parents don’t count for much at all in the development of adult personality. What does count? Genetics, of course, and peer groups. Families just don’t matter.

Baloney. The research by U.C. Berkeley behavioral scientist Frank Sulloway, summarized in his book Born to Rebel, shows that both historically and presently, siblings and family dynamics are highly influential in the development of personality, which, in turn, shapes the interactions with siblings and parents, that feeds back into personality, and so forth, round and round, in a chaotic and complex feedback loop. Now, whether you prefer Harris’ peer-group theory or Sulloway’s family-dynamics theory (or like an amalgamation of the two, with some Bowlby attachment theory and Jerome Kagan developmental theory thrown in for good measure), it would be helpful to readers to at least get a paragraph or two about competing models. Harris is not without her critics (and neither is Sulloway, or Bowlby or Kagan for that matter), and for readers to understand the nuances of the complex development of something called “personality,” they really need to be given a few alternative views. Given that I have not mastered the literature for all 23 of Ridley’s chapter subjects, this example leaves me wondering what else he might have left out.

That critique aside, however, Ridley’s numerous caveats throughout the book warning readers not to take the metagene gene argument too seriously, Genome is an important contribution to the popular science literature in helping us find that delicate balance between nature and nurture, even if the tendency to so delineate such an argument may itself genetically influenced!

(HarperCollins, 2001, ISBN 0060894083)
This review was originally published in American Scientist.

A review of Stephen Jay Gould’s Full House: The Spread of Excellence from Plato to Darwin.

For the past 15 summers I have either competed in or directed the 3,000-mile, nonstop, transcontinental bicycle Race Across America; for the first decade the transcontinental record plummeted from 12 days 3 hours to 7 days 23 hours, but for the past five years it hasn’t budged even though half the field now routinely breaks earlier records. Why? Some of the pioneers, not surprisingly, believe that they were simply better; current riders claim weather conditions and other variables. I now know that both sides are wrong, thanks to the work of paleontologist, evolutionary biologist, and trend setter (and observer) Stephen Jay Gould, whose new book, Full House, explains how systems change over time — from the history of life to the history of sports.

Gould claims that things like .400 hitting in baseball are not “things” at all, in the Platonic sense of fixed “essences.” They are artifacts of trends, which disappear when the overall structure of the system changes over time. No one has hit .400 in baseball since Ted Williams did it in 1941 (for every 10 times at bat he got 4 hits), and this unsolved mystery continues stimulating books and brou-ha-has. The mystery is now solved, says Gould. It is not because players were better then (what he calls the Genesis Myth — “There were giants in the earth in those days” — or as Ted Williams said, “the ball isn’t dead, the hitters are, from the neck up”), or because players today have tougher schedules, night games, and cross-country travel (Rod Carew says night games are easier on the eyes and travel by jet beats a train any day). It is because the overall level of play — by everyone from Tony Gwynn and Eddie Murray to Backup Bob and Dugout Doug — has inexorably marched ever upward toward a hypothetical outer wall of human performance. Paradoxically, .400 hitting has disappeared because today’s players are better, not worse. But all of them are better, making the créme de la créme stand out from the mediocre far less than before. The best players may be absolutely better (better training, equipment, diet) than players 50 years ago, but they are relatively worse compared to the average level of play. It was easier for Ted Williams to “hit ’em where they ain’t” 50 years ago than it is for Wade Boggs today, because every position in the field is manned by players whose average level of play is much better than before.

So what? For Gould the disappearance of .400 hitting is just one of many examples of how systems change over time and how our bias of progress and complexity has led us to misunderstand historical change. “All of these mistaken beliefs arise out of the same analytical flaw in our reasoning — our Platonic tendency to reduce a broad spectrum to a single, pinpointed essence. This way of thinking allows us to confirm our most ingrained biases — that humans are the supreme being on this planet; that all things are inherently driven to become more complex; and that almost any subject can be expressed and understood in terms of an average.” In baseball there is a bell curve variation from worst to best players; what has happened in the past century is that while the league average has remained the same, the “spread” (in Gould’s subtitle) has shrunk as the entire system has marched closer toward that outer limit. It is this spread that matters, not the single point on it. As an example of the latter Gould relates his personal battle with abdominal mesothelioma, a rare and usually fatal form of cancer for which he was given eight months to live. That was in 1982. What happened? The “eight months” was a median that did not describe the variation within the entire system (the spread) which, fortunately for Gould, has a long right tail on which he is located.

As in baseball and disease prognosis, evolution can be illustrated by a bell curve of organisms from simple cells to complex mammals of today. But what else could evolution have done, Gould asks? In the spread of life, there is a left wall of simplicity — any simpler and it would not be alive. For life to evolve it could only have gotten more complex — evolution reflects “an increase in total variation by expansion away from a lower limit, or ‘left wall,’ of simplest conceivable form.” Same thing with size: “Size increase is really random evolution away from small size, not directed evolution toward large size.”

Why is this idea revolutionary? Because, Gould says, change is a result of the whole system (the “full house”) expanding, not a progressive march of an average “toward” something. As Gould has expounded in several books and countless essays before, evolution is not “going” anywhere in a teleological sense. It is massively contingent and we are but a minor twig on the richly branching bush of life. “The vaunted progress of life is really random motion away from simple beginnings, not directed impetus toward inherently advantageous complexity.”

Full House finishes with an epilog on culture, applying the model to science and the performing and creative arts. Like the disappearance of .400 hitting Gould wonders why, in a gene pool significantly larger than in the 17th century, and with endlessly greater opportunity, we don’t see the likes of Bach, Handel, Haydn, Mozart, and Beethoven. Gould cautiously suggests that “perhaps the range of accessible styles can become exhausted, given the workings of human neurology and the consequent limits of understanding. Perhaps we can reach a right wall of potential popularity, where our continued adherence to an ethic of innovation effectively debars newcomers, whatever their potential talents, from becoming the Mozart of the new millennium.”

Gould is on to something about baseball, possibly about bacteria, but I’m not so sure about Bach. For baseball consider these numbers: only seven players have hit .400 since 1900, and three of those in one year (1922). Add Williams in 1941 and the list is complete at eight, out of tens of thousands that have played. It’s amazing anyone comes close in today’s game of specialization. But the difference between .400 and George Brett’s .390 in 1980, for example, based on his 175 hits in 449 at bats, is five hits! That computes to only one hit in every 32 games. How many times did Brett face top relievers in late innings, or defensive alignments (based on computer analysis of his hitting style) that Williams and Cobb never faced? Surely at least once every 32 games. William’s feat of 1941 would not be discussed today except for three hits (the difference between .406 and .399 in his 185 hits out of 456 at bats). Would Williams have been deprived of one hit per 54 games by today’s players who routinely dive and leap to steal what used to be sure hits? Definitely.

As for bacteria, Daniel Dennett and Ed Wilson will challenge Gould on his rejection of progress in evolution, but they will need to provide evidence that small lineages free to vary in either direction have a tendency to move to the right (more complex) rather than the left, and why the mechanism of natural selection would work to produce greater complexity rather than just local adaptations.

And Bach? Well, cultural relativists will be offended by Gould’s assumption that there is an outer wall in art and music. Is there? Who knows? How is it measured? There is no .400 equivalent in the arts.

So the transcontinental cycling record, like most running, swimming and baseball records, is now hovering near an absolute outer wall of human performance. Liquid diets, aerodynamic equipment, specialized training, and experienced strategies every year take the best cyclists near this upper wall, and along with them mediocre athletes are now shattering what used to be “unbreakable” marks. The transcontinental record, like .400 hitting, will be broken, but not often and not by much. The house is rather full now, the spread of excellence has narrowed and approaches that outer wall, and the truly great must work extra hard to stand out. But somehow they do.

(Three Rivers Press, 1996, ISBN 0609801406)
This review was originally published in Los Angeles Times.