Two distinguished Harvard biologists, Agassiz professor of zoology emeritus Ernst Mayr and Pellegrino University Professor emeritus Edward O. Wilson, have turned their attention in recent years to very different projects. Mayr, an acknowledged grand master among evolutionary biologists, has, in his early nineties, written a synoptic overview of the science of biology. Wilson has attempted to resurrect (and sketch in) the Enlightenment hypothesis that all knowledge is--and may be demonstrated to be--unified.
The intended audience for Mayr's This Is Biology comprises, on the one hand, those with a professional interest in the life sciences, including practicing biologists (who, Mayr says, tend to focus narrowly and so lose track of collegial disciplines and the larger picture) and, on the other, the educated laity, who ought to have--and do not--"an understanding of basic biological concepts." (Lay persons are advised to affix a permanent bookmark at the glossary, lest they be defeated by the steady stream of jargon--"pleiotropic," "apomorphy," "paraphyletic," "dichopatric," "eukaryota"--whose use is inevitable in a book as compact as this one.)
Mayr defends his field against those who have denigrated it--there is no Nobel Prize for biology--as an insufficiently "hard" science (the life sciences simply don't work like the classical physical sciences), and, correlatively, he defends "organism" biology--those disciplines dealing with whole organisms and higher levels of integration--against claims of superiority for those disciplines that deal with, for example, tissues and cells. But the main task of the book is two-fold. Having broken biology down into key component fields--systematics, cell biology, developmental biology, evolution, genetics, ecology, and so on--Mayr treats them in terms of their history and their present status.
The early history of reproductive biology is briefly told indeed. Aristotle established the field with his writings on animal embryology, works which were "based on such wide comparative observation and governed by such excellent judgment" that no further progress was made until the nineteenth century! Other histories, by contrast, have been tangled, contentious. The struggle for an evolutionary synthesis after Darwin, for example, carried on for more than three-quarters of a century. One school--the early geneticists--"were incapable of population thinking," while the other--comprised of naturalists and biometricians--misunderstood inheritance; and each school misunderstood the other. Finally, in 1937, Theodosius Dobzhansky's Genetics and the Origin of Species built a bridge that led to synthesis, a bridge whose construction had been delayed, as so often in science, not through want of facts or discoveries, but of enabling concept.
Mayr is also interested in the present business of these disciplines. Which of them ask "what" questions, "how" questions, "why" questions? How is it that life, which at the molecular and cellular levels can largely be explained physicochemically, must be approached at higher levels of integration through "population thinking, probability, chance, pluralism, emergence, and historical narratives"? Yes, historical narratives. Whenever a biologist attempts to answer a question about the demise of the dinosaurs or the lack of hummingbirds in the Old World, he must "study all the known facts relating to the particular problem, infer all sorts of consequences from the reconstructed constellations of factors, and then attempt to construct a scenario that would explain the observed facts of this particular case. In other words, he constructs a historical narrative." Which is why, Mayr tells us, there is "more difference between physics and evolutionary biology...than between evolutionary biology...and history."
The book's last chapter--"Can Evolution Account for Ethics?"--will undoubtedly stimulate the most debate. The central business of a moral code, it can be argued, is to counteract the individual's selfishness, a trait universal because rigorously selected for through evolution. But if egoism always serves the individual as individual, Mayr points out, altruism may serve at higher levels of integration, and so may be selected for at the family or group level. Moral codes benefit the group, often at the expense of the individual, and successful codes must themselves evolve as circumstances change. The Judeo-Christian code is no longer adequate, Mayr contends, for the simple reason that it developed to suit a Near Eastern pastoral culture dating from 3,000 years ago, one quite unlike our own.
But are moral values inborn or acquired? Is nature responsible, or nurture? Mayr argues that human beings inherit a capacity for moral behavior, but that codes and values themselves are largely learned. And, crucially, he believes, following C.H. Waddington, that these norms are acquired very early, in a process "akin to the imprinting of animals." This suggests both a critique of our own culture and an educational remedy. "We have just passed through a period in which exaggerated importance was placed on the so-called freedom of the child, allowing it to develop its own goodness." But, as the evolutionary biologist would have predicted, the child has instead indulged its own self-interest, and we are becoming, as a result, an undisciplined and narcissistic people.
Mayr has looked at school books, at children's fiction, and at television programming, and hasn't encountered much in the way of moral instruction. "Why? Because, one may be told, brainwashing a child is an interference with its personal freedom, or moralizing is not entertaining and therefore will not sell." But this, he believes, is a grave mistake. The low crime rates among Mormons and Seventh Day Adventists document the success of moral education, and Mayr suggests "half an hour of ethical education a day in elementary school." Mayr anticipates that some readers "will smile at such seemingly old-fashioned advice." My own guess is that, given the polarized (and politicized) state of the moral education debate, any smiles that may be forthcoming will go unnoticed in the ensuing cacophonous hubbub comprised of equal parts cheering and vilification.
Ernst mMyr declares that the last half of the twentieth century has belonged to biology. If Edward O. Wilson is right, biology will be even more central in the twenty-first, when, he hopes, it will facilitate--and anchor--consilience. Consilience, he writes, means "a 'jumping together' of knowledge by the linking of facts and fact-based theory across disciplines to create a common groundwork of explanation." Consilience is nothing less than the age-old dream of the unity of knowledge, an attempt to demonstrate the validity of Bacon's declaration that the "divisions of knowledge are like the branches of a tree that meet in one stem." The Enlightenment (and Condorcet in particular) "got it mostly right the first time....Nothing fundamental separates the course of human history from the course of physical history, whether in the stars or in organic diversity."
Wilson has no patience for those who disparage the dead white males of Western science. They understood that the external world has an independent reality, and showed us that it operates by discoverable laws. (Only science could discover, for example, "invisible" light. No "exercise from myth, revelation, art, trance, or any other conceivable means....can summon the electromagnetic spectrum.") While Wilson shows a bemused tolerance for contemporaries who deny a knowable external reality--postmodernist philosophers, deconstructionist literary critics, and others who sail under the "black flag of anarchy"--their cause must ultimately fail, because "order, not chaos, lies beyond the horizon." While reductionist science has a relatively easy time breaking systems down, and then showing how the components act according to the laws of physics and chemistry, it will be tougher--but not impossible--to synthesize, to put systems back together in order to discover what laws are operative at the levels of mind, behavior, and ecosystems.
Consilience implies synthesis, and biology is perfectly placed to organize the effort because the discipline's transforming concept, evolution, has shown that life is at once law-abiding and changing in time; is answerable, that is, both to physics and chemistry on the one hand, and history on the other. Wilson's hope is that biology can build a bridge from the sciences to the social sciences and the humanities, whose several disciplines are not only fragmented and internally contentious but ungrounded, treating man and his culture as if the status of Homo sapiens as evolving primate were irrelevant.
But economists, political scientists, sociologists, and psychologists ignore biology at their peril. Take the example of incest avoidance. Finnish anthropologist E.A. Westermarck reported a century ago that children raised together from an early age show an in-born reluctance to mate at maturity. Freud declared that this was nonsense. His own theory depended on an intuited primal intra-familial lust--brothers for sisters, sons for mothers. Culture develops taboos, he said, to countermand this innate lust. Freud carried the day, but was he right? When biologists studied social primates in the wild, they found that the young of one sex (or both) leave the group before reaching sexual maturity, and that remaining individuals avoid sexual contact with near relatives. Non-human primates, that is, have evolved instinctive mechanisms to avoid incest. And when A.P. Wolf studied "minor marriages" in Taiwan--unrelated infant girls, adopted and raised as sisters to biological sons, are later married to them--he found that such couples resisted marriage (consummation sometimes had to be forced), and that divorce, childlessness, and infidelity were much more common than in conventional marriages.
Evidence from both biology and anthropology, then, suggests that Westermarck was right and Freud was wrong. Is incest avoidance, then, instinctive in humans? And if so, why do cultures bother to invent taboos? This is the sort of problem tackled by sociobiology, which investigates the biological bases of human behavior. Wilson was a pioneer in the field, of course, and he believes that the "hard instincts of animals" have been translated "into epigenetic rules of human behavior." Epigenetic rules are the "regularities of sensory perception and mental development that animate and channel the acquisition of culture," heritable biases that limit behavioral options. (In the arts, archetypes may well be correlates of these rules.) Epigenetic rules (the "genetic leash") mediate between genes and culture, both of which evolve and which co-evolve, since culture is part of the environment selecting among genes. Both naturists and nurturists are right: culture is grounded in biology, but the genetic leash allows it considerable free play.
It is no surprise that, on the matter of moral codes, Wilson is an empiricist rather than a transcendentalist. Such precepts don't derive from revealed codes; they are products of the human mind, arising "by evolution through the interplay of biology and culture," another product of epigenetic rules. The reason biology or history or any other discipline--much more so consilience--is difficult is that natural selection has built the human brain not to understand the world (or itself) but to survive in it, a fact with unhappy implications for ethics. Where a philosopher or an ethicist may see merely wicked behavior, an evolutionary biologist sees behavior selected for early survival value. It made good sense for our tribal ancestors to distrust strangers, but we decry xenophobia. Nor do we consider the dominance/subordinance structure typical of social vertebrates when we lament the ease with which people are "seduced by confident, charismatic leaders, especially males." As genetic engineering allows us to become the first species to direct its own evolution, what characteristics and behaviors will we select for and against, and to what end?
Readers of this audacious book will, in the end, be left to ponder this question: Is consilience a grand intellectual breakthrough or a pipe dream? Wilson admits that the claim is staked far ahead of present proofs, but he believes that evidence is at hand, and that more will follow. Will the other disciplines, in any case, and especially the social sciences, allow themselves to be guided by biology? Wilson realizes that the "unification agenda" won't sit well with everyone, that both turf defense (a time-honored primate behavior) and ideology will mitigate against acceptance. Skeptics will undoubtedly raise the specter of George Eliot's Casaubon, but Wilson, who admires Icarus, has accepted the risks of bold theorizing before. He returns again and again to a nautical metaphor. While most scientists are "journeymen prospectors" who "hug the coast," the best will sometimes "steer for blue water, abandoning sight of land" for a time. E.O. Wilson is now clearly out of sight of land; and while his critics will claim that he is lost at sea, neo-Enlightenmentarians will carry on with the expectation that enough of his fleet will eventually make port to carry the day.