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Survival of the Nicest?

In Higher Superstition, a book remarkable both for its influence on the intellectual community and for its obtuse ignorance of the actual state of science, the authors told us that

Science is, above all else, a reality-driven enterprise…. Reality is the overseer at one’s shoulder, ready to rap one’s knuckles or to spring the trap into which one has been led…by a too complacent reliance on mere surmise…. Reality is the unrelenting angel with whom scientists have agreed to wrestle.1

Any reader who wants to test this charmingly naive view of science should immerse himself or herself in the literature of evolutionary biology. Indeed, the immersion does not have to be very deep before the currents and countercurrents of ideology can be felt tugging at one’s understanding. Unto Others, a collaboration between Elliott Sober, one of the founders of the modern philosophy of biology, and David Sloan Wilson, one of the most creative theoreticians in evolutionary studies, wades into this turbulent stream at precisely the point where so many other adventurers have been swept away: the problem of the origin of altruistic behavior. Can natural selection have made us genuinely cooperative and unselfish in pursuit of the greater good of the many, or is apparent altruism nothing but an artfully disguised version of every man for himself? Have Professors Sober and Wilson really collaborated in order to spread enlightenment, or are they engaged only in a bit of academic career building, each using the other as a tool of their separate ambitions?

Darwinism, born in ideological struggle, has never escaped from an intimate reciprocal relationship with world views exported from and imported into the science. No one challenges the claim that evolutionary theory has had a wide effect on social theory. It is a cliché of cultural history that the explanation of evolution by natural selection served as an ideological justification for laissez-faire competitive capitalism and the colonial domination of the lesser breeds without the law. Nor are these evidences only of the quaint naiveté of the nineteenth century. Social Darwinism has had a continuous and vigorous life until today. Only three years ago a leading publisher of psychological monographs produced a book by a professor of psychology at a first-rank Canadian university claiming that the evident moral and cognitive superiority of Europeans over Africans was a consequence of natural selection in a cold rather than tropical climate. All the Africans got out of their experience of the survival of the fittest were greater libidos and longer penises.2 The slightest suggestion, however, that evolutionary biology has imported some of its conclusions from social theory and political prejudice will be greeted by incredulity and indignation on the part of scientists convinced of the intellectual autonomy of the study of nature. Even those who insist that they concentrate on the “internal” history of science agree that Darwin’s notion of the struggle for existence, and the consequent differential survival of those types with greater fitness for the struggle, owed a great deal to the economic and social theorists of the late eighteenth and early nineteenth centuries, such as Dugald Stewart and the Scottish economists; and they recognize that so-called “Social Darwinism” was a popular ideology long before the composition of the Origin of Species.

Yet the mere mention in the pages of The New York Review of Books of this now conventional understanding was enough to invoke an irate response from one of the leading physical scientists of our time, Max Perutz, who assured readers that Darwin would have reached his conclusions irrespective of the intellectual atmosphere of the mid-nineteenth century because, after all, those ideas were a revelation of natural reality. Scooping the authors of Higher Superstition by a dozen years, Perutz claimed that any suggestion of the importance of social context was evidence of the corrupting influence of Marxism on intellectual life.3

The pervasiveness of general world views in evolutionary biology, however, goes well beyond the relatively uncontroversial influence of nineteenth-century social attitudes on the historical origins of the science. They have informed at all times, including the present, the way in which evolutionary biologists describe the reality of nature. Hegel’s lament in The Lectures on the Philosophy of History that “instead of writing history we are always striving to find out how we ought to write history” is more applicable to evolutionists than to German historians.4 There is no simple and direct “truth” about how to understand the history of life on earth.

The descriptive facts of evolution are not at issue. Natural scientists agree that roughly three billion years ago life appeared from inanimate materials and that since then the organisms that have inhabited the earth have been connected to one another by a chain of ancestry that can be reconstructed from the fossil record and from molecular, physiological, morphological, and behavioral similarities among living organisms. When there are disagreements about facts they are a consequence of the necessary ambiguities of historical reconstructions from limited observations.

There are brief, bloody struggles over fine details of ancestry, such as, for example, whether human beings have a more recent common ancestry with chimpanzees or with gorillas, or whether one’s favorite fossil primate is in the direct line of human ancestry. There are, as well, disagreements about whether or not the appearance of new species is often the consequence of very short but dramatic periods of splitting and morphological change, separated by long periods of boring stasis (the theory of “punctuated equilibrium”) and whether the disappearance of old species is often the result of literally world-shaking events like a collision with a meteor. Some ideological predispositions may enter in these latter cases, pitting those who are committed to the view that history is a long and gradual incremental movement against those who see revolution as a vital element in historical change.

In the end, however, such disagreements do not create deep and long-lasting divisions among evolutionists. Sometimes, as in the case of the human-chimpanzee-gorilla puzzle, it is agreed that no observations can ever resolve the question, and, anyway, what difference does it really make? Sometimes, as for the arguments about punctuated change and catastrophic extinction, a pluralistic agreement is reached with only local skirmishes persisting about whether this or that particular sequence of fossils fits more closely the gradualist or catastrophist scenario. Individual careers are made by emphasizing one sort of case rather than the other, but evolutionary biology as a whole is not threatened with reformulation.

It is when we move from evolution as narrative to evolution as universal history, from Hegel’s category of Original History to his Reflective History, that the predispositions of ideology come to dominate the science. The practitioners of evolutionary biology, no less than their philosophical and literary hangers-on, seem determined to impose on the history of life a single unifying principle or viewpoint that is said to be what evolution is “really all about.” And not only evolution as a process, but every detail of the life activities of every species that has ever lived, certainly including Homo sapiens. There are three such unifying themes that plague evolutionary biology today, and all three converge in the problem of altruism that is the main subject of Unto Others.

The first claimed universal in evolution is that it is an optimizing process. External nature poses problems for organisms, problems of life maintenance and of reproduction. Different individual organisms “solve” these “problems” differently and those who solve them “best” leave more offspring who also inherit their method of solution through their genes. Organisms propose and nature disposes. As a consequence the best solution becomes more common and finally comes to characterize the species. Thus, natural selection, a process of conjecture and refutation, leads ineluctably to the optimum solution to the problem. The claim of optimization arises in part from an unreflective literal reading of a nineteenth-century slogan, “survival of the fittest,” but also from a widespread misunderstanding of a technical issue. Given a particular environment, each genetic type in a population has some probability of survival and reproduction, what we call the fitness of the type. These fitnesses can be averaged, weighting each by how frequent the genetic type is in the population, to produce a number called the mean fitness of the population. Evolution is a change in the frequencies of the different types from generation to generation, with the result that the mean fitness of the population changes from generation to generation. It turns out that if natural selection is the only force operating on the population, the frequencies change in such a way that the mean fitness of the population only increases and never decreases.

The standard metaphor is therefore evolution as a mountain climber. Mean fitness is like the altitude in a mountain range, and natural selection is like an inner compulsion of a climber to climb yet higher and higher. Hence evolution by natural selection is seen as a maximizing or optimizing process driving species to greater and greater fitness. But that conclusion is a misunderstanding of the metaphor. A mountain range, including the Fitness Mountains, contains many peaks of different heights, and a climber who wishes to ascend the highest peak must be able to see into the distance and choose an appropriate path to Everest. Unfortunately, the mechanism of natural selection does not allow such global behavior and forces the population upward along the particular local slope on which it finds itself. In this case the mountain climber cannot see beyond the end of his alpenstock and has no way of “knowing” that higher peaks exist elsewhere, that there are even better possible solutions than the present one.

The false view of natural selection as a process of global optimizing has been applied literally by engineers who, taken in by a mistaken metaphor, have attempted to find globally optimal solutions to design problems by writing computer programs that model evolution by natural selection. In fact, none of these schemes of “genetic algorithms” has yet succeeded in solving a design problem that was not already solved by more conventional methods. The most talked-about example is the famous “Traveling Salesman’s Problem,” which has implications for any design question that involves connecting a large number of points by straight pathways. This problem calls for a generalized Willy Loman to visit a large number of cities that are spread out over the map in an irregular way, taking the shortest (or cheapest) possible total path, without visiting any city twice. Vast amounts of computing are required to get even an approximate solution, and genetic algorithms are worse than other techniques.

Believers in evolution as an optimizing process assert more than that natural selection is a rule for finding the best. They claim, too, that all properties of all species are a consequence of direct natural selection for those characteristics. None is accidental, none is a failure of optimum adaptation, none is the epiphenomenal consequence of other, perhaps optimal, features, none is the ineluctable outcome of being flesh. The mountain climber never tumbles down a crevasse, dizzy from a deficiency of oxygen or an excess of brandy. It has been seriously proposed by a respectable evolutionary ecologist, for example, that the holes that rot in the trunks of older trees are really a favorable adaptation because small animals are attracted to live in them and these animals help to spread the seed of the tree. A more extreme form of this hypothesis is that even the fact of death is a consequence of natural selection, designed to prevent those of us who are reproductively worn out from eating the bread of our still-fertile offspring.

  1. 1

    Paul R. Gross and Norman Levitt, Higher Superstition: The Academic Left and its Quarrels with Science (Johns Hopkins University Press, 1994), p. 234.

  2. 2

    Anyone who thinks this a caricature of a serious position should consult J. Philippe Rushton, Race, Evolution and Behavior: A Life History Perspective (Transaction, 1995).

  3. 3

    See M.F. Perutz, “High on Science,” The New York Review, August 16, 1990, and the exchange of letters between Perutz and me, The New York Review, December 6, 1990.

  4. 4

    Statt Geschichte zu schreiben, bestreben wir uns immer zu suchen, wie Geschichte geschrieben werden müsse.”

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