Greg Radick, 2003. “Cultures of Evolutionary Biology.” Essay review of Michael Ruse’s Mystery of Mysteries: Is Evolution a Social Construction? Studies in History and Philosophy of Biological and Biomedical Sciences 34: 187-200.

(Published version: https://doi.org/10.1016/S1369-8486(02)00075-4)

In 1981, Michael Ruse testified in court on behalf of evolutionary biology. He spoke as an expert witness, not as a biologist but a philosopher. At stake was the right of Darwinian theory to monopolize the biology textbooks and classrooms of Arkansas schoolchildren. As Ruse recalls in Mystery of mysteries, he argued that, unlike evolutionary biology, the would-be rival science, creation science, ‘fails every criterion of demarcation between science and pseudo-science’ (p. 135). With help from Stephen Jay Gould and others, the evolutionists carried the day. Two decades later, Ruse is still defending Darwinism (to quote the title of one of his many books). Now, it is not creationists but social constructionists who need fending off. Once again, Ruse rides forth; and once again, victory is declared. Apart from a couple of caveats, he answers the question in his subtitle, ‘Is evolution a social construction?’, with a resounding ‘no’.

His title comes from a letter to the geologist Charles Lyell from the astronomer and theorist of scientific method John F. W. Herschel in 1836. The ‘mystery of mysteries’, wrote Herschel, was ‘the replacement of extinct species by others’. Just over a year later, Charles Darwin began secret, sustained reflection on species replacement and extinction. Herschel and Lyell were admired mentors for Darwin—he had studied their writings closely, had met Herschel in South Africa on the return leg of the Beagle voyage, and now socialized regularly with Lyell. Unsurprisingly, Darwin acquired his sense of where the scientific action was from these men. Equally unsurprisingly, his thinking soon took a dissident turn. He came to believe that some version of the old, derided transmutation theory, associated with his grandfather Erasmus and the French naturalist Lamarck, was right: each new species was the modified descendant of a pre-existing species. The transmutation theory Darwin eventually settled on, the theory of natural selection, indeed explained the extinction as well as the replacement of species, and with appeal only to variation, inheritance and the struggle for existence—causes that, in line with Herschel and Lyell’s teachings, could not be dismissed as merely hypothetical.

In the story-book history of evolutionary biology, the Darwin chapter closes thus, with the mystery of mysteries solved and the dawning of a new science as great as physics or chemistry. The Darwin chapter in Mystery of mysteries is more circumspect. Evolutionary biology in Darwin’s day was heading for greatness, Ruse argues, but it still had a way to go. His tale of evolutionary theorizing from Erasmus Darwin to the present is a tale of ‘cultural values’, specific to certain times and places, gradually giving way to transcultural ‘epistemic values’. In 1859, when Darwin published On the origin of species, cultural values still loomed large. But by the late twentieth century, when professional evolutionary biologists were publishing narrowly focussed and heavily mathematized work in peer-reviewed journals, the epistemic ruled. This argument, I will suggest, has several failings. It is not as triumphalist as Ruse sometimes makes it sound, however. He insists that professional evolutionary biology is neither free from cultural influences nor should aspire to be. On the contrary, the surrounding culture is the source of the metaphors that inspire fruitful new theories and the ideals—what he calls ‘metavalues’—that foster ‘emergence from culture into epistemic purity’ (p. 47). Nor is it that the new professionals have ceased to share the values of their cultures. Ruse is assiduous in showing otherwise. Nevertheless, he argues, the theories of present-day evolutionary biology front for those values far less than they did in the past.

After some introductory material, Ruse presents chapter-length studies of ten individuals, paired to illustrate the epistemic progress of evolutionary biology. The first eight are famous: Erasmus Darwin and Charles Darwin; Julian Huxley and Theodosius Dobzhansky; Stephen Jay Gould and Richard Dawkins; and Richard Lewontin and Edward O. Wilson. The final two, Geoffrey Parker and Jack Sepkoski, have major professional reputations but minor public ones. Each chapter takes more or less the same form. After a colourful, wake-the-students opener—‘Erasmus Darwin liked to eat’ (p. 37), ‘In 1962 William Hamilton was very lonely’ (p. 122), ‘Spending your days out in the cow field, waiting for the brutes to defecate, is not most people’s idea of a perfect camping holiday’ (p. 194), and so on—we get summaries of the life and work, often accompanied by textbook-style boxes on the scientific principles (there is also a glossary of technical terms). At this point, Ruse scrutinizes the work for epistemic virtue and cultural vice. To assay the former, he has a checklist of epistemic values taken from the philosopher of science Ernan McMullin: predictive accuracy, internal coherence, external consistency, unifying power, fertility and simplicity.¹ The cultural values change as the surrounding cultures change; but one constant, on Ruse’s analysis, is a belief in progress. The chapters round out with further ruminations, often on how the work was regarded in its own time among the scientifically serious.

The Darwins provide Ruse with his most dramatic contrast. In the evolutionist writings of the late eighteenth century, the cultural-epistemic mix was, he finds, weighted heavily toward the cultural. A little unificatory power notwithstanding, Erasmus’ loosely argued prose and flowery verse score poorly indeed on the McMullin criteria. Contemporaries too looked askance at his evolutionism. What drove him, Ruse suggests, was enthusiasm for social and material progress, abetted by the Deist’s faith that God worked not through miraculous interventions but natural, law-governed causes. These cultural values in favour of divinely-legislated progress blended in grandson Charles’ evolutionist thinking with the additional influence of Anglican design theology. Nonetheless, for Ruse, the Origin and other writings are in an altogether higher epistemic class. In line with scientific critics of the day, Ruse finds fault mainly in the matter of external consistency. The theory of pangenesis, for example, published in 1868, held that cells from around the body contributed material to the sexual elements, contradicting the already widely accepted view, due to the ‘new’ cell theory of Virchow, that these elements were cells and that a cell could arise only from the division of a single pre-existing cell. Still, on Ruse’s account, epistemic values were beginning to crowd out cultural ones.

If the late nineteenth and early twentieth centuries saw little further epistemic advance, that was because the theory of evolution, writes Ruse, ‘had become a kind of metaphysical background that conveyed a cultural message—primarily the message of progress but also the rightful role of the sexes and the significance of various political doctrines—and there was little inclination to disturb the status of this very convenient vehicle’ (p. 83). With the emergence of a mathematized population genetics in the early 1930s, however, the stage was set for professionalization. Ruse’s pairing of Huxley with Dobzhansky repeats the earlier pattern of failure–success. There are three main lessons. First, high status in science goes to those who provide the next generation with new questions and new ways of answering them. Where Huxley’s Evolution: The modern synthesis (1942) helped students mainly in preparing for exams, Dobzhansky’s Genetics and the origin of species (1937) presented interesting and soluble new problems—most famously, about the extent and maintenance of genetic variation in natural populations. Second, metaphors have been at least as important as mathematics in priming epistemic uplift. Mathematics features little in either of the books just mentioned; but, in the form of Sewall Wright’s notion of the adaptive landscape, the American tradition made available to Dobzhansky a heuristically rich metaphor that was unparalleled, Ruse argues, in the British, Fisherian tradition. Third, when a science professionalizes, its most successful practitioners give vent to wider cultural sympathies only in popular writings. Although Huxley and Dobzhansky were both openly supportive of Teilhard de Chardin’s mystical Christian gloss on evolutionary progress, Dobzhansky took care, as Huxley did not, to tone it down for the professional audience.

For Ruse, Dawkins and Gould are the Huxleys of the present era, doomed to the second-rate status of the synthesist popularizer, while Lewontin and Wilson, along with Hamilton (discussed in passing) are its paradigm-begetting Dobzhanskys. The chapters on Dawkins and Gould are surprisingly weak biographically. No reference is made, for example, to Dawkins’ training under the Dutch ethologist Niko Tinbergen at Oxford, though Tinbergen’s undergraduate lectures were the source of the notorious Selfish gene (1976) image of bodies as ‘survival machines’.² Gould too at one point passed through Oxford, where he met the political philosopher and historian of ideas Isaiah Berlin, famed for his emphasis on the necessity of pluralism. It is interesting to speculate whether Gould’s attachment to pluralism in evolutionary theory derived at least in part from Berlin.³ Ruse does not raise the issue, and, sadly, it is now too late to ask Gould himself. Despite these gaps in coverage, Ruse’s conclusions about professional standing—in Gould’s case backed up by citation data and, more recently, by the tepid reception given his final, major work, The structure of evolutionary theory (2002)—do seem about right.

With the achievements of Gould’s Harvard colleagues Lewontin and Wilson, the epistemic are of evolutionary biology rose still higher, Ruse argues. That will sound implausible to anyone who knows these two mainly as combatants slugging it out on opposite sides of the sociobiology debate of the 1970s. In these excellent chapters, however, Ruse reminds us that Lewontin, Dobzhansky’s prize student, helped initiate the molecular study of genetic diversity through the introduction of the now-standard laboratory technique of gel electrophoresis; while Wilson, in collaboration with Robert MacArthur, developed a quantitative theory of island biogeography now credited with revolutionizing that branch of ecology.⁴ For Ruse, Lewontin embodies speculative restraint, Wilson speculative boldness. With others busily extending their exemplary work of the 1960s, they have indulged wider intellectual appetites with impunity. A few glaring exceptions aside, they have kept their professional and popular writings distinct. As Ruse says of the avowedly left-leaning Lewontin, for ‘all the talk about the evils of reductionism and the virtues of holism, when it comes to his actual science, no one is more reductionistic’ (p. 169).

After the climax, the denouement. The final pair, Parker and the late Sepkoski, are ‘professionals par excellence’ (p. vii), cleverly extending admired models before an audience of equally cloistered peers. Here Ruse gives us not just quotations from the published work but also snippets from interviews. The English Parker studies dung fly reproductive strategies (hence those scatological vacations), taking a Hamiltonian, game-theoretic approach that is indeed representative of much evolutionary biology now. The American Sepkoski was ‘a new breed of paleontologist’, who had probably never ‘dug up a real fossil’ (p. 214). His career was built around the use of computer programmes that searched for statistical patterns among the fossil data of others. His sort of science calls attention to the rise of the computer as a tool in evolutionary biology. But it also recalls a moment when an ambitious group of palaeontologists—Sepkoski’s teacher and Wilson’s soon-to-be sparring partner Gould among them—looked to the new island biogeography for inspiration. Following MacArthur and Wilson’s example, they sought to treat the past as a gradually colonized island, and in so doing to upgrade what they saw as their own stubbornly descriptive science. Taken together, the chapters on Parker and Sepkoski are meant to show that, in Kuhnian terms, evolutionary biology has now entered a normal-science phase. This generation does not so much create paradigms and institutions as inhabit the ones they have found. The work is highly technical, and they like it that way. Predictive excellence is all.

For a book on how cultural values have shaped, or ceased to shape, evolutionary theorizing, there is little here by way of cross-cultural perspective. With the minor exceptions of the Russian ‘mutual aid’ theorist Petr Kropotkin, discussed briefly in the concluding chapter, and the anonymous German morphologists mentioned as having influenced Gould, the cast of thinkers on evolution is Anglo-American, and mostly American (although Russian-born, Dobzhansky, like Ernst Mayr, made his career almost entirely in the United States). Nevertheless, Ruse does manage to convey a sense of the big historical picture. His subjects are well chosen, and his sketches, at their best, full of information and insight. Moreover, the parts add up to a larger whole. Subthemes are introduced and developed. One of the most provocative concerns the Victorian evolutionary philosopher Herbert Spencer, commonly thought to have had no lasting influence on biology. Ruse has little difficulty showing, on the contrary, how Spencer’s preoccupation with dynamic equilibria in evolution passed, via the Harvard chemist L. J. Henderson, to Wright, and thence to the Dobzhansky-led Modern Synthesis.⁵ Ruse gets a little carried away, arguing for Spencerian influence wherever the word ‘equilibrium’ is used thereafter, as though it had no independent routes into evolutionary biology—via Fisher’s interest in thermodynamics, for instance. But the basic revisionist point stands.

So, has Ruse seen off those arguing for evolution as a social construction? Who are these social constructionists about evolution, anyway? Ruse affiliates them loosely with Kuhn’s philosophy of science; but he does not name names, and his bibliography contains not one item announcing itself as for ‘evolution as a social construction’. In The social construction of what?, a more general historical-philosophical book about the sciences, also published in 1999, Ian Hacking had to reach back to the 1970s and 80s to find self-identified exemplars of constructionist historical writing.⁶ It would be natural enough to suppose that, whatever it was, social constructionism has long been abandoned and, in the case of historians concerned with evolution, was never even adopted. But that would mistake a fashion in labelling for the historical interpretation once so labelled. The ‘constructing attitude’, as Hacking calls it, has become a defining feature of the collective scholarly imagination about the sciences. The up-to-date historian asks how local, contingent social and material circumstances conditioned what was found out, how it was found out, who decided what had been found, and how the authorized findings came to be held as public knowledge. Far from idling at the sidelines, historians of evolutionism have been key players.

Early efforts emphasized class at least as much as other sources of contingency. There is a tradition of Marxian critique, descending from Marx himself and most incisively framed by Engels, that sees Darwinian theory as a projection from the competitive capitalism of Victorian society onto nature, the better to ‘naturalize’ the market and its inequities. In the late 1960s, Robert Young, then at Cambridge, revitalized and extended this tradition with important writings on Darwin’s Malthusianism and related topics. Not, of course, that previous historians had denied a role to the wider setting of evolutionary theorizing. ‘It is ironic and intriguing’, wrote Loren Eiseley in his sublimely Whiggish Darwin’s century (1958), ‘that the fixed hierarchical order in biology began to pass almost contemporaneously with the disappearance of the feudal social scale in the storms of the French Revolution’.⁷ For Young and those he influenced, the match between changing social context and changing theoretical content was certainly intriguing but, in the era of sociobiology and resurgent political conservatism, not in the slightest ironic. On the strength of a far finer-grained analysis of Victorian science and society than Young ever ventured, Adrian Desmond and James Moore in particular have continued to argue that Darwinian theory was a ruling idea of an emerging ruling class.⁸

Broadly speaking, what is socially constructed in this historiography are theories of evolution. Different theories of species origins are aligned with different social interests: the theory of special creation with the interests of aristocratic Tories (preferring to keep society static); the theory of evolution by natural selection with the interests of bourgeois Whigs (preferring slow, gradual, lawful, competition-driven reform); and Lamarckian theories with hardscrabble radical democrats (preferring rapid change directed from below). The Whigs won out socially, and, the argument goes, the theory expressing and serving their interests won out scientifically. Had the social negotiations worked out differently, and the aristocrats or the radicals come out on top, then, it seems, creationism or Lamarckism would now be the stuff of textbook biology, not the Whig theory of natural selection. To the social winner went the theoretical spoils.

The element of contingency here is more qualified than might appear. What is treated as contingent is primarily the success of a social group, not the success of a theory. There is nothing contingent about the relationship between a social group and its favoured view of species origins. If the Whigs succeeded socially, then something like the theory of natural selection was bound to succeed as well. That theory was ‘isomorphic’ with a social order favourable to bourgeois power, and such a theory was needed to naturalize, and thereby legitimate, that order.⁹ The anti-Marxian historians of science in an earlier generation flinched from such determinism. Quoting Alexandre Koyré, Ernst Mayr complained of attempts to ‘deduce’ the character of a science from its social matrix.¹⁰ In the tradition culminating in Desmond and Moore’s writings, given bourgeois success, the theory of natural selection is indeed treated as necessary, inevitable.

Mystery of mysteries engages this tradition. Ruse asks about evolutionary theories as responses to what use to be called ‘external’ imperatives—external, that is, to the search for the timeless truth about nature. But his narrative of professionalization goes nowhere near to answering the central Marxian charge. Consider Ruse’s handling of the appeals Darwin made to the concept of a division of labour. As Ruse acknowledges, the concept took shape in the free-market political economy of Adam Smith:

Before, during, and after the Origin, the sociocultural idea of a division of labor was transferred right into the evolutionary thought of Charles Darwin. Yet in all of the uses, in some way it is not just the nonepistemic idea which is being endorsed and promoted. Darwin does not just break off discussion to talk in isolation of the virtues of the division of labor. Nor does he praise the division at the expense of the epistemic power of his theorizing. In fact it is not because it is a valued concept that it is important. Rather, Darwin is using the cultural concept (irrespective of his feelings of its worth) to further his epistemic ends. He can, for instance, predict what will happen when a group is faced by different open ecological niches … (pp. 243–4)

In other words, Darwin intended his talk of ‘division of labour’ to advance the explanatory and predictive power of his theory of natural selection, not bourgeois interests. Therefore, in making use of that concept, however cultural its origins, Darwin was answering the call of epistemic values, not cultural values. But this misses the point. In the Marxian tradition, it does not matter what Darwin or anyone else intended, consciously, in developing their theories. What matters is whether, unconsciously, they worked to satisfy the needs of the ruling order for theories that could legitimate it—by, say, making an ever increasing division of labour appear natural, good, inevitable, and so not worth fighting, no matter how alienated and dehumanized the workers became in the process. Nothing in Ruse’s narrative undermines this argument. On the contrary, the institutional success he charts might be regarded as precisely demonstrating the ideological usefulness of evolutionary biology. That is not my view, and I have tried to show elsewhere why, at least in Darwin’s case, the Marxian analysis should be resisted.¹¹ But it has a moral and intellectual seriousness that Ruse does not reckon with, let alone overmatch.

At the outset, Ruse promises that despite his pitting epistemic and cultural values against each other, there will nevertheless emerge a sense in which ‘the epistemic is itself cultural’ (p. 34). It is important to see both what he does and does not mean here. Emphatically he does not mean what the phrase ‘the epistemic is itself cultural’ most naturally suggests: that epistemic values differ from culture to culture. No, for Ruse, the values that McMullin identified are universal, upheld to varying degrees wherever something like what we call science can be found. There is ‘something transcultural about them. They are above the vagaries of societal change or whim or fashion. In this sense, they are pointing toward truths about the real world: objectivity’ (p. 236). Thus we feel a certain kinship with Erasmus Darwin’s classier scientific contemporaries, who revered Lavoisier but rejected Mesmer.

What Ruse has in mind are metavalues and metaphors. The Deism of the Darwins, for example, was a cultural inheritance that, in Ruse’s view, reinforced the desire to discover natural laws. In the Darwins’ case, the Deist conception of God ‘is functioning as a metavalue’ (p. 71)—that is, as a special sort of cultural value, promoting greater adherence to the universal epistemic values. The general point is familiar enough, if still controversial. Sociologists from Max Weber to Robert Merton and beyond have argued that the natural sciences thrive more against certain religious backgrounds than others. Lewontin provides Ruse with another, non-Christian example. Growing up during the Second World War as a Jew in the United States, Lewontin learned how biological science in Europe had been twisted to serve murderous, racist politics. According to Ruse, both the topics and rigour of Lewontin’s subsequent research—think of his well known conclusion that there is more genetic variation within the human ‘races’ than between them—should be understood as stemming from a desire to expose biological determinism as false. Lewontin’s Jewishness, writes Ruse, ‘inclines him into an interest in certain kinds of problems and avoidance of others’, manifesting itself ‘not by making “friendly-toward-Jewishness” an operative value but by making the satisfaction of epistemic values more stringent’ (p. 168).

Metavalues are at once epistemic and cultural. So are metaphors. Again, it is almost a commonplace that metaphors, models and analogies figure prominently in scientific reasoning. Ruse insists on their cognitive necessity, but also on their cultural rootedness. His exploration of the role of metaphor in Wilson’s work prompts the most remarkable concession to social constructionism in the book:

Without the metaphors of his society, his science would not exist. Which all seems to imply that at a different time and in a different place, Wilsonian science would have been different. Not necessarily better, but different. And different in ways that reflect cultural differences. Such a conclusion is not quite as bad as saying that Wilson’s science is simply a figment of his imagination—an exercise in wish fulfillment or an extended polemic about the way he would like things to be. But not a great deal better. It still says that science is a reflection of society rather than the real world. It is in this sense deeply subjective. Science is indeed a social construction, and the fact that we may like the end product does not make it less relative. (p. 240)

Those are the caveats to the negative answer Ruse gives to his subtitle question. Otherwise, for Ruse, the epistemic is not at all cultural. From the Enlightenment onward, the marks of objectivity have been the same. To which one can only reply, yes and no. Viewed at low resolution, the sorts of theories celebrated then do have a family resemblance to the sorts celebrated now. But closer inspection can reveal important shifts. Consider the differences between two of Ruse’s subjects, Charles Darwin and Stephen Jay Gould, on whether natural selection is responsible for evolutionary progress. Darwin wrote that selection is indeed progressive. Gould argued that it is not, accounting for this divergence from Darwin by arguing that his predecessor, as a Victorian bourgeois, was beholden to progress as a cultural value and so, at least in public, could not help but present selection as underpinning progress, though the private man knew better.The argument is based on anachronism. Unlike Darwin, Gould lived and worked in an epistemic culture saturated with statistics. Statistical reasoning was fundamental not only to his profession of evolutionary palaeontology—recall the collaboration with Sepkoski—but to his most general epistemic culture. In his main book on evolutionary progress, Life’s grandeur (1996), the discussion of selection and progress pivots on an analogy with that most ‘stats’-obsessed sport, baseball (a Gould passion). Another book, The mismeasure of man (1981), invokes canons of sound statistical reasoning to criticise fallacies in another American pastime, racialist IQ studies. Gould had no doubt that to discover whether natural selection is responsible for evolutionary progress, we should find out whether, more often than not, descendent species have been more complex than ancestral species. But Darwin’s habits of reasoning were formed in a different matrix altogether. He did tot up numbers here and there, making inferences based on trends. On selection and progress, however, his reasoning was more akin to the older celestial mechanics and emerging laboratory sciences than the still-unborn statistical sciences. For Darwin, what mattered was not whether selection was responsible for progress more often than not, but whether progress followed when other causes did not interfere with selection. On this question, Darwin and Gould had culturally specific epistemic values. Those values led in contrary but no less objective directions.¹²

The theme of progress, then, far from illustrating what has remained constant in evolutionary biology, reveals how much has changed, and in the supposedly changeless realm of epistemic values. Nor is this the only irony in Ruse’s treatment of progress. His is, after all, an unabashedly progressionist history of evolutionary biology, tracking its gradual ascent up the ladder of respectability. He presents that history, moreover, as decisive for evaluating social constructionism. Do cultural values indeed dominate evolutionary theorizing, as alleged? Ruse invites us to have a look. The epistemic progress we shall find, he tells us, is there in the record, waiting to refute the sceptics. But when the theorists he discusses have claimed to find progressive patterns in their own data, Ruse convicts them over and over again of sinning against objectivity. Like Gould, he treats a belief in progress as a cultural value infecting evolutionary theorizing from start to finish. After a while, it becomes a joke even for Ruse, who starts referring as early as the Huxley chapter to ‘our old friend, progress’ (p. 94). Yet a belief in evolutionary progress is in many ways an odd candidate for a cultural value. Understood as the notion that life began simply, with ever more complex kinds of organisms emerging at intervals thereafter, evolutionary progress seems not just well attested empirically, but, for an evolutionist, non-negotiable, in the sense that nothing we would recognize as a theory of evolution could posit otherwise.

There is more to social constructionism than the theories-as-ideologies tradition that occupies Mystery of mysteries. Another tradition, often indifferent or openly hostile to the first, has been more concerned with how groups of scientists come to act upon the world. The emphasis is less on theories than on techniques. The cultures that matter are the material cultures of the sciences, especially the apparatus-filled laboratories where much investigation takes place. Claims about social construction in this tradition are often literal. Hacking’s examples involve the quark and the hormone TRH. Both entered the scientific inventory of the world after extensive experimental work. Both are now widely taken for granted as belonging to the discovered order of nature. And both have been the subjects of books with “construct-” words in their titles. The quark-lab sociologist Andrew Pickering (1984) has urged that there was nothing inevitable about a high-energy physics centred on quarks. The TRH-lab sociologists Bruno Latour and Steve Woolgar (1979) have urged that there was nothing inevitable about an endocrinology identifying as TRH the macromolecule now so identified. Rather, these outcomes are inseparable from the contingent assembly and spread of certain laboratory items: detectors in the case of quarks, bioassay systems in the case of TRH.

A book that asks ‘Is evolution a social construction?’ should have taken into account at least the spirit of this labs-and-techniques tradition. But culture for Ruse means values, not matériel. In keeping with the Popperianism he flourished in Arkansas, he treats the experiments he discusses as straightforward tests of theories. At the end he prescribes what he has described: ‘However socially or culturally congenial one may find the science, if it does not succeed in the fiery pit of experience, it can and should be rejected’ (p. 246). Even with Dobzhansky, who made his name as a member of the most famous laboratory in the history of biology, T. H. Morgan’s “fly room”, Ruse has little to say about the details of experimental practice or of theory-experiment dialectic. Characteristically, he dwells instead on possible Cold War alignments between Dobzhansky and his main rival on questions about genetic variation, Herman Muller, also a veteran of the Morgan lab. After the Second World War, Ruse argues (following others), Dobzhansky continued to hold that natural populations harbour a great deal of variation in part because he was hawkish on the American build-up of nuclear weapons, and so eager to allay concerns about the effects on evolution of mutations arising from fallout after weapons tests. As Ruse summarizes, with so much variation around anyway, ‘a few more radiation-induced mutations will not make much difference’ (p. 110). Muller took the opposite views on variation and testing.

Such correspondences between theories and ideologies are, as ever, intriguing. But the Morgan lab and its most illustrious students could have served as a point of entry into the other, more materialist sort of social constructionism. Though Ruse does not mention it, Robert Kohler’s Lords of the fly (1994) examines the Morgan lab from just such a perspective.¹³ Of course, the lab belongs to the history of evolutionary theorizing in retrospect, since the Mendelian-chromosomal theory of the gene, so largely elaborated and evidenced there, later came to be esteemed as underwriting Darwinian theory. But, as Kohler shows, Morgan was studying evolution and variation, not heredity, when he began to experiment with fruit flies around 1908. He was interested in whether the process of selection itself might have mutational effects. Morgan at that time was no Mendelian and the flies were not obvious candidates for Mendelian studies, since fly lineages in nature do not exhibit tidy Mendelian trait ratios. But the mutations that emerged in the lab surprised Morgan in lending themselves much better to Mendelian analysis than experimental evolution. Before long, Morgan and his students were attempting to map genes to chromosomes. In the course of this mapping work, the group gradually bred into being a lineage of flies conforming ever more closely to the predictions of the Mendelian-chromosomal theory. At the same time, that theory came to answer in the first instance not to flies in nature, but to this new, standardized, lab-bound lineage.

In step with other historians of laboratory life, Kohler tries to uncover the tacit codes of behaviour governing, among other things, the distribution of credit and even of flies (as material for further experimentation) in and around the lab at Columbia. More striking is his emphasis on the lab as a new ecological niche for the evolving fruit fly. Just as fruit flies changed the history of evolutionary biology, so, he argues, evolutionary biology changed the history of the fruit fly. What happened in Morgan’s fly room thus counts, if anything does, as the social construction of evolution, or at least of the evolution of Drosophila melanogaster. (One of the key chapters in Kohler’s study is entitled ‘Constructing Drosophila’.)¹⁴ The material culture of the lab appears inseparable from the epistemic inroads made there. Biologists possessed by a certain theory about evolution caused one lineage of organisms to evolve in a certain direction. As the lineage evolved thus, the theory changed, leading to further manipulations of the lineage, then further revisions in the theory, and so on. The flies that resulted were as much a social construction as the theory that could be checked only against those flies.

The contingency in Kohler’s account is not qualified in the Marxian way. He does not suggest that the fortunes of the mutational theory of selection were bound up with the fortunes of a social group whose interests the theory advanced. The theory was abandoned not because it had become a political liability but, he argues, because Morgan was working with flies on an unprecedented scale, and so had a much better chance of noticing variations that fitted more closely with Mendelian theory. And he had flies to observe at all only because they had become prized teaching aids in the burgeoning biology departments in American universities. If not for such mundane needs, then no flies in the lab at Columbia, no abandonment of the mutational theory, no standard fly, and none of the mapping that soon turned much of biological opinion in favour of the Mendelian-chromosomal theory. At the extreme, such an analysis invites us to contemplate the possibility of a successful biological science that did not include genes at all.

All of this escapes Ruse’s attention, and constructionist readers will rightly complain. More damagingly, I suspect many of them will not recognize themselves as Ruse’s opponents in the debate he has framed. When Ruse asks whether evolution is a social construction, what he really wants to know is whether, in contrast to the theories of epistemically pure sciences, the theories of evolutionary biology are riddled with cultural values. But neither of the constructionisms I have described takes quite that view of the epistemic and the cultural. It is not that Ruse has mistaken allies for enemies. It is that those taking a constructing attitude do not conceive of culture as he does: as, caveats aside, an epistemic contaminant—something that, with due vigilance, can and should be kept out of claims about the world. From the constructionist point of view, there is no such thing as emergence from culture into epistemic purity, since there is no such thing as epistemic purity, even in principle. Culture for the constructionist is not what prevents scientists from making true claims, but what enables them to do so, by fixing the rules that determine how truth and falsehood are to be assessed in the first place.

As a rebuttal of social constructionism, then, Mystery of mysteries has serious limitations. Its contribution lies elsewhere. Above all, what Ruse has given us is the story of the professionalization of evolutionary biology, as reflected in the lives of some of its most distinguished representatives. That story is useful to have in its own right. It should also serve as a welcome corrective to the tendency of commentators on the science to notice only areas of controversy. Absorbed in debates about the units of selection or the explanatory scope of developmental constraints, they too easily overlook how much of evolutionary biology has become uncontroversial, routinized, stable. The portrait of Parker in particular makes the point memorably. ‘By his own admission’, writes Ruse, ‘Parker is not given to grand system building, preferring rather to work away on specific problems’ (p. 205). As with Parker, so, Ruse concludes—not without nostalgia—with evolutionary biology as a whole. A once gloriously unruly science has been well and truly disciplined.