ALBERT

Notes: Conclusion The central role played by Darwin's analogy between selection under domestication and that under nature has been adequately appreciated, but I have indicated how important the domesticated organisms also were to other elements of Darwin's theory of evolution-his recognition of “the constant principle of change,” for instance, of the imperfection of adaptation, and of the extent of variation in nature. The further development of his theory and its presentation to the public likewise hinged on frequent reference to domesticates. We have seen that Darwin's reliance on the analogy between domesticated varieties and wild species was a bold and original step, in light of contemporary views on the nature of domesticates. However, as Darwin undoubtedly foresaw, his reliance on the analogy created difficulties as well as solving problems, and these began with his Malthusian codiscoverer of the principle of natural selection, Alfred Russel Wallace. Wallace's paper “On the Tendency of Varieties to Depart Indefinitely from the Original Type,” presented to the Linnean Scoiety along with the first public unveiling of Darwin's theory, states: We see, then, that no inferences as to varieties in a state of nature can be deduced from the observation of those occurring among domestic animals. The two are so much opposed to each other in every circumstance of their existence, that what applies to the one is almost sure not to apply to the other. Domestic animals are abnormal, irregular, artificial; they are subject to varieties which never occur and never can occur in a state of nature.62 Much has been made of the similarity of views of Darwin and Wallace, but this quotation surely reveals how utterly different their views were on what to Darwin was an important matter. Several critics of the Origin saw Darwin's reliance on the domesticates as his Achilles heel. As Young has pointed out, Samuel Wilberforce included the following passage in his attack on the Origin: Nor must we pass over unnoticed the transference of the argument from the domesticated to the untamed animals. Assuming that man as the selector can do much in a limited time, Mr. Darwin argues that Nature, a more powerful, a more continuous power, working over vastly extended ranges of time, can do more. But why should Nature, so uniform and persistent in all her operations, tend in this instance to change? Why should she become a selector of varieties?63 Another critic, Fleeming Jenkin, found the analogy a weakness in Darwin's theory because of the limited extent of variation in any one direction in domestic animals and plants.64 We have already seen that Darwin had confided a similar view to his notebook thirty years earlier, but changed his mind as a result of his profound study of domesticates. De Beer's reference to “an English country gentleman's knowledge of domestic plants and animals and their breeding”65 fails totally to recognize the originality and depth of Darwin's knowledge of domesticates. Why did Darwin, against the currents of his time, rely so heavily on mankind's experience with domesticated organisms to shape his theory about species in nature? On reason is that only with domesticates was an approach that came close to experimental verification possible. Darwin fully realized the inadequacies of the experiment, as is emphasized by his repeated contrasting of selection under nature and selection by man. Yet the extensive experience and data of plant and animal breeders offered the only reliable base against which Darwin could continually challenge his views. As he wrote in the introduction to Variation, with domestication, “man ... may be said to have been trying an experiment on a gigantic scale.”66 Given Darwin's high opinion of the quantitative work of Malthus and Quetelet (as emphasized by Schweber),67 and his unremitting efforts to secure data by which to test his theories, it was inevitable that he should attach high significance to domesticated varieties. John Tyndall, in his Belfast address of 1874, said: “The strength of the doctrine of Evolution consists, not in experimental demonstration (for the subject is hardly accessible to this mode of proof), but in its general harmony with scientific thought.”68 Darwin would have agreed with the latter thought, but I think he would have challenged the preceding one on the grounds that long experience with domesticated varieties did provide an element of experimental demonstration. It gave him confidence in his theory, and he used his vast knowledge of artificial selection boldly and creatively.

Notes: Conclusion: Toward a reassessment It should be clear that Lyell's scientific contemporaries would hardly have agreed with Robert Munro's remark that Antiquity of Man created a full-fledged discipline. Only later historians have judged the work a synthesis; those closer to the discoveries and events saw it as a compilation — perhaps a “capital compilation,”95 but a compilation none the less. Its heterogeneity made it difficult to judge as a unity, and most reviewers, like Forbes, concentrated on the first part of Lyell's trilogy. The chapters on glaciation were admired by Lyell's friends but had relatively little appeal to more general readers. His discussion of the species question hedged far too much to please those who accepted the cogency of Darwin's evidence and arguments. This last section of the book blatantly lacks originality or commitment and certainly has no claim to classical status in anthropology. We are left, then, with the first twelve chapters, for it was this portion that dictated the book's title and that amassed the available evidence favoring the antiquity of the human species. Did it do anything more than marshall the evidence that others had discovered? I think not. Lyell could write with style and verve. Principles of Geology is a remarkably readable book. But Antiquity is the work of a geologist, not of a systematic student of man. Despite its occasional touches of power, it never captures the freshness and immediacy of Lubbock's Pre-historic Times nor the theoretical brilliance of E. B. Tylor's Researches into the Early History of Mankind (1865).96 Antiquity utilizes little of the comparative method whereby Lyell's contemporaries used data from modern “savagery” to elaborate the possible social functions of the prehistoric remains being uncovered. It contains little social theory and has virtually no integrated framework. Even the first twelve chapters do not really hang together. As Hooker, commenting to Darwin on Lubbock's review, sadly wrote: “Lubbock in [the] N[atural] H[istory] Review, had in a note called attention to Lyell's ... ‘doing injustice’ to Prestwich & Falconer. I modified this expression ‘injustice’ in Lubbock's paper (which was friendly and apologetic). I am deeply sorry for it, but what can one do? I do think Lyell's first XII chapters a complete mess.”97 In another letter to Darwin, Hooker described this first portion of Antiquity as “confused and confusing.”98 Part of the problem, of course, lay in the subject's novelty for Lyell and for most of his contemporaries. At a deeper level, however, I believe that the book accurately reflects Lyell's uncertainties about Darwin's work and its implications for man.99 Leonard Wilson's edition of Lyell's Scientific Journals provides a unique insight into Lyell's mind during the years just before he began to write Antiquity.100 Preoccupied with the human implications of evolutionary biology, Lyell was not clear how many of those implications were compatible with his deep convictions about the dignity of man's place in the cosmos. With a certain naiveté, Lyell complained in 1873 that many of his readers had failed to see the “natural connections” among the three portions of Antiquity.101 Connections could indeed be drawn between man's antiquity and his evolutionary origins; Lyell's private Scientific Journals movingly demonstrate that he was well aware of this fact. But he never fully made the connections in his published writings. Antiquity of Man is more appropriately seen as the last gasp of the heroic period in British geology than as the opening salvo in a new, post-Darwinian anthropological synthesis. Between the founding of the Geological Society of London in 1807 and the middle of the nineteenth century, geology was recognized as one of the most exciting and innovative scientific fields in Britain.102 Lyell himself had contributed much to that drama, and by the 1860's he was a public figure of venerable proportions. More then any other man he represented a geology that had extended the boundaries of process, time, and life. The fundamental achievements of Lyell and his colleagues had been assimilated into the wider Victorian consciousness, yet the earlier public debates about “genesis and geology” had left untouched in its essentials the concept of Man as a moral, responsible, created being.103 Lyell never abandoned this view of his own species, and in 1863 it was a completely responsible creature which, under the weight of empirical evidence, Lyell admitted had lived on earth far longer than had previously been thought. Certainly this more generous allowance for human existence was constitutive to what Burrow calls the evolutionary social theory of midcentury Britain.104 Unlike Lyell, the younger representatives of this anthropology quietly accepted both man's antiquity and his aboriginal animality. Herbert Spencer's Principles of Psychology (1855), as well as the other volumes of his grand Synthetic Philosophy, presented as part of the cosmic process the development of human from prehuman beings.105 Tylor's discussion of what in his Researches (1865) he called the “gesture-language” presupposed the gradual and de novo origin of language in early human populations.106 Lubbock's young and polished mind was untroubled by the human implications of Darwin's work, and he cast his Prehistoric Times into such a perfect mold that it and its companionpiece (On the Origin of Civilization, 1870) went through seven editions each between 1865 and World War I, with their original theoretical structures intact. In a way that Lyell could not grasp, Lubbock was intrigued by questions concerning the origins of moral and religious beliefs and did not flinch at the thought of an amoral, atheistic creature as an ancestor.107 Indeed, as the German naturalist Carl Vogt pointed out in his Lectures on Man, translated into English the year after Antiquity, both Darwin's theories and the primitive flint knives of the Stone Age bore witness to a time beyond that imaginable from the condition of the lowest present-day “savage”: From such a low condition [little better than anthropomorphous apes], compared to which that of the so-called savages of the old and new world is a refined civilisation, has the human species gradually extricated itself, in a bitter struggle for existence, which it was well able to maintain, by being gifted with a larger amount of brain and intelligence than that possessed by the surrounding animal world.108 The easy integration of biological and social themes was perhaps the distinguishing hallmark of Victorian anthropology of the 1850's and 1860's. After his fashion, Lyell got both themes into Antiquity, but he carefully separated them with a seven-chapter wall of glacial ice. Lyell's anthropology was not that of a thoroughgoing evolutionist like Lubbock, Tylor, or Spencer. For Lyell prehistoric man was not a product of biological evolution. Rude and superstitious he may have been, but he possessed ritual and a belief in a future state, and thus deserved “the epithet of ‘noble,’ which Dryden gave to what he seems to have pictured to himself as the primitive condition of our race: as Nature first made man/when wild in woods the noble savage ran.”109 As a systematic argument, Lyell's book was at best a significant failure. As a popularization, it was a success — largely because of the personal stature of its author and the particular moment of its appearance. It helped establish the fact of man's antiquity with a wider Victorian audience, in itself no mean achievement. But Lyell was unable to exploit the fuller implications of his material in the service of a secular science of man. Ironically, he exploited only his colleagues' discoveries. Though the aging Lyell, with failing eyesight but unfailing mental powers, can still be seen as a man of considerable importance, his Antiquity belongs to the carefully circumscribed world of British geology rather than to the

Notes: Conclusions Early scientific investigation of the reproductive process was neither a cause nor a direct result of changing social attitudes toward sex. It was instead part of the continuing search, initiated in the 1890s, to discover internal secretions that might be isolated and prove useful in therapy. Laboratory scientists, nonetheless, were among the many groups altering understanding of human sexual physiology in the first quarter of this century. The new data they generated regarding the dependence of human sexuality and fertility on chemical substances elaborated by the ovaries and testes became part of the evidence which hastened that quite tortuous transformation called the sexual revolution. Increasingly, as social reformers demanded more information about human reproduction, scientists were asked to provide it, and scientific concerns were shaped in the process. In the 1920s, especially in the United States, studies of the physiology of reproduction began to receive financial backing from social reformers. This was because for many, contraception had become a fact of life. Expression rather than repression of sexuality was accepted as being necessary to the stability of the fundamental social unit, the family. Theoretical and practical incentives for continued study of the reproductive process could thus be joined in common effort. This convergence of goals occurred just as the gonadal hormones were being isolated. The 1920s, therefore, mark an important juncture in the congruence of interests represented by theoretical science on the one hand and expressed social needs on the other. As a result of this convergence of interests and goals, physiologists gained a new realm of influence, claiming authoritative knowledge over a subject which once had been allocated to the priest and then, by the mid-nineteenth century, transferred to the physician. Since that formative period other research scientists, such as Alfred Kinsey and, more recently, William Masters and Virginia Johnson, have explored that niche and applied the scientific method to study of behavioral and physiological aspects of the human sexual response. They have been beset by many of the same tactical issues that confronted the earliest investigators of reproductive physiology. The definition, specification, and measurement of phenomena relating to sexual and reproductive activity have been as inherently difficult as they have been taboo.79 Traditional resistance to scientific study of the reproductive process was overcome in the early twentieth century by the expectation that this particular line of inquiry would lead to understanding and therefore medical control of the complex of disorders—physiological, psychological, and social — associated with the generative glands. Early investigators, particularly in Britain, did not wish to be social reformers. Especially in the 1910s such a stance would have threatened their credibility in a field determined to establish itself as a theoretical science. Once scientific progress was assured, as it was from about 1920, new problems opened for investigation and began to be motivated by social needs as well as by the concerns of a rapidly developing science. Especially in the United States new resources encouraged this work, allowing development of the specialized focus on gonadal hormones represented by the emerging field of reproductive endocrinology.

Notes: Conclusion “The difficulty of discussion between people brought up in different frameworks is to be admitted,” Karl Popper writes. “But nothing is more fruitful than such a discussion; than the culture clash which has stimulated some of the greatest intellectual revolutions.”71 Certainly Kirby and Darwin were brought up in different cultures — Kirby with his Anglican-Tory orientation, Darwin with his Whig-liberal background — and certainly the clash generated some interesting theories; but it also resulted in the revival of Lamarck's discredited habit theory, which took another century of careful experimentation to weed out.

Notes: Conclusion In the light of contemporary allelopathic research, the intuitively based statements of the early botanists stand up surprisingly well. The walnut tree is now understood to affect the growth of neighboring plants via juglone leached from the leaves, roots, and fruits.118 The replant or soil sickness problem of peach orchards has been related to the toxigenic breakdown of amygdalin, a constituent of peach roots.119 The declining yield of many crop species grown under continuous monoculture has been linked to the accumulation of allelopathic substances in the soil, especially through the mediation of microorganisms.120 Numerous plants cited by de Candolle as being injurious, such as Erigeron,121 thistle (Cirsium),122 flax (Linum),123 and various crucifers (such as Brassica nigra),124 have been found to posses marked allelopathic activity. Over fifty years before the discovery of rhizobia, de Candolle considered the excretory material of legumes to be beneficial to cereals.125 Modern reviews of allelopathy commonly credit de Candolle with an insight that was not equaled by the technology of his era.126 In fairness to his detractors, his toxin theory of plant interactions was largely the by-product of an outdated and misconstrued notion of plant nutrition. His critics and most earlier botanists had similarly erred in seeking a single factor responsible for plant growth, much as had the alchemists sought the legendary philosopher's stone. Taking all this into account and considering the forceful personality of Liebig, one can readily appreciate how, 130 years ago, Liebig's theories preempted and stifled those of de Candolle. Today, with modern techniques of plant physiology and soil biochemistry, allelopathy has been shown to be a real but subtle factor in the dynamics of natural and agricultural plant communities. It is unfortunate that the single-mindedness characteristic of previous centuries still persists. The dichotomy between allelopathy and competition is exacerbated by the inherited bias toward the nutritional model of plant interaction fostered by Liebig, and is accentuated in the fact that in modern nutritional studies it is still basically unnecessary to consider plant-plant chemical interactions and their concomitant effects, whereas in allelopathic investigations the converse is regarded as axiomatic. In summary, de Candolle should not be seen as “a prophet crying in the wilderness,” as Fisher would have it.127 The bases of de Candolle's concept of allelopathy were the dubious experiments of Macaire and his own obsolete theory of plant nutrition. Despite this, modern experimental work indicates that allelopathy is important in many plant interactions. De Candolle seems to have been right, at least in part—but for the wrong reasons.

Notes: Conclusion Experimental taxonomy was a diverse area of research, and botanists who helped develop it were motivated by a variety of concerns. While experimental taxonomy was never totally a taxonomic enterprise, improvement in classification was certainly one major motivation behind the research. Hall's and Clements' belief that experimental methods added more objectivity to classification was almost universally accepted by experimental taxonomists. Such methods did add a new dimension to taxonomy — a dimension that field and herbarium studies, however rigorous, could not duplicate. Nonetheless, experimental techniques were never completely divorced from traditional taxonomic methods. In practice, all experimental taxonomists employed a combination of descriptive and experimental methods. Most researchers freely acknowledged a debt to traditional taxonomy. Furthermore, the greater rigor of twentieth-century taxonomy was not due entirely to experimentalism. Both the experimental and descriptive aspects of taxonomy were improved by the increased use of quantitative methods, particularly statistics.52 From the beginning, a number of experimental taxonomists were interested primarily in classification. But many approached their research from fields other than taxonomy. These botanists were concerned primarily with ecological and genetic problems rather than with classification. There is little indication that they drew a sharp distinction: for example, taxonomic and cytogenetic conclusions were interwoven in Babcock and Stebbins' 1938 study of Crepis 53 (this was even more true of Babcock's final mongraph on the genus, published in 1947). Similarly, the extensive series of monographs, “Experimental Studies on the Nature of Species,” initiated by the Carnegie Institution group in 1940 combined ecological, cytogenetic, and taxonomic conclusions. Indeed, the significance of the major projects completed by experimental taxonomists was largely due to the fact that they were comprehensive studies rather than strictly taxonomic or cytogenetic. In a general sense, the primary motivation behind much of experimental taxonomy was evolutionary. Beginning in the second decade of the century Hall and Clements exhorted taxonomists to take an explicitly evolutionary perspective on research. Hall undoubtedly spoke for the majority of experimental taxonomists when he stated, “If there be anything at all to organic evolution, then taxonomy is dealing with the products of evolution and it is this that gives to taxonomy both its highest mission and its greatest responsibility.”54 Aside from a common interest in evolution, however, the theoretical orientations of experimental taxonomists were varied. This diversity is strikingly illustrated by the evolutionary views of members of the Carnegie Institution research group. Experimental taxonomy was initiated by Clements as one aspect of his Lamarckian study of adaptation and speciation. In contrast, Hall's research was inspired by a broad concern for evolutionary problems. Hall rarely referred to specific evolutionary mechanisms; rather, he applied a general conception of evolutionary processes to deduce phylogenetic relationships. His later associates at the Carnegie Institution explicitly dissociated themselves from Clements' theoretical framework. The neo-Darwinian interpretations of adaptation and speciation presented by Clausen, Keck, and Hiesey could hardly have been more different than those of Clements. However, this major shift in theoretical orientation should not obscure significant similarities between the research of Clements and later Carnegie workers. In terms of research problems and methodology, the first volume of “Experimental Studies on the Nature of Species” was an extension of the Clementsian research program. Clausen, Keck, and Hiesey's monograph was the mature discussion of transplant experimentation that Clements had very tentatively initiated during the first decades of the twentieth century. The bond that linked the members of the Carnegie Institution research group to experimental taxonomists in general was one of shared methodology rather than common theoretical orientation. While Clements' evolutionary views were eventually repudiated, his enthusiasm for innovative experimental methods was shared by later workers. The development of experimental taxonomy faced significant problems. During the period 1920–1950 this area of botanical research remained a hybrid discipline. The aims and scope of experimental taxonomy were never articulated in a completely unified manner. Consequently, even among experimental taxonomists, there were disagreements over the relation of their research to other botanical endeavors. Even though experimental taxonomy had close ties with general taxonomy, a number of experimental taxonomists questioned the “taxonomic” nature of their research55. Even to the extent that this hybrid discipline could be identified as a branch of taxonomy, problems arose. Taxonomists, as we have seen, were justifiably skeptical of what appeared to be a rapid influx of untested methods and ideas. Experimental taxonomists were not merely incorporating well-accepted methods from ecology and cytogenetics; during the period 1920–1950 the fields from which experimental taxonomists borrowed were themselves undergoing major theoretical and methodological changes. Despite problems and conflicts, experimental taxonomists did contribute improvements to classification. Furthermore, they made significant contributions to plant ecology and evolutionary genetics. The development of experimental taxonomy indicates that twentieth-century botanists were not necessarily isolated in naturalist and experimentalist camps. The joint session of taxonomists, cytologists, and geneticists at the 1926 International Congress of Plant Sciences indicates communication among specialists fairly early in the century. The papers and commentaries presented during this session do not reveal the hostility and intolerance that supposedly characterized encounters between experimentalists and naturalists. Nor do they suggest incompatible conceptual worlds separating geneticists and taxonomists. Discussions between taxonomists and other specialists were not limited to a single international congress. Particularly during the 1930s discussions among specialists appear to have been fairly widespread. Groups such as the Biosystematists and the Society for the Study of Systematics in Relation to General Biology served as forums for discussion among biologists from a variety of disciplines. The naturalist-experimentalist dichotomy tends to obscure the broad research interests of a number of prominent twentieth-century botanists. Most of the experimental taxonomists cannot be characterized adequately as either naturalists or experimentalists. Traditionally trained taxonomists such as Hall, Keck, and Turrill throughout their careers participated in both experimental and herbarium research. And a number of specialists in fields other than taxonomy took an active interest in taxonomic problems, not necessarily limited to experimental aspects. For example, Anderson suggested a number of innovations to make herbarium collections more amenable to statistical analysis. This historical study of experimental taxonomy indicates a different relationship between experimentalism and taxonomy than that portrayed by the naturalist-versus-experimentalist dichotomy. F. E. Clements originated experimental taxonomy as a revolt against descriptive botany. In retrospect, this revolution was not vigorously waged and was not successfully completed. Experimental taxonomy was never an entirely experimental approach to botanical research. Even the most ardent advocates of experimentalism relied heavily on methods inherited from traditional taxonomy. Moderate exponents of experimental taxonomy stressed the compatibility of experimental methods, field observation, and herb

Notes: Summary Six schools of thought can be detected in the development of evolutionary theory in German paleontology between 1859 and World War II. Most paleontologists were hardly affected in their research by Darwin's Origin of Species. The traditionalists (School 1) accepted evolution within lower taxa (genera and families) but not for organisms in general. They also rejected Darwin's theory of selection. The early Darwinians (School 2) accepted Darwin's theory of transmutation and theory of selection as axioms and applied them fruitfully to the fossil record, thereby laying the foundation for the new research areas of phylogeny and paleo-biology. The enthusiasm of the early Darwinians faded when the fossil record and the problems of its interpretion became more widely known. The pluralists of the turn of the century (School 3) invented and adopted a wealth of hypothetical mechanisms in order to explain individual features of the fossil record. They failed, however, to provide one coherent theory. Dissatisfaction with this situation led to adoption of a dogmatic neo-Lamarckism (School 4), which was regarded as a coherent theory providing a fruitful research program. The rejection of the Lamarckian mechanism early in this century left paleontologists with only one kind of evolutionary mechanism: inner causes. Like many neo-Lamarckians several orthogeneticists (School 5) were highly interested in adaptation and did not see any contradiction between the inner causes of evolution and adaptation. The dominance of stratigraphical research programs in paleontology led in the 1930s and 1940s to a decrease in interest in adaptation. Stratigraphical records of taxa were accepted as meaningful in the context of evolutionary theory. Orthogenesis and the new concepts of saltation and cyclicism were amalgamated into one theory: typostrophism (School 6). This theory dominated German paleontology for decades after the war and only recently has the synthetic theory been seriously considered. Evolution was never very intensively discussed in German paleontology in the hundred years after Darwin's book. Most information used here comes from textbooks or from papers given on special occasions. It has been impossible to summarize how members of one school defended their views or discussed the ideas of competing schools.

Notes: Conclusion With the rejection of group selectionist derivations of ecological phenomena so incisively given by George Williams in 1966,43 Nicholson's long-ignored messages met with acceptance. Species benefit became, explicitly, incidental. But the reorientation was not just about a point of ecological theory. It was more fundamentally about theoretical style, the element shared by Wynne-Edwards' work and the newer, evolutionary ecology. That current approach is well expressed in an already classic paper by the British plant ecologist John Harper: Ultimately all the discoveries of descriptive, production or population ecology must find their meaning in evolutionary phenomena... Evolutionary thinking concentrates attention on the behaviour of the individual and his descendants. If nothing in biology has meaning except in the light of evolution and if evolution is about individuals and their descendants — i.e. fitness — we should not expect to reach any depth of understanding from studies that are based at the level of the superindividual... What we see as the organised behaviour of systems is the result of the fate of individuals.44 The emphasis in this passage is on style of thinking more than on study matter. What is so different from earlier ecologists is the rejection of the superorganism and its associated baggage of selfimposed constraints in an end-oriented process, such as balance of nature or species-level adaptation. The hallmark of post-1959 evolutionary ecology is the recognition, the making explicit of the question that the selective, genetical process of fitness (fates of genes) has to be separated from the observations of different levels of adaptiveness. An easy conflation of cause and result is no longer satisfying; now attempts to disentangle the complex strands tying population phenomena to the different levels of selection are providing the excitement of a new research program. In this program evolutionary theory is used to define the appropriate questions, as exemplified by the organization of the textbook Evolutionary Ecology.45 Our discussion of the invention of a new approach, with a characteristic style and set of interests, must also be about how the practitioners of ecology have perceived themselves. The early attempts of Poulton and Nicholson were not taken up by the vigorously growing science of ecology, which developed first - and intentionally — along a narrower, hierarchically restrained set of questions about population. The depth of Poulton's and Nicholson's submergence is indicated by the fact that even Wynne-Edwards did not argue in the manner of one rescuing a minor tradition. Rather, he thought he had a new approach, that of placing evolution in the foundations of ecology. Although this approach was not exactly original, we should be cautious in grouping all evolutionary concerns within ecology in one intellectual tradition. The particular style of selectionist deduction invigorated by Wynne-Edwards was successful only in the volatile situation of a rapidly growing discipline, full of self-critical examination and new rigor. Whereas in 1930 evolutionary concerns did not provide that rigor, by 1960 they could - and did.

Notes: Conclusion The distinction between taxonomic plant geography and ecological plant geography was never absolute: it would be historically inaccurate to portray them as totally divergent. Taxonomists occasionally borrowed ecological concepts, and ecologists never completely repudiated taxonomy. Indeed, some botanists pursued the two types of geographic study. The American taxonomist Henry Allan Gleason (1882–1975), for one, made noteworthy contributions to both. Most of Gleason's research appeared in short articles, however. He never published a major synthetic work comparable in scope or influence to the ecological texts of Clements, Schimper, and Warming. Despite exceptions such as Gleason, most plant geographers throughout the twentieth century have emphasized the distinction between ecological and taxonomic plant geographies. Why have these distinct traditions developed? In his book Geographical Ecology, Robert MacArthur has suggested a psychological explanation for the dichotomy: “Unraveling the history of a phenemenon has always appealed to some people and describing the machinery of the phenomenon to others... The ecologist and physical scientist tend to be machinery oriented, whereas paleontologists and most biogeographers tend to be history oriented.”46 Without necessarily rejecting MacArthur's explanation, my study suggests a more complex relationship between taxonomic and ecological plant geographies. At the turn of the century a group of botanists self-consciously defined a new area of botanical research. These ecologists defined their new discipline in opposition to what they believed was a moribund, nineteenth-century, natural-history tradition. They turned from historically oriented, descriptive, taxonomic plant geography to experimental physiology. The new ecological plant geography was to focus on communities rather than on species, on proximate environmental causes rather than on historical explanations, and on physiological experiments rather than on morphological descriptions. As we look back, much of the “revolt from morphology” was rhetorical. Ecologists never completely replaced species as units of distribution, nor did they set geography on an explicitly physiological basis. Indeed, much of early ecological research was, quite simply, descriptive. Plant communities were defined in terms of dominant species, representative life forms, or general physiognomy. The underlying physiological basis for community characteristics was more often assumed than demonstrated by experiments. Despite the fact that ecological plant geography was not a truly physiological specialty, it was significantly different from more traditional taxonomic plant geography. First, ecologists were less explicitly evolutionary in their approach than were taxonomists. Following Darwin, most taxonomic plant geographers viewed distribution in historical terms. In contrast, early ecologists tended to ignore the traditional geographic problems. Most ecologists were skeptical of historical explanations, emphasizing instead the proximate, environmental causes of distribution. While some nineteenth-century biogeographers had studied the correlation between climate and vegetation, twentieth-century ecologists focused much more sharply on the interactions between plant and environment. Plant ecologists did not place biogeography on a physiological basis, but by emphasizing physiology they laid the foundation for a more detailed understanding of adaption. This emphasis on physiology and environmental causation was a second distinguishing characteristic of ecological plant geography. Finally, the idea of the plant community, articulated by Eugenius Warming in 1895, provided ecologists with a unique perspective on the distribution of plants. For early ecologists, the community was more than an assemblage of species; it was an integrated unit. The distribution of these units became the major focus of ecological plant geography. Communities never completely replaced species as geographic units, and the distinction between flora and vegetation was often blurred. Nonetheless, ecologists were innovative in studying the distribution of structurally and functionally integrated groups of plants. In the twentieth century plant geography has occupied an anomalous position in biology. It has not developed into an autonomous discipline, nor has it been incorporated into the developing discipline of ecology. Ecologists and taxonomists have pursued fairly distinct styles of geographic research, with the result that two relatively independent approaches to the study of plant distribution have persisted.

Notes: Conclusion We should now be able to come to some general conclusions about the main lines of Cuvier's development as a naturalist after his departure from Normandy. We have seen that Cuvier arrived in Paris aware of the importance of physiology in classification, yet without a fully worked out idea of how such an approach could organize a whole natural order. He was freshly receptive to the ideas of the new physiology developed by Xavier Bichat. Cuvier arrived in a Paris also torn by many overlapping debates on the nature of classification, and in particular that between the natural and artificial systems. The very validity of the enterprise of classification was questioned in many quarters. Cuvier's achievement on his entry into the Parisian world of science was not simply to establish himself as a highly competent anatomist: far more important, he also began to use ideas from many different specialties to change completely the notion of what was involved in natural history.124 At the same time that he himself swung away from the guiding image of the field naturalist as the ideal of the specialty, he took ideas from the new physiology to answer questions about the order of the animal world, and from comparative anatomy to resurrect extinct creation — and to come to conclusions from that creation about the history of the forms of life and the manner of their succession. He showed himself able to alter the relationships between natural history and many other fields of study in a way that implied, rightly or wrongly, his own complete mastery over such a movement. Partly he was able to do this because the ideas he borrowed were not themselves logically articulated and thus could be easily adapted and refocused for many different specific purposes. The value of the heuristic possibilities inherent in the idea of life, for example, far outweighed its inability to generate full systems of classification. Cuvier also consistently refused to consider in science matters relating to the first causes of events. Freed from the consideration of first-order phenomena, he was able to use second-order explanations across a far wider field of applicability. Personal doubts about the validity of a theology that had used science in order to bolster its own claims were combined here with the strong influence of the Kantian critique of the limits of human reason.125 Cuvier's characteristic mode of procedure was that of intellectual appropriation and a bold capacity for altering the relationships between different fields of knowledge, rather than, with the exception of taxonomy, the technique of expanding their subject matter. His claims to originality came, first, from this reappropriation and reorientation and, second, from the sheer scope of his work, which aimed at nothing less than the cataloging and classification of all animate objects.126 They rested also on his acute use of his assertion of a certain relationship with the past of his subject. Very often he would present this history in such a way as to obscure his own intellectual genealogy, and often too he would give differing accounts of the priority of use of an idea in order to distract attention from the questionable exactitude of his own claims to originality. Cuvier came to Paris at precisely the time when society and institutions were most profitably malleable for a newcomer; it was also a time when many scientific disciplines had reached a stage advanced in terms of their factual content, yet relatively inadequate in conceptual organization. They were ripe for takeover by large-scale organizing ideas such as the animal economy and the subordination of characteristics. Paleontology is a particularly good example of a specialty in this particular form of underdevelopment in 1795. Cuvier paid a high price for his initial success. His electic applications of large-scale organizing ideas tended to mean that little of his own work had complete coherence at all levels. Ideas, as we have seen, that proved capable of providing a complete reform of the larger groups of the animal kingdom were incapable of producing its detailed working-out in the taxonomy of smaller groups, which had to be supplied from observed analogical correlations. Further, his physiological approach to classification involved the breakdown of strict correspondence between organs and functions, which left the way open for workers such as Geoffroy St. Hilaire gradually to tilt the balance away from the study of the correlations of hierarchies of functions, and toward morphology as the basis of the order of nature. Cuvier's brilliant appropriations from physiology from the beginning, therefore, contained the seeds of conflict with Geoffroy. Cuvier's eclectic approach made it very nearly impossible for him to present a clear idea of the ways in which the life sciences could be said to be lawful. In spite of his efforts to assimilate them to the position of the physical sciences in this respect, he was forced in the end to accord only an ambiguous status as “laws” to observational correlations. From this area of failure came much of the attempt to give his own two laws — the correlation of parts and the subordination of characteristics — predictive qualities, particularly in relation to paleontological research. It is not surprising that Cuvier's title as the “legislator” of natural history should represent more a claim than a reality. How, then, was he able to emerge as the leading French naturalist of his day? First of all must be adduced the sheer scale of his undertakings. Then comes his expertise as a practical anatomist, and the range of different topics toward which he turned his interest. His collaborators cannot be given credit for his output nor, as we have seen, for slavish adherence to his ideas. Cuvier was able to successfully claim to have dominated the underdeveloped specialties, such as paleontology, and turned them into a major heuristic input into both geology and comparative anatomy; but in other fields, such as physiology, he appropriated concepts and encouraged research but made little impact on the field himself. His attempts in 1812 to head off, or neutralize and absorb the growth of morphological studies landed him in a dangerously rigid position, which despite his encouragement of the new physiological research under the Restoration made further elaboration of his own conceptual underpinnings almost impossible. Cuvier's authority in the scientific world would in any case have been great because of his substantive achievement in taxonomy, but the rest of his work had enough ambiguities and dislocations for it to need the support of his political and social power. Cuvier's detractors seized on a vital fragment of the truth when they accused him of finding the political dimension all-important: it obscured the disjunctions in his theories and at the same time gave him the authority to make new claims for the status of the observational sciences - and for their relations of power with their surrounding specialties. Cuvier's science both thrived on and was halted by the power games of intellectual appropriation, manipulation of the past to confirm the present, and continual claims for hegemony.

Notes: Conclusion The major tenets of the recent hypothesis of punctuated equilibrium are explicit in Darwin's writing. His notes from 1837–1838 contain references to stasis and rapid change. In the first edition of the Origin (1859), Darwin described the importance of isolation of local varieties in the process of speciation. His views on the tempo of speciation were influenced by Hugh Falconer and also, perhaps, by Edward Suess (1831–1914). It is paradoxical that, although both topics were recorded in his unpublished notes of 1837–1838, the second was not explicitly and fully discussed until the fourth edition of the Origin (1866). While no wholly satisfactory explanation of this paradox suggests itself, it seems probable that Falconer's work on the persistence of fossil species of elephant helped Darwin to see the wider significance of the tempo of evolution for his general theory.

Notes: Conclusion The classical/balance controversy continued along these lines throughout the first half of the sixties. Then, at about the same time that the classical position lost its leading advocate, the balance position received striking new support from Harry Harris, and independently from Dobzhansky's former student Lewontin, and Lewontin's research partner, Jack Hubby.80 These developments served more to reorient the controversy than to end it — and the resulting “neoclassical”/balance controversy is different enough to be grist for another mill. Social policy considerations no longer play a role in keeping the dispute alive. This particular respect in which the issues have changed is, as Diane Paul suggests in her contribution to this volume, as striking as any other.82 There is, however, little danger of our forgetting that this was once much more than just a narrowly technical controversy — the additional social policy issues were far too blatant. However, although blatant, they were by no means the only, or even the most important, issues. In choosing to concentrate on the social policy considerations, I do not mean to suggest that the empirical issues were irrelevant, or simple and straightforward, or otherwise uninteresting. That is by no means the case. What I have tried to show is that there was much more to the classical/balance stalemate than just the empirical underdetermination of the theoretical issues, and that the empirical issues cannot be treated adequately without taking into account the social policy considerations that were involved. Dobzhansky and Muller both appealed to the dangers of misguided social policy that might have resulted from prematurely resolving their controversy in the other's favor. They called for high empirical standards on those grounds, more than once seeking to forestall the resolution of their dispute in this way.

Notes: Conclusions In spite of these efforts in the 1920s and 1930s to initiate ongoing research on contraception, the subject of birth control remained a problem of concern primarily to the social activist rather than to the research scientist or practicing physician.80 In the 1930s, as has been shown, American scientists turned to the study of other aspects of reproductive physiology, while American physicians, anxious to eliminate the moral and medical dangers of contraception, only reluctantly accepted birth control as falling within their professional domain. As a result, the problem of cheap, effective, and safe contraception was not solved by these earliest attempts. Consideration of the subject was initiated afresh by private philanthropy after World War II, sparked by a new wave of interest in population studies.81 Summarizing such efforts to support research in the reproductive sciences, a recent Ford Foundation study has noted: “To initiate and sustain serious research in the reproductive sciences has required for more than half a century concerted effort by interested individuals and private organizations, mainly from outside the mainstreams of the biomedical research community.”82 The early laboratory research on chemical contraception described in this paper was but one important outcome of the concerted effort made by reformers in the 1920s to eliminate a variety of social problems thought to derive from excessive fertility. Scientific arguments and expertise were employed to advocate reform as well as to define the appropriate solution to such social problems. Scientists were recruited as advocates for the movement, but they were also employed as researchers in laboratory investigations sponsored by these same reformers. Sponsors of these early laboratory studies noted the difficulty of obtaining first-class investigators.83 The routine analyses necessary for such research, as well as the traditional scientific aversion to applied problems, provide only a partial explanation for this response. The real difficulty lay in recruiting investigators to a field (reproduction and human sexuality) that had previously been taboo. Once opened up — first as socially relevant, and finally as scientifically sound — there was much interest in this area, and the appeal to researchers of the scientific issues surrounding fertility and reproduction soon surpassed that of the reforming value of birth control. A survey of the kinds of experimental investigations sponsored by birth control advocates indicates the range of physiological problems explored by contraceptive research. The most definitive work was done on the efficacy and safety of spermicides, but the potential of other contraceptive methods was also examined. Investigators attempted to develop spermatoxins that would effectively immunize women against sperm, and they also tried to elucidate the mechanism of hormonal control of reproduction. In fact, speculations about the possible hormonal manipulation of fertility were expressed at the Seventh International Birth Control Conference held in Zurich in 1930.84 In the 1920s, clinical studies were undertaken to assess the effectiveness of the various birth control methods. Laboratory investigators complemented this work by screening spermicides for safety and testing for their ability to kill sperm. There were a variety of birth control preparations on the market (most of which were sold as feminine hygiene products), but no one really knew whether these were effective or even safe.85 Although the physiology of other major organ systems was well advanced, the scientific study of reproductive physiology and contraceptive technology was clearly in its infancy in this period. Routine analyses simply could not be conducted, because the fundamental research establishing baselines had not yet been done. Scientists used this fact to redirect attention to basic research on reproduction. Laboratory research on contraception indicated important unexplored areas for physiological investigation. Social activists, who had encouraged prominent scientists to become interested in both the social value and the genetic implications of birth control, found these investigators revising the goals of their research. The biologists had formed their own network and had begun to seek out funding, reformulating the justification for sponsorship of further investigations. The eugenic motivations underlying these studies, which had initially made them theoretically attractive to biologists, were gradually eroded. Concern with “human evolution” ceded its place to interest in physiological mechanisms. Crew and others began to note that the use of biological theory to justify essentially political decisions had serious limitations. Biologists had become uncomfortable with those very arguments which had originally captured their interest. Recognition of the potential political abuse wrought by applying scientific principles to society was expressed by Crew just one year after the Zurich meeting. Referring to previous assessments of the role of sex in reproduction, he generalized: “In the past the biologist has justified feudalism, Manchester Liberalism, socialism and every other type of social organization and political programme by reference to selected biological phenomena.”86 By 1932 Crew had also begun to question the biological logic of regulated breeding, and had made it clear to his American sponsor that there was no simple correspondence between the practice of birth control and the genetic improvement of the human race.87 Biologists further began to recognize, however, that although the hopeful genetic solution to human problems was probably an illusion, contraception still remained one tangible means to alleviate, human misery. Some laboratory scientists, like Crew, acknowledged the applicability of their own particular skills to this problem. For a few brief years, social needs and scientific goals were mutually supportive and closely intertwined. But as laboratory researchers gained interest in the study of reproduction and established their own priorities in this field, they temporarily withdrew from the arena of debate over birth control as an important mechanism for social reform. With the rise of Hitler, the genetic arguments for birth control rapidly lost their appeal. But by that time the scientific problem of how to achieve effective contraception had entered the professional consciousness. Both physicians and scientists began to be aware of birth control as a subject within their domain of expertise, although outside the principal focus of their research. Scientific discussion of birth control permanently altered from a question of justification to a problem of method: How could one achieve reliable and safe contraception? This had been Sanger's and Dickinson's goal from the beginning. Laboratory scientists had indeed been persuaded to undertake this work; this research had in turn affected biologists' perceptions of the whole field of reproductive physiology, encouraging further study of reproductive mechanisms. The promise of new knowledge provided for continued funding of this research, despite the caution by scientists that the social benefits would not be as immediate or as far-reaching as advocates and they themselves had first argued. The activities of birth control activists and their supporting agencies, and the financial backing of private contributors and foundations, notably the Rockefeller philanthropies, provided an important new stimulus to the development of research on the biology of reproduction in the late 1920s and early 1930s. Biologists were able to claim an enlarged realm of issues for scientific study through their activities as advocates and as investigators for the birth control movement. At the same time, they promised as-yet-undiscovered possibilities for regulating human reproduction once its physiology was understood. The knowledge a

Notes: Concluding statement Wallace's contributions to biological thought tend to be overlooked or overly praised, neither of which produces a satisfactory assessment. Examples of the latter tendency are the recent expositions by Brackman and Brooks; although both books contain much worthwhile material, both are flawed. At critical points their theories fail to measure up, Brackman's because of his misinterpretations of events in the month of June 1858, and Brooks's Darwin's September 5 letter to Gray could, and probably did, represent an ordering of his ideas in response to a felt challenge. A fruitful way to characterize the relationship between Darwin and Wallace may be found in terms of game theory. Most scholars look upon the relationship as a zero-sum game, with a winner and a loser, the matter of priority being considered as a “single event.” Another approach would be to look upon it as a non-zero-sum game with each man influencing the other. In this case, the productivity of one is stimulated by the contributions of the other, resulting in a net gain in knowledge overall, and both men become winners, or codiscoverers. This approach is possible if Wallace's contributions to the theory of evolution by means of natural selection are recognized.

Notes: Conclusion If we arrange in chronological order the various statements Darwin made about God, creation, design, plan, law, and so forth, that I have discussed, there emerges a picture of a consistent development in Darwin's religious views from the orthodoxy of his youth to the agnosticism of his later years. Numerous sources attest that at the beginning of the Beagle voyage Darwin was more or less orthodox in religion and science alike.78 After he became a transmutationist early in 1837, he concluded that the doctrine of secondary causes must be extented even to the history of life and that after the first forms of life were created, there was no further need for divine intervention, except where man was concerned. Man's body, he thought, was produced by the process of transmutation, but he believed for a time that man's soul was “superadded.” By mid-1838 he had become convinced that nothing, after the creation of life, was due to miracles. God works only through laws, which are capable of producing “every effect of evey kind which surrounds us.” The existence of man, the idea of God in man's mind, and the harmony of the whole system were in his eyes prearranged goals of deterministic laws imposed by God. Such a conception excludes the miracles on which Christianity depends; but it is not possible to say whether Darwin's loss of Christian faith, which occurred at about this same time, preceded and made possible his “materialism” or was rather caused or hastened by it.79 In the weeks after his reading of Malthus, Darwin's belief in a plan of creation gave way to the belief that God created matter and life and designed their laws, leaving the details, however, to the workings of chance. This remained his view until the 1860s. There is no exact parallel between this development of Darwin's religious views and the development of his ideas on evolution, but there is a general correspondence. When he believed in a plan of creation, Darwin's theory of transmutation did not depend on struggle or the selection of chance variations. Adaptation was, for him, an automatic response to environmental chance. From late 1838 to 1859 he believed in designed laws and chance, and this belief, too, has its parallel in his theory. The element of chance in natural selection meant that there could be no detailed plan,in which even man's idea of God would be a necessary outcome of nature's laws (man himself is not a necessary outcome of the working of natural selection).80 But Darwin still believed nature was programmed to achieve certain general ends. We might say that he believed in a general, though not a special, teleology. Natural selection was for him a law to maximize utility, creating useful organs, retaining vestiges for future use. For many years it was a law designed to produce organisms perfectly adapted to their environments. Only later did Darwin come to doubt even this sort of design in nature.81 One way of describing the development of Darwin's evolutionary thought is to say that it shows a gradual abandoning of his “theistic” assumptions, so that by the late 1860s his theory was informed to a slighter extent by notions of purpose and design than it was in 1838 or 1844 or 1859.

Notes: Conclusion Several stages can be identified in Darwin's effort to formulate natural selection. The first stage corresponded, roughly speaking, to the period up to 1844. It was characterized by Darwin's attempt to base his model of geographic speciation on an individualistic dynamics, with species understood as reproductively isolated populations. Toward the end of this period, Darwin's ignorance of the laws of variations and heredity led him to adopt varieties and species as the units of variations. This had the extremely important effect of stimulating him to consider the process of speciation as involving populations. At the end of this period, Darwin also began to regard adaptation as being exclusively toward places in the economy of nature. Thus he faced the problem of integrating the process of natural selection with the process of speciation. Individual variants were the units that fueled the first process, whereas varieties produced new speices. There was no link between adaptation and speciation, except whatever could be supplied by a quasi-historical, developmental idea of optimizing the amount of life. In the second stage, I contend, Darwin's reading of Milne-Edwards crystallized his previous insights into a coherent whole. Milne-Edwards' comments on the advantage of functional specialization could readily be understood in terms of the advantage accruing to the individual, relative to other members of its species, from occupying a different niche. Milne-Edwards' discussion of the division of labor suggested that organisms which moved into unoccupied niches would enjoy reduced competition, and hence a differential advantage in survival and reproduction; thus they would induce the species to do likewise. Rather than base his explanation on an analogy with the artificial economy, Darwin chose the principle of the optimalization of the amount of life per unit area as the overall explanatory principle. The difficulties connected with integrating different levels of description were therefore circumvented, insofar as the problem of diversity and speciation was concerned. Although natural selection considered individuals as the units of selection, and the units of variations were varieties and species, the dynamics of the process understood in terms of natural selection, competition, division of labor and niches could give a plausible account of how individual advantage could be transferred to the species, and how diversity resulted from this mechanism. The problem of the different levels of descriptions was confined to how the properties of variations in individuals (in particular, the frequency of variations and their transmission) were responsible for the assumed variability characteristic of varieties and species. This problem Darwin never solved. A third stage occurred in 1858 with the amalgamation of the tree-of-life vizualization of the process of speciation. Speciation, geographic distribution, and systematics were all then embedded in a conceptual matrix with vast explanatory powers.