Scholars have provided competing explanations for this cleavage of professional interests. Daniel Kevles concentrates on the individuals within the eugenics movement. He characterizes the split between the professions as due to an increasing trend toward pseudo-science among eugenicists, and a realization by geneticists that the strategies utilized in agricultural breeding as prescribed by the eugenicists would take too long to totally eliminate genes from the population. Since many harmful genes were found to be recessive genes, individuals that did not express these genes could carry a copy of the harmful gene lying latent in their genome. Artificial selection, however, could only select for genes that had been expressed during development. It had no way of directly visualizing the unexpressed recessive genes. Although his study presents an interesting perception of the union between genetics and eugenics, Kevles fails to recognize that the growing complexity of the genetic component of heredity has as much to do with the geneticists' perception of the eugenics movement as increasingly based on pseudo-science as with the 'perversion' of the discipline of eugenics.
Charles Rosenberg, in an essay characterizing the career of the prominent eugenicist and human geneticist Charles Davenport, also recognizes the union, and subsequent rift, between geneticists and the eugenics movement in the United States. Rosenberg quotes the geneticist Raymond Pearl's characterization of the eugenics movement as "based on pre-Mendelian genetics," and as "outworn and useless as yesterdays melon." Pearl's quotation hints at the dynamism of the theoretical structure of genetics and places the rift at the absorption of Mendelian concepts within the eugenics community. Yet Rosenberg allows the quotation to stand for itself without pressing exactly how Mendelism helped contribute to this professional cleavage.
It is my argument that the researchers of heredity attempted to rationalize organic beings, by selecting parents for these beings that expressed socially desirable characteristics, in order to better predict and control life. Organizations like the American Breeders Association (ABA), whose members were interested in genetics, agricultural research, and eugenics, provided a forum for which research on the mechanisms of heredity was never far removed from the promise of its application.
In the growing field of genetics, the standardization of life involved defining two different conceptual domains in relation to an organism. The first domain accounted for the small variability among organisms that were derived from the same ancestral lineage. This domain was the interactive border between the organism and its surroundings. For the single cell, the cytoplasm represented this domain. The second domain, residing within the nucleus of the cell and protected from the environment by the cytoplasm, accounted for stable, heritable identity. It was this domain that supplied the instructions that standardized each organic being, ensuring continuity between the generations. For the geneticists, it was this stored repository of information that offered the greatest promise for future biological control.
The strategies of eugenicists, based on the ethos and metaphors of agricultural breeders, relied upon assessing the heritable worth of an organism by visual inspection. Practical and moral concerns kept eugenicists from utilizing techniques that the geneticists were relying on in their studies of laboratory animals. Furthermore, because eugenic strategies of social control could not penetrate to the level of the genetic conception of the organism, eugenicists increasingly appeared as pseudo-scientific.
I have divided my paper into two main sections. In the first section, I organize my arguments using individuals as markers for larger channels of discourse. I show how Mendelian genetics was quickly adopted by the ABA because of the promise of control it offered. I then demonstrate how researchers interested in genetics began to define the domain of genetic identity. In the second part of this paper I narrow my focus, concentrating on the change of attitude among geneticists as reflected by the members of the laboratory of Thomas Hunt Morgan at Columbia University. I treat the Morgan lab as a nexus for individuals, social concerns, and experimental strategies. The Morgan laboratory incubated more than the Drosophila they studied. It incubated the careers of many of the scientists who would shape the next generation of biological research. It incubated a new sense of biological identity for western individuals based on the stability of Mendelian characters mapped on the linear rods of the chromosomes. And consequently, it incubated a dissatisfaction with biological control based on the strategies and metaphors of breeders. This dissatisfaction did not keep the Morgan lab geneticists from prescribing their own biological antidotes to the human social condition. On the contrary, each of the researchers I follow outlined his goals for a new, more far-reaching plan of social control uniquely shaped by personal concerns. While forging a more intricate view of life, they were simultaneously forging more intricate formulations of biological social control.
US agricultural reforms adopted the industrial values of rationalization, centralization, and efficiency that shaped so many aspects of turn-of-the-century American lives. Agricultural researchers desired to establish new varieties(a technical term designating a group of organisms in closer relationship than a species) that could combine the productiveness of European strains with the ruggedness of American varieties, and to diversify crop types in an attempt to avoid the overproduction of certain varieties. Two major questions emerged from these concerns: What were the mechanisms of plant physiology? and, What were the mechanisms of cross fertilization and hybridization? As expressed by W. M. Hays, a researcher at the USDA experimental breeding station in Minnesota, the study of genetics became part of a larger drive to rationalize plant breeding and agriculture as an industrial technique:
The work of breed and variety improvements and of breed and variety formation is now going forward, but at a pace too slow for these times when the world is advancing with accelerated speed all along the line. As science, inventive genius, constructive skill, business organization, and great market demands at home and abroad have pushed forward things mechanical, so should ways be found of improving these living things which serve as machines for transforming the substance of soil and air and the force of the sun's rays into valuable commodities.... The energy of the generative cell, and its development into the mature plant or animal, is more abstruse and more profound than the mechanisms of the mightiest locomotive.... As one machine is more efficient than another, so the blood of one generative, or of a small group of generative cells combined into an efficient variety or breed unit, is more valuable than another.
This quotation is marked by the language and the values of the industrial revolution applied to biological organisms. The spirit of the industrial revolution affected both the goals of the breeders and the metaphors of description. Agricultural science, with it's quest for the improvement of biological entities, treated life as a machine. Increasing productiveness came to mean engineering a better machine.
American agricultural researchers' drive for efficiency and rationalization reflected the desires of other aspects of American society. James Beniger, in his book The Control Revolution, argues that in the last half of the nineteenth century the US began a large shift from local, segmented markets to mass organization, utilizing advances in communication technology and data processing. The industrial revolution spurred a crisis of control in the US by increasing material products. This crisis was managed by the control revolution, during which throughputs and material flows were organized by an emphasis on rationalization and efficiency. The goals of breeders were formulated by this drive, and tools or strategies that might help meet the goal were quickly adopted. Mendelism was such a tool.
Founded in 1903, the ABA became a centralized organ for the dissemination of information relevant to the agriculturist. The opening address, given by W.M. Hays, clearly expresses the desire to utilize heredity research to improve agricultural efficiency:
We have assembled at the suggestion of the American Association of Agricultural Colleges and Experiment Stations to consider the improvement of plants and animals. That association for three years has had under favorable consideration the formation of an American Association of Plant and Animal Breeders and those interested in the problems of heredity. That association, which is in touch with scientific and experimental agriculture as is no other organization of the world, has suggested that the scientists in biological lines turn for a time from the interesting problems of historical evolution to the needs of artificial revolution. It asks practical breeders, while seeking financial returns from breeding living things, to occasionally pause and study the laws of breeding. It has invited the breeders and the students of heredity to associate themselves together for their mutual benefit and for the common good of the country and the world. It has thus recognized that the wonderful potencies in what we are wont to call heredity may in greater part be placed under the control and direction of man, as are the greater physical forces of nature. It suggests that the scientists should know the conditions of the living organisms under improvement, and the practices and the problems of the practical breeder, that they may apply their scientific methods to these problems. It suggests to the practical breeders that they, in turn, study the facilities, methods, facts, and theories of the scientists, that they may not only take advantage of the accumulating facts, but may place in the crucible of practical test any promising facts and theories which may be brought out by the scientists.
The ABA sought to develop the theoretical and the applied facets of the study of heredity by suggesting that they could set the agenda for scientific research by defining the important scientific problems and offering the trial ground for accumulating facts. Mendelian genetics was referred to with increasing frequency by the association over the years. As the geneticist William Castle recollected, Mendel was infrequently mentioned at the first meeting in 1903, but by 1907 "papers on theoretical problems began to outnumber those on the purely practical aspects of the subject." Castle continues: "it will be seen that Mendelism was really getting a firm hold in the thinking of the American Breeders Association."
Eugenics also received increasing exposure. The 1908 meeting included papers by David Starr Jordan and Alexander Graham Bell on eugenics; the 1909 meeting included papers by Bell, Jordan, V. L. Kellogg, F. A. Woods, and others. After the 1909 meeting, the association was discontinued and replaced by the American Genetic Association. The association's serial changed it's name to The Journal of Heredity. This magazine continued the ABA's original spirit of promoting a fruitful relationship between scientists of heredity and agricultural breeders. One of the reasons given for changing the name of the association was to emphasize the growing interest of the organization in eugenics.
In the April 29, 1911 issue of the Scientific American Supplement No. 1843, G. Clark Nuttal summarized the relationship between genetics and eugenics in his article "Eugenics and Genetics: 'Good Breeding' and its significance." Both sciences were born from the desire to understand the age old dilemma of inheritance:
The terms are new-the problems they stand for are as old as Cain and Abel. And yet it is well that the nomenclature should be of today, for these terms represent the points of attack at which we of the present, with the latest weapons of modernity, are attempting to storm the hitherto impregnable strongholds of the mysterious heritage of the children of men.
Eugenics was seen as the moral aspect of the problem while genetics was more concerned with mechanism. In Nuttal's eyes, "Genetics is the handmaid of Eugenics" because it will supply the facts that will inform the eugenicists in their delineation of the best way to increase the genetic contribution of "the best classes in the community," while discouraging the "degenerate and unfit from perpetuating their weaknesses." Genetics, the pure science, dealt with mechanisms of inheritance and studied any organism, while eugenics was considered the branch of the applied science that studied humans.
Galton observed that the filial center, or average, of pea seed weights fell closer to the total center of the population than the average of the parents weights did. He interpreted this to mean that organisms possessed a racial center and that the tendency of the filial generation was to return to this center from which the parents had departed. This law became known as his "law of regression of characters." Galton suggested that this tendency of the filial generation to return to center was an argument that progressive evolution could not operate on the small character variability that Darwin had envisioned in his theory of natural selection. Evolution could only come about through the large variations known as sports. Galton also thought that this suggested that only a small portion of an individual's heritable constitution became visible, that there was a "vast but unused power vested in each generation." Indeed, "for every patent element there are countless latent ones." Galton divided an individual's nature into two parts: a variable part, expressed as deviation from the norm, and a constant part, defined as the statistical mean of a population. The latent elements helped contribute to this constant, heritable nature.
Wilhelm Johannsen most clearly articulated the nature of these latent genetic elements. He also established rigorous methods of pure line breeding and Mendelian hybridization as experimental strategies to elucidate latent elements. After two generations of inbreeding, Johannsen selected two different pure lines of self-fertilizing bean plants: a line producing seeds distributed around a mean heavier than the original, and one with a lighter mean. He then bred these lines for several more generations while continuing selection in an attempt to push the means even further away from the original. He found that there was a limit to the alteration of bean weights that selection could offer. He interpreted this to mean that there was a limit to the ability of selection to act on variability. Selection could 'purify' a line but it could not create a new species. Since both lines showed a normal distribution around a mean of seed weights, this suggested that there was a visible variation that didn't exist at the level of the genetic elements. This variation was thought to arise through the interaction of the organism with its environment.
Later Johannsen recognized a different type of variability: the large variations that Galton had called sports. This type of variation arose from "more complicated molecular interactions" within the organism. Johannsen hypothesized that these large internally derived changes supplied the variation for beneficial evolution; he thereby contributed to the definition of a rationalized conception of life. Consequently, all deviations from an idealized norm were explained as variations from interactions with the surroundings of the organism - small variations - or an internal deviance within the idealized nature - large variations. The large variations were the agents for heritable beneficial and destructive change.
Johannsen later stated that Darwin had overemphasized the "scientific value of breeders' testimonies." Johannsen claimed that pure lines were only a recent experimental tool. He intentionally distinguished his pure lines from the pure lines that the breeders had been using. He characterized these as a "questionable and, at any rate, unilateral and insufficient method of practical breeding." He believed that breeders as a lot were
somewhat difficult people to discuss with. Their methods of selection combined with special training and 'nurture' in the widest possible sense of this word are most unable to throw any light upon questions of genetics....
If only back in Darwin's day they had had the correct application of pure line breeding, then many questions about evolution and heredity could have been solved. For Johannsen, a line ceases to be pure when inter-crossing or hybridization "disturbs the continuity" of self-fertilization. The previous conception of pure lines, grounded in the practical application of producing agricultural seed stock, was produced from interbreeding species and was not considered pure by Johannsen. Mendel supplied a notion of unchangeable inherited characters, which Johannsen exploited in his notion of pure lines. Johannsen's frustration with the breeders grew with their continued failure to recognize a pure line of hereditarily continuous individuals according to the stringent standards he had defined. Where breeders had once been seen as illustrative, they were now seen as sloppy. This was mainly because they hadn't applied the methods to recognize the distinction Johannsen articulated. Johannsen had created a stricter notion of purity, but this purity relied on the definition of an idealized conception of biological organisms.
Johannsen is indicative of the drive of researchers, in their quest to rationalize heredity, to isolate a component of continuity within life isolated from the vagaries of experience. In his 1909 paper and his English language review published in 1911 entitled "The Genotype Conception of Heredity," he expanded this argument. In these papers he developed his conception of the phenotype and genotype. The genotypic conception of an organism could be gained by two different ways: through pure line breeding, which would help establish the genotype of populations; or through Mendelian hybridization, which could help define the genetic constitution of an individual. It is impossible to tell from inspection of the individual's phenotype whether they have the same genotype; the genotype is hidden and only amenable to analysis through the above two methods. Selection, artificial and natural, only operates at the level of the phenotype.
Johannsen claimed that the genotype is an "ahistoric" view of the reactions of living beings. He uses metaphors of chemistry to define the fixed characteristic of this different non-visible nature:
This view is an analog to the chemical view, as already pointed out; H2O is always H2O, and reacts always in the same manner, whatsoever may be the 'history' of its formation or the earlier states of its elements. I suggest that it is useful to emphasize this 'radical' ahistoric genotype-conception of heredity in its strict antagonism to the transmission or phenotype-view.
A new metaphorical description was needed to articulate an abstract "ahistoric" view of life.
Johannsen had severed biological identity into two components: the phenotype and the genotype. He then emphasized that the genotype was the authentic aspect of that individual. According to Johannsen, eugenicists and breeders attempted to define the authentic or normal individual through value judgments at the level of race or population. With older breeding techniques, analysis of ahistoric biological identity was only possible by establishing pure lines. Johannsen asserted that visual inspection of the phenotype was an inadequate means of judgment, and self-consciously distanced himself from the ethos and strategies of the breeders. Johannsen grasped that Mendel offered another view towards ahistoric identity through the back cross of Mendelian analysis (a technique that could tell if an individual was homozygous for a specific Mendelian character in only two generations); only through this analysis could one identify the recessive or latent genetic identity of an individual. Two conceptions of the organism resulted: the phenotype, which is the visible nature and a product of the genotypic identity and the surroundings; and the genotype, a steady reservoir of information protected from the environment, existing without external influence, but subject to internal interruption. These two conceptions of biological identity are summarized in the following table:
Large variability through internal reaction
Pure line breeding and Mendelian analyses
Small variability through interaction with surroundings
Natural and artificial selection
Charles Davenport, geneticist and eugenicist, embodied the growing inconsistencies between the eugenic concerns of the breeding agriculturists and the genotype model of heredity. In his 1911 book, Heredity in Relation to Eugenics, Davenport demonstrated a knowledge of the latest developments of cytology in relating the mechanism and repository of the genetic identity, and an acquaintance with the Mendelian independence of assortment of characters. Yet he also spoke of human sexual interaction as breeding, and referred to the material of heredity as blood. These seeming contradictions are packaged with a clear articulation of how the knowledge of genetics has revolutionized agricultural science and how the goals of eugenics should be the eventual application of these techniques to society.
Davenport's eugenics were not the eugenics of Galton. Whereas Galton tried to define characters through the establishment of statistical norms, Davenport utilized the Mendelian concept of the character in an attempt to analyze families. Since Mendelian hybridization could not be performed on humans, the extended familial pedigree became important for Davenport. Human genetic identity was defined as an assemblage of characters. It was these characters that were the source of the continuity between the generations. The correlation between the phenotypic trait and the character was not straight forward. Consequently, unit characters were rarely recognized by the inspection of physical traits: some traits were created by the multiplicity of characters, and some traits were due to the absence of determining characters.
Davenport misapplied Mendel's conception of recessive characters. Mendelian recessive characters are contained within the genetic constitution of the individual, but are only expressed in the homozygotic recessive state. That is, they are only expressed when both of the traits that determine a character are recessive. Davenport, however, equated recessive characters with "relative absence." Characters in relative absence are expressed as a modification of the dominant character, with a visible gradation in the expressed character. Relative absence is different from absolute absence where the character is not expressed because it is not present in the genetic constitution. Relative absence is a character inherited from a single parent; dominant characters are inherited from both parents. In Mendelian genetics one can only ascertain the presence of a recessive character through a two generation back-cross. Davenport's conception of recessive character can be immediately recognized by the presence of the gradated or modified appearance of the expressed dominant character. This misunderstanding of Mendel was convenient for Davenport. Davenport studied human genetics in an environment where arranging a two generation back-cross was considered immoral and impractical.
The bulk of Davenport's book is dedicated to the elucidation of physical traits as characters through genealogical analyses and the mapping of the distribution of characters over geographical distances. Many traits are treated as single characters and illuminated through pedigree analyses including musical ability, memory, mechanical skill, temperament, as well as general bodily energy, and diseases of various organ systems. Although Davenport does see clear cut circumstances where specific traits should not be propagated in the population, the general tone of the book is cautionary. The main thrust is for the gathering of information so that the human race, can be bettered through educating people on what constitutes intelligent mate choice. Davenport warns against legislative enactment at this date. There just isn't enough clarity for such harsh measures as enforced celibacy or sterilization.
The primary offering of the Eugenics Society of Cold Spring Harbor, conceived as an offshoot of the ABA and directed by Davenport, was a central repository of information and eventually a clearing house for education. Davenport encouraged the collection of pedigrees from everyone in the US. All this material would be stored in a fire proof safe. This repository of genetic information would thus be safe from the vagaries of the environment, the same way the encapsulation of the genetic characters within the nucleus protects the individual's heritable constitution from environmental effects. This information storage house was an attempt to reassert an objective viewpoint in order to gain a glimpse of the genetic nature of humankind, while recognizing the limits of the pedigree in genetic analyses.
A subtle irony permeates the writing of Charles Davenport. He appeals to the sense of identity characterized by the elucidation of Mendelian analyses at the level of the individual, but because he cannot utilize Mendelian analytical techniques, he subsumes the importance of the individual to the larger structures of the family and the nation. An individual, in Davenport's vision, is only the vector for the Mendelian character. Judicious marriages will express beneficial characters and repress the harmful. The unit for analyses of these characters is the family, but the assemblage of characters is controlled with an eye toward developing the nation. The record office of the Eugenics Society becomes a metaphorical genotype, a latent national identity, where through education, the patent phenotype of our national identity will be rationally expressed:
The commonwealth is greater than any individual in it. Hence the rights of society over life, the reproduction, the behavior and the traits of the individuals that compose it are, in all matters that concern the life and proper progress of society, limitless, and society may take life, may sterilize, may segregate so as to prevent marriage, may restrict liberty in a hundred ways.
Society has not only the right, but upon it devolves the profound duty, to know the nature of the germ plasm upon which, in the last analysis, the life and progress of the state depend.
The Morgan laboratory has been documented from many personal and historiographic perspectives. Robert Kohler emphasizes the study of the systems of production within the Morgan laboratory. He depicts an environment where individual skills and emotional dynamics contributed to the larger economy of the laboratory. Kohler's argument that "theory is a game that few can play" and that what counts is experimental production, is a helpful emphasis illuminating the internal atmosphere of the laboratory, while demonstrating how laboratories serve in building larger structures in science such as departments and disciplines. My intention is to focus on Morgan's laboratory as a node in a larger web of cultural discourse that reflects, because of its unique properties, the larger professional bifurcations of genetics and eugenics.
Morgan's lab was a magnet for young researchers interested in the study of heredity. In the Morgan lab, students were trained and developed scientific viewpoints through efforts at scientific production. These researchers became some of the most influential scientists of their generation. Morgan's lab also attracted many veteran researchers, who visited the laboratory because of its international standing. In short, it operated as a generative nexus, an incubator, that developed the scientific judgments of students while attracting more seasoned scientific researchers interested in understanding the developments produced within the laboratory.
I will survey the opinions of a few individuals from Morgan's laboratory in an effort to show that geneticists broke from the eugenics movement because it lacked the clarity of the definition of genetic identity that the scientists were creating. This did not mean that the geneticists kept silent on issues of biological social control. On the contrary, the individuals portrayed here each formulated their conception of biological social control that reflected their own unique interests.
T.H. Morgan's 1933 Nobel Address is the clearest articulation of his views on the relationship between genetics and eugenics. It is obvious by this time that he saw the aims of selectively breeding humans as undesirable, except under clear cases of hereditary defect. His argument for this revolved around the claim that
...the complexity of the genetic composition of man makes it somewhat hazardous to apply only the simpler rules of Mendelian inheritance; for, the development of many inherited characters depends both on the presence of modifying factors and on the external environment for their expression.
Morgan made the distinction between the properties that are "implicit in the gene" and the characters that are "explicit in the protoplasm." He suggested an implicit biological identity which can be recognized by genetic analyses and consists solely of the reservoir of information on the chromosomal mechanism, and an explicit biological identity which is the interface between the expression products of the genes and the environment. Morgan reiterated and added to this distinction the historic and ahistoric biological identities elaborated by Johannsen. The table below compares Morgan's elaboration on Johannsen's categories of biological identity.
Implicit identity Explicit identity
Genes Genes and environment
Johannsen (and Galton)
Large variability Small variability through internal through interaction with reaction surroundings
Pure line breeding and Natural and artificial Mendelian analyses selection
However, by the time Morgan began writing this, he had rejected the notion of the simple Mendelian character and consequently began to complicate the relationship between the implicit character and the explicit physical trait. Many genes do not produce singular effects; no longer was there the notion of a strict one-to-one correspondence. The gene for eye color, for instance, also affects life span and body color. Also, many traits are the complex mixture of many different genes. This complicated genetic component defied a general course for breeding humans, even without the added difficulties of environmental influences. Morgan openly criticized Davenport's attempt at a synthesis of Mendelian genetics and eugenics by pedigree analyses. It was an inadequate tool for human social control: "Man is a poor breeder-hence many of these family pedigrees are too meager to furnish good material for genetic analyses." Reflecting the concern for the complexity of implicit biological identity, Morgan then concentrated on the environmental component of explicit identity for a strategy of biological social control. He supported the creation of public hygiene programs, in which the environmental component is directly tamed by the removal of harmful agents, and inoculation against disease, where the environment and the individual interact under more controlled, less threatening, circumstances.
Morgan's relatively soft-spoken concerns were shaped by his desire to define an autonomous discipline of genetics. His Nobel acceptance speech can be read as an attempt to clarify the role of genetics in relation to medical applications as well as an outline for the future of biological social control. Morgan relied on the pure and applied science distinction that G. Clarke Nuttal articulated in his Scientific American article (quoted above), but in this case Morgan sought to ally the pure science of genetics with the applied science of medicine. Genetics would concentrate on defining implicit identity while medicine managed explicit identity. It is no coincidence that Morgan was simultaneously creating a department of biology at California Institute of Technology that was novel in its independence from medical associations.
Dobzhansky wrote the book Mankind Evolving, which articulated his views on evolutionary theory, genetics and their applicability to humans. In this book, Dobzhansky criticized a number of points within the program of the eugenics movement. He parried the traditional claim, as old as Francis Galton's original concerns with natural selection, that humans now are beyond the powers of natural selection, and through misguided benevolence are producing individuals who could be detrimental to the genetic constitution of society. Instead, he claimed that humans are continuing to adapt to new environments and that this should be viewed as a process of natural selection. Therefore, we must be careful not to judge individuals with standards forged under outdated relations between humans and the environment. He also felt most people do not understand the type of fitness that natural selection is actually selecting for. Dobzhansky pointed out that Darwinian selection selects for reproductive fitness, and not the broad cultural fitness required by the eugenicists. Also, he realized that sterilization programs would be ineffective because heterozygous individuals act as carriers for recessive traits.
Dobzhansky's most elegant objection to the eugenics movement revolved around natural selection and the emphasis placed on variability. Specifically, he objected to eugenicists' conception of the 'normal man.' The normal man carries normal genes and defines the adaptive norm from which all other organisms would be selected. He used Sewall Wright's conception of genetic drift to show that the interactive genetic components of a population adapt not only to the environment but to each other; they must form "coadapted gene systems" if beneficial selection will occur. Dobzhansky crossed two races of flies from different geographical localities. From this new generation he isolated ten groups of twenty flies apiece. These groups were colonized separately, but within the same environment. After a year and a half the ten groups of flies were each found to have different genetic constitutions. Each group of flies determined its own gene system derived from the slight genetic variability of the individual flies first selected. For Dobzhansky and Wright, this inherent variation among populations turned out to be the driving force of progressive genetic drift. No longer was value placed on a single adaptive norm; rather, genetic value became multifaceted. The individuality created by variation was no longer a threat to the national gene pool as the eugenicists suggested in their attempts to create hyper-normal individuals. Rather, individuality became the main source of a plural value.
Although Dobzhansky disagreed with the aims of the eugenic societies, he shared with them broad eugenic concerns. He took the same position on hereditary defects that Morgan took, namely, that people carrying these defects must be counseled not to reproduce. But Dobzhansky even added that if the individual with the defect can't comprehend the counseling, then they should be sterilized. For Dobzhansky, writing after the elucidation of the chemical nature of the gene, suggested it was possible to manipulate specific stretches of genetic material. Yet, the real benefit genetics could offer for biological social control was in the distant future - then individual genes could be targeted for directed mutation. Still, the threat was serious enough not to wait for the development of these more specific technologies. Human directed evolution must go ahead.
Hermann Muller worked in the Morgan laboratory from 1912 to 1920, but ended up leaving Morgan's lab under estranged circumstances, convinced that Morgan's group had used his ideas without adequate credit. Muller was the member of Morgan's lab who most seriously embraced the eugenic precepts of directed human selection, and as a result, he was also the member of Morgan's lab to be the loudest in his objections to the path on which the Eugenic Society was moving.
In 1927, Muller published an article that suggested that treatment of germ cells of Drosophila with X-rays raised the mutation rate 15,000%. This finding simultaneously hinted at the fragility of the chromosomal mechanism, and suggested a possible avenue for controlling it. Muller's work with mutations sensitized him to the genetic load of deleterious mutations that we all have, and he perceived a threat to the genetic constitution of society if we did not take natural selection in our own hands in an attempt to decrease this load. In his 1950 article, "Our Load of Mutations," he claimed that the spontaneous mutation rate of humans is great enough to produce "not less than one newly arisen mutant gene in ten germ cells, on the average, and not more than one in two germ cells." The average individual is probably heterozygous for "at least eight genes, and possibly for scores, each which produce a significant but usually slight detrimental effect on him." For Muller, the threat to the human genetic constitution came specifically from "breakage" of the chromosomal mechanism - a susceptibility we all shared. Every individual displayed a unique pattern of weakness that merged indistinguishably with the environment.
The aims of the eugenicists were too simple to address adequately the problem. Muller's talk at the Eugenics Conference of 1932, "The Dominance of Economics over Eugenics," was intended to take the society to task for its simplistic definition of 'unfit,' while espousing his socialist political proclivities. He claimed that
genetic worth is a practically continuous variant, and there is no hard and fast line between the fit and the unfit, nor does relative fitness in the great majority of individuals depend on one or a few pre-specified genes.
Only under "a socially directed economic system" could eugenics programs adequately define a person's genetic constitution as distinct from more capitalistic class conscious definitions of success:
Only the impending revolution in our economic system will bring us into a position where we can properly judge, from a truly social point of view, what characters are most worthy a man, and what will best serve to carry the species onward to greater power and happiness in a united struggle against nature, and for a mutual betterment of its members.
For Muller, separating out the contributions of heredity and environment to explicit biological identity, required a perspective untainted by the values of capitalism. Genetic social management could only be achieved through a revolution in the economic system. In his 1935 book Out of the Night, he outlined his conception of utopia. To ensure the integrity of the genes and the raw material of explicit identity, a breeding program would be instituted that involved inseminating females with cryopreserved sperm from selected, genetically superior males. Muller originally suggested the following for his choices: "Lenin, Newton, Leonardo, Pasteur, Beethoven, Omar Khayam, Pushkin, Sun Yat Sen, [and] Marx." Apparently only males acted as the genetic pinnacle of society. In an attempt to guard against public idolatry, Muller proposed that an individual's sperm be held for twenty years to ensure that the distance of time would allow a more objective choice of genetic worth.
Muller did not champion the concept of variety like Dobzhansky did, but he did recognize the impossibility of a singularly defined norm. The genetic load was too heavy for this. All normal individuals already harbored a number of mutations in their genes. Rather, he asserted his own views of genetic worth by the selection of various males deemed worthy to reproduce on a large scale. With these individuals he offered a genetic goal for biological social control. But without the technology to look into the genetic makeup to evaluate the precise genetic load, Muller decided on making subjective judgments, hoping that his static conception of history could eventually supply the objective glimpse into implicit genetic identity that science lacked.
This did not mean that geneticists devalued human biological control, nor did it mean that they stopped prescribing strategies for human biological management. For the geneticists I have outlined from Morgan's lab, biological social control was taken for granted. Morgan turned towards taming the environment to reassert a sense of control in the confusion over implicit and explicit biological identity, while simultaneously defining a pure science of genetics liberated from the concerns of eugenics and medicine. Dobzhansky called for greater technological improvements before the real diagnosis of human implicit identity could be achieved and managed. Muller thought time and social revolution might be an adequate instrument to give him a glimpse into implicit identity. All distanced themselves from the eugenics movement, not because of its implication of biological control, but rather, because of its inability to see the need to look at implicit identity as defined by genetics. No wonder the geneticists found this new sense of identity so important. They were creating it.
 This article could not have been written without the help of Hans Gumbrecht and Jeffrey Schnapp (who created an incubator of stimulating ideas and methodological approaches), my colleagues Matt Price and Richard Westall (who have challenged and delighted me with their insights), my colleague Christina Holbo (who took the time and effort to work on early drafts of this paper, broadening my intellectual focus and sharpening my prose), and my mentor Timothy Lenoir (whose ideas have inspired me while his suggestions have guided me). Finally I would like to thank my parents, William (1923-1988) and Pat Thurtle, to whom I owe much more than my genetic identity.
 For an analysis of the American contribution to German racial Hygiene see Robert Proctor, Racial Hygiene: Medicine under the Nazis (Cambridge: Harvard University Press)97-104.
 Daniel J. Kevles, In the Name of Eugenics: Genetics and the Uses of Human Heredity (Berkeley: University of California Press, 1985) 164-6.
 Charles E. Rosenberg, No Other Gods: On Science and American Social Thought (Baltimore: The Johns Hopkins University Press, 1961) 96.
 Barbara Ann Kimmelman, A Progressive Era Discipline: Genetics at American Agricultural Colleges and Experiment Stations, 1900-1920 (Ph.D. dissertation, University of Pennsylvania, 1987) 21.
 Kimmelman 378.
 Willet Hays, "Breeding Problems" Proceedings of the American Breeders' Association, Vol.1, pt.2 (1905) 197, quoted in Kimmelman 379.
 James R. Beniger, The Control Revolution: Technological and Economic Origins of the Information Society (Cambridge: Harvard University Press, 1986).
 William E. Castle, "The Beginnings of Mendelism in America" Genetics in the 20th Century: Essays on the Progress of Genetics During its First 50 Years, ed. L. C. Dunn (New York: The Macmillan Company, 1951) 62.
 Castle 63.
 American Breeders Magazine, Vol. IV, no.4 (1913) 177.
 G. Clark Nuttal, "Eugenics and Genetics: 'Good Breeding' and its significance," Scientific American Supplement, No. 1843 (1911) 271-2.
 Nuttal 271.
 Francis Galton, Hereditary Genius: An Inquiry into its Laws and Consequences (1869; repr., New York: St Martin's Press, 1978) xvii.
 Galton xx.
 Galton xx.
 See Garland E. Allen, "Naturalists and Experimentalists: The Genotype and the Phenotype," Studies in the History of Biology Vol. 3, (1979): 179-209. Allen points to Johannsen's phenotype and genotype distinctions as unifying the experimental and naturalistic traditions by delimiting the domains of analyses.
 Wilhelm Johannsen, "The Genotype Conception of Heredity," The American Naturalist, Vol. xlv, no. 531 (March, 1911) 158.
 Johannsen 143.
 Johannsen 143.
 Johannsen 142.
 Johannsen 135.
 Johannsen 135.
 Johannsen 139.
 Johannsen 139.
 Johannsen 139.
 Kevles, 48. And Charles B. Davenport, Heredity in Relation to Eugenics (New York: Henry Holt and Co., 1911) 6-26.
 Davenport 18.
 Davenport 18.
 Davenport 204-51.
 Davenport 267.
 Robert Kohler, "Drosophila and Evolutionary Genetics: The Moral Economy of Scientific Practice," History of Science xxix (1991) 368.
 Lily E. Kay, The Molecular Vision of Life: CalTech, The Rockefeller Foundation, and the Rise of the New Biology (New York: Oxford University Press, 1993) 94-97.
 Garland E.Allen, Thomas Hunt Morgan: The Man and His Science (Princeton: Princeton University Press) 227-234.
 Thomas H. Morgan, "The Relation of Genetics to Physiology and Medicine," The Scientific Monthly Vol. 41, 17.
 Morgan 8.
 Morgan 8.
 Morgan 16.
 Kay 71-73.
 Theodosius Dobzhansky, Mankind Evolving: The Evolution of the Human Species (New Haven: Yale University Press, 1962) 129.
 L. C. Dunn and Theodosius Dobzhansky, Heredity, Race and Society (New York: Penguin Books, 1946) 69-76.
 Dobzhansky 283.
 Dobzhansky 283.
 Dobzhansky 325-33.
 Elof A. Carlson, Genes, Radiation, and Society: The Life and Work of H. J. Muller (Ithaca, Cornell University Press, 1981) 145-50.
 H. J. Muller, "Our Load of Mutation," American Journal of Genetics Vol. 2, No. 2 (June, 1950), Also found in H. J. Muller, Studies in Genetics: The Selected Papers of H. J. Muller (Bloomington: Indiana University Press, 1962) 568.
 Muller, "Our Load" 568.
 Muller, "Our Load" 568.
 H. J. Muller, "The Dominance of Economics over Eugenics," A Decade of Progress in Eugenics (New York: Williams and Wilkins, 1934) Quoted in Carlson 179.
 H. J. Muller, "The Dominance of Economics over Eugenics," A Decade of Progress in Eugenics (New York: Williams and Wilkins, 1934) Quoted in Carlson 179.
 H. J. Muller, Out of the Night: A Biologist's View of the Future (New York: Vanguard Press, 1935), Quoted in Carlson 394.