The role of theory in experimental life

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The Role of Theory in Experimental Life Nils Roll-Hansen * Robert E. Kohler, Lords of the Fly: Drosophila Genetics and the Experimental Life (Chicago & London: Chicago University Press, 1994), xv + 321 pp., ISBN o-226-45062-7 Cloth $45.00/&35.95, ISBN O-226-45063-5 Paperback $17.95/ E14.25. Robert Kohler’s book about ‘The Fly People’ is a substantial contribution to the history of early twentieth-century biology. Kohler effectively locates classical genetics at the centre of general biology in this period. Kohler’s study of fruit fly research demonstrates very nicely how the new discoveries in physiological, embryological and evolutionary genetics in the 1930s and 1940s by Boris Ephrussi, George Beadle, Edward Tatum, Theodosius Dobzhansky and others grew out of conscious efforts by the core members of the original Drosophila group, Thomas Hunt Morgan, Calvin Bridges, Alfred Sturtevant and Herman J. Muller. They were trying to develop a comparative evolutionary genetics as early as 1914, before the first full chromosome maps had been published, and by the mid-1920s serious efforts in developmental genetics had begun (p. 205). Kohler’s topic, however, is ‘experimental life’. His expressed aim is to study scientific practice and not theory. In this he sides with the new wave of sociological and historical studies of science emerging in the 1970s and 1980s. Kohler rejects traditional concerns with ‘the conceptual and disciplinary dynamics of genetics’ and wants to try ‘a different historical approach, one focused on practices and material culture’ (p. 2). His hope is that investigations of ‘the material culture of scientific work’ will contribute to ‘a general history of science’ accessible not only to the scientific specialists but also to those who are not acquainted with theoretical knowledge of the various scientific disciplines. No doubt a history of science not ‘Balkanized by disciplinary specialization’ is a major desideratum for professional

*Filosofisk institutt, Avdeling Pergamon

for Filosofi, Postboks

1020, Blindem,

0315 Oslo, Norway.

Stud. Hist. Phil. Sci., Vol. 26, No. 4, pp. 673-679, 1995 Copyright 0 1995 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0039-3681/95 $0.00 + 0.00

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Studies in History and Philosophy of Science

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historians

of science as well as the general public (p. 15). But Kohler’s way of

satisfying

this legitimate

desire also faces us with a problem. Can an account that

leaves out theoretical questions and results provide an adequate understanding of scientists’ behaviour and scientific development? This question forms the leitmotif of my review.

Epistemological

Assumptions

Kohler puts the emphasis on scientific practice rather than theory but he dissociates himself from the issues of epistemology and ‘social construction’ characteristic of the new wave in the 1970s and 1980s. In Kohler’s view the epistemic relativism of the new wave was contingent on the peculiar situation of science studies at that time rather than an inherent feature of the new approach that was adopted. The temporary emphasis on social relativism was a consequence of the need to deconstruct the traditional view of scientific ‘facts’ as being simply naturally given. In the 1990s there are other and equally good reasons for doing ‘empirical

studies of experimental

practices’ (p. 3). For Kohler it is ‘the production process itself that is the object of interest--the material culture, social conventions, and moral ordering of experimental production’ (p. 3). And he freely appropriates methods and insight from various constructivist schools. For instance, he finds that Bruno Latour and Steve Woolgar’s ‘pragmatic conception of credibility and truth’ which ‘locates the causes of scientists’ behaviour in the production process rather than in the realm of theoretical beliefs or professional and political ideologies’ is ‘absolutely right and fundamental’. Kohler also concurs with the epistemological point of Steven Shapin and Simon Schaffer that ‘judgements of true knowledge and personal credibility are social conventions embedded in the material, social, and moral fabric of particular communities’

(p. 4).

This is a laboratory study with a difference. Like Latour and Woolgar, Michael Lynch, Karin Knorr and others, Kohler is inspired by the idea of a naturalistic study of scientific ‘practice’, what scientists ‘really’ do when they work in the laboratory or the field.’ But Kohler is much closer to the na’ive realism that most unphilosophical and unreflective

scientists intuitively

The ‘Moral Economy’

adhere to.

of Science

The

key concept in Kohler’s programme for a new general history of science is ‘moral economy’. The concept is borrowed from an analysis of eighteenth-century English bread riots by the social historian Edward P. Thompson where it designates the unstated customs, traditions and moral rules that govern people’s behaviour. With ‘The two most well-known classics in the genre of laboratory studies are presumably Bruno Latour and Steve Woolgar, f&oratory Life. The Social Construction ofScien@c FUCIS(Beverley Hills: Sage, 1979), and Karin D. Knorr-Cetina, The Manufacture of Knowledge. An Essay on the Constructivist and Contextuai Nature of Science (Oxford: Pergamon Press, 198 1).

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The Role of Theory in Experimental Life

this concept and inspiration interesting

new insights

from the new wave of science studies, Kohler gives

into the social dynamics

of the Drosophila

group. He

describes how its original social structure, T. H. Morgan and his ‘boys’, is gradually strained and outgrown.

Lack of ability to adapt to the changing

circumstances,

not

least on the part of the ‘boss’, creates conflicts. Kohler depicts vividly how the work and careers of the various persons involved are affected by the special moral economy of this group. Through comparison and description of interactions he also illuminates more general features of laboratory science.

with other groups

An interesting project would be to compare Kohler’s ‘moral economy’ of science with the ‘scientific ethos’ of Robert Merton and his followers. One significant difference may be between a local and a global perspective, another the difference between a mainly descriptive account and one that is also normative. Kohler’s ‘moral economy’ explains the careers of scientists and the growth and decline of research groups and schools in a ‘naturalistic’ sociological manner. The Mertonians also study the structure and dynamics of the scientific community analysing individual and group careers. In addition the Mertonians assume that the function of this social sub-system is to produce reliable and generally valid knowledge for the rest of society. The ‘ethos of science’ expresses ideals to promote this function.’ While the Mertonians emphasize the difference between science as a social system or institution and science as a set of knowledge claims, this distinction is usually rejected or played down by the adherents of the new wave. Kohler makes good use of his concept of ‘moral economy’ in analysing personal conflicts within the Drosophila group. The junior members did not have regular university appointments but lived on grant money. Their freedom to concentrate exclusively on research was bought at the price of a high degree of personal dependence on the boss, Morgan. Kohler describes the hierarchical structure of the group as a hybrid between a university department and a research institute. Morgan’s authoritarian

style of leadership was complemented

by an often self-effacing

loyalty

from the boys. From early on Sturtevant

was the crown prince. Following

the move to Caltech

in 1928 Morgan promised Sturtevant an independent job as full professor and director of the Biology Division’s department of genetics with the right to hire faculty etc. As it turned out Morgan was not prepared for the large-scale transfer of power that Sturtevant had been led to expect. But rather than rebel openly against Morgan, Sturtevant retreated ‘into gloomy silence’ (p. 123). Kohler also interprets the rift between Sturtevant and Dobzhansky in the late 1930s as a result of the group’s particular moral economy. When Dobzhansky came to the group in 1927 Sturtevant soon became his best support and friend. But in his untenured position as Morgan’s

*For a recent statement of the Mertonian position with a thorough discussion of its relation to the constructivist and relativist ideas of the new wave see Stephen Cole, Making Science: Between Nafure and Society (Cambridge, MA: Harvard University Press, 1992).

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Studies in History and Philosophy of Science

Sturtevant

Dobzhansky

began

to feel uneasy

with the energetic

and ambitious

who was gradually attaining a scientific standing rivalling his own (p.

253ff). In both cases Kohler provides good evidence for his low-keyed but penetrating and revealing

analysis.

Subjective and Objective Aspects of Science

‘Meet Drosophila, the friendly fruit fly’, begins chapter two, which describes how Drosophila melanogaster became a legendary laboratory animal. Kohler’s personification of the fly is strictly stylistic. There is no attempt to make it part of an actor’s network communicating with the scientists in the style of Latour. In Kohler’s account, the fly is mainly an instrument for the fulfilment of the scientists’ intentions. A main purpose for Kohler is to demonstrate the crucial role of the Ay in giving coherence to the research group and direction to its work. Firstly, there was the laborious ‘construction’ of the ‘standard fly’ through the research work of the drosophilists. Secondly, this fly turned out to be a veritable ‘breeder reactor’, a prolific producer of interesting scientific problems and results. It became the material basis for an unusually productive and successful group of scientists. Kohler uses the number of papers published by various members of the group in different periods as his main indicator of scientific productivity. Thus Kohler does not limit his account to the subjective side of the scientific process. He does not only investigate the interaction among the scientists and between the scientists and their social surroundings. He also attends to the main object of their investigations, namely the fly. Still, one might say that he considers the fly as a constructed ‘instrument’ rather than a naturally given object that the scientists intend to understand and explain. This instrumental view of the fly does not give it full status as an object for natural science. Kohler’s neglect of the scientists’ theoretical beliefs and problems gives a subjective bias to his account as a whole. It is through their theoretical concepts and questions that the scientists are most clearly directed toward an external and common world. It is through the intention to understand and explain things and events in this world that their activity becomes meaningful for other groups of scientists as well as for non-scientists. The question which Kohler has to face (in much the same way as Latour, Woolgar, Knorr-Cetina, Shapin and Schaffer) is whether an historical account in terms of ‘production processes’ without reference to the theoretical problems and beliefs of the scientists can give a satisfactory explanation of their behaviour. Or, to put the question in a somewhat different way: must not the objective side of science, namely the properties of the object under investigation, have a central place in any full account of the phenomenon that we call science? No doubt appropriate cultural and social conditions as well as effective instruments are necessary for scientific achievement. But is this sufficient? According to a traditional view of science, fruitful theoretical questions and reliable (‘objective’) registration of observations or experimental

The Role of Theory in Experimental Life

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responses of the object are essential to scientific success. This is what gives empirical science a direction

and distinguishes

it as science. Without

a secure anchoring

of

scientific activity in the objects under study it easily degenerates into wishful thinking.

Chromosome

Theory and Genetic Mapping

Mapping the genes of the fruit fly by discovering their location on the chromosome was a central activity and the most important achievement of T. H. Morgan and his first group of Drosophila geneticists. These events are given due attention by Kohler, but his historical explanation neglects the stimulating and guiding role of theoretical concepts and problems. The chromosome theory was well known in its early forms and much discussed among students and staff in the Columbia zoology department. Morgan had been reluctant to accept the idea of genetic factors as material structures ordered along the chromosomes, but one of its main proponents was Edmund B. Wilson, who was the grand old man of that same department. According to Kohler the invention of genetic mapping was not impelled by theoretical ideas but by the practical need to manage the deluge of mutants that were produced by the new experimental system. ‘The fly people were driven to invent a system of classifying and managing data that was indefinitely expandable. Hence the genetic map. And hence the standard fly: the one could not exist without the other’ (pp. 54-56). As far as it goes this description may be seen as perceptive and unobjectionable. But the local and sociologically oriented perspective is too narrow for a full understanding of the scientific achievement of the Drosophila group. One has to add that neither the mutations nor the map would have had the same scientific interest without their relevance to a general theory about biological inheritance. In his account of genetic mapping Kohler applies an instrumentalist interpretation of the theoretical concepts. This view of the genetic factors and other theoretical entities is different from that of the scientists whose activities he wants to understand and explain.

‘Formula and map are the visual representations,

summary, of different instruments

and alternative modes of experimental

writes Kohler (p. 58). The contemporary collaborators,

for instance,

blueprint

and graphic production’,

accounts given by Morgan and his young

in their book The Mechanism

(1915), are mostly realist. They usually expressed themselves

of Mendelian

Heredity

in a ndive realist manner

about the theoretical entities that they were investigating. Thus Kohler is imposing on the scientists a philosophical theory that is foreign to their own thinking.

The Guiding Role of Theory

There were, however, theoretical and philosophical differences between the members of the Drosophila group as indicated above. Morgan’s scepticism toward the chromosome theory was supported by a well-developed empiricist epistemology. The anti-realist implication of this philosophy is visible in some of his treatments of

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Studies in History and Philosophy of Science

gene theory in the late 1920s and 1930s3 The theoretical difference between Morgan and his young student colleagues difference

is not overlooked

by Kohler. He describes

between the presence and absence theory and the chromosome

the

theory.

While the first admitted only two possible states of a genetic factor the second could accommodate an unlimited number of varieties of a factor located in a certain position (‘locus’). Kohler notes that Morgan continued to work with the terminology of the presence and absence theory for some time after his students had abandoned it, and he tells us of Muller’s repeated remarks that Morgan was confused and unable to comprehend the chromosome theory at first. Kohler also adds new traits to the picture of Morgan as a theoretical straggler reluctantly dragged forward by the innovative ideas of his young students. Morgan most likely ‘regarded the mapping project as the dissertation work of two precocious graduate students’ and preferred himself to concentrate on more important tasks, writes Kohler. When Morgan met with Bridges and Sturtevant on 5 March 1912 and gave the green light to their mapping project he had little idea of what this work could lead to (pp. 61-62). On this background Muller’s repeated recall of how Morgan lagged behind his students in understanding the new genetic theory appears quite appropriate and not ‘obsessive’, as Kohler characterizes it.4 Kohler’s account of scientific practice highlights a challenge to those who believe that theory and realist intentions are essential to the explanation of science; namely, to write a history of the gene. It is high time for more synthesis in the history of twentieth-century genetics and of biology more generally.5

Science as Knowledge 1 have emphasized

and Social System

Kohler’s positive contributions

to our understanding

of the

social side of science. But I have also argued that his view of the scientific ‘production process’ gives too little attention

to the role of the objects and therefore leads to

dubious historical claims at some points. As I have suggested above, neglect of objects is linked to neglect of theory. The theoretical questions that the scientists intend to answer are perceived as questions about an objective and external world. The problem is not so much that Kohler concentrates

on the subjective side of science but that he

seems insufficiently aware of this one-sidedness. It is when his accounts are presented as full explanations of scientists’ behaviour that they become misleading. The difference between science as a social system and science as a system of knowledge is blurred. ‘A discussion of Morgan’s epistemology and its role in his biological research is found in M. Vicedo, ‘T. H. Morgan, Neither an Epistemological Empiricist nor a “Methodological” Empiricist’, Biology and Philosophy 5 (1990), 293-311; followed up by N. Roll-Hansen, ‘Philosophical Ideas and Scientific Practice: A Note on the Empiricism of T. H. Morgan’, Biology and Philosophy 7 (1992). 69-76. 4An account which emphasizes the role of theory is Nils Roll-Hansen, ‘Drosophila Genetics: A Reductionist Research Program’, Journal of the History of Biology 11 (1978), 159-210. ‘The most comprehensive and insightful overview of twentieth-century genetics still seems to be E. A. Carlson’s The Gene: A Crirical History (Philadelphia: Saunders, 1966).

The Role of Theory in Experimental Life

For instance,

when Kohler states that ‘chromosomal

679

mapping generated a set of

rich and leading theoretical problems for the drosophilists

to explore’ (p. 174), this

is to turn things upside down. What made mapping so interesting

from the start was

its potential for answering the problems that the chromosome theory posed. Of course the theories evolved as new facts were established, but that does not eliminate necessity of having theories to guide the research activity.

the

In another place Kohler writes that: ‘Beadle and Ephrussi were inspired not by theories of genes and enzymes, which were as vague as they were ubiquitous, but by specific experimental efforts that were being made within the fly group and elsewhere to connect genetics and embryology. Here were real practical incentives to try something bold’ (pp. 215-216). To deny that theories about genes and enzymes were an essential part of their inspiration appears strange. Such concepts were essential to the discussions that preceded and accompanied their experiments. They could not even have formulated their research problems without such concepts. The important point which Kohler demonstrates so nicely is that a suitable experimental system is essential to progress on the questions posed by theoretical considerations. A satisfactory historical explanation needs to include both theoretical intentions and experimental opportunities. To be fair, Kohler does in many accounts. For instance, in describing work on evolutionary genetics: they this field and when they saw an Drosophila it just had to be exploited

places include the theoretical problems in his the origins of Sturtevant’s and Dobzhansky’s both had a long-standing theoretical interest in opportunity to do relevant investigations on (p. 269). Furthermore, the general picture that

emerges from Kohler’s book exhibits very nicely the guiding and synthesizing role played by general theories about genes and their biological effects, however vague they were. Questions concerning

individual development

and the evolution of species

were part of the theoretical framework within which genetic research was conducted. Kohler’s book on ‘The Fly People’ is not only an important addition to our historical insight and knowledge,

it also presents materials and specific claims that

can help make the current debate on the nature of science and its social role more precise and fruitful. The history of genetics is an excellent field for testing various constructivist, relativist and realist views of science. Genetics has provided some of the most influential

scientific results in this century, and it is loaded with moral values

and political dilemmas.