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Script, Code, Information: How to Differentiate Analogies in the "Prehistory"

of Molecular Biology

Article in History & Philosophy of the Life Sciences · January 2012

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© 2012 Stazione Zoologica Anton Dohrn

Hist. Phil. Life Sci., 34 (2012), 595-626

Script, Code, Information:How to Differentiate Analogies in the “Prehistory”

of Molecular Biology

Werner Kogge

Freie Universität Berlin - Institut für PhilosophieBMBF-Forschungsverbund “Embodied Information”

Habelschwerdter Allee 3014195 Berlin, Germany

AbstrAct - The remarkable fact that twentieth-century molecular biology developed its conceptual system on the basis of sign-like terms has been the object of numerous studies and debates. Throughout these, the assumption is made that this vocabulary’s emergence should be seen in the historical context of mathematical communication theory and cybernetics. This paper, in contrast, sets out the need for a more differentiated view: whereas the success of the terms “code” and “information” would probably be unthinkable outside of that historical context, general semiotic and especially scriptural concepts arose far earlier in the “prehistory” of molecular biology, and in close association with biological research and phenomena. This distinction, established through a reconstruction of conceptual developments between 1870 and 1950, makes it possible to separate off a critique of the reductive implications of particular information-based concepts from the use of semiotic and scriptural concepts, which is fundamental to molecular biology. Gene-centrism and determinism are not implications of semiotic and scriptural analogies, but arose only when the vocabulary of information was superimposed upon them.

Keywords - History of molecular biology, semiotic vocabulary, scriptural concepts, code, information, metaphors

Pflger’s, Beitr zur Lehre von der Respiration”: pp 251-367. Page 342 is the page I refer to.

Introduction

The conceptual system of molecular biology rests upon a large number of semiotic concepts such as “letter,” “transcription,” “reading,” “code,” “information,” “message,” and “translation.” The resulting terminology

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– with phrases such as “open reading frame,” “transcription assay,” “ed-iting,” “translational read-through,” “high throughput library screen,” “sequence motifs,” or “cDNA encoding proteins” – cannot be attrib-uted merely to the purposes of popularization, as has been observed for the case of the “draft” of a genome (Bostanci 2010). Rather, it is constitutive in the sense that today the terms are “all implemented into powerful technologies” (Rheinberger 2001, 124).1

On the other hand, the past few decades have seen the formation of a discourse criticizing the deployment of semiotic vocabulary in molecular biology, from the skeptical reflections of scientific actors in the 1960s and 1970s,2 via Susan Oyama’s The Ontogeny of Information of 1985, to the extensive studies and controversies that have marked the debates of the past ten years.3

Some of the criticisms of molecular biology’s semiotic terminology have been formulated as an objection to the terms’ metaphorical na-ture. We read, for example, that the concept of information in molecular biology is “little more than a metaphor that masquerades as a theoreti-cal concept” (Sarkar 1996, 187).4 Other authors do not criticize the use of metaphorical language as such, considering it unavoidable, but the problematic effects and blind spots that are caused by specific meta-phors. Thus, for example, it is the result of “powerful metaphors of in-formation and programs” that the “discourse of gene action . . . lent the cytoplasm scientific invisibility” (Keller 1995, 24). Crucial to many of these criticisms is the argument that molecular biology’s semiotic termi-nology implies a gene-centered and deterministic view that does not do justice to the complexity of cellular processes. This is the claim made, for

1 John Maynard-Smith succinctly expressed the cardinal function of semiotic concepts in molecular biology when he drew a close parallel between the genetic code and human communication (“The signals are symbolic, just as words are,” Maynard-Smith 2000b, 217) and noted “that in describing molecular proofreading, I found it hard to avoid using the words ‘rule’ and ‘correct’” (Maynard-Smith 2000a, 78).

2 As early as 1963, Erwin Chargaff observed mockingly (if with less than complete historical accuracy) that between 1937 and 1944 “the concept of ‘biological information’ raised its head and began to sport a multicolored beard which has become ever more luxurious despite numerous applications of Occam’s razor” (Chargaff 1963, 163).

3 The most important works to be noted in this context are Refiguring Life: Metaphors of Twentieth-Century Biology (1995) and The Century of the Gene (2000) by Evelyn Fox Keller and Who wrote the Book of Life: A History of the Genetic Code by Lily Kay (2000); of the philosophical debates, most relevant is the one that arose in the wake of John Maynard-Smith’s The Concept of Information in Biology, documented in Philosophy of Science 67 (2000). On more recent debates, see Griffiths (2001); Nehrlich and Hellsten (2004); Jablonka and Lamb (2005); Rosenberg (2006); Stotz (2006); Stotz, Botanci and Griffiths (2006); García-Sancho (2006); Ŝustar (2007); Stegmann (2009); Bergstrom and Rosvall 2009; Godfrey-Smith 2008; Chow-White, García-Sancho 2011.

4 Similar views can be found in Janich (1999) and Mahner and Bunge (2000).

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example, by Lily Kay when she argues that the “information discourse” rests on a notion of the genetic code as “the site of life’s command and control” that was born in the historical situation of World War II and the Cold War, whereas today the aim must be “to loosen the grip of ge-netic determinism” (Kay 2000, 5, XIX).

The present paper aims to take further the idea that it is particular metaphors that imply problematic effects and invisibilities. I argue that the confrontation between advocates and opponents of semiotic termi-nology in molecular biology can be defused to a considerable extent: a reconstruction of different discursive and research traditions between 1870 and 1950 shows that the development of semiotic concepts – and in particular scriptural concepts – was historically antecedent to, and systematically independent of, the communication-technology concepts of code and information. And although the philosophy and history of science have delivered convincing arguments that the terms “code” and “information,” derived from the technical transmission of information, are closely associated with a hierarchical, deterministic logic, the same does not apply to scriptural vocabulary. Script-based terms were initially only expressions of a particular image of the biology of heredity that arose out of the confluence of different research traditions, an image that was – and is – by no means necessarily gene-centered or deterministic.5

In this paper, the distinction between scriptural vocabulary and the vocabulary of communication technology is established by means of a historical presentation. In the emergence of molecular biology, semiotic and scriptural concepts did not arise only with the rise of discourses of communication technology and cybernetics, but earlier and in close con-nection with specific biological studies and phenomena.

If I address different genetic, biochemical, and biophysical discourses under the label of a “prehistory” of molecular biology, this is not to pre-suppose a teleology of development that is somehow inevitable. Rather, I assume a notion of stabilization in the history of science, based on what Ian Hacking, following Andrew Pickering, called “robust fit.” “Robust fit” refers to a stabilization in the relationship between “theory, phenom-enology, schematic model, and apparatus,” arising out of the “dialectic of resistance and accommodation” in the experimental process (Hack-ing 1999, 72). A stabilization of this kind comes about through a large

5 The talk of script and text tends to valorize the role of cellular processes as against that of DNA, as can be seen, for example, when one of the best-known cell biology textbooks uses the analogy with scriptural concepts to show that the shape of the living being cannot be derived from the “DNA text”: “a complete description of the DNA sequence of an organism […] would no more enable us to reconstruct the organism than a list of English words in a dictionary would enable us to reconstruct a play by Shakespeare” (Alberts et al. 2004, 267).

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number of correlations and corroborations, but it is not predetermined: the course of research might have taken a different route and molded dif-ferent, stable patterns.6 Although the “prehistory” of molecular biology is not a single, continuous experimental system, this does not preclude us from regarding the conceptual system of molecular biology as it was elaborated by, in particular, Francis Crick in the early 1950s as the prod-uct of a stabilization of different discourses, practices, and technologies.

The “robust fit” approach implies a second important point. In this way of thinking, it becomes immediately plausible that conceptual inno-vations may occur on different levels. The spectrum reaches from inter-ventions that are close to the research and the phenomenon, to those on the level of general “theoretical models” and “speculative conjectures” (Hacking 1999, 71). The central claim of my historical reconstruction is therefore as follows. The scriptural concepts that emerged between 1870 and 1950 not only linguistically, but also pictorially and technologically, prove to be analogies that were delineated within the research process and close to the phenomenon, whereas the concepts of code and infor-mation should be viewed as terminological loans on the level of general theory. Regarding the status of the metaphors, then, a distinction can be drawn between the scriptural concepts that took shape as catalysts and products in the course of a process of stabilization in research, and the superimposition onto them of the concepts of code and information, a superimposition that would probably have been impossible without the historical situation of World War II and the Cold War.

Criteria for Script

Before turning to the historical context, some theoretical consider-ations on the concept of script are in order. To define scripts strictly as notations of spoken language is merely a prejudice. Looking at how we use words such as “reading” and “writing” for mathematical or chemi-cal formulas, for musical or dance notations, and for programming or accounting, it becomes apparent that it is not the reference to language that is central to the semantics of scriptural terms, but instead the ob-jectifying representation of a structure of an object field, in the form of a configuration of definite individual signs. The use of scriptural terms, therefore, is not bound to a specific object field, but appears to be mo-

6 On the relationship between robust fit and contingency in the development of science, see also Trizio (2008).


tivated whenever a phenomenon fulfils certain general criteria.7 These include:

Differences in an order A correlate with differences in an order B that is separate from A. For example, differences between individual notes in a musical notation correlate with differences between the sounds in a performance of the piece. A mere collection of elements without correla-tion to a second order (for example, ornamental elements, game pieces) is usually not described as writing. The duality of two systems of order-ing and the referential relationship between them is thus a crucial con-ceptual criterion.

The structure of order B is represented by combining discrete ele-ments taken from order A. Texts are configurations built from a limited pool of element types (the alphabet), in which, in principle, each ele-ment type can occur any number of times (an average English text, for example, contains a characteristic number of elements of the type “a”, “b”, “c”, …).8

Normally, scriptural notations are ordered in a linear fashion. The lineation can be horizontal, perpendicular, diagonal, or even crooked; what matters is not a precise line in space, but the possibility of cre-ating directionality by means of lineation and, thereby, of creating an ordered succession of writing or reading acts.9 A third, central criterion for scriptural concepts is therefore sequentiality – and the simplest way of producing sequentiality is to link together elements in a directional, linear chain.

Referentiality, the combination of elements, and sequentiality are pragmatically relevant criteria for scriptural concepts. Techniques of writing down, of rewriting, of transcribing or calculating all rely on be-ing able to wield a “medium” that correlates with a second “object” without physically interacting with it, works with unambiguously defin-able elements which can be combined as freely as possible, and enables an ordered sequence of acts and therefore ordered processes.

Methodologically, these aspects will help to draw out larger relation-ships within the thicket of the historical material. I will trace how con-cepts of duality, of the combination of elements, and of chains became

7 For more detail on this, see Kogge and Grube (2007).8 Nelson Goodman explored the theoretical foundations for a notational combinatorial logic

of definite elements in his explanation of the term “notational scheme” (Goodman 1976).9 For written notations, this orderly sequence does not necessarily need elements to be lined up

(examples such as long division or “jumping” to footnotes show that written presentations allow jumps). The crucial point is that the link between the acts of reading and writing not be dissolved (a sack filled with letters, or even a tidied box of type pieces, does not qualify as something written).

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connected within the epistemic formation of a linear, combinatorially variable, and referential sequence of elements – a formation that sug-gests the scriptural terminology.

The Continuity of a Biological Problem

The limitation of many histories of molecular biology is that they do not reach back far enough in time and, as a result, fail to pay sufficient at-tention to longer-term, overarching biological questions. I would like to open up that wider scope of inquiry by juxtaposing two passages written at an interval of roughly seventy years. The first quotation is taken from an 1886 review of August Weismann’s The Continuity of the Germ-plasm as the Foundation of a Theory of Heredity (Weismann 1885/1889).

The mysterious phenomenon we call heredity has always been a puzzle to the thinking mind, and has again inspired lively discussions in very recent times: the phenomenon that an organism reproduces itself over and over again, and a single cell, namely the sperm or egg cell, is capable of unfolding a complete set of traits of the “parent”, from whom it separates, in the new individual growing from it. (Review 1886, 6)

Almost seventy years later, the same set of problems, albeit presented in a different diction, appears in Francis Crick’s work. Under the sub-heading “A Code for Heredity?” he writes:

[t]here remains the fundamental puzzle as to how DNA exerts its hereditary influence. A genetic material must carry out two jobs: duplicate itself and control the development of the rest of the cell in a specific way. (Crick 1954, 60)

The two quotations reveal two fundamental problems of biology. First, how is it possible that the same forms are reproduced over and over across many generations (a spruce will always produce another spruce, a plant louse another plant louse, a human being another human being) and, second, how is it possible that the development of every single living being with its specific organization and form emerges from a tiny amount of material?

The difference between the forms of expression in these two excerpts marks the path from nineteenth-century biology to molecular biology. While the nineteenth century still referred to sperm and egg cells as car-riers of the genetic material, it is now a molecule of sub-cellular dimen-sions, namely DNA, that is thought to hold the key to the genetic puzzle. However, in the 1950s the structure and function of this molecule came to be conceptualized in semiotic terms. In May of 1953, Crick and Wat-


son coined the wording that has been so momentous for the develop-ment of molecular biology.

[I]n a long molecule many different permutations are possible, and it therefore seems likely that the precise sequence of the bases is the code which carries the genetical information. (Watson and Crick 1953, 965; emphasis added)

I will now show that the expression “sequence of the bases” refers to a scriptural-notational structure, closely tied to the biological questions and phenomena which grew out of the interaction between different traditions of knowledge from the 1870s on. It was this structure which provided the foundation for conceptualizations using the semantics of encoding and transmission technologies in the 1940s and 1950s, even though it does not itself imply the deterministic relationship that the later versions attempted to express.

The Origins of the Phenomenon of a Material, Continuous Referen-tial Order

In his survey of the history of heredity in The Logic of Life, François Jacob succinctly captures the duality with which we are concerned.

[W]ith what Nägeli called “trophoplasm” and “idioplasm”, there appeared a duality in the organism as a whole: the trophoplasm, which formed the major part of the body, was responsible for nutrition and growth; the idioplasm, in contrast, represented only a small component in volume, but played an essential part in reproduction and development; it was the substratum of heredity. (Jacob 1982, 215)

Jacob’s formulation reveals how the fundamental biological question we saw in 1885 and 1954 finds expression in the assumption of a basic duality. On one hand, there is a genetic substance which remains con-stant over generations and on the other, there is an individual organic apparatus, the articulation of whose form and whose life processes are determined by genetic substances.

To assume two ordering systems as a means of addressing these two aspects of the biological problem is actually a theoretical turn that had already occurred a hundred years before Nägeli’s influential treatise Mechanisch-physiologische Theorie der Abstammungslehre (1884). This turn occurred as part of the shift from the previously predominant pre-formationism towards an epigenetic theory. Epigenesis entails the notion that the organization of an organism’s form is not to be found preformed

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in the germ, but only emerges as a result of specific forces or principles of movement. In 1781, Johann Friedrich Blumenbach, for example, char-acterized his nisus formativus, Bildungstrieb, or formative force, as being “distinct from the other qualities of living bodies, (sensibility, irritability, and contractility) as from the common properties of dead matter: that it is the chief principle of generation, growth, nutrition, and reproduc-tion” (Blumenbach 1792, 20). What was new in the nineteenth century was initially only the idea that the formative entity was not a force or a drive, but itself a material – though a material containing special forma-tive potentials. Here we see the new configuration of the fundamental biological problem during the last quarter of the nineteenth century: it has to be possible to understand the material structure of the genetic substance in such a way that the substance both ensures the continu-ity of individuals’ forms over generations and underlies the respective development of those individual organisms. My choice of the general, common verbs “ensure” and “underlie” is deliberate, for the following decades struggled with precisely the issue of how to conceptualize the material passing of a form from parents to offspring and the specific de-velopment of form, starting from a single cell and resulting in the living figure of a multicellular organism.10

As the title of his work suggests, Nägeli was looking for a mechanistic answer which, as we will see, led him nonetheless to imagine mechani-cal production as being also the production of a semiotic composition. He assumes “that a richer morphological articulation and a greater divi-sion of labor in the developed stage corresponds to a more composite ordering of the smallest particles of idioplasm” (Nägeli 1884, 25). Nägeli expresses this correspondence in the notion of an “image,” which would suggest a representational relationship, the genetic substance being a vi-sual representation of the physical organism. I use the conditional form because Nägeli introduces the idea of an image merely as a hypothesis. “The idioplasm of the germ would therefore be the microcosmic image of the macrocosmic (fully developed) individual”, he writes ( Nägeli 1884, 26; emphasis added). The sentence appears at an explanatory junction in his argumentation, and is immediately clarified. “But of course this does not mean that the micelles of idioplasm correspond to the cells of the mature organism in an analogous order. On the contrary, these two orders are fundamentally different” (Nägeli 1884, 26). At stake, then, is not a representational correlation that would imply an “analogous ar-

10 On further developments, and on whether the split into two separate orders already laid the foundations for the “reductionist worldview of a genetic determinism” (61), see Müller-Wille and Rheinberger (2009).


rangement” (Nägeli 1884, 26) between the corresponding orders, but in-stead the relation between two “fundamentally different” orders. Nägeli is, once again, operating within the context of the problems around epi-genetic duality. He takes two steps to distance himself from preforma-tionist theory: in contrast to the preformationist notion of the miniature model, materialization as an image means an initial translation into a semiotic system; in a second step, the assumption of a more abstract sys-tem abrogates the relationship of analogy to the organic form. But how does Nägeli envision this more abstract system?

Nägeli writes that the concept of idioplasm rests upon “the ordered assemblage [Zusammenordnung] of the smallest particles” (Nägeli 1884, 26); that is, the “arrangement” [Anordnung] (Nägeli 1884, 27) and “configuration” [Configuration] (Nägeli 1884, 38) of the elements into micelles. Thus, the idioplasmic system is no longer conceived as an analogous image, but rather as a basic combinatorial logic: the cells “allow for an almost indefinite number of combinations regarding their composition out of parts” (Nägeli 1884, 44). In addition, Nägeli con-tinues, forms change slightly from generation to generation so that, in defiance of preformationism, it appears “practically impossible that the idioplasm actually stores all the thinkable combinations […]. Rather, it seems that the combinations are composed from the elements in each case” (Nägeli 1884, 44).

At this point, Nägeli presents a comparison with piano playing in order to address the question of how something enormously polymor-phous can emerge from something so very small (an egg cell) without already being contained in that cell as a miniature model.

We have to imagine that the idioplasm unfolds the hereditary factors of various organs similarly to the way the piano player expresses on his instrument the consecutive harmonies and disharmonies of a piece of music. He will always strike the same string for each A, and for each of the other notes. The groups of adjoining micelle rows in the idioplasm are like those strings, each representing a different elemental form. (Nägeli 1884, 44)

The arrangement of the elements, thus, occurs through a process of combination, in which a limited number of elements can be combined to produce a number of different forms that is, in principle, unlimited. Each individual note can be produced any number of times, enabling the combination of ever differing melodies. This relationship between the inventory of elements and the “compositional expression” is, pre-cisely, a characteristic of notational sign systems, and it is therefore not surprising that Nägeli – in his assumption of a limited number of ele-ments of idioplasm – also introduces a comparison with language. He

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writes that “a limited number” suffices, “just as language is composed of a limited number of words and music of a limited number of notes” (Nägeli 1884, 67).

Nägeli thinks of idioplasm as a network that, analogous to nerve cords, consists in part of continuous cords and in part of the concatena-tion of a chain of pieces of cords (Nägeli 1884, 58). While this network is “fundamentally different” from the substances governing vital func-tions, it is nevertheless a coherent structure of the living being. Writing only a year afterwards, August Weismann drew attention to the open question of exactly how a coherent structure of this kind can effectuate the “thousand different structures and differentiations of cells in one of the higher organisms” (Weismann 1889, 182). Nägeli needs an organiz-ing entity – analogous to a piano player – that can create a differentiated work out of the recombination of the elements.

In Die Continuität des Keimplasmas, Weismann gives a more radi-cal form than Nägeli did to the duality of genetic substance and organ-ism, by assuming that the “nuclear substance must be the sole bearer of hereditary tendencies” (Weismann 1889, 179). This idea of radically separating the genetic material from the vital functions of the organism allowed him to hypothesize that

a part of the specific germ-plasm contained in the parent egg-cell is not used up in the construction of the body of the offspring, but is reserved unchanged for the formation of the germ-cells of the following generation. (Weismann 1889, 168)

By isolating the germ plasm, Weismann tried to solve the problem of the continuity of form. He put it very succinctly. How is it possible that

we find in all species of plants and animals a thousand characteristic peculiarities of structure continued unchanged through long series of generations; we even see them in many cases unchanged throughout whole geological periods? (Weismann 1889, 165)

The answer is that genetic substance is not subjected to the diverse and varying history of somatic development at all, but forms an inde-pendent material unit, insulated from the ontogenetic development of the individual.

Weismann conceives of the material unit of genetic substance as germ plasm comprising “that part of a germ-cell of which the chemical prop-erties – including the molecular structure – enable the cell to become, under appropriate conditions, a new individual of the same species” (Weismann 1889, 174). But, he wonders, how is it “that such a single cell


can reproduce the tout ensemble of the parent with all the faithfulness of a portrait?” (Weismann 1892, 165).

Trying to comprehend the relationship of genetic substance to soma, Weismann develops terms such as “carrier of characteristics” and “de-terminants” to describe how the genetic substance, safe in the cell nu-cleus, can shape somatic development and form without itself entering into any physical interactions. As Weismann articulates this relationship, he, like Nägeli before him, builds a bridge to semiotic terminology. It is, writes Weismann, in the “complicated unbundling of the determinants” that “the transmission of traits of the most general kind – that is to say, the blueprint of an animal” (Weismann 1893, 69; emphasis added) takes place. In this case, too, the theoretical starting point of the duality of two materials leads to the concept that the realization of the organism is semiotic.

The subsequent research paradigm of genetics was initially able to set aside the problem of how genetic substance relates to the soma, pre-cisely because the basic duality of two categorially different order sys-tems had by then become terminologically established. When, in 1909, Wilhelm Johannsen introduced the term “gene” and the distinction be-tween genotype and phenotype, he created the precondition for the field of genetics – emerging around 1900 in the wake of the much-quoted multiple “rediscovery” of Mendel’s laws – initially to treat the material structures and processes of heredity as a “black box.” This becomes es-pecially clear in the programmatic approach of Thomas Hunt Morgan’s research group, whose work revolved around the question of how phe-nomenal characteristics of the organism correlate with places (loci) on the chromosomes. For this correlation, it did not matter whether genes even existed as material entities or what these entities, if they did exist, might consist of. Morgan said in his acceptance speech for the Nobel Prize in 1934:

[I]t does not make the slightest difference whether the gene is a hypothetical unit, or whether the gene is a material particle. In either case the unit is associated with a specific chromosome and can be localized there by purely genetic analysis. Hence, if the gene is a material unit it is a piece of a chromosome; if it is a fictitious unit, it must be referred to a definite location in a chromosome – the same place as in the other hypothesis. (Morgan 1965, 315)

In the following years – wherever the question of genetics was not central – the duality of gene and organism faded from view, in particular in the context of attempts to shed light on the material structure of ge-netic processes. A factor in this was that researchers looked to proteins to explain both functions, the genetic and the organic. The heart of the

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“Nucleoprotein Theory of the Gene,” as Olby called it (Olby 1974, 99; see also 101-115), was the idea that nucleic acid and proteins were a functional unit; the genetically relevant specificity lay in the proteins, whereas nucleic acid was viewed only as a supporting substance or a template of protein replication (Olby 1974, 105 ff.). Here, too, an el-emental duality was assumed, but that duality was not a duality of two substances, one in charge of the continuity of form across generational succession and the other in charge of shaping the concrete individual organism. Only when the division between the labor of nucleic acid and protein came to coincide with the distinction between genetic predispo-sition and organic form, did biochemical research link up with earlier questions on genetics and physiological development. At the moment when this occurred – when genetic predisposition could be identified with a specific substance of a specific molecular structure, and organic life processes with another substance of another specific structure – one of the foundation stones for the conceptual edifice of molecular biology was laid.

For this to happen, it was necessary to split up the concept of a “nu-cleo-protein.” In the 1940s, the idea of genes correlating with specific chemical reactions stimulated by specific enzymes gradually took shape. This notion found its sharpest expression in Beadle’s and Tatum’s “One Gene – One Enzyme” hypothesis in 1945 (Olby 1974, 145). However, only when it became clear through other research (also in the mid-1940s) that protein-free DNA could be a functionally determinant molecule11 did researchers begin to identify the gene with DNA and to view the correlation of genes and enzymes as that of DNA and enzymes. Even though this notion raised doubts for years to come, it became the estab-lished frame of thought within which Crick and Watson’s early-1950s studies moved (Olby 1974, 204).

Crick’s above-cited text from 1954 expresses this most clearly. Soon after his mention of genetic material’s “two jobs,” Crick – referring to the signs of Morse code – argues that the recombination of a DNA se-quence might hold all genetic information. He then inquires further about the structure of this code, asking “what precisely is it a code for?” (Crick 1954, 61). The answer had been gradually emerging since the Cold Spring Harbor Symposium of 1947, when the idea of a transition from DNA to RNA to enzymes arose in a high-profile arena (Rhein-

11 Olby illustrates this by quoting from a 1944 work by Avery et al.: “What did come out clearly in the discussion at the end of the ’44 paper was that DNA was much more than a mere ‘midwife molecule,’ it was not just a structural frame, for it was ‘functionally active in determining the biochemical activities and specific characteristics of pneumococcal cells’” (Avery, Macleod and McCarty 1944, 155, cited in Olby 1974, 188).


berger 2000, 649).

It is therefore very natural to suggest that the sequence of the bases of the DNA is in some way a code for the sequence of the amino acids in the polypeptide chains of the proteins which the cell must produce. (Crick 1954, 61)

Most important for the present argument are the expressions to be a code for and to encode (which Crick uses in the same context: “there is enough DNA in a single cell of the human body to encode about 1,000 large textbooks” [Crick 1954, 60]). The grammatical structure of both expressions articulates the relationship between two sides: A is a code for B; B is translated into code A.

The fundamental duality of two orders, already apparent in Blumen-bach’s theories and conceptualized by Nägeli as a material and by Weis-mann also as a spatial duality, now appears as the relationship between two substances which are biochemically different, one envisioned as a code for the other. I will discuss later how the term “code” came into play. For now, it is important to note that molecular biology took shape in the continuity of a research problem that presupposes a duality of two material orders (order A and order B), such that order A “ensures” or “underlies” the form of order B.

Now, considering that order A is supposed to be a formatively de-termining but at the same time physiologically immune order, it may become plausible that this starting point left open a structural gap, a placeholder attracting semiotic-semantic vocabulary by way of its own inner logic. We will now see that a very specific set of semiotic terms sug-gested itself, namely terms from the field of notation and scripturality.

The Genesis of the Phenomenon of a Linear Sequence of Combina-torial Elements

Let us briefly return to Nägeli. What his work does not yet contain is the idea that the combinatorial elements of idioplasm are ordered in a linear sequence. Nägeli does ask whether “perhaps the fibers in the nucleus which can be made visible with dye might be taken for strings of idioplasm” (Nägeli 1884, 65), but he ascribes genetic specificity (“the constancy of hereditary traits over generations”; Nägeli 1884, 38) not to the linear rows of micelles, but to the combinatorial logic of a horizontal cut. However, improved microscopical techniques yielded new evidence about the structure of genetic material. Anton Schneider and Emil Flem-ming (in 1873, 1879, and 1882) used dyeing methods to render visible

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nucleic fibers (see Figure 1) and in 1881 Wilhelm Pfitzner was able to break these fibers down and explore their internal structure further. Using a new system of lenses to examine a salamander larva, Pfitzner discovered amitosis patterns “whose fibers were not, as described else-where, homogeneous and regular, but […] seemed to consist of many individual granules” (Pfitzner 1881, 290).

This fiber structure “built from a sequence of granules,” often associ-ated with a pearl chain or a rosary (Pfitzner 1881, 309), offered a new ba-sis for interpreting the elemental arrangement of genetic factors. Within this framework, Wilhelm Roux, as early as 1883, understood amitosis as a process during which heterogeneous granules are strung together and “split into two while maintaining the order” (Roux 1883, 11; emphasis added).

In the 1890s, August Weismann combined his theories of heredity with these descriptions of chromatin structures. Weismann had already assumed chromatin, being the constant element in cell division, to act as the vehicle of hereditary traits. Working from Nägeli’s term “idioplasm,” Weismann named the chromosome fibers, which are shortened to rods during cell division, “idants,” and the segments that sit on these idants “ids” (Weismann 1892, 130), an id being a unit of properties passed on from the ancestors to the developing organism.

Fig. 1 - From: Flemming1882, Fig. 34-38, Tafel III.

Fig. 2 - From: Pfitzner 1881, 290.


Sexual reproduction creates variants of idants through the recombi-nation of ids. The idants duplicate and split lengthwise during meiosis, meaning that they “render possible an almost infinite number of differ-ent kinds of germ-plasm, so that every individual must be different from all the rest” (Weismann 1892, 135). It becomes clear in Figure 4 just how closely Weismann associated the idea of a recombination of hereditary traits with the idea of a pearl-chain structure of the chromosome. There, in “B” (the letter is missing here, it refers to the figure on the right) “the loops have split and at the same time a rosary-like composition emerges” (Weismann 1902a, 383).

Weismann explained his observations as follows. “When we observe […] in some animals larger loop- or rod-like ‘chromosomes’, and when these […] are composed of a row of granules, then we will have to re-gard each of these granules as an Id” (Weismann 1902a, 383).

In other words, in Weismann’s work we find a model whereby the germ-plasm – which in correlation with the somatoplasm opens up

Fig. 3 - From: Weismann 1892, 137, fig. 3.

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the duality of genetic substance and vital processes – is imagined as a pearl-chain-like structure whose particular combination of elements de-termines the properties of the individual organism. Not unlike Nägeli, Weismann argues that rather than a “depiction” of the entire being be-ing laid down in the genetic material, it is the “collaboration of all of its ids” (Weismann 1902b, 43) that constitutes each individual right from the beginning. Nägeli’s notational and combinational logic thus finds a material foundation in Weismann’s complicated structure of hetero-

geneous elements (granules) lined up in a particular string-like order. Weismann had little to say, though, about how exactly the predisposition and recombination of these elements relate to phenotypical properties. Only with the gene cards of Morgan’s genetics, which also showed linear sequences, would progress be made on this point.

The “rediscovery” of Mendel’s genetics around 1900 gave a new boost to research on breeding, but for experimental genetics, biochemical and physical structures of cellular processes were still considered irrelevant, as Morgan’s Nobel Prize lecture showed. For Morgan, the notion of chromosomes as a string-like structure resembling a pearl chain sufficed as a material basis. As Figure 5 indicates, the crossover of chromosomes investigated by Morgan’s Drosophila Group continued the visual tradi-tion of Weismann’s genetics.

Fig. 4 - From: Weismann 1902a, 383.

Fig. 5 - From: Morgan et al. 1915, 60.


However, the “pearls” making up the chromosome threads or rods are here associated with Mendelian factors. Studying the behavior of the factors during crossover allowed inferences to be made about their distances and ordering sequences ( Morgan et al. 1915, 68). A “strong argument” emerged “that the factors are actually arranged in line in the chromosomes” (Morgan et al. 1915, 65). In terms of visual representa-tion, this notion found expression in the first gene cards (Figure 6).

These cards show Mendelian factors, i.e. potential phenotypical properties, in a linear sequence. For the first time, a specific correlation emerges between a linear sequence of genetic factors and the properties of the phenotype. The chromosome thread now becomes a “pearl chain” of locations correlating with proper-ties. Its linear sequence immediately suggests writing down the Mendelian factors as a sequence of letters. “Let us write the factors derived from one parent […] in the order which they have on the map” (Morgan et.al. 1915, 67), notes Morgan, and offers the visualization in Figure 7.

We see here how, thirty years after Nägeli’s analogy between idioplasm and combinations of signs, the ge-netic substance is now considered recordable as a linear sequence of let-ters, not in the sense of a mere trans-lation but in the sense of the image of a structure (Krämer 2003, 163). “It is supposed that at least the order of the factors in the diagram represents their real order” (Morgan et al. 1915, 68) – i.e. their actual order on the

chromosome thread. By retracing how the disciplines that would even-tually open the genetic black box and describe its biochemical material also arrived at images of chains that could be understood and recorded as sequences of letters, we will be able to delineate the most important motivations governing the emergence of molecular biology.

Fig. 6 - From: Morgan et al. 1915, Frontispiece.

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Biochemical Chains, Sequences and Successions of Letters

Around 1858, Friedrich August Kekulé, one of Emil Fischer’s teach-ers, developed the theorem of carbon-carbon compounds, which he ex-panded in 1878 to include the idea of carbon chains.

The separate atoms of a molecule are not connected all with all, or all with one, but, on the contrary, each one is connected only with one or with a few neighbouring atoms, just as in a chain link is connected with link. (Kekulé 1878, 212)12

Already at the very beginning of the time frame regarded in this essay as the “prehistory” of molecular biology, a figure of thought arose that conceived of fundamental life processes as resting on chain-like mol-ecules in which elements combine in a great variety of ways. The unifor-mity of these combinatorial elements, however, contradicted the idea of

12 Kekulé was inspired by Eduard F. W. Pflüger‘s, “Beiträge zur Lehre von der Respiration. Über die physiologische Verbrennung in den lebendigen Organismen” (1875, 342). See also Olby (1974, 5).

Fig. 7 - From Morgan et.al. 1915, 67.


associating them with genetic substance, such as idioplasm. The most influential figure in the historical development of the dis-

course around the structural analysis of biochemically relevant sub-stances is surely Emil Fischer. From the late 1880s, Fischer studied the organization and function of enzymes, and analyzed the structure of pro-teins using synthetic procedures. His work became the reference point throughout the entire “prehistory” of molecular biology whenever the structure of proteins was discussed. For Fischer, this structure is marked overall by “the formation of long chains with diverse variations in their sequence” (Fischer 1906, 22). By repeating the steps of synthesis, he succeeded in building artificial protein molecules from amino acids; he called them “polypeptids” (Fischer 1906, 10). As opposed to the arti-ficial products, he assumed for the natural proteins “that nature never produces long chains of the same amino acids, but instead prefers mixed forms in which the amino acids change from link to link” (Fischer 1906, 51).

However, the procedure of structural analysis did not remain limited to proteins. Already in 1893, Albrecht Kossel had concluded that chro-matin was at least in part made from nucleic acid (Olby 1974, 75), but he, too, perceived the much more complex structure of proteins as hold-ing the key to the genetically critical processes. Kossel’s descriptions of proteins as rows of building blocks closely resembled Fischer’s notion. In his Harvey Lecture in 1911, Kossel compares them to a train.

The number of Bausteine [sic] which can take part in the formation of the proteins is about as large as the number of letters in the alphabet. When we consider that through the combination of letters an infinitely large number of thoughts may be expressed, we can understand how vast a number of the properties of an organism may be recorded in the small space which is occupied by the protein molecules. It enables us to understand how it is possible for the proteins of the sex-cells to contain, to a certain extent, a complete description of the species and even of the individual. (Kossel 1911, 45, emphasis added)

We are now in the year 1911. Weismann had associated hereditary traits with the pearl-like units on chromatin threads, but had nothing to say about their biochemical constitution. Morgan and his group had just started to correlate places on the chromosome threads with phenotypi-cal properties, but had systematically avoided inquiring into biochemi-cal aspects. Yet even then, the biochemical perspective made it possible to establish a connection between the problem of physiological devel-opment and theories of heredity. Regarding the linear chain structure of proteins, it appeared possible to understand how both continuity of form and the developmental potential of a differentiated organism could

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be found in a single cell. The figure of thought that made this possible was the analogy drawn between the elemental chain structure of the pro-tein and letter combinations, between properties of an organism and expressions of thought. Kossel’s choice of terms documents the continu-ity of a horizon of inquiry that determined the “prehistory” of molecular biology, echoing the way Nägeli and Weismann had framed their ques-tions thirty years earlier and foreshadowing Crick forty years later. At the same time, his formulation indicates just how important the discourse of researching biochemical molecular structures was to that history.13

Despite this continuity, the “prehistory” of molecular biology is not a linear narrative that leads straight to Crick’s and Watson’s ideas. There was a period in the early-twentieth century when the aggregate theory of colloidal particles gained acceptance. According to this theory, bio-molecules did not consist of long chains, but of an agglomeration of smaller molecules. The enormous length of the presumed chain mol-ecules led crystallographers, too, to question the polymer concept in the 1920s (Olby, 6ff.). Only in the 1930s did the idea of long chains gradu-ally regain strength, due to Hermann Staudinger’s research using the ultracentrifuge and the resulting idea of the macromolecule (Olby 7ff.).

Of longer-lasting influence was an idea known as the Tetranucleo-tide Hypothesis. In 1931, Levene described nucleic acid as “constructed each of one set of its four building blocks […] at most from shorter or longer monotonous sequences of such tetranucleotides,” meaning that they “could not be carriers of biological specificity” (Rheinberger 2000, 644). This fed into the protein paradigm of the gene, which, as I have hinted, was based on the assumption that only the most complex mol-ecule of the cell could be a carrier of hereditary traits.

A further problem resulted from cognitive barriers between different discourses. Because of such obstacles, as Olby points out it was far from obvious “to make the connection between the linear sequence of the genes and that of the amino acids in a polypeptide chain” (Olby 1974, 116 ).

Yet in fact that connection had been made again and again since Kossel, in continual elaborations of the concepts introduced by Nägeli, Weismann, and Fischer. In 1927, the Russian experimental biologist Nikolai Koltzoff, turned to Nägeli’s notion of micelles precisely because he found the boundary “between the colloidal and crystalloid state” in-creasingly blurred (Koltzoff 1928, 352). Admitting that “today, we still do not know much about the structure of protein molecules,” and con-

13 Olby rightly notes that Fischer’s and Kossel’s approach led to the sequential analysis of proteins at the end of the 1940s.


sequently not much about “the structure of chromatin” (Koltzoff 1927, 360), he arrived at the idea that each protein molecule is generated by a “crystallization of amino acids and other small protein fragments present in the solution surrounding it” (Koltzoff 1927, 362f.).

In this “propagation” (Koltzoff 1927, 363) of identical forms, Koltzoff saw the basis of heredity and growth. He framed it as a “process of assimilation, i.e. the complete approximation of the new protein molecules, generated from the amino acids, to the patterns of molecules al-ready in existence at that point” (Koltzoff 1927, 361). In developing his idea of how the pattern of protein chains is constituted, Koltzoff reverts to Emil Fischer’s model of a polypeptide made of eighteen amino acids, which he visualized as shown in Figure 8.

The image clearly indicates the chain structure in which the different elements are strung together. This chain structure of eighteen elements allowed for a much more complex recombination than what seemed pos-sible in Weismann’s work. “The number of possible isomers during the intramolecular repositioning of the 18 amino acids is very large, approximately one quintil-lion” (Koltzoff 1927, 361). Referring to this linear ar-rangement of distinct elements, Koltzoff continues his explanation.

Should we wish to take on the task of printing in the simplest form, in the way the logarithm tables are printed, this quintillion of isomers of the octakaideca peptides (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, R, S, T; B, A, C, E, F, G, H, I, J, K, L, M, N, O, P, R, S, T, etc.), and if we had, to complete this task, at our dis-posal all the world’s currently existing printing presses, putting out 50,000 volumes with 100 print sheets each per year, the completed work would take up as many years as have passed from the archaic period till today. (Koltzoff 1927, 362)

By invoking such an unimaginable number of combi-natorial possibilities, Koltzoff pursues two goals. First, he wants to show that the immense combinational ca-pacities of natural protein molecules – of which the oc-takaideca peptide is only a fragment – makes it possible to fathom “that all of the innumerable traits each hu-

Fig. 8 - From: Koltzoff 1927, 360, fig. 16.

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man being inherits from his father are enclosed in the twenty-four dif-ferent chromosome molecules in the sperm head” (Koltzoff 1927, 366 ).14 Second, it becomes evident that chromosomes remain constant in their original order during cell division, because “the probability of all the separated parts coming together anew in their previous order is not higher than the probability of all the disassembled letter blocks for a print sheet positioning themselves on their own and by coincidence in their previous order” (Koltzoff 1927, 367f ).

Koltzoff’s choice of an analogy between molecular and scriptural structures obviously arises from certain properties that are also char-acteristic of writing: a lasting, linear arrangement of distinct elements, whose exact order is constitutive and is therefore replicated in identical

patterns (Figure 9).Fig. 9 - But what does this order ac-

tually contain? In Koltzoff’s and Kossel’s work, we find the bridge leading from molecular structures to genetics, already with the reference to Morgan.

If we assume that the essential part of the chromosome consists of long protein molecules […] then this provides Morgan’s notion of the chromosome as a linear row of genes with a clear, concrete foundation. The radicals of the chromosome molecule, the genes, have a very particular place in this row and the tiniest chemical change in these radicals, e.g. the tearing-off of some atoms and the substitution of those atoms with others (the substitution of hydrogen with methyl) must appear as the cause of new mutations. (Koltzoff 1927, 368)

Note that Koltzoff also describes chemical and physical manipulations within the logic of notational operations: they are figured as the removal and ex-change of distinct elements, producing effects on a different, namely the pheno-

typical level (“mutations”). The idea that the character and function of proteins depend on the

arrangement of their elements in a chain reappears frequently in the late

14 Note how gender relations are portrayed one-sidedly as a matter of course.

Fig. 9 - From: Koltzoff 1927, 367, fig. 17.


1920s.15 The possible connection between the pearl-chain formation of proteins and Morgan’s gene cards, too, repeatedly attracted attention (Olby 1974, 103f).

Dorothy Wrinch took a further step in linking genetics to biochemis-try in 1935, when she proposed a model of the chromosome’s structure that drew on her mathematical background. She summarized the state of research.

The genetic constitution of a chromosome is capable of linear specification – so runs the first requirement of genetics. Proteins according to the work of Fischer [...] contain polypeptides and as such are capable of linear specification. These two facts, one from classical chemistry, the other from the closed system of genetics, illume one another. I locate the genetic identity of a chromosome in its characteristic protein pattern. The linearity which has persistently and consistently dominated genetics as an experimental and observational science is then provisionally interpreted as an expression of the linear pattern in the protein molecules of the chromosome micelle. (Wrinch 1936, 557)

Wrinch operates in the same discursive environment as Koltzoff. Like him, she combines the approaches of Fischer and the Morgan school, and Nägeli’s notion of micelles plays a role as well (although she does not name him). For our purposes, it is important to note that Wrinch portrays the two linear arrangements, the genetic and the biochemical, as rows of letters and deploys the term “sequence” for, as far as I can see, the very first time in the “prehistory” of molecular biology. Wrinch de-picts the fusion of two chromosomes as follows: “then two separate se-quences abcdef, ghijkl give place to one sequence abcdefghijkl” (Wrinch 1936, 553).

As becomes obvious here, the assumption that the linear succession of protein molecules within a molecule chain is responsible for genetic iden-tity, prompts the use of sequences of letters and of groups of letters to re-cord that succession. Put slightly differently, the employment of script is based on the assumption of a structural analogy between a chromosome and writing.16 Although Wrinch described the material structure of the chromosome within the nucleic protein paradigm as a configuration of protein and nucleic acid, her crucial contribution was to connect genetic specificity with a sequential arrangement of molecules. It was this figure

15 E.g. in John B. Leathes: “There are not more than about twenty different amino acids, so that some of them must occur several times in the chain […]. In any such isolated protein it is probable that the order as well as the proportion in which each amino acid occurs in the molecule is fixed, and it is this specific order and proportion that accounts for the specific character and properties of the protein” (Leathes 1926, 388).

16 Similar notation styles can be found in Bergmann and Niemann 1937, 188.

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of thought that, in the years thereafter, would provide the framework for analyses of physical structures and biochemical sequences. At the Cold Spring Harbor Symposium on Quantitative Biology in 1938, William Astbury followed directly in Wrinch’s footsteps when he presented the results of his studies of X-ray structures, which supported the hypothesis of a “linear sequence of genes” based on protein chains. Pointing to the various possibilities of configuration and folding of these chains, he con-cluded: “It is but natural to assume […] that they form the long scroll on which is written the pattern of life” (Astbury and Bell 1938, 114). In the 1940s, new techniques of fractionation allowed Fred Sanger and his research group in Cambridge to sequence proteins – explicitly as a con-tinuation of Emil Fischer’s work (Chaderevian 1996).

With Sanger and Astbury, we have reached the immediate scientific environment of Francis Crick and James Watson; that is, the connec-tion between the crystallographic and biochemical research groups in England at the beginning of the 1950s was close enough for Crick and Watson to be able to work with both Astbury’s pictures and the first re-sults of Sanger’s sequence analyses.17 Two epistemic reorientations were still necessary, both of which took place during the 1940s. The first was the conceptual shift away from proteins or nucleo-proteins and towards DNA as the hereditary substance and the second was the move away from the Tetranucleotide Hypothesis, to dissolve the fixed order of the nucleic acid bases so that DNA could emerge as a combinatory sequence with the potential to become hereditary substance. In terms of the histo-ry of ideas, this considerable accomplishment embodied the move from the thinking developed around the protein molecule to the nucleic acid molecule, giving shape to a substance, DNA, which was devoted exclu-sively to the two genetic tasks, and not to any task involving physical life processes.

We see, therefore, that in the “prehistory” of molecular biology the different strands of tradition gave rise to an ever firmer picture of genetic substance as a sequential arrangement of elements which manifests itself materially in a linear chain structure. We also see that this finding sug-gests the analogous reference to scriptural phenomena such as letters, texts, and scrolls, as well as the regular use of linear letter sequences on the level of technical notation. Faced with the phenomenon of a se-quence that is durable and constant--that is constituted of a recombina-tion of distinct elements, and that relates referentially to a second order--it seems eminently sensible to resort to scriptural concepts, forms of

17 See Watson’s letter to Max Delbrück on March 12, 1953 (Watson 2001, 208-210); Chaderevian (1996); García-Sancho (2010); Hall (2011).


representation, and terms. This notion of sequence, with all its scriptural implications, has – as we have demonstrated – a decades-long tradition in genetic and biochemical discourses, and it is closely tied to genuinely biological problems and research.

Code, Information, and a Confusing Blend of Analogies

The term “code” entered the picture only after almost all of the crucial theoretical steps we have reconstructed in the “prehistory” of molecular biology had been taken. In his book, What is Life? The Physical Aspect of the Living Cell (1944), Erwin Schrödinger uses the term “code-script” to refer to the genetic structure for the first time. A detailed analysis of Schrödinger’s text (of which I can only present some conclusions here) reveals motives for this usage that are far less closely linked to biologi-cal phenomena than were the motives that led to the notion of a letter sequence.

In his book, Schrödinger offers a perfectly period-appropriate sum-mary of the biological problems. He takes the gene to be a “large protein molecule” (Schrödinger 1967, 30), a common assumption in the 1930s and 1940s. With Darlington, he presents the belief that the striped struc-ture on the chromosome threads embodies the genes (Schrödinger 1967, 30); with Muller and Morgan, he describes the inheritability of muta-tions (Schrödinger 1967, 34ff. ); and he poses the fundamental problem of biology in the way we have seen in the work of Nägeli, Weismann, and Crick. “It has often been asked how this tiny speck of material, the nucleus of the fertilized egg, could contain an elaborate code-script in-volving all the future development of the organism” (Schrödinger 1967, 61). It is at this theoretical juncture that Schrödinger introduces the term “code.”

Let me use the word “pattern” of an organism in the sense in which the biologist calls it “the four-dimensional pattern”, meaning not only the structure and functioning of that organism in the adult, or in any other particular stage, but the whole of its ontogenetic development from the fertilized egg cell to the stage of maturity, when the organism begins to reproduce itself. Now, this whole four-dimensional pattern is known to be determined by the structure of that one cell, the fertilized egg. Moreover, we know that it is essentially determined by the structure of only a small part of that cell, its nucleus. […] It is these chromosomes, or probably only an axial skeleton fibre of what we actually see under the microscope as the chromosome, that contain in some kind of code-script the entire pattern of the individual´s future development and of its

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functioning in the mature state. (Schrödinger 1967, 20-21) This passage is the first occasion in the “prehistory” of molecular biol-

ogy where the word “code” appears. In its content, we easily discern the familiar biological problem. Well-known figures of thought surface: the duality of genetic substance and organism and the relationship between the two structural units, expressed here in the form of order A contains structure and functions of order B as a kind of code. Would anything change if we replaced this last phrase with “as a kind of letter sequence”?

The inherent polysemy of the word “code” derives from its two his-torical roots, “in the public sphere of law and in the covert sphere of cryptography”(Nöth 2000, 216). Schrödinger calls on both meanings when he speaks of Morse code, on the one hand, and of the code of law, on the other. While a code of law, such as the Code Napoléon, “contains a prescription,” cryptographic codes are “secondary sign systems,” i.e. systems of signs representing other systems of signs (Nöth 2000, 216). Schrödinger’s argument can be read as a subtle strategy to evoke both sets of meanings connoted by the term “code,” and to merge them. The fact that he refers not to the organism, but to the pattern of the organism contained in the genetic code already marks a decisive turn in this direc-tion. It evokes an image in which the genetic structure refers primarily to a different formal structure and only secondarily, via this second struc-ture, to a living being. The theme of the “pattern of an organism” may have been Schrödinger’s motivation for then also invoking the idea of a secondary sign system, as opposed to speaking of letter sequences. That motivation is evidently rooted in the question of ordering, the perspective that the physicist Schrödinger applies to address biological problems:18 It is not the living organism but its ordering principle--its pattern--that characterizes it as a being nourished by negative entropy (Schrödinger 1967, 72f. ). However, the idea that a being in its living, phenomenal form might have a pattern that could be interpreted as semiotic, had thus far not appeared in the “prehistory” of molecular biology. Based on the biological phenomena, it had always seemed reasonable only to regard the structure of genetic substance as a combination of elemental signs, and the life processes and forms of living beings as products of this combination – not as sign systems in themselves. Just as it hardly makes sense to say that the performance of a musical piece is coded in the notes (rather than written down) or that the construction of a house is coded in the architect’s plans (rather than drawn or designed), there will hardly be factual reasons in the “prehistory” of molecular biology to identify genetic substance with a secondary sign system. Furthermore, the notion

18 See Keller (1995, 65-103); Yoxen (1979).


of a code is not only ill-founded with regard to its biological context; be-yond that, the term tends to cover up fundamental biological questions because of its other meaning, the “code of law.” Regarding the issue of how the complete form of an organism can be contained genetically in a tiny molecular structure, Schrödinger writes that there is no question of adopting a code “arbitrarily, for the code-script must itself be the opera-tive factor bringing about the development” (Schrödinger 1967, 61-62). Elsewhere, he expresses this thought in the shape that would later be so widely quoted. “But the term code-script is, of course, too narrow. The chromosome structures are the development they foreshadow. They are law-code and executive power – or, to use another simile, they are archi-tect’s plan and builder’s craft – in one” (Schrödinger 1967, 22).

The introduction of the notion of a code, therefore, was not only accompanied by a textualization of the physiological, it also ascribed agency to the genetic substance. From then on, genetic substance does not simply find expression in scriptural terms. Instead, it becomes a code-script that is able to produce the organism as plain text. Once we understand how this concept of the code of law as a self-executing pre-scription is motivated, it becomes obvious that there is much to be said for the analyses of critics such as Oyama, Kay, and Keller, who detect the presence of a metaphysical construct, an “unmoved mover,” in these ideas.19 Indeed, in its use of the term “code” molecular biology lost its bond with biological phenomena.

The situation becomes even more problematic when the term “in-formation,” in the shape of the idea of “information transfer,” is super-imposed onto this conception. When Schrödinger set out his physical philosophy of the living in 1943/44, information as a term did not yet play any role for biological inquiry. Cybernetics, information theory, and mathematical theories of biological automata only slowly condensed into a discursive field over the following years. By the end of the 1940s, it had gained some prominence through a number of publications. Norbert

19 Along with Lily E. Kay, Susan Oyama and Evelyn Fox Keller also expressed this critique incisively. “A material object housed in every part of the organism, the gene seemed to bridge the gap between inert matter and design; in fact, genetic information, by virtue of the meanings of in-formation as ‘shaping’ and as ‘animating’, promised to supply just the cognitive and causal functions needed to make a heap of chemicals into a being.” (Oyama 2000, 14; emphasis in the original) “This [... ] way of talking endowed the gene with a most curious constellation of properties. At one and the same time, the gene was bestowed with the properties of materiality, agency, life, and mind. [...] Part physicist’s atom and part platonic soul, it was assumed capable simultaneously of animating the organism and of directing (as well as enacting) its construction.” (Keller 2000, 46f) “In a single masterly stroke, Crick encapsulated the imperative logic of the genetic code and the ideology and experimental mandate of the new biology: genetic information, qua DNA, was both the origin and universal agent of all life (proteins) – the Aristotelian prime mover – according to Delbrück.” (Kay 2000, 30)

622 Werner Kogge

Wiener’s Cybernetics or Control and Communication in the Animal and the Machine and Claude Shannon’s The Mathematical Theory of Commu-nication were published in 1948. In 1949 and 1952, John von Neumann brought the topic to the public sphere with his lecture series The Theory and Organization of Complicated Automata and Probabilistic Logics and the Synthesis of Reliable Organisms from Unreliable Components (Kay 2000, 111) and the ten interdisciplinary Macy Conferences between 1946 and 1953 provided an important catalyst for the confluence of bio-logical and mathematical concepts.

The history of cybernetics and its entanglement with the inquiry into the structures of the organic has been extensively documented and dis-cussed (Kay 2000; Keller 1998; Galison 2001; Hagner M., Hörl E. 2008), as has the technical term “information” in the sense of messaging tech-niques as it was used in this discourse. However, what still needs to be more clearly emphasized is the following crucial point. If we place the introduction of the term “information” in the context of a “prehistory” of molecular biology as reconstructed here, we see that this central term veils the biological question rather than sharpening its contours, sus-pends the problem rather than resolving it. After all, the question was how to understand the organism’s process of formation (in the sense of a reproduction of the same) from something that is phenomenally completely different (namely the elemental structures of the genetic sub-stance); in other words, how to comprehend the obviously effective gen-esis of the organism’s organizational form. By introducing the concept of information and thus creating an ontological entity – “information” – that was assumed to be contained in the DNA and capable of being stored and transmitted, the question of how to understand this “mys-terious” formation process is masked. By assuming the form as always-already given and ontic “information,” the eminent process of the form’s genesis is conceptually cloaked.

Repeated superimpositions by layers of terminological borrowings, culminating in a reformulation in the terms of information theory, have rendered molecular biology’s terminology questionable in its relation to the problems and phenomena. When Crick writes, “the sequence of the bases acts as a kind of genetic code”, adding “Such an arrangement can carry an enormous amount of information” and finally asking “how this information might be transmitted” (Crick 1954, 60f.; emphasis added), he merges the different concepts – whose heterogeneity and chronologi-cal distinction I have reconstructed here – into a single convolute, one which can only be considered plausible on the surface and only under very specific discursive conditions.

The idea of a combinatorial and referential sequence of elements


only started to acquire attributes of deterministic control and execution once it became superimposed with notions of encoding and information transfer. The scriptural terminology did not imply these powers at all. We do not conceive of texts, sheets of music, blueprints or recipes as be-ings with agency which autonomously produce performances or things, but as structures in need of competent interpretation. To put it differ-ently, textual structures do not also contain the rules of their execution or performance (trying to textualize those rules would mean having also to regulate the use of the regulation, and so on ad infinitum). Scriptural terminology is therefore highly unlikely to foster what the critique of molecular biology names determinism.

Granted, scriptural terminology also runs the risk of obscuring differ-ences and specificities. However, its inherent potential to describe and name fundamental life processes closely tied to actual phenomena has by no means been exhausted – too quickly did those concepts become superimposed with notions closely associated with the possibility of cal-culating and controlling, far more closely than is the case for reading processes, for example. But if we set our claim to know above our claim to control, we can probably expect to find as yet untapped heuristic and conceptual potential in the perspective adopted by research on reading and writing.

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