Henri Atlan, La fin du " tout génétique " ?Vers de nouveaux paradigmes en biologie, Paris: I.N.R.A. Editions, 1999, 90 pp., illus., 39France, for History and Philosophy of Life Sciences
This book is based on a public lecture delivered in May 1998 as part of a series entitled ‘Sciences in question’. It is indeed Atlan’s main goal to ‘question’ molecular biology, to investigate how molecular genetics introduced its dominant paradigms into the whole of biology.
Atlan’s book is a welcome contribution, particularly from this perspective. It should be placed within the broader, commendable effort undertaken in France by biologists such as Antoine Danchin and Michel Morange, who in their latest books (La barque de Delphes and La part des gènes, respectively, both published in 1998 by Odile Jacob Editions) criticized the exaggerated explanatory power given to genes—to the detriment of proteins, for example. As with his peers, Atlan starts with the example of the so-called ‘mad-cow disease’, taking up more generally the matter of prion theory. The term was introduced in 1982 by S. Prusiner to describe the diseases caused by an abnormal and self-catalytic folding of a protein (pp. 21 and 76). He then explains how research on protein folding has been left on the sidelines for the last forty years.
Atlan, who decries the short shrift given to historical background in most scientist’s writings (p. 11), explicitly takes an historical approach. His position is better understood in light of his career as a theoretical biologist, since the beginning of the 1960s working mostly in biophysics with particular attention to the philosophy of science, ethics and Judaism. He recently published the first half of Les étincelles du hasard (Sparkles of Chance) at Editions du Seuil, where all these different interests converge.
Atlan continues to be linked with what is (fashionably) called the ‘second cybernetics’, based on the idea of order from noise. Strongly influenced by information theory, which he championed in France, Atlan deepened the concept and introduced the notion of ‘complexity from noise’ in his book on biological organization (1972). This is the theoretical basis from which he analyzes the metaphor of ‘genetical program?’ dominant today, which he unequivocally denounces in the first part of La fin du tout génétique.
First, he shows that DNA replication errors (‘noise’ for telecommunication engineers or ‘mutations’ for geneticists) may be seen as ‘the source of progressive augmentation of diversity and complexity of living creatures’ (p. 27). Current research which he has participated in and which he alludes to in his text uses information theory in the analysis of immune defenses. Another by-product of information theory—the theory of algorithmic complexity—enables him to tackle a new question: should DNA be considered as a program or as data? Atlan makes the importance of this question clear with the following statement:
In the description of a natural object, one has to distinguish between on the one hand, a ‘program’ part which gives the eventual meaning of its structure, making then a kind of finality at least apparent, defining a class of objects sharing the same structure and the same finality, and, on the other hand, a ‘data’ part which specifies a particular object within this category (p. 31)
Atlan next introduces the notion of ‘complexity with meaning’ (or ‘sophistication’), referring to his work with M. Koppel, and shows how appropriate it is to use the term Data-DNA. The ‘whole genetics’ approach that he denounces relies, on the contrary, on the Program-DNA metaphor—the cellular machinery only serves to read and execute the program—and it is at this point that we understand the true import of his question. If DNA is perceived as data, it becomes possible at last to take into account ‘the interactions between genetics and epigenetics’ (p. 32).
Going forward with his critique of the notion of ‘genetical program’, Atlan deals with the case of embryology (mostly citing the work of E. Fox Keller), before turning to a second question. Quite provocatively, he asks ‘does life exist?’, the answer to which made up the second and last part of his lecture. Clearly refusing vitalistic positions (which may be interpreted as a reaction to the criticisms formulated in France when he was one of the main leaders of the self-organization theory), he minutely deconstructs the representations linked to DNA-as-a-program. Introducing the work of the geneticist R. Lewontin, Atlan shows, for example, how certain decisions taken by official ethics committees can be ambiguous when they take for granted that ‘genes are the principle of life’.
Chief among the credits due to Atlan is that he has established a solid link between current research in molecular biology (not only in genetics) and ethical questions raised by such popular themes as cloning. Thanks to a close analysis of the constitution of these theories, Atlan manages to bring these themes together. Through this historical perspective—even if it stays within the field of intellectual history (and this may be a bit disappointing for historians of science)—Atlan manages to demonstrate how some so-called modern positions can be assimilated to preformationism.
As far as the field of ethics is concerned, there is no reason for Atlan to systematically condemn somatic gene therapy (as opposed to germinal, p. 65) simply because it could alter the ‘essence of life’. Biology is no longer the ‘science of life’ and it should focuses with more modesty on the ‘physiochemical systems in which what we call genes is not genetic and where we have to face a certain amount of chemical reactions integrated in the processes of metabolism and development’ (p. 54). Projects such as the Human Genome Project do not pay attention to the problem of gene expression, and then the constitution of proteins falls outside of their scope, even though proteins are the building blocks of all living matter. Atlan finishes his text with a solid denouncement of the ‘temple merchants’ who gather around the genome-fetish because the genome is considered to be the essence of life.
Atlan follows his well-crafted, pedagogically informed text with a forty-page discussion. Here is where the aims (and also perhaps the limits) of his theoretical evaluation of dominant metaphors becomes apparent. Atlan deals with the case of cloning, for example, in the discussion. For him, the real issue in reproductive cloning is not about fabricating identical human beings, precisely because the genetical-program metaphor is misleading. When we realize what is written these days on such issues, it is commendable that a scientist who has continued to be interested in philosophical matters can clearly answer these questions.
In sum, Atlan’s approach is accessible, even though it is characteristically deeply marked by the information culture (which may still be pertinent). While historians of molecular biology might have wanted an analysis of the paradigm shifts presented in relation to cultural and social contexts, readers will be pleased that Atlan clearly and concisely promotes a real discussion on the influence of dominant paradigms for both molecular biologists and historians of biology.
Jérôme Segal, Max-Planck-Institut für Wissenschaftsgeschichte, Wilhelmstr.44, D-10117 Berlin, Deutschland.
(now at the IUFM de Paris, 10, rue Molitor, 75016 Paris)