Mitosis: a history of division

Mitosis has been studied since the early 1880s, to the extent that we now have a detailed, but still incomplete, description of spindle dynamics and mechanics, a sense of potential mechanochemical and regulatory mechanisms at a molecular level, and a long list of mitotic proteins. Here we present a personal view of how far we have come, and where we need to go to fully understand the mechanisms involved in mitosis.

The discovery of Gramicidin S: the intellectual transformation of G.F. Gause from biologist to researcher of antibiotics and on its meaning for the fate of Russian genetics

The discovery of Gramicidin S is considered to be the outcome of the intellectual transformation of Russian biologist G.F. Gause from simply a biologist to a researcher of antibiotics. Different historical conditions of this change as well as the development of experimental biology itself at this time are analysed in detail. The meaning of Gause's occupation of a new 'niche' in soviet science for the fate of Russian post-war genetics is defined as well.

[Geneva aspects of the Lyssenko affair (recollections of a witness)]

T. Lyssenko (1898-1976) was an Ukrainian agricultural expert who defended and tried to proof the inheritance of acquired characteristics. He rejected the validity of the chromosome theory of heredity inspired by Mendel and Morgan and finally came to the top of the scientific authorities of Soviet biology. Since 1948 he was known in the Western countries, and a few scientists adopted his views, especially in France, Belgium and Geneva. At the Institute of Botany of the University of Geneva several papers inspired by him were written and a doctoral thesis; a public debate also took place in 1949. Lyssenko lost power in the sixties and since then has lost credibility everywhere.

Initial theoretical framework and problem solving concerning the enigma of heredity

The difference in formulation of the question of heredity on a different level of knowledge in Brno in the 1830s and after 1850 is discussed in this article. In order to solve the problem the most important source is foreshown in the new philosophy of plant physiology and in physics. Mendel was pleased to have met excellent teachers of both these fields. This explanation is an example of Mirko Grmek's thesis: 'l'histoire des sciences est le laboratoire de l'épistomologie'.

Mach's phenomenalism and the British reception of Mendelism

The assimilation of Mendel's paper into Britain took place in an Edwardian social context. This paper concentrates on the interplay of empirical and philosophical issues in this reception. A feature of the British reception of mendelism, not duplicated elsewhere, was the role of phenomenalist philosophies of science as developed by the physicist-mathematician and scientific methodologist Karl Pearson from the philosophical positions of Austrian physicist Ernst Mach and British mathematician William Clifford. Pearson's philosophy of science forms the background to his subsequent collaboration with the zoologist W.F.R. Weldon. In this collaborative work, Pearson developed powerful statistical techniques for analyzing Weldon's empirical data on organic variation. Pearson's statistical analysis of causation and his rejection of hidden entities and causes in the explanation of evolutionary change formed the philosophical component of this program. The arguments of Pearson and Weldon were first brought to bear against the pre-Mendel 'discontinuist' analyses of variation of William Bateson. The introduction of Mendel's paper into these empirical and methodological debates consequently resulted in mathematically sophisticated attacks on Mendel's claims by Pearson and Weldon. This paper summarizes this history and argues for the creative importance of this biometrical resistance to Mendelism.

On the internal dynamics of Mendelian genetics

This paper offers a revisionist account of the development of Mendelian genetics, focusing on the 'problem of the gene', 1900-1930. I examine conflicting claims about the composition, location, and action of genes posed by Bateson, the Morgan group, and Goldschmidt. Their research programs focused on different phenotypes and were based on different assumptions about the nature of genes. The problem of the gene transcended such specific research programs, but their findings had to be taken into account to solve it. The need to resolve conflicting claims drove Mendelian geneticists to exploit the resources and invade the turf of other disciplines in their search for a sound characterization of the gene. The problem of reconciling conflicting views greatly influenced the development of genetics and provided the stimulus for many of the discoveries made by geneticists from 1900 to 1940.

Gene function

The problem of gene function--of the relationships between hereditary material and the characteristics of organisms--preceded the rediscovery of Mendel's laws and accompanied the development of genetics in the XXth century. Molecular biologists replaced the simple gene-character relationship by two relationships: the first, between genes and proteins, was well defined, whereas the second between proteins and the complex structural and functional characteristics of organisms remained unknown. I will describe in this article the experimental approaches which helped to characterize during the last twenty years the relationships between proteins and characters. Four principles of macromolecular organization emerged from these studies: conservation of the elementary components during evolution, existence of pathways and networks, pleiotropy and redundancy. These principles are the explanation of the surprising experimental observations that have been made in recent years. The existence of these principles makes problematic any prediction on the consequences of gene modification. It both sounds the death-knell of the simplistic reductionist approach of many biologists, whereby genes were considered as responsible for specific functions, and definitely prevents the distribution of genes in separate, well defined categories.

Theory and practice: the impact of Mendelism on agriculture

The purpose of this paper is a reexamination of the success story of how Mendelian genetics gave birth to a revolution in plant and animal breeding which produced the spectacular 20th century agricultural progress and made it possible to feed the exploding population of the Earth. Critics have pointed to the problematic social effect of the agricultural revolution, and they have doubted the importance of the new genetics, especially during the first three or four decades of the 20th century. This paper argues that the criticism has tended to take a narrow instrumental view of science underestimating the guiding role of theory in practical matters. Plant and animal breeding continued to depend mainly on the old 19th century techniques, hybridization, mass selection and individual selection. But they were combined and used in much more efficient ways than before. New theoretical knowledge, general theories as well as particular knowledge about species, strains and individuals, radically improved the planning and execution of breeding work.

Mendelism and medicine: controlling human inheritance in local contexts, 1920-1960

The rise of Mendelism has often been associated with the development of agricultural sciences and the attempts to improve varieties and select new plants. In contrast, historians have tended to stress the tensions between Mendelism and medicine originating in the influence of eugenicists. The use of Mendel's laws in the context of discussing human inheritance and the transmission of pathologies was nonetheless pervading the medical literature from the 1920s onwards. This paper investigates the dynamics of medical Mendelism by comparing developments in France and in Britain. In contrast to reluctant botanists and zoologists, the elite of the French medical profession was often 'Mendelian'. Mendel's laws have accordingly been integrated into a complex approach to the familial transmission of pathologies, into a theory of pathological inheritance, which combined genetics, germ theory and hygiene. This approach was widely accepted among the paediatricians and obstetricians active in both the eugenics movement and the natalist movement. The career of the pediatrician R. Turpin is a good example of the visibility of this form of medical Mendelism and of its long-lasting impact on genetic research in the country. In Britain, where the social basis of eugenics was not the medical profession, eugenics' claims often clashed with public health and hygiene priorities. Medical Mendelism was in the first place supported and advanced by doctors and scientists participating in the public debates about the care of 'feeble minded' and the classification of social groups. As revealed by the trajectory of L. Penrose this context favoured the linkage between statistics and pedigree analysis, thus leading to the 'Mendelization' of human pathologies. After the war, this Mendelization in turn facilitated the rise of medical genetics as a speciality focusing on genetic counselling and on the management of computable hereditary risks. This comparative analysis thus highlights: a) the influence of local medical cultures on the fate of Mendelism; b) the continuities between the pre-war studies of pathological inheritance and the post-war rise of medical genetics.

The problem of the gene

During the early 20th century the diverse practices of genetics were unified by the concept of the gene. This classical gene was simultaneously a unit of structure, function, mutation, and recombination. Starting in the 1940s, however, the classical gene began to fragment. Today when we speak of a gene for some malady, a regulatory gene, a structural gene, or a gene frequency, it is entirely possible that we are deploying different gene concepts even though we are using the same term. The problem of the gene addresses the fragmentation of the classical gene concept by asking to what extent a comprehensive and unifying gene concept is possible or desirable. Fully comprehensive gene concepts seem untenable today, but, within different disciplinary domains, unifying, but non-comprehensive, gene concepts can be epistemically worthwhile. The problem of the gene persists, however, not because of its epistemic value, but because of its political value. Using both the arguments for newly proposed gene concepts and the historical dispute over the classical gene, I argue that the desirability of gene concepts rests in part on the political ramifications of their deployment and contestation.

Mendelism: from hybrids and trade to a science

In this paper I explore the historical context in which news of the rediscovery of Mendel's laws was received in England. This exploration leads me to the Cambridge zoologist, William Bateson, to his exploitation of the prestige and support of the Royal Horticultural Society, and to his interaction with certain of the leading horticultural tradesmen prominent in that society. I argue that the policy of the RHS in the 1890s to promote hybridisation rather than plant collecting was of crucial importance in bringing about a productive symbiosis between Bateson and his circle and the horticultural community. I look for parallels between the aims of the horticulturists and the character of the Mendelian programme as it is represented in Bateson's foundational text: Mendel's Principles of Heredity (1909).