Hans Spemann's use of the concept double assurance, drawn from engineering models in cytology, is discussed in his work on lens development and the action of the organizer. His transformation of this concept within his neo-Lamarckian program is demonstrated and connected with the cultural factors which shaped engineering and embryology in Weimar Germany.

William Bateson (1861-1926) has long occupied a controversial role in the history of biology at the turn of the twentieth century. For the most part, Bateson has been situated as the British translator of Mendel or as the outspoken antagonist of W. F. R. Weldon and Karl Pearson's biometrics program. Less has been made of Bateson's transition from embryologist to advocate for discontinuous variation, and the precise role of British and American influences in that transition, in the years leading up (...) to the publication of his massive Materials for the Study of Variation (1894). In this paper, I first attempt to trace Bateson's development in his early career before turning to search for the development of the moniker "anti-Darwinist" that has been attached to Bateson in well-known histories of the neo-Darwinian Synthesis. (shrink)

William Bateson has long occupied a controversial role in the history of biology at the turn of the twentieth century. For the most part, Bateson has been situated as the British translator of Mendel or as the outspoken antagonist of W. F. R. Weldon and Karl Pearson's biometrics program. Less has been made of Bateson's transition from embryologist to advocate for discontinuous variation, and the precise role of British and American influences in that transition, in the years leading up to (...) the publication of his massive Materials for the Study of Variation. In this paper, I first attempt to trace Bateson's development in his early career before turning to search for the development of the moniker "anti-Darwinist" that has been attached to Bateson in well-known histories of the neo-Darwinian Synthesis. (shrink)

Ascidian tadpole larvae, composed of only about 2500 cells, have a primitive nervous system which is derived from the neural plate. The stereotyped cell cleavage pattern and well characterized cell lineage in these animals allow the isolation and culture of identified blastomeres in variable combinations. Ascidian embryos express cell‐type‐specific markers corresponding to their cell fates, even when cultured under cleavage‐arrest by cytochalasin B. This system provides us with a unique opportunity to study the roles of cell lineage and cell contact (...) in early neuronal differentiation in the absence of events associated with complex morphogenesis. In addition, the isolated, cleavage‐arrested blastomeres are ideally suited to electrical recording, permitting the use of ionic channels as specific markers for differentiation. In the cleavage‐arrested embryos, suppression of one type of K+ channel, and induction of two types of Na+ channels, occur following cell contact with the vegetal blastomere. The combination of molecular and electrophysiological analyses on this simple animal system may provide insights into the nature of the cell interactions important in early neurogenesis, both in ascidians and in vertebrates. (shrink)

In this article we argue that the classical—linear and bottom-up directed—models of causation in biology, and the ‘‘proximate/ultimate’’ dichotomy, are inappropriate to capture the complexity inherent to biological processes. We introduce a new notion of ‘‘multilevel causation’’ where old dichotomies such as proximate/ultimate and bottom-up/ top-down are reinterpreted within a multilevel, web-like, approach. In briefly reviewing some recent work on complexity, EvoDevo, carcinogenesis, autocatalysis, comparative genomics, animal regeneration, phenotypic plasticity, and niche construction, we will argue that such reinterpretation is a (...) necessary step for the advancement of the ‘‘Extended Synthesis.’’. (shrink)

The case of embryo research provides insight into the challenges for historians and philosophers of science who want to engage social issues, and even more challenges in engaging society. Yet there are opportunities in doing so. History and philosophy of science research demonstrates that the public impression of embryos does not fit with our scientific understanding. In cases where there are competing understandings of the phenomena and public impacts, we have to negotiate social responses. Historians and philosophers of science can (...) both inform and learn from engaging in the process, by helping to recognize underlying assumptions and by demonstrating changing ideas over time and what factors have caused the changes. (shrink)

The phrase “regenerative medicine” is used so often and for so many different things, with such enthusiasm or worry, and often with a sense that this is something radically new. This paper places studies of regeneration and applications in regenerative medicine into historical perspective. In fact, the first stem cell experiment was carried out in 1907, and many important lines of research have contributed since. This paper explores both what we can learn about the history and what we can learn (...) from the history of regenerative medicine research. (shrink)

Abstract“Development” suggests that there is something that is developing, or changing over time. We can ask about temporal boundaries of that developmental process, asking when development begins or ends and whether it has defined stages along the way, for example. We can ask about spatial boundaries as well: where does the developing object start and end? For this article, I ask about the boundary definition of the developing organism in particular. What is an individual organism, and what defines it as (...) the same organism as it changes over time? In particular, how has this been answered historically: how have researchers described and explained what an individual developing organism is? This article explores ideas and approaches especially starting in the late 19th century, and in particular looks at the role of “organization.”. (shrink)

In his 1987 book "Controlling Life: Jacques Loeb and the Engineering Ideal in Biology", Philip Pauly presented his readers with the biologist Jacques Loeb and his role in developing an emphasis on control of life processes. Loeb's work on artificial parthenogenesis, for example, provided an example of bioengineering at work. This paper revisits Pauly's study of Loeb and explores the way current research in regenerative medicine reflects the same tradition. A history of regeneration research reveals patterns of thinking and research (...) methods that both echo Loeb's ideology and point the way to modern studies. Pauly's work revealed far more than we readers realized at the time of its publication. (shrink)

In the 1950s, embryology in socialist China underwent a series of changes that adjusted the disciplinary apparatus to suit socialism and the national goal of self-reliance. As the Communist state called on scientists to learn from the Soviets, embryologists’ comprehensive view on heredity, which did not contradict Trofim Lysenko ’s doctrines, provided a space for them to advance their discipline. Leading scientists, often trained abroad in the tradition of experimental embryology, rode on the tides of Maoist ideology and repositioned their (...) research. Some of their creative realignment of previous research questions, materials, and traditions to Marxist philosophy and agricultural objectives generated productive programs. In particular, Tong Dizhou translated Engels’s dialectics of nature into a research question about cytoplasmic inheritance. His continuing investigation on it led to the first goldfish “clone” through a nuclear transplantation experiment; Zhu Xi and his associates transferred a goldfish model in embryology into studies on improving carp aquaculture, leading to a rare success in the Great Leap Forward of 1958. These directions for embryology continued well into the 1960s. At a time when global embryology was diversifying and began to be molecularized, eventually forming “developmental biology,” socialist embryology took shape in China with a different set of epistemic and practical commitments. The history of its development challenges and enriches our understanding of the concrete process of change in one discipline under Mao, showing ways in which scientists creatively adapted state-sanctioned ideologies and visions to do productive work outside the framework of molecular biology during the Cold War. (shrink)

In the 1950s, embryology in socialist China underwent a series of changes that adjusted the disciplinary apparatus to suit socialism and the national goal of self-reliance. As the Communist state called on scientists to learn from the Soviets, embryologists’ comprehensive view on heredity, which did not contradict Trofim Lysenko (1898–1976)’s doctrines, provided a space for them to advance their discipline. Leading scientists, often trained abroad in the tradition of experimental embryology, rode on the tides of Maoist ideology and repositioned their (...) research. Some of their creative realignment of previous research questions, materials, and traditions to Marxist philosophy and agricultural objectives generated productive programs. In particular, Tong Dizhou (1902–1979) translated Engels’s dialectics of nature into a research question about cytoplasmic inheritance. His continuing investigation on it led to the first goldfish “clone” through a nuclear transplantation experiment; Zhu Xi and his associates transferred a goldfish model in embryology into studies on improving carp aquaculture, leading to a rare success in the Great Leap Forward of 1958. These directions for embryology continued well into the 1960s. At a time when global embryology was diversifying and began to be molecularized, eventually forming “developmental biology,” socialist embryology took shape in China with a different set of epistemic and practical commitments. The history of its development challenges and enriches our understanding of the concrete process of change in one discipline under Mao, showing ways in which scientists creatively adapted state-sanctioned ideologies and visions to do productive work outside the framework of molecular biology during the Cold War. (shrink)

The technique of nuclear transplantation – popularly known as cloning – has been integrated into several different histories of twentieth century biology. Historians and science scholars have situated nuclear transplantation within narratives of scientific practice, biotechnology, bioethics, biomedicine, and changing views of life. However, nuclear transplantation has never been the focus of analysis. In this article, I examine the development of nuclear transplantation techniques, focusing on the people, motivations, and institutions associated with the first successful nuclear transfer in metazoans in (...) 1952. The conflict between embryologists and geneticists over the mechanisms of differentiation motivated Robert Briggs to pursue nuclear transplantation experiments as a way to resolve the debate. Briggs worked at the Lankenau Hospital Research Institute, a research facility devoted to the study of cancer. The goal of understanding cancer would play a role in the development of the technique, and the story of nuclear transplantation sheds light on the role that biomedical contexts play in biological research in the second half of the twentieth century. (shrink)

The relatively new field of evolutionary developmental biology continues to attract considerable attention from biologists, philosophers, and historians, in part, because work in this field demonstrates that important changes are underway within biology. Though studies of development and evolution were closely connected during the 19th century, continued work in genetics fostered a general split between the two during the first decades of the twentieth century (e.g., Allen 1978; Gilbert 1978; Mayr and Provine 1980; Gilbert, Opitz and..

This paper aims to provide a fresh historical perspective on the debates on vitalism and holism in Germany by analyzing the work of the zoologist Hans Spemann (1869–1941) in the interwar period. Following up previous historical studies, it takes the controversial question about Spemann’s affinity to vitalistic approaches as a starting point. The focus is on Spemann’s holistic research style, and on the shifting meanings of Spemann’s concept of an organizer. It is argued that the organizer concept unfolded multiple layers (...) of meanings (biological, philosophical, and popular) during the 1920s and early 1930s. A detailed analysis of the metaphorical dynamics in Spemann’s writings sheds light on the subtle vitalistic connotations of his experimental work. How Spemann’s work was received by contemporary scientists and philosophers is analyzed briefly, and Spemann’s holism is explored in the broader historical context of the various issues about reductionism and holism and related methodological questions that were so prominently discussed not only in Germany in the 1920s. (shrink)

This article explores the collaborative research of the Nobel laureate Hans Spemann (1869–1941) and the Swiss zoologist Fritz Baltzer (1884–1974) on problems at the intersection of development and heredity and raises more general questions concerning science and politics in Germany in the interwar period. It argues that Spemann and Baltzer’s collaborative work made a significant contribution to the then ongoing debates about the relation between developmental physiology and hereditary studies, although Spemann distanced himself from _Drosophila_ genetics because of his anti-reductionist (...) position. The article analyzes how Spemann framed the issues of heredity in terms of an epigenetic principle in the context of his work on the “organizer,” and it explores the experimental dynamics of research on newt merogones carried out by Baltzer in a methodological development of Spemann’s constriction experiments. Finally, these research attempts are discussed as part of a broader “prehistory” of the mid-twentieth century cell nuclear transplantation experiments, which provided the basis for later animal cloning. (shrink)

The discovery by Hans Spemann of the “organizer” tissue and its ability to induce the formation of the amphibian embryo's neural tube inspired leading embryologists to attempt to elucidate embryonic inductions’ underlying mechanism. Joseph Needham, who during the 1930s conducted research in biochemical embryology, proposed that embryonic induction is mediated by a specific chemical entity embedded in the inducing tissue, surmising that chemical to be a hormone of sterol-like structure. Along with embryologist Conrad H. Waddington, they conducted research aimed at (...) the isolation and functional characterization of the underlying agent. As historians clearly pointed out, embryologists came to question Needham's biochemical approach; he failed to locate the hormone he sought and eventually abandoned his quest. Yet, this study finds that the difficulties he ran into resulted primarily from the limited conditions for conducting his experiments at his institute. In addition, Needham's research reflected the interests of leading biochemists in hormone and cancer research, because it offered novel theoretical models and experimental methods for engaging with the function of the hormones and carcinogens they isolated. Needham and Waddington were deterred neither by the mounting challenges nor by the limited experimental infrastructure. Like their colleagues in hormone and cancer research, they anticipated difficulties in attempting to establish causal links between complex biological phenomena and simple chemical triggering. (shrink)

The discovery by Hans Spemann of the “organizer” tissue and its ability to induce the formation of the amphibian embryo’s neural tube inspired leading embryologists to attempt to elucidate embryonic inductions’ underlying mechanism. Joseph Needham, who during the 1930s conducted research in biochemical embryology, proposed that embryonic induction is mediated by a specific chemical entity embedded in the inducing tissue, surmising that chemical to be a hormone of sterol-like structure. Along with embryologist Conrad H. Waddington, they conducted research aimed at (...) the isolation and functional characterization of the underlying agent. As historians clearly pointed out, embryologists came to question Needham’s biochemical approach; he failed to locate the hormone he sought and eventually abandoned his quest. Yet, this study finds that the difficulties he ran into resulted primarily from the limited conditions for conducting his experiments at his institute. In addition, Needham’s research reflected the interests of leading biochemists in hormone and cancer research, because it offered novel theoretical models and experimental methods for engaging with the function of the hormones and carcinogens they isolated. Needham and Waddington were deterred neither by the mounting challenges nor by the limited experimental infrastructure. Like their colleagues in hormone and cancer research, they anticipated difficulties in attempting to establish causal links between complex biological phenomena and simple chemical triggering. (shrink)

La matière pensante du corps n'est donc pas une intentionnalité mentale du corps à l'instar de l'intentionnalité cognitive. La pensée n'est plus à définir à partir d'une réflexion consciente par un dédoublement du sujet et de l'objet. Car la matière corporelle produit des processus réflexifs d'intensités différents selon les types d'externalité du corps. Par externalité il faut décrire les éléments non mentaux et non interne au corps qui proviennent du monde extérieur. Le corps est soumis à son extérieur comme organisme (...) tant pour la réalisation de ses fonctions que pour la régulation des informations. (shrink)