Oogenesis being performed in the ovary shows two different kinds of nuclei in the nursing cells. The above mentioned nuclei are transferred and incorporated into the nuclei of developing eggs, which become sexually differentiated and showWolanski's methyl-green reaction. The sex determination is, therefore, cytologically progamic and genotypical. The spawned eggs in the jelly strings appear first of identical shape and are all coated from the very beginning with grainy bonellian pigment, but afterwards, being reared in free water cultures in the (...) absence of females, they differentiate into distinctly different male and female larvae. The numerical ratio of the sexually differentiated larvae is discussed. The true chromosomes in gamogenesis as well as in somatic cells have not been found. L'oogénèse qui a lieu dans l'ovaire montre deux sortes de noyaux dans les cellules nourricières. Les noyaux mentionnés ci-dessus sont transportés dans les noyaux des ovules en voie de développement qui se différencient sexuellement et montrent la réaction deWolanski au vert de méthyle. Le déterminisme du sexe est, par conséquent progamique et génotypique, du point de vue cytologique. Les ovules déposés en gelée sont d'abord de forme identique et sont tous recouverts, dès le début, du pigment granulé de boneliéne, mais, élevés par la suite, dans des cultures en eau courante, en l'absence des femelles, ils se différencient distinctement en larves mâles et femelles. La proportion numérique des larves différenciées sexuellement est discutée. Dans la gamétogénèse, comme dans les cellules somatiques, les vrais chromosomes restent introuvables. Während der Oogenese, die sich im Eierstock abspielt, zeigen sich zwei differente Kerntypen in den Nährzellen. Diese Kerne werden allmählich in die Kerne des sich entwickelnden Eies übertragen und dort inkorporiert. Das Ei wird dadurch geschlechtlich differenziert und zeigt dann dieWolanski's Methyl-grün Reaktion. Die sexuelle Determination ist somit progam und genotypic. Die in schnurartigen Gallerten abgelegten Eier sind am Beginn von gleicher Form und Grösse, so wie von Anfang an mit Körnchen des Pigmentes Bonellein bekleidet. In freien Wasserkulturen,ohne Weibchen, entwickeln sie sich in deutlich differenzierte männliche und weibliche Larven. Das numerische Verhältniss der geschlechtlich differenten Larven wird diskutiert. Echte Chromosomen sind weder bei der Gamogenese noch in somatischen Zellen gefunden worden. (shrink)

This articles suggests that the root of the current crisis in modern scientific innovation is mainly due to the method that science applies towards the real world. The scientific method reduces its possibilities by not considering the comprehensiveness of the human person, i.e. science is impersonal. Philosophers of science in the 20th century have identified this anthropological reductionism and further detected the limits of the scientific method. The lack of alternative solutions leads science into a cul-de-sac. The notion of crisis, (...) recently pointed out by Leonardo Polo’s Transcendental Anthropology, allows us to detect the limit, to abandon that limit and to open knowledge to further dimensions of unrestricted novelty such as freedom or love. Here we highlight the following distinctions: firstly, the state of crisis and the critical conscience, secondly, the ‘desperate vs. puzzle-solver’ critical conscience, thirdly, the limit of science and its abandonment. (shrink)

In biology, the ‘ecological orientation' rests on a commitment to examining systems, and the conceptual challenge of defining that system now employs techniques and concepts adapted from diverse disciplines (i.e., systems philosophy, cybernetics, information theory, computer science) that are applied to biological simulations and model building. Immunology has joined these efforts, and the question posed here is whether the discipline will remain committed to its theoretical concerns framed by the notions of protecting an insular self, an entity demarcated from its (...) environment, or will shift its focus of interest to a wider context. An ecological perspective emphasizes the interchange between the organism and its environment, the processing of information, and the regulation arising from responses to this larger context. Moving from the first attempts at modeling the immune system as a closed network, immunologists have joined the general interest in systems analysis, and that move might portend a significant shift to an open, more holistic consideration of immune regulation. *Received December 2006; revised August 2007. †To contact the author, please write to: Center for Philosophy and History of Science, Boston University, 745 Commonwealth Ave., Boston, MA 02215; e-mail: [email protected]. (shrink)

Current Perspectives in Philosophy of Biology.

This paper aims to propose an inferential and dynamic approach to understanding with models in biology. Understanding plays a central role in the practice of modeling. From its links with the other two central elements of scientific research, experimentation, and explanation, we show its epistemic relevance to the case of explanation in biology. Furthermore, by including the notion of understanding, we propose a non-referentialist perspective on scientific models, which is determined by their use.

The ways in which the various activities of synthetic biology connect to those of conventional biology display both a multiplicity and variety that reflect the multiplicity and variety of meanings for which the term synthetic biology has been invoked, today as in the past. Central to this variety, as well as to the connection itself, is the complex relationship between knowing and making that has prevailed in the life sciences. That relationship is the focus of this article. More specifically, my (...) aim is to explore the different assumptions about how knowing is related to making that have prevailed, implicitly or explicitly in the various activities—now or in the past—subsumed under the name synthetic biology. (shrink)

The aim of regenerative medicine is to reconstruct tissue that has been lost or pathologically altered. Therapeutic cloning seems to offer a method of achieving this aim; however, the ethical debate surrounding human therapeutic cloning is highly controversial. Artificial parthenogenesis—obtaining embryos from unfertilised eggs—seems to offer a way to sidestep these ethical pitfalls. Jacques Loeb , the founding father of artificial parthogenesis, faced negative public opinion when he published his research in 1899. His research, the public’s response to his findings, (...) and his ethical foundations serve as an historical argument both for the communication of science and compromise in biological research. (shrink)

Morphological engineering is an emerging research area in synthetic biology. In 2008 “synthetic morphology” was proposed as a prospective approach to engineering self-constructing anatomies by Jamie A. Davies of the University of Edinburgh. Synthetic morphology can establish a new paradigm, according to Davies, insofar as “cells can be programmed to organize themselves into specific, designed arrangements, structures and tissues.” It is obvious that this new approach will extrapolate morphology into a new realm beyond the traditional logic of morphological research. However, (...) synthetic morphology is a highly idealized vision of morphology which derives its visionary ideas from morphological engineering and mathematical idealizations in order to understand the principles of molecular morphology. Thus, the question is, if this approach will help to understand morphogenesis better or if it will just enable biologists to engineer morphogenesis. The paper investigates the development of synthetic morphology and its relation to synthetic biology as well as its epistemic gains. (shrink)

Inspired by the success of synthesising organic substances by Friedrich Wöhler in 1828, the vision of creating life in the laboratory synthetically has become increasingly accessible for today’s synthetic biology and synthetic genomics, respectively. The engineering of biology – a contemporary version of the liaison of technology and organic form – creates cellular machines, biobricks, biomolecular ‘borgs’, and entire synthetic genomes of artificial organisms. Besides major ethical concerns, the shift in scientific epistemology is of interest. Unlike classical analytical science, synthetic (...) science understands by a process of generation, through which myriads of new things are created, dramatically changing the living environment. (shrink)

In modern discourse about the history of science, it seems to be widely accepted that at the end of the nineteenth century, Germany was one of the leading countries in the production of science. In the past, historians of science tried to trace back a specific ‘German style’ of science that—in combination with other factors—determined this German dominance around 1900, especially in the life sciences. Considering the theoretical concept of ‘national styles’, it has to be kept in mind that around (...) 1900, contemporaries already proclaimed ‘national styles’ of science as representations of national identity. Thus, the question arises as to how far existing historiographical conceptions of national styles may include earlier claims and prejudices. Careful reconstructions of contemporary discourses on national styles and inquiries into the ‘stylisation’ of a dominant, successful ‘German style’ are necessary. One of the contemporary critics of a ‘German style’ of science was the physiologist Jacques Loeb (1859–1924), who emigrated to the USA in 1891. Loeb corresponded regularly with the physicist and philosopher Ernst Mach (1838–1916). Ernst Mach can be considered Loeb's intellectual father with whom he corresponded about strategic, philosophical, and epistemological questions. Using the Loeb–Mach correspondence, the aim of the paper is to reconstruct Loeb's conception of a ‘German style’ of science and its differences to an ‘American style’. Changes in his views are discussed as well as the roots of his views and some of their consequences. Finally, Loeb's ideas on national styles and his working profiles before and after his emigration are compared to historiographical analyses of ‘American’ or ‘German’ styles of science around 1900. (shrink)

This paper examines recent developments in the construction of insect cyborgs by the Defense Advanced Research Projects Agency , a branch of the u.s. Department of Defense, as part of its Hybrid Insect Microelectromechanical Systems project. It takes a sociological approach in order to account for the processes involved in the creation of insect cyborgs, arguing that such creatures should be seen as the outcome of social, as well as technological, conditions. The paper critically reflects on the ethical implications of (...) the hi-mems project and discusses the philosophical repercussions of treating insects as if they are machines. (shrink)

Dissatisfied with the descriptive and speculative methods of evolutionary biology of his time, the physiologist Jacques Loeb , best known for his “engineering” approach to biology, reflected on the possibilities of artificially creating life in the laboratory. With the objective of experimentally tackling one of the crucial questions of organic evolution, i.e., the origin of life from inanimate matter, he rejected claims made by contemporary scientists of having produced artificial life through osmotic growth processes in inorganic salt solutions. According to (...) Loeb, the answer to the question of whether or not life could be created artificially had to come from macro-molecular chemistry, in particular from the research on the recently discovered DNA. He was convinced that a prerequisite for making living matter from inanimate substances was the chemical synthesis of nuclear material capable of self-replication. Moreover, Loeb, experimentally refuting some vitalistic explanations as well as colloidal chemists’ far-reaching claims that biologically relevant macromolecules follow colloidal rather than chemical laws, pioneered research on the physical and chemical explanations of biological phenomena. (shrink)

Synthetic biology is a research field that has grown rapidly and attracted considerable attention. Most prominently, it has been labelled the ‘engineering of biology’. While other attempts to label the field have been also pursued, the program of engineering can be considered the core of the field’s disciplinary program, of its identity. This article addresses the success of the ‘engineering program’ in synthetic biology and argues that its success can partly be explained by distinct practices of persuasion that aim at (...) persuading scientific, but also non-scientific audiences. The article explores two different modes of persuasion:, building tools as heuristic models and posing visionary claims. Objects such as the toggle switch or the synthetic oscillator in synthetic biology can more adequately be described as heuristic models of engineering instead of simply as prototypes of ‘tools’. Posing visionary claims can be also understood as a persuasion practice, since the claims are used to construct the societal relevance of the field. Drawing upon Michel Callon’s ‘sociology of translation’, I argue that both practices of persuasion aim at ‘enrolling’ entities into the disciplinary identity. The article is based on the textual analysis of rhetorical practices in three synthetic biology review articles which are considered seminal for the history of the field. (shrink)

For many years, biology was largely descriptive (natural history), but with its emergence as a scientific discipline in its own right, a reductionist approach began, which has failed to be matched by adequate understanding of function of cells, organisms and species as whole entities. Every effort was made to explain biological phenomena in physico-chemical terms.It is argued that there is and always has been a clear distinction between life sciences and physical sciences, explicit in the use of the word biology. (...) If this distinction is real, it implies that biological phenomena can never be entirely satisfactorily explained in terms of extant physicochemical laws. One notable manifestation of this is that living organisms appear to -- actually do -- behave in purposeful ways, and the inanimate universe does not. While this fundamental difference continues to be suppressed, the purposiveness (or teleology) which pervades biology remains anathema to almost all scientists (including most biologists) even to the present day. We argue here that it can, however, become a perfectly tenable position when the Theory of Natural Selection is accepted as the main foundation, the essential tenet, of biology that distinguishes it from the realm of physical sciences. In accepting this position, it remains quite legitimate to expect that in many but not all circumstances, extant physical laws (and presumably others still to be discovered) are in no way breached by biological systems, which cannot be otherwise since all organisms are composed of physical material. (shrink)

Well prior to the invention of the term ‘biology’ in the early 1800s by Lamarck and Treviranus, and also prior to the appearance of terms such as ‘organism’ under the pen of Leibniz in the early 1700s, the question of ‘Life’, that is, the status of living organisms within the broader physico-mechanical universe, agitated different corners of the European intellectual scene. From modern Epicureanism to medical Newtonianism, from Stahlian animism to the discourse on the ‘animal economy’ in vitalist medicine, models (...) of living being were constructed in opposition to ‘merely anatomical’, structural, mechanical models. It is therefore curious to turn to the ‘passion play’ of the Scientific Revolution – whether in its early, canonical definitions or its more recent, hybridized, reconstructed and expanded versions: from Koyré to Biagioli, from Merton to Shapin – and find there a conspicuous absence of worry over what status to grant living beings in a newly physicalized universe. Neither Harvey, nor Boyle, nor Locke (to name some likely candidates, the latter having studied with Willis and collaborated with Sydenham) ever ask what makes organisms unique, or conversely, what does not. In this paper I seek to establish how ‘Life’ became a source of contention in early modern thought, and how the Scientific Revolution missed the controversy. (shrink)