Evelyn M. Witkin (1921-2023).

Pioneer of cell mutagenesis and DNA repair research.

A Commemorative Issue in Honor of 200th Anniversary of the Birth of Gregor Johann Mendel: The Genius of Genetics.

In celebration of the bicentennial of the birth of Gregor Johann Mendel, the genius of genetics, this Special Issue presents seven papers [...].

The Gregor Mendel Bicentennial Tribute-Enduring Mementos of the Founder of Genetics.

This Arts and Medicine feature summarizes events and scholarship honoring Abbot Gregor Mendel, founder of the science of modern genetics, on the occasion of the bicentennial of his birth.

Frascos de cristal, plátanos y moscas: género, emociones y prácticas de la genética de Drosophila / Glass jars, bananas, and flies gender, emotions, and practices of Drosophila genetics

Los plátanos y los tarros de cristal fueron y son componentes de la cultura material de la genética de Drosophila, como lo fueron y son también las moscas que crecían en su interior. Estos objetos son objetos híbridos —materiales, sensoriales y emocionales—, que circularon entre el campo y el laboratorio, entre las aulas, puestos de investigación y cocinas de las casas de quienes se dedicaron a los estudios de la herencia y la evolución. Circularon también a través del tiempo y del espacio geográfico al formar parte del conocimiento colectivo de la comunidad de genetistas de Drosophila, de sus recuerdos y de los de sus hijas e hijos. A través de la combinación de fuentes escritas, académicas e institucionales y de otras que son orales, subjetivas y emocionales, cobran vida y con ellos las actividades y prácticas de quienes los utilizaban, casi siempre mujeres. Al evocarlos, aparecen también normas como las de género, que rodeaban a las personas en el momento de la experiencia y juicios de valor que elaboraron, y se elaboraron, sobre los objetos, sus usos y las identidades de quienes los emplearon. Este artículo pretende así, estudiando prácticas y objetos de una disciplina como la genética de Drosophila, contribuir a la construcción de una historia de la genética más inclusiva, a la historia de las mujeres científicas y a los estudios sobre el papel de las emociones, el cuerpo y la memoria en la construcción de conocimiento histórico y científico. (AU)

Bananas and glass jars were and are components of the material culture of Drosophila genetics. These hybrid (material, sensory and emotional) objects circulated between the field and the laboratory and among the classrooms, research stations, and kitchens of those who dedicated themselves to studies of heredity and evolution. They also circulated through time and geographic space as they became part of the collective knowledge of the community of Drosophila geneticists and the memories of their daughters and sons. The combination of written, objective, conceptual and, above all, oral, subjective and emotional sources brings them to life along with the activities and practices of those who used them, almost always women; they have not been erased from these emotional records as they have been from institutional records. Norms also appear, such as gender norms, which surrounded people at the time of the experience and influenced their value judgments about the objects, practices and identities of those who carried them out. Thus, by studying the practices and objects of a discipline such as Drosophila genetics, this article aims to contribute to the construction of a more inclusive history of genetics, to the history of women scientists and to studies on the role of emotions, the body, and memory in the construction of historical knowledge. (AU)

"Batesonian Mendelism" and "Pearsonian biometry": shedding new light on the controversy between William Bateson and Karl Pearson.

This paper contributes to the ongoing reassessment of the controversy between William Bateson and Karl Pearson by characterising what we call "Batesonian Mendelism" and "Pearsonian biometry" as coherent and competing scientific outlooks. Contrary to the thesis that such a controversy stemmed from diverging theoretical commitments on the nature of heredity and evolution, we argue that Pearson's and Bateson's alternative views on those processes ultimately relied on different appraisals of the methodological value of the statistical apparatus developed by Francis Galton. Accordingly, we contend that Bateson's belief in the primacy of cross-breeding experiments over statistical analysis constituted a minimal methodological unifying condition ensuring the internal coherence of Batesonian Mendelism. Moreover, this same belief implied a view of the study of heredity and evolution as an experimental endeavour and a conception of heredity and evolution as fundamentally discontinuous processes. Similarly, we identify a minimal methodological unifying condition for Pearsonian biometry, which we characterise as the view that experimental methods had to be subordinate to statistical analysis, according to methodological standards set by biometrical research. This other methodological commitment entailed conceiving the study of heredity and evolution as subsumable under biometry and primed Pearson to regard discontinuous hereditary and evolutionary processes as exceptions to a statistical norm. Finally, we conclude that Batesonian Mendelism and Pearsonian biometry represented two potential versions of a single genetics-based evolutionary synthesis since the methodological principles and the phenomena that played a central role in the former were also acknowledged by the latter-albeit as fringe cases-and conversely.

Christine Guthrie (1945-2022).

RNA trailblazer who illuminated splicing mechanics.

The genotype-phenotype distinction: from Mendelian genetics to 21st century biology.

The Genotype-Phenotype (G-P) distinction was proposed in the context of Mendelian genetics, in the wake of late nineteenth century studies about heredity. In this paper, we provide a conceptual analysis that highlights that the G-P distinction was grounded on three pillars: observability, transmissibility, and causality. Originally, the genotype is the non-observable and transmissible cause of its observable and non-transmissible effect, the phenotype. We argue that the current developments of biology have called the validity of such pillars into question. First, molecular biology has unveiled the putative material substrate of the genotype (qua DNA), making it an observable object. Second, numerous findings on non-genetic heredity suggest that some phenotypic traits can be directly transmitted. Third, recent organicist approaches to biological phenomena have emphasized the reciprocal causality between parts of a biological system, which notably applies to the relation between genotypes and phenotypes. As a consequence, we submit that the G-P distinction has lost its general validity, although it can still apply to specific situations. This calls for forging new frameworks and concepts to better describe heredity and development.

Gregor Johann Mendel: From peasant to priest, pedagogue, and prelate.

Gregor Mendel was an Augustinian priest in the Monastery of St. Thomas in Brünn (Brno, Czech Republic) as well as a civilian employee who taught natural history and physics in the Brünn Modern School. The monastery's secular function was to provide teachers for the public schools across Moravia. It was a cultural, educational, and artistic center with an elite core of friar-teachers with a well-stocked library and other amenities including a gourmet kitchen. It was wealthy, with far-flung holdings yielding income from agricultural productions. Mendel had failed his tryout as a parish priest and did not complete his examination for teaching certification despite 2 y of study at the University of Vienna. In addition to his teaching and religious obligations, Mendel carried out daily meteorological and astronomical observations, cared for the monastery's fruit orchard and beehives, and tended plants in the greenhouse and small outdoor gardens. In the years 1856 to 1863, he carried out experiments on heredity of traits in garden peas regarded as revolutionary today but not widely recognized during his lifetime and until 16 y after his death. In 1868 he was elected abbot of the monastery, a significantly elevated position in the ecclesiastical and civil hierarchy. While he had hoped to be elected, and was honored to accept, he severely underestimated its administrative responsibilities and gradually had to abandon his scientific interests. The last decade of his life was marred by an ugly dispute with civil authorities over monastery taxation.

Mendel and Darwin.

Evolution by natural selection is an explicitly genetic theory. Darwin recognized that a working theory of inheritance was central to his theory and spent much of his scientific life seeking one. The seeds of his attempt to fill this gap, his "provisional hypothesis" of pangenesis, appear in his notebooks when he was first formulating his evolutionary ideas. Darwin, in short, desperately needed Mendel. In this paper, we set Mendel's work in the context of experimental biology and animal/plant breeding of the period and review both the well-known story of possible contact between Mendel and Darwin and the actual contact between their ideas after their deaths. Mendel's contributions to evolutionary biology were fortuitous. Regardless, it is Mendel's work that completed Darwin's theory. The modern theory based on the marriage between Mendel's and Darwin's ideas as forged most comprehensively by R. A. Fisher is both Darwin's achievement and Mendel's.

The "New Synthesis".

When Mendel's work was rediscovered in 1900, and extended to establish classical genetics, it was initially seen in opposition to Darwin's theory of evolution by natural selection on continuous variation, as represented by the biometric research program that was the foundation of quantitative genetics. As Fisher, Haldane, and Wright established a century ago, Mendelian inheritance is exactly what is needed for natural selection to work efficiently. Yet, the synthesis remains unfinished. We do not understand why sexual reproduction and a fair meiosis predominate in eukaryotes, or how far these are responsible for their diversity and complexity. Moreover, although quantitative geneticists have long known that adaptive variation is highly polygenic, and that this is essential for efficient selection, this is only now becoming appreciated by molecular biologists-and we still do not have a good framework for understanding polygenic variation or diffuse function.

Mimush Sheep and the Spectre of Inbreeding: Historical Background for Festetics's Organic and Genetic Laws Four Decades Before Mendel's Experiments in Peas.

The upheavals of late eighteenth century Europe encouraged people to demand greater liberties, including the freedom to explore the natural world, individually or as part of investigative associations. The Moravian Agricultural and Natural Science Society, organized by Christian Carl André, was one such group of keen practitioners of theoretical and applied scientific disciplines. Headquartered in the "Moravian Manchester" Brünn (nowadays Brno), the centre of the textile industry, society members debated the improvement of sheep wool to fulfil the needs of the Habsburg armies fighting in the Napoleonic Wars. Wool, as the raw material of soldiers' clothing, could influence the war's outcome. During the early nineteenth century, wool united politics, economics, and science in Brno, where breeders and natural scientists investigated the possibilities of increasing wool production. They regularly discussed how "climate" or "seed" characteristics influenced wool quality and quantity. Breeders and academics put their knowledge into immediate practice to create sheep with better wool traits through consanguineous matching of animals and artificial selection. This apparent disregard for the incest taboo, however, was viewed as violating natural laws and cultural norms. The debate intensified between 1817 and 1820, when a Hungarian veteran soldier, sheep breeder, and self-taught natural scientist, Imre (Emmerich) Festetics, displayed his inbred Mimush sheep, which yielded wool extremely well suited for the fabrication of light but strong garments. Members of the Society questioned whether such "bastard sheep" would be prone to climatic degeneration, should be regarded as freaks of nature, or could be explained by natural laws. The exploration of inbreeding in sheep began to be distilled into hereditary principles that culminated in 1819 with Festetics's "laws of organic functions" and "genetic laws of nature," four decades before Gregor Johann Mendel's seminal work on heredity in peas.

Mendel the fraud? A social history of truth in genetics.

Two things about Gregor Mendel are common knowledge: first, that he was the "monk in the garden" whose experiments with peas in mid-nineteenth-century Moravia became the starting point for genetics; second, that, despite that exalted status, there is something fishy, maybe even fraudulent, about the data that Mendel reported. Although the notion that Mendel's numbers were, in statistical terms, too good to be true was well understood almost immediately after the famous "rediscovery" of his work in 1900, the problem became widely discussed and agonized over only from the 1960s, for reasons having as much to do with Cold War geopolitics as with traditional concerns about the objectivity of science. Appreciating the historical origins of the problem as we have inherited it can be a helpful step in shifting the discussion in more productive directions, scientific as well as historiographic.

The people behind the papers - Chunyan Fang and Xiaoling Tong.

Hox genes play a key role in determining body plan, but previous research indicated that forewing development occurs independently of Antennapedia, the Hox gene expressed in the thoracic region. Now, a new paper in Development describes an essential role for Antennapedia in wing development of silkworm, Drosophila and Tribolium. We caught up with first author, Chunyan Fang, and corresponding author, Xiaoling Tong, a group leader at the State Key Laboratory of Silkworm Genome Biology at Southwest University in China, to find out more about their research.

The pushback against state interference in science: how Lysenkoism tried to suppress Genetics and how it was eventually defeated.

Genetics in the Soviet Union (USSR) achieved state-of-the-art results and had reached a peak of development by the mid-1930s due to the efforts of the scientific schools of several major figures, including Sergei Navashin, Nikolai Koltsov, Grigorii Levitsky, Yuri Filipchenko, Nikolai Vavilov, and Solomon Levit. Unfortunately, the Soviet government distrusted intellectually independent science and this led to state support for a fraudulent pseudoscientific concept widely known as Lysenkoism, which hugely damaged biology as a whole. Decades of dominance of the Lysenkoism had ruinous effects and the revival of biology in the USSR in the late 1950s-early 1960s was very difficult. In fact, this was realized to be a problem for Soviet science as a whole, and many mathematicians, physicists, chemists, and other scientists made efforts to rehabilitate genetics and to transfer biology to the "jurisdiction" of science from that of politics. The key events in the history of these attempts to pushback against state interference in science, and to promote the development of genetics and molecular biology, are described in this paper. These efforts included supportive letters to the authorities (e.g., the famous "Letter of three hundred"), (re)publishing articles and giving lectures on "forbidden" science, and organizing laboratories and departments for research in genetics and molecular biology under the cover of nuclear physics or of other projects respected by the government and Communist party leaders. The result was that major figures in the hard sciences played a major part in the revival of genetics and biology in the USSR.

Dosage compensation in Drosophila in the 1960s: a personal historical perspective.

Early genetic studies with Drosophila revealed similar mutant phenotypes for many X-linked genes, in males with one and in females with two copies of the mutant allele following the XY/XX mode of sex determination. These observations led to evocation of the phenomenon of dosage compensation. By the 1960s, contrasting theories were advanced by H. J. Muller and R. B. Goldschmidt to explain the equalized expression of many X-linked genes despite their dosage difference in male and female flies. Evidence from genetic studies led Muller to propose existence of many modifiers whose action on individual X-linked genes resulted, through a 'piecemeal' regulation, in equalized expression of the dosage compensated X-linked genes, while Goldschmidt believed that invocation of multiple modifiers or compensators was unnecessary since dosage compensation was a direct outcome of the sex-specific physiologies of male and female flies. Muller did not agree with some cytological studies that suggested that the single X-chromosome in male cells works twice as hard as each of the two X-chromosomes in female cells (hyperactive male X model), but preferred partial repression of each X-chromosome in female flies. This historical perspective relates these divergent theories with my own doctoral work in A. S. Mukherjee's laboratory at Calcutta University, which, while ruling out Golschmidt's sex-physiology theory, established cell-autonomous regulation of the earlier proposed hyperactivity of the single X in male Drosophila in a piecemeal manner.