ArticlePDF Available

Cyril Dean Darlington: the man who 'invented' the chromosome

Authors:

Abstract

Cyril Darlington (1903-1981) was the most famous cytologist in the world in the decades preceding the molecular revolution of the 1950s. He crossed disciplinary boundaries to create a synthesis of cytology, genetics and evolution by revealing the mechanics of chromosomal recombination and the importance of its evolution. Always controversial during his lifetime, obituaries ultimately referred to him as the 'Copernicus' or 'Newton' of cytology. This article reviews Darlington's scientific contributions, the reasons for their difficult reception at the time and their continuing relevance.
Scanned by CamScanner
Scanned by CamScanner
Scanned by CamScanner
Scanned by CamScanner
Scanned by CamScanner
Scanned by CamScanner
Scanned by CamScanner
... Advances has become the "chromosome bible" for some scientists, but at the same time, the book and its author stirred controversy from day one (e.g. Belling, 1933;Lewis, 1983;Harman, 2003Harman, , 2004Harman, , 2006. Why did Darlington's book provoke such a fierce polemic? ...
... Advances has become the "chromosome bible" for some scientists, but at the same time, the book and its author stirred controversy from day one (e.g. Belling, 1933;Lewis, 1983;Harman, 2003Harman, , 2004Harman, , 2006. Why did Darlington's book provoke such a fierce polemic? ...
... Recombination between the ends of two nonhomologous chromosomes is described in scientific literature by various Darlington (1903Darlington ( -1981 (Harman, 2004). Photo of CDD and MU courtesy of Clare Passingham. ...
Article
Full-text available
The evolution of eukaryotic genomes is accompanied by fluctuations in chromosome number, reflecting cycles of chromosome number increase (polyploidy, centric fissions) and decrease (chromosome fusions). Although all chromosome fusions result from DNA recombination between two or more non-homologous chromosomes, several mechanisms of descending dysploidy are exploited by eukaryotes to reduce their chromosome number. Genome sequencing and comparative genomics have accelerated the identification of inter-genome chromosome collinearity and gross chromosomal rearrangements and have shown that end-to-end chromosome fusions (EEFs) and nested chromosome fusions (NCFs) may have played a more important role in the evolution of eukaryotic karyotypes than previously thought. The present review aims to summarize the limited knowledge on the origin, frequency, and evolutionary implications of EEF and NCF events in eukaryotes and especially in land plants. The interactions between non-homologous chromosomes in interphase nuclei and chromosome (mis)pairing during meiosis are examined for their potential importance in the origin of EEFs and NCFs. The remaining open questions that need to be addressed are discussed.
... J. B. S. Haldane worked part-time at the John Innes Horticultural Institution (JIHI) in Merton in Surrey, a London suburb, from 1927 to 1937. His appointment has been discussed in several biographical accounts (in most detail in Clark 1968;Harman 2004). Although the main outlines of this history are well known, this decade in Haldane's life is worth closer scrutiny. ...
... Haldane's domain did not extend over the pomology or cytology sections of JIHI, although he maintained a friendly interest, particularly in the young Darlington, and encouraged and supported where he could (Harman 2004). One feels that Darlington's biographical memoirs overplay Haldane's isolation from his coworkers. ...
... Darlington, in turn, was drawing on Haldane's work, especially between 1931 and 1932 when Haldane freely gave Darlington ideas and access to his articles in press. Darlington also received Haldane's help with his Oenothera paper (a key publication for Darlington)-Haldane contributing a mathematical appendix on the number of possible pairing types in the genus and a mathematical theory of ring formation in general (Darlington 1931;Harman 2004). ...
... The queen of the life sciences in the last quarter of the nineteenth century, cytology now came to be viewed as an ancilla to genetics and, worse-as a stultified field prone to amassing exceptions to genetic theory (Darlington 1932;Harman 2004). These, it was claimed, were not addressed in any rigorous theoretical fashion by cytologists, demoting them to mere cautious empiricists, hardly the bold theoreticians that geneticists believed themselves to be. ...
... The disciplinary fortunes of cytology took their own route. The eclipse of cytology in the first quarter of the twentieth century would be abruptly challenged from within by the British cytologist Cyril Dean Darlington (1903Darlington ( -1981 in his 1932 book Recent Advances in Cytology, which argued that the mechanisms of evolution that acted at the level of the chromosome created possibilities for richer variation than the simple mutations and deletions that affect single genes (Darlington 1932;Harman 2004). Evolutionary considerations, the Fly Room researchers themselves now agreed -long the purview of either mathematical biologists or field workers -"were back in style in genetics" (Sturtevant and Beadle 1939, p. 363). ...
Article
Full-text available
In 1869, Johann Friedrich Miescher discovered a new substance in the nucleus of living cells. The substance, which he called nuclein, is now known as DNA, yet both Miescher’s name and his theoretical ideas about nuclein are all but forgotten. This paper traces the trajectory of Miescher’s reception in the historiography of genetics. To his critics, Miescher was a “contaminator,” whose preparations were impure. Modern historians portrayed him as a “confuser,” whose misunderstandings delayed the development of molecular biology. Each of these portrayals reflects the disciplinary context in which Miescher’s work was evaluated. Using archival sources to unearth Miescher’s unpublished speculations—including an analogy between the hereditary material and language, and a speculation that a series of asymmetric carbon atoms could account for hereditary variation—this paper clarifies the ways in which the past was judged through the lens of contemporary concerns. It also shows how organization, structure, function, and information were already being considered when nuclein was first discovered nearly 150 years ago.
... One writer has noted that the science of genetics had from its inception been an international venture with collaborations and international networks of science across continents (Krementsov 2005, p. 3). This paper traces that trajectory primarily through the lens of the relationship between the Indian woman cytogeneticist E. K. Janaki Ammal, the population geneticist, J. B. S. Haldane and 'the man who discovered the chromosome', C. D. Darlington (Harman 2004). ...
... The writer Paul suggests there may have been more Lysenkoists in India, France and Brazil than England, but in England people were forced to choose between science and communism (Paul 1983). C. D. Darlington however, was vocal in his criticism of Lysenkoism (Harman 2004) arguing that, 'a government which relied on the absence of inborn class and race differences in man as the basis of its political theory, was naturally unhappy about a science of genetics which relies on the presence of such differences' (Harman 2004, p. 151). Other critics such as R. A. Fisher also condemned Lysenko (Paul 1983). ...
Article
Full-text available
Right from the beginning, genetics has been an international venture, with international networks involving the collaboration of scientists across continents. Janaki Ammal’s career illustrates this. This paper traces her scientific path by situating it in the context of her relationships with J. B. S. Haldane and C. D. Darlington.
... There he came under the wing of the recently appointed cytologist, W. C. F. Newton, who introduced him to cytological techniques. But after Bateson's sudden death in 1926 followed by Newton's two years later, Darlington was left to pursue his own agenda (Harman 2004). In this sense he was untethered from cytological "tradition" and orthodoxy, approaching chromosome structure and behavior less guided by the morass of detail and more by the evolutionary meaning that could come from a general perspective. ...
Article
Full-text available
The marriage of Sally Peris Hughes (1895–1984) and Franz Schrader (1891–1962) in November 1920 launched a highly successful scientific collaboration that lasted over four decades. The Schraders were avid naturalists, adroit experimentalists, and keen theoreticians, and both had long, productive, and fruitful careers in zoology. They offer an extraordinarily rich case study that provides an insightful view of the work carried out in several areas of the life sciences from the 1920s to the 1960s—fieldwork, cytology, cytogenetics, and entomology—as well as critical aspects of the social world of contemporary science. By focusing on the fieldwork the couple carried out in Mexico and Central America in the late 1920s and early 1930s, this paper seeks to illuminate how this collaborative scientific marriage embodies a collective, complex, and integrated personal and social arrangement that served to enhance both knowledge production and disciplinary development in several areas of science. It also reveals ways in which marriage could serve as a means to help both parties navigate and negotiate restrictive sociocultural norms and institutional arrangements in science involving gender, power, and authority in the early twentieth century.
... On the history of chromosome research, seeHsu (1979),Kevles (1995),Lima-de- Faria (2003),Harman (2004) andHarper (2006). WHOSE TURN? ...
Article
Full-text available
A common account sees the human genome sequencing project of the 1990s as a “natural outgrowth” of the deciphering of the double helical structure of DNA in the 1950s. The essay aims to complicate this neat narrative by putting the spotlight on the field of human chromosome research that flourished at the same time as molecular biology. It suggests that we need to consider both endeavors – the human cytogeneticists who collected samples and looked down the microscope and the molecular biologists who probed the molecular mechanisms of gene function – to understand the rise of the human genome sequencing project and the current genomic practices. In particular, it proposes that what has often been described as the “molecularization” of cytogenetics could equally well be viewed as the turn of molecular biologists to human and medical genetics – a field long occupied by cytogeneticists. These considerations also have implications for the archives that are constructed for future historians and policy makers.
Chapter
Full-text available
Sir Fred Hoyle made fundamental contributions to nucleosynthesis in stars and may have pioneered the notion that organic matter pervades our Universe. However, his claims for diatoms, bacteria and viruses in space remain unproven, and his approach to being challenged on these matters may have diminished his legacy.
Article
Full-text available
The first reliable pattern of the human chromosome set was manufactured between the late 1950s and early 1960s. This paper will account for the historical background of such reliability, of the production of a reference, an image, the schematic figure – the ideogram – that represented what would from then on be held in the minds of medical practitioners and laboratory scientists of human cytogenetics as the cytological identity of being human. Human genetics as a history of images and the skills of drawing, making photo(micro) graphs and diagrams, developed through a reference drawn on the basis of the consensus reached by a small group of early human cytogeneticists in Denver in 1960. Schemes and idealizations, as well as the fully realistic transposition of the contours and interiors of each chromosome, participated in the emergence of a particular, specific and enduring way of representing the tiny parts of the cell where division began, and accounting for both the forms and function of chromosomes at the origins of medical genetics.
Article
Full-text available
In introgressive hybridization (the repeated backcrossing of hybrids with parental populations), Edgar Anderson found a source for variation upon which natural selection could work. In his 1953 review article "Introgressive Hybridization," he asserted that he was "bringing taxonomy to the service of genetics" whereas distinguished colleagues such as Theodosius Dobzhansky and Ernst Mayr did the precise opposite. His work as a geneticist particularly focused on linkage and recombination and was enriched by collaborations with Missouri Botanical Garden colleagues interested in taxonomy as well as with cytologists C.D. Darlington and Karl Sax. As the culmination of a biosystemtatic research program, Anderson's views challenged the mainstream of the Evolutionary Synthesis.
Article
This article describes how empirical discoveries in the 1930s-1950s regarding population variation for chromosomal inversions affected Theodosius Dobzhansky and Richard Goldschmidt. A significant fraction of the empirical work I discuss was done by Dobzhansky and his coworkers; Goldschmidt was an astute interpreter, with strong and unusual commitments. I argue that both belong to a mechanistic tradition in genetics, concerned with the effects of chromosomal organization and systems on the inheritance patterns of species. Their different trajectories illustrate how scientists' commitments affect how they interpret new evidence and adjust to it. Dobzhansky was moved to revised views about selection, while Goldschmidt moved his attention to different genetic phenomena. However different, there are significant connections between the two that enrich our understanding of their views. I focus on two: the role of developmental considerations in Dobzhansky's thought and the role of neutrality and drift in Goldschmidt's evolutionary account. Dobzhansky's struggle with chromosomal variation is not solely about competing schools of thought within the selectionist camp, as insightfully articulated by John Beatty, but also a story of competition between selectionist thinking and developmental perspectives. In contraposition, Goldschmidt emphasized the role of low penetrance mutations that spread neutrally and pointed out that drift could result from developmental canalization. This account adds to the dominant story about Goldschmidt's resistance to the splitting of development from genetics, as told by Garland Allen and Michael Dietrich. The story I tell illustrates how developmental thinking and genetic thinking conflicted and influenced researchers with different convictions about the significance of chromosomal organization.
Technical Report
Full-text available
A report by the Centre for the Study of Environmental Change in association with Unilever, and with help from the Green Alliance and a variety of other environmental and consumer non-governmental organisations (NGOs).
Article
The goal of the International HapMap Project is to determine the common patterns of DNA sequence variation in the human genome and to make this information freely available in the public domain. An international consortium is developing a map of these patterns across the genome by determining the genotypes of one million or more sequence variants, their frequencies and the degree of association between them, in DNA samples from populations with ancestry from parts of Africa, Asia and Europe. The HapMap will allow the discovery of sequence variants that affect common disease, will facilitate development of diagnostic tools, and will enhance our ability to choose targets for therapeutic intervention.