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© 2019. Published by The Company of Ltd | (2019) 146, dev175448. doi:10.1242/dev.175448

SPOTLIGHT Inclusion and exclusion in the history of developmental Nick Hopwood

ABSTRACT In this view, when ‘’ was founded after Scientific disciplines embody commitments to particular questions World War II, it was not just another word for (Horder, and approaches, scopes and audiences; they exclude as well as 2010). Nor has it been simply an expanded version, although ‘ ’ include. Developmental biology is no exception, and it is useful to experimental embryology across the living world used to come reflect on what it has kept in and left out since the field was founded close, and the field has broadened in recent decades. It is also a ‘ after World War II. To that end, this article sketches a history of how stretch to present developmental biology as the stem of ’ – developmental biology has been different from the comparative, biological disciplines (Gilbert, 2017). That is because to begin – ‘ ’ human and even experimental embryologies that preceded it, as well closer to the beginning 18th-century generation was the common as the embryology that was institutionalized in reproductive biology ancestor of embryology as well as research on heredity and and around the same time. Early developmental biology , while gave rise to many other sciences largely excluded and the environment, but promised (Jacob, 1982; Hopwood, 2018a; Cunningham, 2010). Nineteenth- to embrace the entire living world and the whole course. and early 20th-century embryology did then contribute to several Developmental biologists have been overcoming those exclusions fields, including and , yet developmental ‘ ’ for some years, but might do more to deliver on the promises while biology was not there from the start, but was itself budded off .Itis cultivating closer relations, not least, to reproductive studies. more accurate, and more respectful of the differences, to think in terms of a family of disciplines or research programmes that have KEY WORDS: British Society for Developmental Biology (BSDB), shared interests in and in development, but had their own Comparative, experimental and human embryology, History of identities and asked somewhat different questions (Hopwood, 2009). embryology, Reproductive biology and medicine, Society for I shall argue for the distinctiveness of developmental biology by Developmental Biology (SDB) first introducing the three programmes that dominated research between the 1880s and the 1930s: comparative, experimental and Introduction human embryology. I shall then review how the questions and Last year’s 70th anniversary of the British Society for Developmental approaches, scope and audiences of developmental biology made it Biology (BSDB) was an opportunity to stand back, to consider different from any of those. Meetings, funding, journals, societies, how the subject came about and what has made it distinctive, and to courses and textbooks defined the new speciality. In the 1950s, for reflect on present arrangements. This historical commentary takes the first time, when a colleague asked, ‘What do you do?’, you could stock through the theme of inclusion and exclusion. answer, ‘I’m a developmental ’. By the 1970s, you could Science is organized into disciplines that shape training, identity expect them to understand the response. and funding; they define the important problems and how these Exceptions to my generalizations may come to mind; I aim to should be addressed. Disciplines are made, not found. Making one sketch a big picture within which to place developmental biology, is a political project of carving out questions, approaches and scope, not to paint the detailed portrait that would need more historical and recruiting patrons and audiences, in relation to what went before research. Though I shall conclude by exploring the significance of and to other sciences (e.g. Nyhart, 1995; Lenoir, 1997). Claiming an inclusion and exclusion today, I have not published in Development identity involves deciding what to include or exclude, what will be for over a quarter of a century (Hopwood et al., 1992). Having in and what will be out. Practitioners negotiate the boundaries of become a historian of science and medicine, I know more about their own field and the terms of their relations with neighbours. research on embryos in 1819 and 1919 than in 2019. So I shall not Developmental biologists have done this explicitly in electing not to presume to take a strong line on the present, let alone the future, but merge with societies in the 1980s and early 1990s, and in shall risk a few remarks about how thinking in terms of what is in the BSDB’s 2013 decision not to add ‘’ to its name. [For a and what is out might put strategies for renewal into perspective. possible merger of the BSDB with the British Society for Cell Biology, see Martin Johnson’sChairman’s report 1985-86, BSDB Newsletter, Three embryologies no. 13 (Spring 1986), pp. 10-11 (1986-1(#13) at bsdb.org/2018/04/29/ Embryology was made a science in the decades around 1800 when bsdb-archive/). For the 1992 vote against merging the (American) the old anatomy and the broad framework of ‘generation’ began Society for Developmental Biology and the American Society for Cell to break down. was established rather separately in Biology, see SDB and ASCB records (library.umbc.edu/speccoll/ the same period. Much research compared the development of findingaids/coll022.php and library.umbc.edu/speccoll/findingaids/ embryos, and analysed them in terms of germ layers coll008.php). For the stem cell vote, see Martinez Arias (2013).] and cells. By the 1850s, professors in the German universities were teaching medical students in dedicated courses. Although ‘ Department of History and Philosophy of Science, University of Cambridge, their lectures and demonstrations nominally tackled human Free School Lane, Cambridge CB2 3RH, UK. embryology’, the chick and domestic mammals provided much of the content, especially for early stages. For a long time, embryology *Author for correspondence ([email protected]) had no societies and seldom its own departments, but evolutionism

N.H., 0000-0001-7069-7497 soon drew attention to the science (Hopwood, 2009). DEVELOPMENT

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From the 1860s, Darwinists prized embryos as evidence of reproduction, and cine films. In the 1940s, researchers there analysed , and as an aid to constructing the results of early attempts to fertilize human in vitro phylogenies (Gould, 1977; Hopwood, 2015). Comparative (Maienschein et al., 2004; Buklijas and Hopwood, 2008; Morgan, embryology built much of the edifice of Darwinian biology as it 2009; Marsh and Ronner, 2008, pp. 104-110). inspired imperial safaris to bring home ‘living fossils’ and ‘missing Of the three research programmes – comparative, experimental links’ (Bowler, 1996; Hall, 2001). The most extreme was the ‘winter and human – experimentation was dominant by the 1930s, when journey’ of Robert Falcon Scott’s Antarctic expedition in 1911. The various new initiatives sprang up around it, notably developmental biologist Edward Wilson attached ‘the greatest possible importance’ genetics and chemical embryology (Keller, 1986; Abir-Am, 1994; to the embryology of the emperor penguin, that ‘nearest approach to Fantini, 2000). and Hilde Mangold’s discovery of a primitive form…of a bird’ (Wilson, 1907, p. 31). He froze to the amphibian organizer was thrilling, but failure to find out its with Scott, but a team-mate brought back three eggs – to a sadly mode of action dampened the excitement considerably (Hamburger, rather lukewarm reception (Raff, 1996, pp. 1-4). 1988; Fäßler, 1997). Embryology faced more general challenges by Evolutionists rarely claimed medical relevance; embryology the 1940s. Especially in the USA, it was separated from and was not in that sense a matter of life and death. It was much threatened by genetics, which profited from its uses in breeding more important than that: at stake was where humanity came , and humans (Gilbert, 1998). In an age of striving for from, why we are here and where we are going. This gave the unity of science, research on embryos was fragmented and embryology public prominence for the first time. But marginal. On the eve of the massive postwar expansion in embryologists, comparative anatomists and palaeontologists government funding, embryology was poorly placed to benefit. increasingly disagreed on the relations of ontogeny and phylogeny, Developmental biology might have been designed to solve these and particularly the doctrine of recapitulation. Their rancorous problems, and to an extent it was. disputes threw the field into crisis and by 1900 were driving young researchers away (Gould, 1977, pp. 167-206; Hopwood, 2015, Defining developmental biology pp. 171-187). Comparative embryologists still innovated. For The expression ‘developmental biology’ first gained wide currency example, in 1911 they founded the first society for the science, the in the postwar USA, by then the major world power and pouring International Institute of Embryology. Members of this elitist club money into science. Taking the lead, Paul Weiss, the emigré collected embryos of endangered mammals in European colonies and Austrian, Chicago professor and Chairman of the Division of produced normal plates (Nieuwkoop, 1961; Hopwood, 2007). Yet Biology and Agriculture at the National Research Council, pushed after World War I, other research programmes made the running, the National Science Foundation (NSF) to adopt the term. In 1952, led by experimental embryology or ‘developmental mechanics’:the the NSF replaced old divisions with a few categories that applied most direct ancestor of developmental biology. across the living world and so could integrate biology while From the 1880s, and other experimentalists had allowing support for medical research (Appel, 2000, pp. 63-66; asked not how evolved, but how in physiological Brauckmann, 2013; Crowe et al., 2015) (Fig. 1). In 1956, a series of terms one stage becomes the next, especially how an turns into a international meetings promoted the field (Weiss, 1957, 1958). or (Maienschein, 1991; Nyhart, 1995). That is a prime Three years later, when the journal Developmental Biology was illustration of how questions about embryos have varied and launched, with significant European input, the subject was already a changed. Developmental mechanics paid much attention to going concern. Practitioners traced this back to an important regulation and , and had links to medicine, for incubator for the convergence between embryology and genetics: example, through the experimental generation of malformations the Society for the Study of Development and Growth, renamed the and claims to human rejuvenation (Maienschein, 2011; Sengoopta, Society for Developmental Biology in 1965 (Oppenheimer, 1966) 2003). Plants were included in principle (Roux et al., 1912), but (Table 1). embryology was more integrated into the rest of ; most Weiss introduced the first issue of Developmental Biology by articles in Roux’s journal dealt with amphibia and marine calling on authors to unite the phenomena of ‘development and . In the early 20th century the approach was growth’, which had been dealt with in many disciplines, from plant conspicuous in the first centres for biology as distinct from to oncology, and included the ‘seriation of stages of anatomy, or botany. But the earliest specifically chick embryos’, ‘nutrient control of bacterial growth’ and ‘repair of embryological research institute focused on humans. a broken ’. The processes of interest ranged from growth, That institute was the Department of Embryology at the Johns differentiation and through maturation and , Hopkins University in Baltimore, which the Carnegie Institution regulation and regeneration. Tackling these would require of Washington, one of those private philanthropies that had begun engagement with ‘broad problems’, but Weiss otherwise to fund new fields, founded in 1914. The Carnegie Department committed to ‘diversity’ and to accepting work ‘[w]hether institutionalized the methods, invented in German-speaking Europe, of analytical or descriptive, technical or theoretical, whether using a collaborating with clinicians to collect early human embryos, molecular or an organismic approach, whether dealing with then analysing these by serial sectioning and plastic reconstruction , plants, animals, or man’ (Weiss, 1959; further: (Hopwood, 2000, 2002). The mission was anatomical and pathological Keller, 1995). Weiss claimed activities that had a place in Roux’s – to set up norms of development and explain deviations from them – grandest plans for developmental mechanics, but put more emphasis and potential medical benefits helped justify support. Evolution was than Roux’s followers ever had in practice on embracing the whole largely off the agenda and few experiments were possible. The living world, including microbes. Carnegie instead concentrated on detailed descriptions of In that heyday of science funding by block grants, developmental human developmental anatomy, eventually including the first two biologists found it fairly easy to claim applicability. Weiss himself weeks. These fed into medical teaching and are still used today (e.g. de had worked during the war on nerve regeneration and even Bakker et al., 2016). Between the world wars, the department also contributed to surgical innovations. A ‘growth and development’ pioneered culture, studies of monkey embryology and perspective potentially illuminated numerous medical problems, but DEVELOPMENT

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Fig. 1. Annual totals in millions of dollars, by category, for US federal grants and contracts for unclassified research in the basic life sciences for calendar year 1952 (white), fiscal year 1954 (hatched) and fiscal 1955 (black). Detail reproduced, with permission from AAAS, from Consolazio and Jeffrey (1957), figure 2.

fed into and drew most generally on cancer research, which had ignore the environment beyond the laboratory (but see e.g. Mintz, been prominent in the foundation of the Growth Society itself 1958). That was in part because the field followed experimental (Crowe, 2014). It was widely accepted that ‘organized embryology and in part because of the lure of biomedical dollars. It development’‘may throw light upon’‘malignant growth’ and is less often noted that not only did ‘embryology’ mean something vice versa (Berrill, 1971, p. 516). altogether more traditional to generations of medical students, and Inclusivity had its limits. It is well known that developmental to some of their teachers, but developmental biologists also biology, also as established through textbooks and graduate organized separately from reproductive biology. This was programmes in the early 1970s, excluded evolution and tended to institutionalized around the same time, but in laboratories linked to farms, clinics and population control (Clarke, 1998) (Table 1). Table 1. Years of foundation for selected organizations and journals of Mammalian developmental biologists moved between these worlds, developmental biology and of reproductive biology and medicine in the however (and in Markert and Papaconstantinou, 1975, the SDB USA and UK embraced reproduction). In the 1970s, transfer was made an Year Organization or journal agricultural industry and in the 1980s in vitro fertilization became a Developmental biology medical one (Betteridge, 2003; Henig, 2004; Hopwood, 2018b). USA A few developmental biologists joined more medically oriented 1939 Society for the Study of Development and Growth embryologists, paediatricians and others in the teratology societies → Society for Developmental Biology in 1965 that were set up from 1960, initially in the USA and Japan. These 1952 National Science Foundation program responded to worries about congenital malformations – their 1956 Series of meetings visibility greater after World War II, as mortality and morbidity 1959 Developmental Biology – 1966 Current Topics in Developmental Biology from other causes declined and attracted funding from a new Human Embryology and Development Study Section of the UK National Institutes of Health. The thalidomide tragedy then 1948 London Embryologists’ Club → Society for Developmental Biology in 1964 amplified their concerns (Kalter, 2003; Dron, 2016; further: → British Society for Developmental Biology in 1969 Donnai and Read, 2003). 1953 Journal of Embryology and Experimental Morphology The UK, like other countries which I cannot cover here, made a → Development in 1987 less researched and apparently more gradual transition to Reproductive biology and medicine developmental biology, with much interaction across the Atlantic USA (Table 1). [For other countries, see the special issues of the 1944 American Society for the Study of Sterility International Journal of Developmental Biology, www.ijdb.ehu.es/ → American Fertility Society in 1965 web/issues/special-countries/.] Young initiatives, including → American Society for Reproductive Medicine in 1995 chemical embryology and developmental genetics, had been well 1948 International Planned Parenthood Federation represented in the UK since the 1930s. But the London 1950 Fertility and Sterility ’ 1955 Human Embryology and Development Study Section, NIH Embryologists Club, the forerunner of the BSDB, did not portray 1960 Teratology Society itself as a disciplinary innovation when founded 71 years ago in 1967 Society for the Study of Reproduction 1948. The minutes of the first meeting identified three useful, but 1969 Biology of Reproduction hardly revolutionary, aims: ‘[i]nformal discussion of problems of 1974 International Embryo Transfer Society embryology’, ‘meet[ing] embryologists from other countries’ and UK ‘compil[ing] a record of research material in this country’ (Slack, 1944 Family Planning Association meetings 2000) (Fig. 2). Yet given the divisions between comparative, → Society for the Study of Fertility in 1949 experimental and human approaches, it was novel just to bring them → Society for Reproduction and Fertility in 2001 together (Hopwood, 2009). 1960 Journal of Reproduction and Fertility → Reproduction in 2001 The London club encompassed all kinds of projects, and a wide 1985 European Society of Human Reproduction and Embryology (ESHRE) range of species, including humans, though not much explicitly 1986 Human Reproduction comparative work (Slack, 2000). Research expanded and 1993 Association of Clinical Embryologists diversified, not least through the rise of . The A more complete list would include the recent stem cell institutions. (For club went national as the Society for Developmental Biology in reproductive sciences, see further Clarke, 1998, pp. 140-141.) 1964, an obvious step, although it is unclear why it was taken then. DEVELOPMENT

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Fig. 2. Minutes of the inaugural meeting of the London Embryologists’ Club at University College London on 2 March 1948 (detail). Reproduced, with permission, from the BSDB Archive, John Innes Centre Archives, Norwich.

The remit was ‘those aspects of and plant biology that are connected with developmental processes’ (SDB-1964 at bsdb.org/ 2018/04/29/bsdb-archive/). To avoid confusion with the American society, which was renamed the next year, the British one added the first ‘B’ in 1969. The programme of the inaugural meeting of the national society, hosted by John Gurdon in Oxford, shows varied interests: (proteins and DNA) and transplantation; plants and animals, including humans and ; Fig. 3. Programme of the first meeting of the SDB in Oxford, 20 June 1964. and adult tissues as well as embryos (Fig. 3). But neither evolution Reproduced, with permission, from the BSDB Archive, John Innes Centre nor environmental matters were represented; any clinical relevance Archives, Norwich. was implicit. The Company of Biologists had founded the Journal of has concentrated on IVF (Betteridge, 2003; Brown, 2005). There Embryology and Experimental Morphology (JEEM) in 1953, was and is mutual exclusion, too: the organization that claims, with following an initiative of the International Institute in Utrecht, as ‘a over 800 members, to be ‘the UK’s only professional body new periodical…primarily devoted to morphogenesis’.The representing embryologists’ is not the BSDB, but the Association of cumbersome name signalled a pooling of resources for Clinical Embryologists (www.embryologists.org.uk, last accessed 9 ‘embryologists’, like the London club, more than any November 2018). reorganization of ‘the science of development’. JEEM sought Developmental biology may, then, consider itself the main ‘contributions’ about ‘how living, non-pathological structures are successor of experimental embryology. The somewhat separate built up, increased, maintained, repaired [and] transformed, either at institutionalization of embryos in reproductive biology and the supracellular, or cellular, or macromolecular level’. With a focus medicine cautions against assuming that developmental biology on ‘the animal realm’ and only ‘occasional papers or reviews’ monopolized research after 1960. Like its principal predecessor, it expected to ‘throw out a bridge towards morphogenesis in unicellular has rather been one kind of embryology among several and with a and plant organisms’ (Dalcq, 1953), the taxonomical scope was scope for the most part more restricted even than Weiss’s vision narrower than Developmental Biology or Current Topics in implied. Developmental Biology.Bycontrast,JEEM was less exclusively experimental, biophysical and biochemical – and thus more open Golden ages? to, for example, descriptive human embryology – though it became Detailed historical investigation will be needed to establish the more similar with its relaunch as Development in 1987 (Wylie, 2012). extent to which developmental biologists realized that vision. The BSDB and these journals were not the whole story because Expansion surely made space for new areas of research, from society members wore various other hats. As in the USA, the nuclear transplantation, through embryonal carcinoma and establishment of the reproductive sciences shaped these hybrid embryonic stem cells, to plant systems. But after 30 years ‘the identities (Table 1). With the growing ability to culture mammalian goal of easy discourse between animal and plant developmental embryos, the large UK of mammalian embryologists biologists still seem[ed]’, to one American sea-urchin specialist, played an increasing role in the BSDB and also attended meetings of ‘only on the horizon’ (Wilt, 1990). In 1994, a celebration and stock- the Society for the Study of Fertility (Graham, 2000; Clarke, 2007). taking included ‘all multicellular organisms’, but concentrated on Some have gone to conferences of the International Embryo the core topics of embryogenesis, morphogenesis and regeneration Transfer Society, which is oriented towards animal breeding, or the (Hines et al., 1994), which had long been the focus of

European Society of Human Reproduction and Embryology, which developmental biology textbooks too. DEVELOPMENT

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The initial advance of developmental biology was no simple favoured inclusion or exclusion, but the era of model organisms ‘molecularization’ (Crowe et al., 2015), but cells, and shows that expansion and a certain narrowing could go hand in molecules did move centre stage as the control of expression hand.] It should be reassuring to remember that practical demands became the overriding interest. The pull of genetics gave have often driven fundamental discoveries, such as in bacteriology developmental biology a different species profile from the old and immunology, endocrinology and the control of reproduction experimental embryology; mice, flies and worms were later joined (e.g. Oudshoorn, 1994; Brock, 1999). by thale cress and . In the 1980s, the combination of Other challenges have been organizational, technical and traditional but large-scale genetic and embryological methods with intellectual: the welter of necessary but not always electrifying gene and antibody produced an explosion of knowledge, detail; the stresses of fragmentation into competing subfields; and the which I do not claim to represent fully with two journal covers politics of species choice (Hopwood, 2011). The difficulty of (Fig. 4). Problems set in the earlier 20th century were solved, or their negotiating relations with the rapidly multiplying stem cell field has solution made to appear imminent. loomed large amidst the hope, horror and hype about regenerative The field expanded, on one measure from 690 researchers medicine (Maehle, 2011; Maienschein, 2011). Many developmental internationally in 1949 to some 3400 in 1980 (Faber and Salomé, biologists have talked of ‘decline’ from a ‘golden age’ (e.g. St 1981). Membership of the BSDB rose from 186 in 1965 and 400 in Johnston, 2015), though others, and some of the same people, see a 1980 to 1246 in 2000 (BSDB Newsletter, no. 2, 1980, p. 2, 1980- gilded present and a bright future (St Johnston, 2015; Gilbert, 2017; 1(#2) at http://bsdb.org/2018/04/29/bsdb-archive/; Slack, 2000). Yet Maartens and Tabin, 2018; see also Pourquié, 2012, 2018; and Zon, the investment then necessary to carry out this sort of work reinforced 2019). With renewal in progress, I hope that looking back will place the concentration on a few not entirely representative species (Bolker, recent trends and aid reflection on the next paths to take. 1995; but see also Davies, 2007). Narrowing was a precondition of deepening, and the advantages of exclusion, of concentrating on egg Strategies for renewal to embryo in a handful of model organisms and a few experimental Developmental biologists have long drawn strength from embracing systems, were well rehearsed. In similar ways, a tight focus had approaches and methods of neighbouring fields. The default allowed the Carnegie Department to describe human developmental strategy is to include the latest techniques, such as systems anatomy in exquisite detail and Spemann’s school to elucidate the analysis based on ‘-omics’ and model-building, gene editing and behaviour of the organizer, though with diminishing returns. , advanced imaging and soft-matter physics, but to apply In developmental biology, a period of soul-searching followed them to deepening core studies of embryogenesis (St Johnston, the excitement of the 1980s and 1990s. When the field was founded, 2015). One of the most striking changes since I left the field is a money had flowed and scientists enjoyed more freedom in research general move to quantification, with the mainstreaming of than ever before or since. Calls for applications grew louder in the mathematical modelling and routine interaction between ‘wet’ and 1970s, and eventually reached developmental biology. As funders ‘dry’ biology. It is a source of optimism that new methods enlarge required pay-offs to justify higher levels of support, all biologists the range of options – inclusion and exclusion is not from a fixed felt more pressure to make the case (e.g. Gilbert, 2017; Maartens menu – but this is not enough. On the one hand, the postwar et al., 2018). [Knowing the amount of money available per founders of developmental biology enacted major exclusions that developmental biologist would define pressures that might have have been relaxed as the costs have become clear. On the other,

Fig. 4. Covers of Cell illustrate the successes and prominence of developmental biology in the late 1980s. Left: Weeks and Melton, 1987. Right: Driever and Nüsslein-Volhard, 1988. Reprinted with permission from Elsevier. DEVELOPMENT

5 SPOTLIGHT Development (2019) 146, dev175448. doi:10.1242/dev.175448 those early developmental biologists made promises about Berrill, N. J. (1971). Developmental Biology. New York: McGraw-Hill. inclusion that are relevant still. Betteridge, K. J. (2003). A history of farm animal embryo transfer and some associated techniques. Anim. Reprod. Sci. 79, 203-244. The founding promise was to study development across the living Bolker, J. A. (1995). Model systems in developmental biology. BioEssays world. That sounds inclusive, but researchers’ expectation that the 17, 451-455. principles would be the same in all multicellular organisms Bowler, P. J. (1996). Life’s Splendid Drama: and the ’ – increasingly justified their focus on just a few. Interest in diversity Reconstruction of Life s Ancestry, 1860 1940. Chicago: University of Chicago Press. for its own sake goes back to the renaissance of ‘evolution and Brauckmann, S. (2013). Weiss, Paul Alfred. In Encyclopedia of Life Sciences. development’ around 1980 and gained momentum with the Chichester: Wiley. discovery of the conserved colinearity of Hox genes and the rise Brock, T. D. (1999). Robert Koch: A Life in Medicine and Bacteriology. Washington, ‘ ’ DC: ASM Press. of evo-devo in the 1990s (Laubichler and Maienschein, 2007). Brown, S. (2005). ESHRE: The First 21 Years, https://www.eshre.eu/Home/About- Since then, it has been popular to go beyond model organisms, to us/History, last accessed 25 January 2019. introduce new ones and to work on several, with less of a trade-off in Buklijas, T. and Hopwood, N. (2008). Making Visible Embryos, an online depth than there used to be, thanks to techniques such as RNAi and exhibition, http://www.hps.cam.ac.uk/visibleembryos/. Clarke, A. E. (1998). Disciplining Reproduction: American Life Sciences and ‘the CRISPR/Cas (Hopwood, 2011). Humans, previously marginal to Problems of ’. Berkeley: University of California Press. developmental biology, have attracted renewed attention as stem Clarke, J. (2007). The history of three scientific societies: the Society for the Study of cell cultures have opened differentiation and morphogenesis to Fertility (now the Society for Reproduction and Fertility) (Britain), the Société experimentation (Pourquié et al., 2015). Française pour l’Étude de la Fertilité, and the Society for the Study of Reproduction (USA). Stud. Hist. Philos. Biol. Biomed. Sci. 38, 340-357. A second promise is less generally appreciated: developmental Consolazio, W. V. and Jeffrey, H. L. (1957). Federal support of research in the life biology proposed to study the life course and not just egg to embryo, sciences. Science 126, 154-155. or even sexual . Today, more effort is going into Crowe, N. (2014). Cancer, conflict, and the development of nuclear transplantation understanding later processes, from through techniques. J. Hist. Biol. 47, 63-105. Crowe, N., Dietrich, M. R., Alomepe, B. S., Antrim, A. F., ByrneSim, B. L. and He, histogenesis to physiological . Developmental biology Y. (2015). The diversification of developmental biology. Stud. Hist. Philos. Biol. has played a role in ageing research, not least in relation to Biomed. Sci. 53, 1-15. programmed cell death (Jiang, 2013). Looking to life cycles could Cunningham, A. (2010). The Anatomist Anatomis’d: An Experimental Discipline in reduce the continuing separation from reproductive studies and Enlightenment Europe. Farnham: Ashgate. Dalcq, A. M. (1953). Foreword. J. Embryol. Exp. Morphol. 1, 1-4. might help go further still. The current ecological crisis makes a Davies, J. A. (2007). Developmental biologists’ choice of subjects approximates to a compelling argument for seeking a wider synthesis, and research power law, with no evidence for the existence of a special group of ‘model increasingly includes the environmental regulation of reproduction organisms’. BMC Dev. Biol. 7, 40. and development, evolution and health (Gluckman et al., 2010; de Bakker, B. S., de Jong, K. H., Hagoort, J., de Bree, K., Besselink, C. T., de Kanter, F. E. C., Veldhuis, T., Bais, B., Schildmeijer, R., Ruijter, J. M. et al. Gilbert and Epel, 2015). (2016). An interactive three-dimensional digital atlas and quantitative database of human development. Science 354, aag0053. Conclusions Donnai, D. and Read, A. P. (2003). How clinicians add to knowledge of Developmental biology has not been just (experimental) development. Lancet 362, 477-484. Driever, W. and Nüsslein-Volhard, C. (1988). The protein determines embryology by another name. Rather, developmental biology was position in the embryo in a concentration-dependent manner. Cell 54, made after World War II with a particular set of inclusions and 95-104. exclusions, and has been reworked ever since. By including Dron, H. A. (2016). Teratology transformed: uncertainty, knowledge, and conflict evolution and humans, the field has now expanded to encompass over environmental etiologies of birth defects in midcentury America. PhD dissertation, History of Health Sciences, University of California, San Francisco. versions of all three earlier embryologies that I picked out. As you Faber, J. and Salomé,B.Z.(1981). Introduction. Gen. Embryol. Inf. Service 18,4. continue to remake it today, you are including or excluding Fäßler, P. E. (1997). Hans Spemann 1869–1941. Experimentelle Forschung im questions and approaches, species and audiences, all the time. Spannungsfeld von Empirie und Theorie. Ein Beitrag zur Geschichte der Entwicklungsphysiologie zu Beginn des 20. Jahrhunderts. Berlin: Springer. I have leant towards an inclusive strategy, and pointed to Fantini, B. (2000). L’embryologie, la ‘géographie chimique’ de la cellule et la opportunities, for example, in reproduction and in , in the synthesè entre morphologie et chimie (1930–1950). Hist. Philos. Life Sci. 22, conviction that developmental biology will end up stronger and 353-380. more effective if it can succeed in tackling more. But I accept that, at Gilbert, S. F. (1998). Bearing crosses: a historiography of genetics and embryology. Am. J. Med. Genet. 76, 168-182. almost every historical juncture, a commentator could have Gilbert, S. F. (2017). Developmental biology, the stem cell of biological disciplines. emphasized either inclusion or exclusion as the productive move. PLoS Biol. 15, e2003691. My brief is less for one vision or another, and more for the value of Gilbert, S. F. and Epel, D. (2015). Ecological Developmental Biology: The standing back, seeing the bigger picture and considering how it Environmental Regulation of Development, Health, and Evolution, 2nd edn. Sunderland, MA: Sinauer. matters what is kept in and what is left out. Gluckman, P. D., Hanson, M. A. and Buklijas, T. (2010). A conceptual framework for the developmental origins of health and disease. J. Dev. Orig. Health Dis. Acknowledgements 1, 6-18. Gould, S. J. (1977). Ontogeny and Phylogeny. Cambridge, MA: Harvard University The article is based on a talk at the 2018 BSDB Spring Meeting in Warwick. I thank Press, Belknap Press. Andreas Prokop for the invitation to speak; Aidan Maartens for commissioning this Graham, C. (2000). Mammalian development in the UK (1950–1995). Int. J. Dev. piece; Scott Gilbert, Alex Gould, Jeremy Green, Tim Horder, Martin Johnson, Aidan Biol. 44, 51-55. Maartens, Alfonso Martinez Arias and two anonymous reviewers for comments on Hall, B. K. (2001). John Samuel Budgett (1872–1904): in pursuit of . drafts; and Mike Taylor and Ian Bolton for scans. Bioscience 51, 399-407. Hamburger, V. (1988). The Heritage of Experimental Embryology: Hans Spemann References and the Organizer. New York: Oxford University Press. Abir-Am, P. G. (1994). The philosophical background of Joseph Needham’s work in Henig, R. M. (2004). Pandora’s Baby: How the First Test Tube Babies Sparked the chemical embryology. In A Conceptual History of Modern Embryology (ed. S. F. Reproductive Revolution. Boston: Houghton Mifflin. Gilbert), pp. 159-180. Baltimore: Johns Hopkins University Press. Hines, P. J., Marx, J. and Parks, S. (1994). Frontiers in development. Science 266, Appel, T. A. (2000). Shaping Biology: The National Science Foundation and 523. American Biological Research, 1945–1975. Baltimore: Johns Hopkins University Hopwood, N. (2000). Producing development: the anatomy of human embryos and

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