© 2019. Published by The Company of Biologists Ltd | Development (2019) 146, dev175448. doi:10.1242/dev.175448 SPOTLIGHT Inclusion and exclusion in the history of developmental biology Nick Hopwood ABSTRACT In this view, when ‘developmental biology’ was founded after Scientific disciplines embody commitments to particular questions World War II, it was not just another word for embryology (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 cell 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 medicine around the same time. Early developmental biology reproduction, while anatomy gave rise to many other sciences largely excluded evolution and the environment, but promised (Jacob, 1982; Hopwood, 2018a; Cunningham, 2010). Nineteenth- to embrace the entire living world and the whole life course. and early 20th-century embryology did then contribute to several Developmental biologists have been overcoming those exclusions fields, including immunology and genetics, 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 embryos 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 biologist’. 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 cell biology 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 ‘stem cell’ 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. Teratology 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/ vertebrate 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 1 SPOTLIGHT Development (2019) 146, dev175448. doi:10.1242/dev.175448 From the 1860s, Darwinists prized embryos as evidence of reproduction, and cine films. In the 1940s, researchers there analysed common descent, and ontogeny as an aid to constructing the results of early attempts to fertilize human eggs 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). Hans Spemann and Hilde Mangold’s discovery of a primitive form…of a bird’ (Wilson, 1907, p. 31). He froze to death 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 plants, animals 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