1 Mendel, Gregor, ‘Versuche über Pflanzen-Hybriden’, Verhandlungen des naturforschenden Vereines in Brünn (1866) 4, second part (Abhandlungen), pp. 3–47Google Scholar; in English translation in, e.g., Curt Stern and Eva R. Sherwood (eds.), The Origin of Genetics: A Mendel Source Book, San Francisco and London: W.H. Freeman, 1966, pp. 1–48.

2 Robert Olby's writings on Mendel, the rediscovery and the aftermath remain the best entry points into the relevant scholarship. See especially Robert Olby, Origins of Mendelism, 2nd edn, Chicago and London: The University of Chicago Press, 1985; and Olby, , ‘The dimensions of scientific controversy: the biometric–Mendelian debate’, BJHS (1989) 22, pp. 299–320Google Scholar.

3 Olby, Robert, ‘William Bateson's introduction of Mendelism to England: A reassessment’, BJHS (1987) 20, pp. 399–420Google Scholar; Alan G. Cock and Donald R. Forsdyke, Treasure Your Exceptions: The Science and Life of William Bateson, Dordrecht: Springer, 2008, pp. 248–250, for Bateson's use of ‘genetics’ in private in 1905 and in public in 1906.

4 Weldon, W.F.R., ‘Mendel's laws of alternative inheritance in peas’, Biometrika (1901–1902) 1, pp. 228–254Google Scholar, photograph in the first insert between 254 and 255; Radick, Gregory, ‘Beyond the “Mendel–Fisher controversy”: worries about fraudulent data should give way to broader critiques of Mendel's legacy’, Science (9 October 2015) 350, pp. 159–160CrossRefGoogle Scholar.

5 Here and in the next two points I present schematically what Weldon treated expansively in his writings and correspondence. Among the former, the most important sources include Weldon, op. cit. (4); Weldon, , ‘On the ambiguity of Mendel's categories’, Biometrika (1902–1903) 2, pp. 44–55Google Scholar; Weldon, ‘Theory of inheritance’, 1904–1905, Pearson/5/2/10/4, Pearson Papers, Special Collections, University College London; and Weldon, ‘Inheritance in animals and plants’, in T. B. Strong (ed.), Lectures on the Method of Science, Oxford: Clarendon Press, 1906, pp. 81–109, 92–93. Selections from Weldon's correspondence can be found in Pearson, Karl, ‘Walter Frank Raphael Weldon. 1860–1906’, Biometrika (1906) 5, pp. 1–52Google Scholar.

6 Galton's take on ancestral influence and its regularities came to fresh prominence in the late 1890s with his framing of what became known as the ‘law of ancestral heredity’. For discussion see William B. Provine, The Origins of Theoretical Population Genetics, Chicago: The University of Chicago Press, 2001 (first published 1971), pp. 51–54, 179–187. (Cf. the treatment of Weldon on peas here with that in Provine's book, p. 70.)

7 Weldon, ‘Theory of inheritance’, op. cit. (5). For discussion see Annie Jamieson and Gregory Radick, ‘Putting Mendel in his place: how curriculum reform in genetics and counterfactual history of science can work together’, in Kostas Kampourakis (ed.), The Philosophy of Biology: A Companion for Educators, Dordrecht: Springer, 2013, pp. 577–595, esp. 588–589.

8 In the archive at UCL there is a draft of a chapter from Weldon's ‘Theory of inheritance’ manuscript studded with the Edwardian equivalents of post-it notes, on which Galton had scribbled minor amendments to Weldon's summary of Galton on inheritance (in comparison and contrast with Mendel). Pearson/5/2/9/13, Pearson Papers.

9 Jamieson and Radick, op. cit. (7), pp. 586–587; also Radick, Gregory, ‘Physics in the Galtonian sciences of heredity’, Studies in History and Philosophy of Biological and Biomedical Sciences (2011) 42, pp. 129–138CrossRefGoogle ScholarPubMed, esp. 132–134.

10 On the controversy, the most extensive study since Olby, ‘Dimensions of scientific controversy’, op. cit. (2), is Kyung-Man Kim, Explaining Scientific Consensus: The Case of Mendelian Genetics, New York and London: Guilford Press, 1994.

11 Cock and Forsdyke, op. cit. (3), pp. 561–564; for discussion see Sarah Wilmot, ‘Mendel and the culture of commemoration’, John Innes Historical Collections website, 3 March 2015, at http://collections.jic.ac.uk/mendel-and-the-culture-of-commemoration.

12 See e.g. Skopek, Jeffrey M., ‘Principles, exemplars, and uses of history in early 20th century genetics’, Studies in History and Philosophy of Biological and Biomedical Sciences (2011) 42, pp. 210–225CrossRefGoogle ScholarPubMed; Gregory Radick, ‘Scientific inheritance: how history matters for the sciences’, inaugural lecture, University of Leeds, 16 May 2012, at www.youtube.com/watch?v=D3nyB2lqmRo (very ably summarized by Rebekah Higgitt, ‘Beyond our Kuhnian inheritance’, Guardian Online, 28 August 2012, at www.theguardian.com/science/the-h-word/2012/aug/28/thomas-kuhn); Jamieson and Radick, op. cit. (7), pp. 583–584, 592.

13 Richard J. Evans, Altered Pasts: Counterfactuals in History, London: Little Brown, 2014; ‘“What if” is a waste of time’, Guardian Online, 13 March 2013, at www.theguardian.com/books/2014/mar/13/counterfactual-history-what-if-waste-of-time.

14 Ian Hacking, Representing and Intervening: Introductory Topics in the Philosophy of Natural Science, Cambridge: Cambridge University Press, 1983.

15 Niall Ferguson (ed.), Virtual History: Alternatives and Counterfactuals, New York: Basic Books, 1999 (first published 1997); Stephen Jay Gould, Wonderful Life: The Burgess Shale and the Nature of History, London: Hutchinson Radius, 1989. On the fictionalizing differences between experimental interventions, computer simulations and thought experiments as matters of degree see Radick, Gregory, ‘Why what if?’, Isis (2008) 99, pp. 547–551, 551Google Scholar.

16 On historical explanation as counterfactual see e.g. Geoffrey Hawthorn, Plausible Worlds: Possibility and Understanding in History and the Social Sciences, Cambridge: Cambridge University Press, 1995; Jon Elster, Logic and Society: Contradictions and Possible Worlds, Chichester: John Wiley, 1978, pp. 175–221.

17 Weldon, ‘Inheritance in animals and plants’, op. cit. (5), pp. 92–93.

18 James T. Cushing, Quantum Mechanics: Historical Contingency and the Copenhagen Hegemony, Chicago and London: The University of Chicago Press, 1994; Peter J. Bowler, Darwin Deleted: Imagining a World without Darwin, Chicago and London: The University of Chicago Press, 2013. For a vigorously critical discussion of Bowler's book see Love, Alan C., Richards, Robert J. and Bowler, Peter J., ‘What-if history of science’, Metascience (2015) 24, pp. 5–24Google Scholar. For a playfully counterfactual complement to the book see Stephen Jay Gould, ‘George Canning's left buttock and the Origin of Species’, in Gould, Bully for Brontosaurus: Reflections in Natural History, New York: W.W. Norton, 1991, pp. 21–31.

19 Richard J. Evans, ‘In search of German social Darwinism’, in Evans, Rereading German History: From Unification to Reunification, 1800–1996, London: Routledge, 1997, pp. 119–148, 137, italics added. I learned from Ian Hesketh after my lecture in Swansea that Adam Shapiro, in a 2014 blog posting, had pointed out Evans's contradictions on this front; see Adam Shapiro, ‘What if counterfactuals were acceptable in history?’, 17 March 2014, at https://tryingbiology.wordpress.com/2014/03/17/what-if-counterfactuals-were-acceptable-in-history.

20 Léna Soler, Emiliano Trizio and Andrew Pickering (eds.), Science as It Could Have Been: Discussing the Contingency/Inevitability Problem, Pittsburgh: University of Pittsburgh Press, 2015; Ian Hacking, The Social Construction of What?, Cambridge, MA: Harvard University Press, 1999, esp. pp. 78–80.

21 T. Babington Macaulay, ‘Dryden’ (1828), in Macaulay, Essays, Critical and Miscellaneous, Philadelphia: Hart, Carey & Hart, 1850, pp. 35–50, 35–36; for discussion see Robert K. Merton, ‘Singletons and multiples in science’ (1961), in Merton, The Sociology of Science: Theoretical and Empirical Investigations, Chicago and London: The University of Chicago Press, 1973, pp. 343–370, 353.

22 On Clarkson's honorary degree see www.brunel.ac.uk/about/people/honorary-graduates/honorary-graduates-2003/jeremy-charles-robert-clarkson.

23 On the anti-individualism that is common to both older positivist and more recent contextualist historiographies see Henry, John, ‘Ideology, inevitability, and the Scientific Revolution’, Isis (2008) 99, pp. 552–559CrossRefGoogle Scholar; and Radick, Gregory, ‘Cultures of evolutionary biology’, Studies in History and Philosophy of Biological and Biomedical Sciences (2003) 34, pp. 187–200, 192–193Google Scholar.

24 Alfred Kroeber, ‘The superorganic’, American Anthropologist (1917), n.s. 19, pp. 163–213, 199. Cf. ‘Mendel spoke the truth, but he was not dans le vrai (within the true) of contemporary biological discourse … Mendel was a true monster, so much so that science could not even properly speak of him.’ Michel Foucault, ‘The discourse on language’ (1970), in Foucault, The Archaeology of Knowledge and the Discourse on Language, trans. A.M. Sheridan Smith, New York: Pantheon, 1972, pp. 215–237, 224.

25 Steven Shapin and Simon Schaffer, Leviathan and the Air-Pump: Hobbes, Boyle, and the Experimental Life, Princeton, NJ: Princeton University Press, 1985, p. 13.

26 On the epistemology of counterfactuals considered philosophically, psychologically and historically see respectively e.g. Williamson, Timothy, ‘Knowledge of counterfactuals’, Royal Institute of Philosophy Supplement (2009) 64, pp. 45–64CrossRefGoogle Scholar; David R. Mandel, Denis J. Hilton and Patrizia Catellani, eds., The Psychology of Counterfactual Thinking, Oxford: Routledge, 1995; Bunzl, Martin, ‘Counterfactual history: a user's guide’, American Historical Review (2004) 109, pp. 845–858Google Scholar. On the need to ‘go there' see Nolan, Daniel, ‘Why historians (and everyone else) should care about counterfactuals’, Philosophical Studies (2013) 163, pp. 317–335Google Scholar.

27 The abstract puzzles I have confronted most squarely are to do with the bearing of realism/anti-realism questions, the theory-ladenness of observations, and the individuation of theories (i.e. how different do they need to be to count as different?); see Gregory Radick, ‘Other histories, other biologies’, in Anthony O'Hear (ed.), Philosophy, Biology and Life, Cambridge: Cambridge University Press, 2005, pp. 21–47. Other, less systematic, attempts to bring epistemological difficulties into focus include Radick, ‘Is the theory of natural selection independent of its history?’, in Jonathan Hodge and Gregory Radick (eds.), The Cambridge Companion to Darwin, Cambridge: Cambridge University Press, 2003, pp. 143–167; Radick, , ‘The case for virtual history’, New Scientist (20 August 2005) 187, pp. 34–35Google Scholar; Radick, The Simian Tongue: The Long Debate about Animal Language, Chicago: The University of Chicago Press, 2007, esp. pp. 365–368; and Radick, op. cit. (15) – the introduction to an edited Focus section on ‘Counterfactuals and the historian of science’, Isis (2008) 99, 547–584Google Scholar.

28 Weldon, ‘Theory of inheritance’, op. cit. (5), Chapter 5, p. 24, Jamieson transcription.

29 Theodore M. Porter, Karl Pearson: The Scientific Life in a Statistical Age, Princeton, NJ: Princeton University Press, 2004, p. 302.

30 Quoted in Beatrice Bateson (ed.), William Bateson, F.R.S., Naturalist[:] His Essays & Addresses, Together with a Short Account of His Life, Cambridge: Cambridge University Press, 1928 (and facsimile reprint, New York: Garland, 1984), p. vi, italics in original.

31 On the Resilience Project see Stephen H. Friend and Eric E. Schadt, ‘Clues from the resilient’, Science, 30 May 2014, pp. 970–972, and more generally http://resilienceproject.me.

32 Gholson J. Lyon and Jason O’Rawe, ‘Human genetics and clinical aspects of neurodevelopmental disorders’, in Kevin J. Mitchell (ed.), The Genetics of Neurodevelopmental Disorders, Hoboken: Wiley–Blackwell, pp. 289–317, 291–292.

33 Evelyn Fox Keller, The Century of the Gene, Cambridge, MA: Harvard University Press, 2000; Jenny Lewis, ‘Genetics and genomics’, in Michael Reiss (ed.), Teaching Secondary Biology, 2nd edn, London: Hodder Education, 2011, pp. 173–214, 175.

34 For a more detailed account of the project and its findings see Annie Jamieson and Gregory Radick, ‘Genetic determinism in the genetics curriculum: an experimental test of the effects of Mendelian and Weldonian emphases’ (submitted). The project's sine qua non was a generous research grant from the Uses and Abuses of Biology scheme of the Faraday Institute for Science and Religion, Cambridge University.

35 See http://www.arts.leeds.ac.uk/geneticspedagogiesproject/.

36 A Powerpoint version of the lecture with Annie Jamieson's voiceover can be found at http://arts.leeds.ac.uk/geneticspedagogiesproject/gpp-lectures/.

37 Helpful pointers in the right direction from within recent philosophy of science include Sterelny, Kim, ‘Another view of life’, Studies in History and Philosophy of Biological and Biomedical Sciences (2005) 36, pp. 585–593Google Scholar; Martin, Joseph D., ‘Is the contingentist/inevitabilist debate a matter of degree?’, Philosophy of Science (2013) 80, pp. 919–930Google Scholar; and Kinzel, Katherina, ‘State of the field: are the results of science contingent or inevitable?’, Studies in History and Philosophy of Science (2015) 52, pp. 55–66Google Scholar. On the way that opposing sides in a scientific debate will converge, with the ‘winner’ looking much more ‘loser’-ish by the end than at the start, a philosophical classic remains instructive: William Whewell, ‘Of the transformation of hypotheses in the history of science’, in Whewell, On the Philosophy of Discovery; Chapters Historical and Critical, London: J.W. Parker, 1860, pp. 492–503. Many thanks to Jon Hodge for this reference.

38 Redfield, Rosemary J., ‘Why do we have to learn this stuff?’ A new genetics for 21st century students’, PLoS Biology (2012) 10, pp. 1–4Google Scholar. For further discussion see Jamieson and Radick, op. cit. (34).

39 Commenting on a draft of this paper, a Leeds colleague wrote, ‘I wondered whether there is a difference in determinism between introductory university genetics and more advanced. When I learnt genetics in the late ’70s, I understood plasticity of genes, and all the Weldonian stuff, although I didn't see it as anti-Mendelian (and I loved Mendelian genetics, and particularly ratios).’ A great deal of what I want to find out about is touched upon here. What is the link between Mendelism's teachability and its persistence? How, exactly, shall we characterize that persistence? And what difference would it make if students got the Weldonian stuff earlier in their learning?

40 Bowler, Peter J., ‘What Darwin disturbed: the biology that might have been’, Isis (2008) 99, pp. 560–567Google Scholar.

41 Hasok Chang, Inventing Temperature: Measurement and Scientific Progress, Oxford: Oxford University Press, 2004.

42 For additional remarks on how this sort of enterprise might enrich exchange between science education and the history of science see Jamieson and Radick, op. cit. (34). For future development of the notion of cognitive centrality versus marginality in science, a promising resource is Ronald Giere's perspectival philosophy of science; see Ronald Giere, Scientific Perspectivism, Chicago: The University of Chicago Press, 2006.

43 Chang, op. cit. (41), pp. 235–250.

44 See, in the interim, Radick, Gregory, ‘Should “heredity” and “inheritance” be biological terms? William Bateson's change of mind as a historical and philosophical problem’, Philosophy of Science (2012) 79, pp. 714–724Google Scholar; and the three papers that I authored or co-authored in Christine MacLeod and Gregory Radick, eds., Owning and Disowning Invention: Intellectual Property and Identity in the Technosciences in Britain, 1870–1930, special issue, Studies in History and Philosophy of Science (2013) 44, pp. 188–300Google Scholar.

45 Lyon and O'Rawe, op. cit. (32), pp. 289 and 303. For Lyon's talk at the Nurturing Genetics symposium in Leeds in June 2014 see www.leeds.ac.uk/arts/info/125175/genetics_pedagogies_project/2094/events.

46 Pearson, op. cit. (5), p. 8.

47 ‘The British Association’, Nature (2 September 1880) 22, pp. 410–411Google Scholar; Rep. BAAS 50, pp. lxxvii, 459, 603–605, 625.