Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

How did Mendel arrive at his discoveries?



There are few historical records concerning Gregor Johann Mendel and his work, so theories abound concerning his motivation. These theories range from Fisher’s view that Mendel was testing a fully formed previous theory of inheritance to Olby’s view that Mendel was not interested in inheritance at all, whereas textbooks often state his motivation was to understand inheritance. In this Perspective, we review current ideas about how Mendel arrived at his discoveries and then discuss an alternative scenario based on recently discovered historical sources that support the suggestion that Mendel’s fundamental research on the inheritance of traits emerged from an applied plant breeding program. Mendel recognized the importance of the new cell theory; understanding of the formation of reproductive cells and the process of fertilization explained his segregation ratios. This interest was probably encouraged by his friendship with Johann Nave, whose untimely death preceded Mendel’s first 1865 lecture by a few months. This year is the 200th anniversary of Mendel’s birth, presenting a timely opportunity to revisit the events in his life that led him to undertake his seminal research. We review existing ideas on how Mendel made his discoveries, before presenting more recent evidence.

This is a preview of subscription content, access via your institution

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Notes on the end page of Mendel’s copy of Gärtner’s book10.
Fig. 2: A short article in Neuigkeiten on 26 July 1861, and our English translation.
Fig. 3: Segregation of F2 seed traits in the pods of a selfed F1 pea plant.
Fig. 4: The reconstructed timeline of Mendel’s applied breeding and scientific breeding programs in peas.
Fig. 5: Fertilization of the egg cell by the pollen tube, according to Unger6 in 1852.
Fig. 6: The board of the Brünn Natural Science Society in 1862.


  1. Mendel, G. Versuche über Pflanzen-hybriden. Verh. Ver. Brünn 4, 3–47 (1866).

    Google Scholar 

  2. Correns, C. Gregor Mendel’s briefe an Carl Nägeli 1866-1873. Abh. Math.-Phys. Kl., K. Sächs. Ges. Wiss, 29, 189–265 (1905).

    Google Scholar 

  3. Fisher, R. A. Has Mendel’s work been rediscovered? Ann. Sci. 1, 115–137 (1936).

    Article  Google Scholar 

  4. Van Dijk, P. J., Weissing, F. J. & Ellis, T. H. N. How Mendel’s interest in inheritance grew out of plant improvement. Genetics 210, 347–355 (2018).

    Article  Google Scholar 

  5. Van Dijk, P. J. & Ellis, T. H. Mendel’s journey to Paris and London: context and significance for the origin of genetics. Folia Mendeliana 56, 5–33 (2020).

    Google Scholar 

  6. Unger, F. Botanische Briefe (C. Gerold & Sohn, 1852).

    Book  Google Scholar 

  7. Mendel, G. Experiments on Plant Hybrids (trans Müller-Wille, S. & Hall, K., British Society for the History of Science Translation Series) (2016).

  8. Orel, V. Gregor Mendel: The First Geneticist (Oxford University Press, 1996).

  9. Klein, J. & Klein, N. Solitude of a Humble Genius - Gregor Johann Mendel: Volume 1: Formative Years (Springer-Verlag, 2013).

    Book  Google Scholar 

  10. Gärtner, C. F. Versuche und Beobachtungen über die Bastarderzeugung im Pflanzenreich (Hering, 1849).

  11. Olby, R. C. Origins of Mendelism 2nd ed (University of Chicago Press, 1985).

    Google Scholar 

  12. Fisher, R. A. The Genetical Theory of Natural Selection 1st ed (Oxford University Press, 1930).

    Book  Google Scholar 

  13. De Beer, G. Mendel, Darwin and Fisher (1865–1965). Notes Rec. R. Soc. 19, 192–226 (1964).

    Article  Google Scholar 

  14. Dunn, L. C. Mendel, his work and his place in history. Proc. Am. Philos. Soc. 109, 189–198 (1965).

    Google Scholar 

  15. Mayr, E. The Growth of Biological Thought (Harvard University Press, 1982).

    Google Scholar 

  16. Olby, R. C. Mendel no Mendelian? Hist. Sci. 17, 57–72 (1979).

    Article  Google Scholar 

  17. Gasking, E. B. Why was Mendel’s work ignored? J. Hist. Ideas 20, 60–84 (1959).

    Article  Google Scholar 

  18. Orel, V. & Hartl, D. L. Controversies in the interpretation of Mendel’s discovery. Hist. Philos. Life Sci. 16, 423–464 (1994).

    Google Scholar 

  19. Monaghan, F. & Corcos, A. F. The real objective of Mendel’s paper. Biol. Philos. 5, 267–292 (1990).

    Article  Google Scholar 

  20. Fairbanks, D. J. Mendel and Darwin: untangling a persistent enigma. Heredity 124, 263–273 (2020).

    Article  Google Scholar 

  21. Franklin, A. & Laymon, R. Once Can Be Enough. Decisive Experiments, No Replication Required (Springer Nature, 2021).

    Book  Google Scholar 

  22. Gliboff, S. in Outsider Scientists: Routes to Innovation in Biology (eds. Harman, O. & Dietrich, M.R.) 27–44 (Univ. Chicago Press, 2013).

  23. Müller-Wille, S. in Handbook of the Historiography of Biology (ed Dietrich, M.) (Springer International Publishing, 2018).

  24. Mendel, G. Über Verwüstung im Gartenrettich durch Raupen (Botys margaritalis). Verh. Zool.-Bot. Verein. Wien. 3, 116–168 (1853).

    Google Scholar 

  25. Mendel, G. Über Bruchus pisi, mitgeteilt von V. Kollar. Verh. Zool.-Bot. Verein. Wien. 4, 27–28 (1854).

    Google Scholar 

  26. Eichling, C. I talked with Mendel. J. Hered. 33, 243–246 (1942).

    Article  Google Scholar 

  27. Beadle, G. W. in Heritage from Mendel (eds Brink, R. A. & Styles, E. D.) 335–350 (Univ. Wisconsin Press, 1967).

  28. Knight, T. A. An account of some experiments on the fecundation of vegetables. Philos. Trans. R. Soc. Lond. 89, 195–204 (1799).

    Google Scholar 

  29. Wellensiek, S. J. Erwten toen en nu in Honderd jaar Mendel (Pudoc, Centrum voor Landbouwpublikaties en Landbouwdocumentatie, 1965).

  30. Ellis, T. H. N., Hofer, J. M. I., Swain, M. T. & Van Dijk, P. J. Mendel’s pea crosses: varieties, traits and statistics. Hereditas 156, 33 (2019).

    Article  Google Scholar 

  31. Seton, A. On the variation in the colour of peas from cross-impregnation. Trans. Horticultural Soc. Lond. 5, 236 (1824).

    Google Scholar 

  32. Goss, J. On the variation in the colour of peas, occasioned by cross-impregnation. Trans. Horticultural Soc. Lond. 5, 234 (1824).

    Google Scholar 

  33. Laxton, T. Observations on the Variations Effected by Crossing in the Colour and Character of the Seed of Peas (International Horticultural Exhibition and Botanical Congress, 1866).

  34. Laxton, T. Notes on some changes and variations in the offspring of cross-fertilized peas. J. R. Hortic. Soc. 3, 10–14 (1872).

    Google Scholar 

  35. Giltay, E. Ueber den directen Einfluss des Pollens auf Frucht und Samenbildung. Pringsh. Jahrb. Wiss. Bot. 25, 489–506 (1895).

    Google Scholar 

  36. Pasteur, L. Discours prononcé à Douai, le 7 décembre 1854, à l’occasion de l’installation solennelle de la Faculté des lettres de Douai et de la Faculté des sciences de Lille in Oeuvres de Pasteur (ed Pasteur Vallery-Radot, P.) 131 (Masson and Co., 1939).

  37. Harris, H. The Birth of the Cell (Yale Univ. Press, 1999).

  38. Churchill, F. B. August Weissmann (Harvard Univ. Press, 2015).

  39. Schleiden, M. J. Einige Blicke auf die Entwicklungsgeschichte des vegetabilischen Organismus bei den Phanerogamen. Arch. Naturgesch. 3, 289–414 (1837).

    Google Scholar 

  40. Radlkofer, L. Die Befruchtung der Phanerogamen: Ein Beitrag zur Entscheidung des darüber bestehenden Streites (Engelmann, 1856).

  41. Strasburger, E. Neue Untersuchungen über den Befruchtungsvorgang bei den Phanerogamen, als Grundlage für eine Theorie der Zeugung (Jena Gustav Fischer, 1884).

  42. Nave, J. Ueber die Entwicklung und Fortpflanzung der Algen. Aufsätze. Jahresheft der naturwissenschaftlichen Section der schlesischen Gesellschaft für Ackerbau für das Jahr 1858, 86–101 (Rohrer, 1859).

  43. Iltis, H. Gregor Johann Mendel: Leben, Werk und Wirkung (Springer, 1924).

  44. Kalmus, J. Skizze von dem Leben und Wirken des verstorbenen J. Nave. Verh. Ver. Brünn 3, 82–85 (1865).

    Google Scholar 

  45. Piternick, L. K. & Piternick, G. Gregor Mendel’s Letters to Carl Nägeli. Genetics 35, 1–29 (1950).

    Google Scholar 

  46. Nägeli, C. Die Bastardbildung im Pflanzenreiche, Sitzungsberichte der Königl. Bayer 2, 395–443 (Akademie der Wissenschaften, 1865).

  47. Van Dijk, P. J. & Ellis, T. H. N. Mendel’s reaction to Darwin’s provisional hypothesis of pangenesis and the experiment that could not wait. Heredity (2022).

  48. Darbishire, A. D. Breeding and the Mendelian Discovery (Cassell & Co., 1911).

    Book  Google Scholar 

Download references


We are very grateful to B. O. Bengtsson, J. Hofer, M. de Both and P. van Baarlen for critically reading and commenting on draft versions of the manuscript. T.H.N.E. gratefully acknowledges receipt of an Institute Strategic Fellowship from the John Innes Centre. P.J.v.D. thanks KeyGene for providing a supportive environment for research into the early history of genetics.

Author information

Authors and Affiliations



P.J.v.D., A.P.J. and T.H.N.E. wrote the manuscript. All authors critically read and edited the manuscript.

Corresponding author

Correspondence to Peter J. van Dijk.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Fig. 1 and Notes 1–3

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

van Dijk, P.J., Jessop, A.P. & Ellis, T.H.N. How did Mendel arrive at his discoveries?. Nat Genet 54, 926–933 (2022).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing