Nils Roll-Hansen Department of Philosophy, Classics, History of Art and Ideas, University of Oslo, Blidern, 0315 Oslo, Norway Correspondence: nils.roll-hansenifikk.uio.no

This paper argues that the historiography of genetics ∼1900, the formation period of modern science, is too narrow. It lacks attention to plant breeding. Perhaps this omission also narrows the present understanding of fundamental ideas like the genotype/phenotype distinction and the gene concept? There is a mythical story still told in textbooks and at anniversaries: As modern genetics started with the rediscovery of Mendel's laws in 1900, a fateful controversy over continuous or discontinuous variation of heredity between biometricians and Mendelians. Discontinuity appeared as a threat to the Darwinian theory of evolution by natural selection. Only by the 1920s was the problem solved by a theory of population genetics founded on the chromosome theory of heredity.1 However, in plant breeding ∼1900 ideas of heredity and evolution were closely intertwined, and the combination of discontinuous heredity with continuous Darwinian evolution was an obvious option.