Oenothera lamarckiana

In 1890 the Dutch geneticist Hugo de Vries discovered Oenothera lamarckiana or the evening primrose of Lamarck, growing as a parkland-escape on an abandoned field near Hilversum. In this plant de Vries believed he had found evidence that Charles Darwin was wrong. In contrast to Darwin’s thesis that evolution proceeds gradually by natural selection of small variations over long periods of time, de Vries was convinced that evolution (the generation of new features and ultimately new species) was driven by larger, more dramatic variations.

For years de Vries had systematically searched for such large changes in plants, which he thought must be rare. Oenothera appeared to show the sudden leaps he was looking for. The specimens he found included new types growing side-by-side with the familiar form; more importantly the new types bred true and were not swamped by cross-pollination with the original type.

Oenothera came to form the basis of de Vries’ mutation theory, published in German in 1901-03 and translated into English in 1910-11. De Vries’ theory was met with great excitement in the biological world and a community of researchers rapidly grew up around Oenothera in Europe and America. Their shared belief was that this plant would provide experimental evidence of the laws governing the origin of new species. This was the first time in the history of the life sciences that an organism had played this role.

British Oenothera research was led by Reginald Ruggles Gates, whose book The Mutation Factor in Evolution (1915) was viewed as an explosive challenge to Bateson and the Mendelians. Gates and fellow ‘mutationists’, following de Vries, believed that Mendel’s laws only applied to hybridization between species and his ratios were not all that important. Gates emphasised that Oenothera mutants did not follow Mendelian ratios; he believed that the mutations were something quite distinct from an organism’s normal variability. The new botanical approach promised by Oenothera was never fulfilled because de Vries and his followers failed to find other examples. By about 1915 enthusiasm for Oenothera was beginning to wane and few worked on it after the First World War (Endersby, 2006, Chapter 5).

See:
Jim Endersby, A Guinea Pig’s History of Biology, London: Heinemann, 2007.