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About Wilhelm Johannsen
Wilhelm Ludvig Johannsen (1857 - 1927)
Danish geneticist who, together with Bateson (1861-1926) was one of the chief architects of modern genetics; Wilhelm Johannsen introduced the terms gene, genotype and phenotype (Johannsen 1909).
Short original film clip with Wilhelm Johannsen
The film clip is filmed in May 1923 and shows a few scenes with Wilhelm Johannsen. He is filmed preparing a lecture in genetics and later teaching the students and last in a garden scene in his private home.
It's a silent movie so don't expect any sound. The movie is in mpeg4 format and is tested with Microsoft Media Player 9 (Windows), mplayer 1.0 (Unix) and VLC (Multiplatform)If you are having troubles watching the movie, please contact the webmaster.
- Original movie (5 min) view
- With Danish text (6½ min) view
- With English text (6½ min) view
Publications about Wilhelm Johannsen
Publications by Wilhelm Johannsen
Selected sections from a Danish agriculture encyclopedia (in Danish)
Born in Copenhagen, the son of an army officer, Johannsen was apprenticed to a pharmacist in 1872 and worked in Denmark and Germany, passing his pharmacist's exam in 1879. Two years later he was appointed assistant in the chemistry department at the Carlsberg laboratory under the famous chemist Johan Kjeldahl (1849-1900). Here Johannsen investigated the metabolism of dormancy and germination in seeds, tubers, and buds. In 1892 he was appointed lecturer at Copenhagen Agricultural College and eventually became professor of botany and plant physiology.
Johannsen's most notable experiments concerned his so-called 'pure lines' of the self-fertile princess bean, Phaseolus vulgaris. Studying the progeny of self-fertilized plants, he selected the character of bean weight and found that both the lightest and the heaviest beans produced progeny with the same distribution of bean weights, i e they were genetically identical. He concluded that the variations in bean weight were due to environmental factors and he introduced the terms genotype (for the genetic constitution of an organism) and phenotype (for the characteristics of an organism that result from the interaction of its genotype with the environment). Johannsen favoured the view of de Vries that inheritance was determined by discrete particulate elements and abbreviated de Vries's term 'pangenes' to 'genes'. Johannsen's Arvelighedslaerens elementer (1905; 'The Elements of Heredity') was later (1909) rewritten, enlarged, and translated into German to become one of the founding texts of genetics. In 1905 Johannsen was appointed professor of plant physiology at Copenhagen University, becoming rector in 1917.
See also The Baptism of Genetics at MendelWeb