Alfred Kühn

Alfred Richard Wilhelm Kühn (22 April 1885 – 22 November 1968) was a German zoologist and geneticist.

From 1904 to 1908 Alfred Kühn was as student of zoology and physiology in Freiburg. He received his habilitation in 1910. Starting in 1914 Kühn was associate professor at the University of Freiburg. In 1914 he married Margaret Geiges (1888-1987), the daughter of the artist Fritz Geiges. The marriage remained childless. In 1918, Alfred Kühn was lecturer at the Humboldt University of Berlin. From 1920 on he was professor of zoology and genetics at the University of Göttingen.

After the seizure of power by the national socialists Kühn was, together with Martin Staemmler and Friedrich Burgdörfer, one of the authors of the book Erbkunde, Rassenpflege, Bevölkerungspolitik. Schicksalsfragen des deutschen Volkes. In 1935 he received an evaluation by the NS-authority that says that he is doing his work in line with the national socialists, without feeling committed to the NSDAP. Starting 1937, Kühn was director of the Kaiser-Wilhelm-Institut für Biologie in Berlin-Dahlem. Besides his research he was editor of the Zeitschrift für induktive Abstammungs- und Vererbungslehre and later also in charge for genetics with the Der Biologe, a journal that was taken over by the SS-Ahnenerbe.

After World War II, already in 1945, he became a professor at the University of Tübingen. From 1951 to 1958 he was director of the Max Planck Institute for Biology as well as professor of zoology at the University of Tübingen.

Kühn's fields of research were genetics and physiology of development, especially of insects like Ephestia. He integrated experiments on development and heredity. He proposed a model of the gene-enzyme relation, which is important for the connection or mapping of genes to phenotypes.

Under study was the pigmentation of insect eyes. Together with his colleagues he realized that genes are not directly giving rise to physiological substances. Rather they found that there is a “primary reaction” which leads to enzymes. These enzymes then catalyze particular steps, eventually leading to pigments of the eye. Elements of today's evolutionary developmental biology are related to Kühn's work.

His lecture notes on developmental biology (Vorlesungen über Entwicklungsphysiologie) were a standard textbook.

• 1966: Großes Verdienstkreuz mit Stern of Germany

• Hansjochem Autrum (1982), "Kühn, Alfred", Neue Deutsche Biographie (NDB) (in German), 13, Berlin: Duncker & Humblot, pp. 192–193; (full text online)
• Georg Birukow: Alfred Kühn. 22. April 1885 – 22. November 1968. In: Jahrbuch der Akademie der Wissenschaften in Göttingen. 1968, S. 83-85
• Manfred D. Laubichler, Hans-Jörg Rheinberger: Alfred Kühn (1885-1968) and developmental evolution. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution 302B (2004) 103 - 110