Bernhard Rensch bigraphy, stories - Biologists

Bernhard Rensch : biography

21 January 1900 - 4 April 1990
Bernhard Rensch


Rensch was born in Thale. He served in the German army from 1917–1920, and then continued his education. He received his PH.D from the University of Halle in 1922. He joined the zoological museum of the University of Berlin as an assistant in 1925. In 1927 he participated in a zoological expedition to the Sunda Islands. He studied the geographical distribution of subspecies of polytypic species and of complexes of closely related species with attention to how local environmental factors influenced their evolution. In 1929 he published the book Das Prinzip geographischer Rassenkreise und das Problem der Artbildung that discussed the relationship between geography and speciation. His work in this area would influence Ernst Mayr, who was also an assistant at the museum from 1927–1930, and would contribute to the development of the modern evolutionary synthesis. In 1937 he was forced to leave the museum because he refused to join the Nazi party, and took a position at a zoological garden in Munster. In 1940 he was recalled for military service, but was discharged for medical reasons in 1942.

In 1947 he published a book that would later be translated into English under the title Evolution above the species level.Rensch B. 1947. Evolution above the species level. Columbia, N.Y. The book discussed how the evolutionary mechanisms that drove speciation could also explain the differences between higher taxa. It was considered a major document in the modern synthesis. That same year he became chairman of the zoology department and director of the zoological institute at the University of Münster. In 1953 he would take part in a zoological expedition to India. Later in his career he would work extensively in the areas of animal behavior (ethology), learning, and memory. He published an autobiography in 1979 and remained scientifically active until his death in 1990.


He was awarded the Linnean Society of London's prestigious Darwin-Wallace Medal in 1958.

Rensch's rule

Rensch's rule was proposed by Bernhard Rensch in 1950. It is an allometric law about the relationship between sexual size dimorphism (SSD) and which sex is larger. It observes that across species size dimorphism increases with increasing body size when the male is the larger sex, and decreases with increasing average body size when the female is the larger sex.

Living octopus

Living octopus

In countries which are located near sea coasts, sea food is an important part of national cuisine