Bernhard Rensch

Bernhard Rensch
Born	21 January 1900 Thale
Died	4 April 1990 (aged 90)
Nationality	German
Fields	Ornithology
Known for	Modern evolutionary synthesis
Notable awards	Darwin-Wallace Medal (Silver, 1958)

Bernhard Rensch (21 January 1900 – 4 April 1990) was a German evolutionary biologist, and ornithologist who did field work in Indonesia and India. He is probably best known as one of the architects of the modern evolutionary synthesis, which he popularised in Germany. Besides his work on how environmental factors influenced the evolution of geographically isolated populations and on evolution above the species level, which contributed to the modern synthesis, he also worked extensively in the area of animal behavior (ethology). His education and scientific work were interrupted by service in the German military during both World War I and World War II.

Biography

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.^[1] He studied the geographical distribution of subspecies of polytypic species and of complexes of closely related species with attention to how local environmental factors, especially climate, influenced their evolution.^[2] 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.^[3] 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 Münster.^[1] In 1940 he was recalled for military service, but was discharged for medical reasons in 1942.^[4]

In 1947 he published a book that would later be translated into English under the title Evolution above the species level.^[5] 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.^[2] He published an autobiography in 1979 and remained scientifically active until his death in 1990.^[1]

Rensch's rule

Rensch's rule was proposed by Bernhard Rensch in 1950.^[6] 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.^[7]

Awards and recognition

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

Since 2004, the Society for Biological Systematics (GfBS, Germany) has awarded the Bernhard Rensch prize for achievements of young scientists, writing in German or English, in the field of systematics and biodiversity research.^[8]

Works

• Neuere Probleme der Abstammungslehre. F. Enke. 1947.

References

1. Mayr, Ernst (1992). "In Memoriam: Bernhard Rensch, 1900–1990" (PDF). The Auk 109 (1): 188. doi:10.2307/4088279.
2. Smith, Charles H. "Rensch, Bernhard (Carl Emmanuel) (Germany 1900–1990)". Western Kentucky University. Retrieved 2007-10-20.
3. Mayr, Ernst; W. B. Provine, eds. (1998). The Evolutionary Synthesis: Perspectives on the Unification of Biology. Harvard University Press. p. 416. ISBN 0-674-27225-0.
4. Mayr, Ernst; W. B. Provine, eds. (1998). The Evolutionary Synthesis: Perspectives on the Unification of Biology. Harvard University Press. pp. 293–299. ISBN 0-674-27225-0.
5. Rensch B. 1947. Evolution above the species level. Columbia, N.Y.
6. Rensch, B. (1950). "Die Abhangigkeit der relativen Sexualdifferenz von der Korpergrosse" (PDF). Bonner Zoologische Beitrage 1: 58–69.
7. Fairbairn, D.J. (1997). "Allometry for Sexual Size Dimorphism: Pattern and Process in the Coevolution of Body Size in Males and Females". Annu. Rev. Ecol. Syst. 28 (1): 659–687. doi:10.1146/annurev.ecolsys.28.1.659.
8. "Auszeichnungen: Bernhard Rensch-Preis". Gesellschaft für Biologische Systematik. Retrieved 5 December 2013.