page_title: Erwin Bünning
section_title: Academic career
hierarchical_section_title: Erwin Bünning / Life / Academic career
caption_attribution_description: English: Tübingen waterfront
context_page_description: Erwin Bünning was a German biologist. His most famous contributions were to the field of chronobiology, where he proposed a model for the endogenous circadian rhythms governing plant photoperiodism. From these contributions, Bünning is considered a co-founder of chronobiology along with Jürgen Aschoff and Colin Pittendrigh.
context_section_description: In 1930, Bünning took an assistantship under Otto Renner at the University of Jena, then one of Germany's largest botanical institutes. During the rise of the Nazi Party in Germany in the early 1930s, Renner stood in open opposition to the Nazis, publicly defending Jewish scientists. Similarly, Bünning was considered a communist sympathizer, a stance likely influenced by Bünning's father, a Social Democrat opposed to the Nazis. Bünning's political beliefs created tension between him and some of his students. In response to this tension, Bünning left Jena for a lectureship at the East Prussian University of Königsberg. In 1936, Bünning published his model for plant photoperiodism, wherein he proposed that endogenous (internal) circadian rhythms enable plants to measure day length. Bünning's model of photoperiodism would go largely unnoticed by the scientific community until 1960 when he chaired the 1960 Cold Spring Harbor Symposium on Biological Clocks. There, Colin Pittendrigh drew attention to Bünning's work and named his 1936 model on plant photoperiodism the Bünning hypothesis.
  In 1938, Bünning spent a year traveling through Java and Sumatra. His observations on the islands resulted in the book Tropische Regenwalder (Tropical Rainforests). Upon his return to Germany in 1939, Bünning was conscripted in the German military (World War II). Military authorities appointed Bünning as an associate professor at the University of Strasbourg. After the war, Bünning became a full professor at the University of Cologne in 1945 before moving to the University of Tübingen the next year (1946), where he stayed until his retirement in 1971. At Tübingen, Bünning entered into the workspace of his role model Wilhelm Pfeffer, the man who postulated in 1875 that the orientation of plants in space changes with the time of day. Bünning would later publish a biography on Pfeffer.
caption: Bünning spent most of his academic career at the University of Tübingen
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "102", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "286", "Thumbnail JPEGInterchangeFormatLength": "10468", "EXIF ExifVersion": "0221", "EXIF ComponentsConfiguration": "YCbCr", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "960", "EXIF ExifImageLength": "720", "EXIF SceneCaptureType": "Standard"}