Knut Schmidt-Nielsen

Knut Schmidt-Nielsen (center) with Bodil Mimi Krogh Schmidt-Nielsen (left) and Barbara Wagner (right)

Knut Schmidt-Nielsen (born September 24, 1915 in Trondheim , Norway , † January 25, 2007 in Durham , North Carolina ) was an important researcher and textbook author in the field of animal physiology , especially ecophysiology and comparative physiology . During his lifetime he was honored with a life-size sculpture on the grounds of Duke University : a dromedary that is being watched by a man.

Career

Knut Schmidt-Nielsen first studied mining and metalworking in Oslo , but later zoology in Copenhagen and went to the USA with his family in 1946 . There he spent two years as a post-doctoral student at Swarthmore College , then one year at Stanford University and three years at the College of Medicine at the University of Cincinnati . From 1952 until his retirement in the late 1980s, he was a member of Duke University . Also in 1952 he became a citizen of the USA . At Duke University he had held the James B. Duke Chair in the Faculty of Biology since 1963 and represented the field of physiology. Even in retirement he remained connected to his university and taught in his own entertaining way. a. the writing of technical essays; one of his seminars was called: “ How to write so that nobody will read you” ( “How to Write so that Nobody will Read You” ).

Research topics

Knut Schmidt-Nielsen has published 270 scientific journal articles as well as five books that have been translated into 16 languages. His 1975 textbook Animal Physiology. Adaptation and Environment , which later also appeared in German translation, set international standards for the presentation of knowledge in the field of comparative animal physiology, as the author not only lined up facts, but also always - and often entertainingly - explained the adaptive value of physiological peculiarities . In the obituary of the journal Science it was therefore said that Schmidt-Nielsen is considered "the father of comparative physiology and integrative biology " .

Schmidt-Nielsen studied in particular the physiological adaptive capacities of animals in extreme biotopes such as the deserts of Arizona , the Sahara and the Arctic , i.e. the consequences of lack of water, excess salt and ambient temperatures that differ greatly from their own temperature. At first he was particularly interested in the kangaroo rats of Arizona, later certain frogs that live in salt water and the camels . His autobiography , published in 1998, was titled "The Camel's Nose: Memoirs of a Curious Scientist" in reference to his more than 20 years of camel studies . On the Duke University campus, the life-size bronze ensemble The Scientist and Nature (a camel and a questioning-looking man) has been commemorating Schmidt-Nielsen and his research into the physiology of dromedaries since the early 1950s since July 1997 .

Before Schmidt-Nielsen's long-term work with camels, it was believed that the hump was used to store water; In fact, it is a fat store, and water is only obtained from fat metabolism . Schmidt-Nielsen was able to prove which special adaptations of the kidneys , the heat regulation and even the nasal mucous membranes minimize the water loss of these desert animals despite high ambient temperatures. He also demonstrated that camels rely less heavily on the principle of cooling through evaporation than other animals, but increase their body temperature from 34 degrees in the morning to 41 degrees in the afternoon.

Schmidt-Nielsen also discovered that reptiles , amphibians and many sea ​​birds living in salt water have developed special glands to secrete salt. With their help, sea birds can secrete droplets of concentrated salt into their noses and shake them away with jerky head movements. With the ostrich , he showed which evolutionary adaptations enable him to run fast in the hot steppe landscape without sweating .

Schmidt-Nielsen began his desert ecological studies in Arizona, where he researched the breathing technique of kangaroo rats . He found out that the nasal cavity of these mainly nocturnal animals is cooled by the inhaled outside air and that - conversely - the body-warm air is cooled in the cool noses when exhaling. As a result, when it cools down, the moisture in the breath can be absorbed by the nasal mucosa. He later demonstrated a comparable adaptability in the camels. Together with colleagues, he discovered the opposite adaptive power in dogs: When dogs are heated and panting after a long run, they breathe in through their nose and out through their mouth in order to expel as much heat energy as possible in the form of warm, moist air.

Together with William Bretz, Schmidt-Nielsen finally described the special breathing technique of birds for the first time. In contrast to mammals, whose lungs are a kind of “sack” and whose air is supplied and discharged through a single opening, the lungs of birds consist of many parallel tubes, into one end of which the fresh air enters and at the other end the Breathing air emerges again.

Honors

Knut Schmidt-Nielsen was a member of the National Academy of Sciences of the USA, the Royal Society of London and the French Académie des Sciences . In 1963 he was elected to the American Academy of Arts and Sciences . In 1992 he was awarded the International Prize for Biology in Japan , the prestige of which in Asia is equivalent to the Nobel Prize . From 1980 to 1986 he was President of the International Union of Physiological Sciences .

Works

• The Camel's Nose: Memoirs Of A Curious Scientist. Island Press , 1998, ISBN 978-1559635127
• Animal Physiology: Adaptation and Environment. Cambridge University Press, (5th edition, 1997), ISBN 978-0521570985
• How Animals Work. Cambridge University Press, 1972, ISBN 978-0521096928

Web links

• Literature by and about Knut Schmidt-Nielsen in the catalog of the German National Library

Individual evidence

1. ^ Obituary ( Memento of May 18, 2015 in the Internet Archive ) of the American Physiological Society
2. ^ Obituary from Duke University ( Memento from June 15, 2010 in the Internet Archive ) "Animal Physiology Expert Knut Schmidt-Nielsen Dies"
3. ↑ Deaths: Forever Curious. In: Science . Volume 315, No. 5813, 2007, p. 745, full text
4. ^ A review of the autobiography
5. ^ Tierney Thys: Curiosity and the Camel. In: Duke Magazine. July / August 1997, full text ( Memento of July 7, 2012 in the Internet Archive )
6. ↑ Famed Physiologist's Self-Portrait: Is More than Meets the Camel's Nose. ( Memento of April 7, 2014 in the Internet Archive ) At: www.americanscientist.org .
   Quote "By applying countercurrent-exchange principles to the mucus-lined tube that is a camel's nose, Schmidt-Nielson demonstrated how the animal, through the simple act of breathing, can save about 60 percent of the water that would have been lost from evaporation during respiration. This answered the age-old question of how a camel conserves water so that it may thrive in an environment where other animals would die of thirst. ”(According to Sentiel A. Rommel from the Marine Mammal Pathobiology Laboratory of the Florida Marine Research Institute , Florida Department of Environmental Protection, in a review of Schmidt-Nielsen's autobiography).
7. ^ R. McNeill Alexander: Knut Schmidt-Nielsen (1915-2007). In: Nature . Volume 446, 2007, p. 744, doi: 10.1038 / 446744a