What is Curt Stern?
'''Curt Stern''' (August 30, 1902 &ndash; October 23, 1981) was a German-born American [[geneticist]].<ref>{{Cite journal | last1 = Neel | first1 = J. V. | authorlink = James V. Neel | title = Curt Stern: August 30, 1902-October 23, 1981 | journal = Biographical Memoirs of the National Academy of Sciences | volume = 56 | pages = 443–473 | year = 1986 | pmid = 11621212 }}</ref> He was a [[Germany|German]]-[[United States|American]] [[genetics|geneticist]]. <ref>{{ cite web | last=Burian | first=Richard M. | date=2000 | title=Stern, Curt, in American National Biography Online | url=http://www.anb.org}} </ref> of [[Jewish]] descent.<ref>''Allgemeine Zeitschrift des Judenthums. Ein unparteiisches Organ fuer alles juedische Interesse''. Volume 22, No 7. December 1857 page 92.</ref> Born in [[Hamburg]], Germany, he studied [[zoology]] at the University of [[Berlin]], receiving his PhD in 1923 at the age of 21. He was selected for a fellowship to study at [[Columbia University]], then the site of [[Thomas Hunt Morgan]]'s famous drosophila fly room. == Early career == Stern accepted an appointment at the University of Berlin after his fellowship ended. In 1931, he was the first to demonstrate [[crossover of homologous chromosome]]s in ''[[Drosophila melanogaster]]'', only weeks after [[Barbara McClintock]] and Harriet Creighton had done so with [[maize]]. Stern eventually returned to the United States in 1932. He became an American citizen in 1939. From 1933 to 1947, he taught at the [[University of Rochester]]. From 1947 until his retirement in 1970, he was a professor at the [[University of California, Berkeley]], where he had numerous doctoral students. In 1936, he demonstrated that [[recombination]] can also take place in [[mitosis]] resulting in somatic [[Mosaic (genetics)|mosaics]], organisms that contain two or more genetically distinct types of tissues.<ref>{{ cite book | last=Stern | first=Curt | date=1968 | title=Genetic mosaics and other essays | publisher=Harvard University Press | location=Cambrid