Morgan , Thomas Hunt
(1866–1945) American geneticist
Born in Lexington, Kentucky, Morgan studied zoology at the State College of Kentucky, graduating in 1886. He received his PhD from Johns Hopkins University in 1890 and from 1891 to 1904 was associate professor of zoology at Bryn Mawr College. He carried out his most important work between 1904 and 1928, while professor of experimental zoology at Columbia University. Here he became involved in the controversy that followed the rediscovery, in 1900, of Gregor Mendel's laws of inheritance.
Many scientists had noted that Mendel's segregation ratios fitted in well with the observed pattern of chromosome movement at meiosis. Morgan, however, continued to regard Mendel's laws with skepticism, especially the law of independent assortment, and with good reason. It was known by then that many more characters are determined genetically than there are chromosomes and therefore each chromosome must control many traits. It was also known that chromosomes are inherited as complete units, so various characters must be linked together on a single chromosome and would be expected to be inherited together.
In 1908 Morgan began breeding experiments with the fruit flyDrosophila melanogaster, which has four pairs of chromosomes. Morgan's early results with mutant types substantiated Mendel's law of segregation, but he soon found evidence of linkage through his discovery that mutant white-eyed flies are also always male. He thus formulated the only necessary amendment to Mendel's laws – that the law of independent assortment only applies to genes located on different chromosomes.
Morgan found that linkages could be broken when homologous chromosomes paired at meiosis and exchanged material in a process known as ‘crossing over’. Gene linkages are less likely to be broken when the genes are close together on the chromosome, and therefore by recording the frequency of broken linkages, the positions of genes along the chromosome can be mapped. Morgan and his colleagues produced the first chromosome maps in 1911.
For his contributions to genetics, Morgan received the Nobel Prize for physiology or medicine in 1933. A prolific writer, his most influential books – produced with colleagues at Columbia – are The Mechanism of Mendelian Heredity (1915) and The Theory of the Gene (1926).

Scientists. . 2011.

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  • Morgan,Thomas Hunt — Morgan, Thomas Hunt. 1866 1945. American biologist. He won a 1933 Nobel Prize for discoveries concerning the hereditary function of chromosomes. * * * …   Universalium

  • Morgan, Thomas Hunt — born Sept. 25, 1866, Lexington, Ky., U.S. died Dec. 4, 1945, Pasadena, Calif. U.S. zoologist and geneticist. He received his doctorate from Johns Hopkins University. As a professor at Columbia University (1904–28) and California Institute of… …   Universalium

  • Morgan, Thomas Hunt — (25 sep. 1866, Lexington, Ky., EE.UU.–4 dic. 1945, Pasadena, Cal.). Zoólogo y genetista estadounidense. Obtuvo un doctorado en la Universidad Johns Hopkins. Mientras se desempeñaba como profesor en la Universidad Columbia (1904–28) y el Instituto …   Enciclopedia Universal

  • Thomas Hunt Morgan — Nacimiento 25 de septiembre de 1866 Fallecimiento 4 de diciembre de 1945 …   Wikipedia Español

  • Thomas Hunt Morgan — Thomas Hunt Morgan, 1891 Thomas Hunt Morgan (* 25. September 1866 in Lexington, Kentucky; † 5. Dezember 1945 in Pasadena, Kalifornien) war ein US amerikanischer Zoologe und Genetiker, der durch Kreuzungsversuche mit der …   Deutsch Wikipedia

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  • Thomas Hunt Morgan — (25 de septiembre de 1866 4 de diciembre de 1945) fue un genético estadounidense. Estudió la historia natural, zoología, y macromutación en la mosca de la fruta Drosophila melanogaster. Sus contribuciones científicas más importantes fueron en el… …   Enciclopedia Universal

  • Thomas Hunt Morgan Medal — The Thomas Hunt Morgan Medal is a medal awarded for lifetime contributions to the field of genetics. The medal is awarded by the Genetics Society of America. Award recipients* 1981 Barbara McClintock and Marcus M. Rhoades * 1982 Sewall Wright *… …   Wikipedia

  • Thomas Hunt Morgan Medal — Die Thomas Hunt Morgan Medal ist eine wissenschaftliche Auszeichnung, die seit 1981 von der Genetics Society of America (GSA) für das Lebenswerk auf dem Gebiet der Genetik vergeben wird. Drei der 33 Preisträger haben später auch einen Nobelpreis… …   Deutsch Wikipedia

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