Thomas Hunt Morgan

1866-1945

American Geneticist and Zoologist

Thomas Hunt Morgan was an American geneticist who was awarded the Nobel Prize for Physiology or Medicine in 1933 for his work spanning a 17-year period at Columbia University with mutations in the fruit fly Drosophila. His research specifically established the chromosome theory of heredity. He demonstrated that genes are linked in a series on chromosomes and are responsible for identifiable, hereditary traits. Morgan's work played a key role in establishing the field of genetics.

Thomas Hunt Morgan was born in 1866 in Lexington, Kentucky. Morgan's father, Charlton Hunt Morgan, was a U.S. consul and his uncle, John Hunt Morgan, had been a Confederate army general. As a child Morgan had shown an immense interest in natural history and by the age of 10, he was an avid collector of birds, eggs, and fossils. He was educated at the University of Kentucky, where he obtained his B.S. degree in 1886. During the years 1888-1889, he was engaged in research for the United States Fish Commission at Woods Hole, a laboratory with which he always maintained a close association, making expeditions to Jamaica and the Bahamas during that time. Morgan did his postgraduate work at Johns Hopkins University, where he was awarded his doctoral degree in biology in 1890. Most of his graduate research was concentrated in the area of embryology. In that same year, he was awarded the Adam Bruce Fellowship and visited Europe, working at the Marine Zoological Laboratory at Naples. While there, he met Hans Driesch (1867-1941) and Curt Herbst. Their influence, especially that of Driesch with whom he later collaborated, no doubt helped him to focus on the field of experimental embryology. When he returned in 1891, Morgan accepted a teaching post at Bryn Mawr College.

In 1904, Morgan left Bryn Mawr College and accepted a professorship at Columbia University. He stayed there until he moved to the California Institute of Technology (Caltech) in 1928. Morgan began his revolutionary genetic investigations of the fruit fly Drosophila in 1908 after reading through the recently rediscovered research of the father of genetics, Gregor Mendel (1822-1884). Morgan initially suspected that Mendel's research was inaccurate, but once he performed rigorous experiments that demonstrated genes were indeed discrete chromosomal units of heredity, he changed his mind and vigorously pursued the field of genetics. In 1910 he discovered sex-linked inheritance in Drosophila, and postulated that a connection might exist between eye color in fruit flies and the human trait of color blindness. Morgan's research laboratory was often referred to as the "Fly Room," and his group mapped the relative positions of genes on Drosophila chromosomes. They published an important book titled The Mechanisms of Mendelian Heredity in 1915. In 1928 Morgan and many of his colleagues from Columbia moved to Caltech to continue Drosophila research. Morgan received the Nobel Prize for Physiology or Medicine in 1933 for his cumulative research contributions to the field of genetics. He remained at Caltech until his death, performing administrative duties and pursuing investigations of inheritance in Drosophila, mammals, birds, and amphibians.

In addition to this work in genetics, Morgan also made contributions to experimental embryology and regeneration. He also left a tremendous legacy of research at Columbia and Caltech. Numerous colleagues who worked with Morgan also made significant contributions in their respective fields, and a number of them even went on to receive Noble Prizes themselves.

Morgan married a former student of Bryn Mawr College, who often assisted him in research, named Lilian Vaughan Sampson. They had one son and three daughters. While still active at Caltech, Professor Morgan passed away in Pasadena in 1945.

JAMES J. HOFFMANN