Alfred Sturtevant

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STURTEVANT WAS THE YOUNGEST of six children of Alfred Henry Sturtevant and Harriet Evelyn Morse. His grandfather Julian M. Sturtevant graduated from Yale Divinity School and was a founder and later president of Illinois College. Sturtevant's father taught mathematics for a time at Illinois College but subsequently turned to farming, first in Illinois and later in southern Alabama, where the family moved when Sturtevant was seven. His early education was in Alabama in a one-room country school, but for the last three years of high school he went to a public school in Mobile.

In the fall of 1908 Sturtevant entered Columbia University. The choice, a crucial one, was made because Sturtevant's oldest brother, Edgar, was then teaching Latin and Greek at Barnard College; Edgar and his wife made it possible for Sturtevant to attend the university by taking him into their home. Sturtevant was greatly influenced by Edgar, from whom he learned the aims and standards of scholarship and research.

As a boy Sturtevant had drawn up the pedigrees of his father's horses and of his own family. He pursued this interest as a hobby while he was at Columbia. Edgar encouraged him to read works on heredity and to learn more about the meaning of pedigrees. As a result Sturtevant read a book on Mendelism by Punnett that greatly stimulated his interest, since he saw how Mendel's principles could be used to explain the pattern of inheritance of certain coat colors in horses. Edgar suggested that Sturtevant work out the genetic relationships, write an account of his findings, and submit it to Thomas Hunt Morgan, who held the chair of experimental zoology at Columbia and from whom Sturtevant had already taken a course. Morgan clearly was impressed, since he not only encouraged Sturtevant to publish the account, which appeared in Biological Bulletin in 1910, but also, in the fall of that year, gave Sturtevant a desk in his laboratory, which came to be known as the "fly room." Only a few months before, Morgan had found the first white-eyed mutant in Drosophila and had worked out the principles of sex linkage.

After completing his doctoral work with Morgan in 1914, Sturtevant remained at Columbia as a research investigator for the Carnegie Institution of Washington. He was a member of a research team that Morgan had assembled a few years earlier and that consisted principally of two other students of Morgan's, C. B. Bridges and H. J. Muller. The "fly room" in which they conducted all of their experiments was only sixteen by twenty-three feet, and at times as many as eight people had desks in it. According to Sturtevant, the atmosphere was one of high excitement, each new idea being freely put forth and debated. Morgan, Bridges, and Sturtevant remained at Columbia until 1928; Muller left the group in 1921 to take a position at the University of Texas.

In 1922 Sturtevant married Phoebe Curtis Reed; and in the same year they made their first trip to Europe, visiting museums and laboratories in England, Norway, Sweden, and Holland. They had three children.

In 1928 Sturtevant moved to Pasadena to become professor of genetics in the new division of biology that Morgan had established in that year at the California Institute of Technology. Much of the same stimulating atmosphere and unpretentious way of conducting science that Morgan and his students had practiced at Columbia was transferred to the new Kerckhoff Laboratory at Caltech. Sturtevant became the acknowledged and natural leader of the new genetics group established there. He maintained an active research program in which he often collaborated with other members of the genetics staff, including George W. Beadle, Theodosius Dobzhansky, Sterling Emerson, and Jack Schultz. He gave lectures in the general biology course and taught elementary and advanced courses in genetics and, on occasion, a course in entomology. He remained at Caltech until his death except for a year in England and Germany in 1932, as visiting professor of the Carnegie Endowment for International Peace, and shorter periods when he held visiting professorships at a number of American universities. He received many honors, including the National Medal of Science in 1968.

In addition to his principal publications dealing with the genetics and taxonomy of Drosophila, Sturtevant contributed papers on the genetics of horses, fowl, mice, moths, snails, iris, and especially the evening primroses (Oenothera). Although his chief contributions are in genetics, he was also a leading authority on the taxonomy of several groups of Diptera, especially the genus Drosophila, of which he described many new species. He was much interested in the social insects and published several papers on the behavior of ants.

Sturtevant had a prodigious memory and truly encyclopedic interests. He had a natural bent for mathematics but little formal training in it. He especially enjoyed, and was expert at solving, all kinds of puzzles, especially those involving geometrical situations. For him scientific research was an exciting and rewarding activity not unlike puzzle-solving. a common theme of his investigations was an effort to analyze and explain exceptions to established principles.

Sturtevant knew how to design and execute simple, elegant experiments, describing the results in concise, lucid prose. He set high standards for his own research and expected others to do the same.

Sturtevant's discoveries of the principle of gene mapping, of the first reparable gene defect, of the principle underlying fate mapping, of the phenomena of unequal crossing-over, and of position effect were perhaps his greatest scientific achievements. The account of these and some of his other major contributions to science is arranged in approximate chronological order.

Mendel had found that all of the hereditary factors with which he worked assorted independently of one another at the time of gamete formation. Exceptions to this second Mendelian law began to accumulate in 1900-1909. Morgan was the first to provide a satisfactory explanation for such exceptions in terms of a hypothesis, which assumes that genes tending to remain together in passing from one generation to the next must be located in the same chromosome. He further postulated that