Sturtevant , Alfred Henry

(1891–1970) American geneticist

Born in Jacksonville, Illinois, Sturtevant graduated at Columbia University in 1912 and continued there, working for his PhD under the supervision of T. H. Morgan. His thesis dealt with certain aspects of fruit fly (Drosophila) genetics, the research being conducted in the famous ‘fly room’ at Columbia.

During this period Sturtevant developed a method for finding the linear arrangement of genes along the chromosome. This technique, termed ‘chromosome mapping’, relies on the analysis of groups of linked genes. His paper, published in 1913, describes the location of six sex-linked genes as deduced by the way in which they associate with each other: it is one of the classic papers in genetics.

Sturtevant later discovered the so-called ‘position effect’, in which the expression of a gene depends on its position in relation to other genes. He also demonstrated that crossing over between chromosomes is prevented in regions where a part of the chromosome material is inserted the wrong way round. This had important implications for genetic analysis. Although employed by the Carnegie Institution in 1915, Sturtevant continued working at Columbia until 1928. He then moved to the California Institute of Technology, where he was professor of genetics and biology until his death. He wrote many important papers and books and was one of the authors of The Mechanism of Mendelian Heredity(1915).