Riddle, Oscar, 1877-1968

Oscar Riddle was a zoologist and physiologist. Riddle spent most of his professional career at the Station for Experimental Evolution at Cold Spring Harbor, Long Island, and studied birds, namely pigeons, and reproduction.

Oscar Riddle (1877-1968, APS 1926) was a zoologist and physiologist. He spent most of his professional career at the Station for Experimental Evolution at Cold Spring Harbor, Long Island. His research focused on birds and reproduction. Oscar Riddle was born in 1877 in Cincinnati, Indiana, near Bloomington, the son of Jonathan Riddle and Amanda Emeline Carmichael, farmers. His father died when Oscar was still a boy, and he helped to support his family by working on neighboring farms and trapping animals from a young age. In 1896 he enrolled at Indiana University to study biology but he stayed only until 1897 when he left to collect specimens for the U.S. Commission of Fisheries in Puerto Rico. There he worked as a science teacher in several schools, including the Model and Training School in San Juan and several teachers' institutes. In 1901 he traveled to Trinidad and the Orinoco River delta to collect fish specimens for his own use.

Later that year he returned to Indiana University which granted him his B.A. in 1902. Riddle subsequently enrolled in the University of Chicago’s graduate program in zoology. He worked as a teaching assistant and, under the guidance of Charles O. Whitman, began experimenting with the evolution of color patterns in domestic fowl. Financial difficulties compelled him to interrupt his studies in 1903 to teach physiology at Central High School in St. Louis, Missouri. In 1906 he was able to resume his work at Chicago, and in 1907 he received his Ph.D. in zoology. Riddle continued to work at the University of Chicago for the next four years, first as an associate in zoology and embryology and a research assistant in experimental therapeutics and, after 1908, as an instructor. Riddle lost this position in 1911 as a result of a reorganization in the zoology department; however, Whitman retained him to care for his pigeon colony and help in the preparation of his voluminous papers for publication. The following year Riddle accepted an appointment as research associate at the Carnegie Institution of Washington, and in 1913 he moved to the Institution's Station for Experimental Evolution at Cold Spring Harbor on Long Island. Except for serving as a captain in the U.S. Army Sanitary Corps during World War I, Riddle remained at the station for the rest of his career.

At Cold Spring Harbor Riddle’s research focused on organic development and heredity. He was especially interested in pigment distribution and sexual determination and reversal. He tended to study these phenomena in terms of biochemistry and physiology rather then Mendelian genetics. In this he was influenced by the work of his mentor Whitman. Riddle's three-volume compilation of Whitman's papers, essentially an anti-Mendelian approach to such problems as inheritance of feather patterns, sexual behavior, and reproductive activities, was published in 1914.

Riddle made one important scientific contribution was his discovery in 1932 of a hormone produced by the anterior pituitary gland, which stimulates mammaries to produce milk. Until then scientists had generally believed that lactation was triggered by either the placenta, the corpus luteum, or the ovaries. Riddle and his collaborators discovered that an extract of the pititare gland that had been shown by George W. Corner to induce lactation was a protein. They named it prolactin. Within the next five years Riddle was able to demonstrate that prolactin also induced production of milk in rats and crop milk in pigeons.

The discovery of prolactin remained Riddle’s only significant contribution. Partly as a result of his overconfidence and dogmatism, most of the findings in Riddle’s more than 200 research articles were superseded by the work of geneticists. Ironically, Riddle himself worked diligently to convince the public of the correctness of new scientific discoveries.

In addition to his scientific research, Riddle was also concerned with the ways in which biology was taught in American high schools. He was particularly critical of the failure to convey to high school students major advances in the life sciences because of what he called the “anti-science, anti-medical, anti-vivisection and anti-evolution crusades.” Riddle explained his critical stance in an address he delivered in 1936 in St. Louis as vice president of the American Association for the Advancement of Science and chairman of its zoology section. The lecture, which was published in Science under the title "The Confusion of Tongues," created significant controversy. Six years later Riddle became the chairman of a committee created by the Union of American Biological Societies that substantiated his accusations that religious strictures were responsible for preventing exposure of many public school students to the theory of evolution. In addition, Riddle published numerous articles in which he encouraged teachers to stand up to religious dogmatism and make their students biologically literate. He was a founder of the National Association of Biology Teachers, and in the first article in the first issue of the organization’s journal The American Biology Teacher (1938), Riddle urged teachers of the life sciences to “pull together” in order to prevent further weakening of their discipline.

Riddle was an active member of several professional associations. He served as president of the Association for the Study of Internal Secretions (1928-1929), vice president of the American Academy of Arts and Sciences (1935-1936), and president of the American Rationalist Federation (1959-1960). He chaired the American delegation to the Second International Congress for Sex Research in London, England (1930), and represented the Carnegie Institution at the Second Pan-American Congress of Endocrinology in Montevideo, Uruguay (1941). In addition, he was section editor of Biological Abstracts (1926-1946) and on the publication board of Endocrinology (1931-1934, 1939-1942). Among his awards and honors are the Gold Medal of the American Institute of the City of New York's (1934), the Humanist of the Year Award of the American Humanist Association (1958), and the Distinguished Service Award of the National Association of Biology Teachers (1958). He was elected to the American Academy of Arts and Sciences in 1934 and the National Academy of Sciences in 1939.

In 1937 Riddle married Leona Lewis; they had no children. In 1945 he retired to Plant City, Florida. He continued to study and write about biology until his death in 1968.