John Marion Thoday. 30 August 1916—25 August 2008

Abstract

Professor John M. Thoday, ScD, FRS, was Arthur Balfour Professor of Genetics at the University of Cambridge from 1959 until 1983. In that position, he was influential in establishing genetics as an integral part of the undergraduate programme in biology at Cambridge, and he developed an active research programme that explored genetic processes underlying quantitative genetic traits, natural selection in sympatric populations and genetic variation in human and other populations. In more than 125 publications, he brought insightful attention to questions that had often been overlooked by others. Some of his most significant work explored the genetic basis of quantitative traits and thus pioneered approaches to understanding the mechanisms behind responses to selection. This helped set the stage to uncovering genes in the multiple-gene systems that determine polygenic characters in fields from medicine to agriculture. Other key work focused on disruptive, or diversifying, selection as a potential mechanism for populations to respond to adaptive challenges in nature. When his study of disruptive selection began, many in the field believed it was not even a possible process. In his many roles, John Thoday was a mentor who stimulated an open, respectful and intellectually rich academic environment for the Department of Genetics at Cambridge and for his field of creative activity.