Otmar Freiherr von Verschuer (16 July 1896 – 8 August 1969) was a German-Dutch human biologist and geneticist, who was the Professor of Human Genetics at the University of Münster until he retired in 1965. A member of the Dutch noble Verschuer family, his title Freiherr is often translated as baron. He was regarded as a pioneer in the twin methodology of genetics research and in the study of the inheritance of diseases and anomalies. A Nazi-affiliated eugenicist with an interest in racial hygiene, he was an advocate of compulsory sterilization programs in the first half of the 20th century. Among his many students was Josef Mengele, a war criminal who directed experiments on children at Auschwitz. He successfully redefined himself as a geneticist in the postwar era. During the 1950s and 1960s, he was known for research on the effects of nuclear radiation on humans and for his warnings against the possibility of creating "scientifically improved" human beings offered by genetic science. Verschuer was the director of the Institute for Genetic Biology and Racial Hygiene from 1935 to 1942 and director of the Kaiser Wilhelm Institute of Anthropology, Human Heredity, and Eugenics (KWI-A) from 1942 to 1948. From 1951 to 1965, he was Professor of Human Genetics at the University of Münster, where he also served as Dean of the Faculty of Medicine. At Münster, he established one of the largest centers of genetics research in West Germany, and remained one of the world's most prominent genetics researchers until his death. He became Professor Emeritus in 1965; he received numerous memberships in learned societies. In 1952 he was elected President of the German Anthropological Association. His son Helmut von Verschuer was a high-ranking official of the European Commission. Family Otmar von Verschuer was born into a noble family. From birth he held the title of Freiherr (baron), a title that had been granted to several family branches by the Holy Roman Emperor, the Dutch king, and the elector of Hesse. He was mainly of Dutch, German, Estonian/Baltic German, and Swedish descent, and had distant Scottish ancestry. His father Hans von Verschuer was a businessman who owned a mining company, while his mother Charlotte née von Arnold was originally from Estonia; her family was ennobled in Russia in the mid-19th century and was partially resident in Sweden. He was a descendant of the House of Stuart through his 6th great