Wilhelm Weinberg (25 December 1862 – 27 November 1937) was a German obstetrician-gynecologist, practicing in Stuttgart, who in a 1908 paper, published in German in Jahresheft des Vereins für vaterländische Naturkunde in Württemberg (The Annals of the Society of National Natural History in Württemberg), expressed the concept that would later come to be known as the Hardy–Weinberg principle.
Weinberg is also credited as the first to explain the effect of ascertainment bias on observations in genetics.
Hardy–Weinberg principle
Weinberg developed the principle of genetic equilibrium independently of British mathematician G.H. Hardy. He delivered an exposition of his ideas in a lecture on 13 January 1908, before the Verein für vaterländische Naturkunde in Württemberg (Society for the Natural History of the Fatherland in Württemberg), about three months before the Hardy's notes from April 1908 of that year and five months before Hardy's paper was published in English in June 1908. His lecture was printed in the society's yearbook in September 1908. Before 1943, the concepts in genetic equilibrium that are known today as the Hardy–Weinberg principle had been known as "Hardy's law" or "Hardy's formula" in English-language texts.
In 1999, James F. Crow wrote: “Why was Weinberg’s paper, published the same year as Hardy’s, neglected for 35 years?" The reason probably is that he wrote in German. At the time, genetics was largely dominated by English-speakers and work in other languages was often ignored.”
Ascertainment bias and analysis of phenotypic variance
Weinberg pioneered in studies of twins, developing techniques for analysis of phenotypic variation that partitioned this variance into genetic and environmental components. In the process, he recognized that ascertainment bias was affecting many of his calculations, and he produced methods to correct for it.
He studied medicine at Tübingen, Berlin and Munich, receiving an M.D. in 1886. In 1889, he returned to Stuttgart, where he remained running a large practice as a gynecologist and obstetrician until he retired to Tübingen a few years before his death in 1937. Much of his academic life he spent studying genetics especially focusing on applying the laws of inheritance to populations.
Additional contributions by Weinberg to statistical genetics included the first estimate of the rate of twinning – Realizing that identical twins would have to be same-sex, while dizygotic twins could be either same or opposite sex, Weinberg derived the formula for estimating the frequency of monozygotic and dizygotic twins from the ratio of same sex and opposite twins to the total of maternities.