Richard Benedict Goldschmidt (April 12, 1878 – April 24, 1958) was a German-American geneticist. He is considered the first to attempt to integrate genetics, development, and evolution. He pioneered understanding of reaction norms, genetic assimilation, dynamical genetics, sex determination, and heterochrony. Controversially, Goldschmidt advanced a model of macroevolution through macromutations popularly known as the "Hopeful Monster" hypothesis. Goldschmidt also described the nervous system of the nematode, a piece of work that influenced Sydney Brenner to study the "wiring diagram" of Caenorhabditis elegans, winning Brenner and his colleagues the Nobel Prize in 2002. Childhood and education Goldschmidt was born in Frankfurt-am-Main, Germany to upper-middle class parents of Ashkenazi Jewish heritage. He had a classical education and entered the University of Heidelberg in 1896, where he became interested in natural history. From 1899 Goldschmidt studied anatomy and zoology at the University of Heidelberg with Otto Bütschli and Carl Gegenbaur. He received his Ph.D. under Bütschli in 1902, studying development of the trematode Polystomum. Career In 1903 Goldschmidt began working as an assistant to Richard Hertwig at the University of Munich, where he continued his work on nematodes and their histology, including studies of the nervous system development of Ascaris and the anatomy of Amphioxus. He founded the histology journal Archiv für Zellforschung while working in Hertwig's laboratory. Under Hertwig's influence, he also began to take an interest in chromosome behavior and the new field of genetics. In 1909 Goldschmidt became professor at the University of Munich and, inspired by Wilhelm Johannsen's genetics treatise Elemente der exakten Erblichkeitslehre, began to study sex determination and other aspects of the genetics of Lymantria dispar, the gypsy moth, of which he was crossbreeding different races. He observed various stages of their sexual development, and found that some of the animals were neither male, nor female, nor hermaphrodites, but represented a whole spectrum of gynandromorphism. He named them 'intersex', and the phenomenon accordingly 'intersexuality' (Intersexualität). His studies of the gypsy moth, which culminated in his 1934 monograph Lymantria, became the basis for his theory of sex determination, which he worked on from 1911 until 1931. Goldschmidt left Munich in 1914 for the position as head of the genetics section of the newly founded Kaiser Wilhelm Institute for Biology in Berlin. During a field trip to Japan in 1914, he was unable to return to Germany due to the outbreak of the First World War, and was detained