Richard Goldschmidt's research on homeotic mutants from 1940 until his death in 1958 represents one of the first serious efforts to integrate genetics, development, and evolution. Using two different models, Goldschmidt tried to show how different views of genetic structure and gene action could provide a mechanism for rapid speciation. Developmental systems were emphasized in one model and a hierarchy of genetic structures in the other. While Goldschmidt tried to find a balance between development and genetics, critics, such as Sewall Wright, urged him and eventually helped him incorporate population dynamics into his models as well. As such, the history of Goldschmidt's research on homeotic mutants highlights the continuing challenge of producing a balanced and integrated developmental evolutionary genetics.