G. Ledyard Stebbins

His most important publication was ''Variation and Evolution in Plants'', which combined genetics and Darwin's theory of natural selection to describe plant speciation. It is regarded as one of the main publications which formed the core of the modern synthesis and still provides the conceptual framework for research in plant evolutionary biology; according to Ernst Mayr, "Few later works dealing with the evolutionary systematics of plants have not been very deeply affected by Stebbins' work." He also researched and wrote widely on the role of hybridization and polyploidy in speciation and plant evolution; his work in this area has had a lasting influence on research in the field.
From 1960, Stebbins was instrumental in the establishment of the Department of Genetics at the University of California, Davis, and was active in numerous organizations involved in the promotion of evolution, and of science in general. He was elected to the National Academy of Sciences and the American Philosophical Society, was awarded the National Medal of Science, and was involved in the development of evolution-based science programs for California high schools, as well as the conservation of rare plants in that state. Provided by Wikipedia