de Vries, Hugo (hü`gō də vrēs), 1848–1935, Dutch botanist. He opened a new approach to the study of evolution by using the experimental method to investigate the processes of evolution. His study of discontinuous variations, especially in the evening primrose evening primrose, common name for the Onagraceae, a family of plants of worldwide distribution, most species of which grow as herbs in the temperate New World, and specifically for members of the genus Oenothera.
..... Click the link for more information. , led to his rediscovery (reported in 1900) of Mendel's laws of heredity and to the development of the theory of mutation mutation, in biology, a sudden, random change in a gene , or unit of hereditary material, that can alter an inheritable characteristic. Most mutations are not beneficial, since any change in the delicate balance of an organism having a high level of adaptation to its
..... Click the link for more information. , which he expounded in The Mutation Theory (1901–3, tr. 1909–10) and in Plant-Breeding (1907). He maintained that mutations—sudden, unpredictable, inheritable changes in an individual organism—are the chief method by which new species develop in the course of evolution and that each quality subject to change is represented by a single physical unit (which he called a pangen). De Vries's work on osmosis is also important; he coined the term isotonic. He was professor (1878–1918) at the Univ. of Amsterdam, and he established an experimental garden at Hilversum.

de Vries, Hugo (Marie)

(born Feb. 16, 1848, Haarlem, Neth.—died May 21, 1935, near Amsterdam) Dutch botanist and geneticist. He taught at the University of Amsterdam (1878–1918), where he introduced the experimental study of organic evolution. His rediscovery in 1900 (simultaneously with Carl Erich Correns and Erich Tschermak von Seysenegg) of Gregor Mendel's principles of heredity and his own theory of biological mutation explained concepts about the nature of variation of species that made possible the universal acceptance and active investigation of Charles Darwin's theory of organic evolution. De Vries discovered and named the phenomenon known as mutation, and he also contributed to knowledge of the role of osmosis in plant physiology. See also William Bateson.