de Vries gave his mutation theory on organic evolution while working on

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Hugo de Vries (1848-1935) proposed mutation theory for the formation of new species. According to him, new species are not formed by continuous variations but by sudden appearance of variations which he assigned as mutations. He stated that these mutations are heritable and persist in successive generations. For proposing this theory he performed experiments on Oenothera lamarckiana (evening primrose).