Sudden heritable changes in organisms are defined as mutations. The term mutation was first used by Hugo de Vries (1901) who observed it in Oenothera lamarckiana.
Hugo de Vries (1848-1935) of Netherlands was born in Haarlem in February 16, 1848 in Holland. He was a professor of Plant Physiology at the University of Amsterdam in 1881. He has observed mutation in Oenothera lamarckiana (Evening Primrose) and proposed the mutation theory. Hence he is called as the “Father of Mutation”.
T.G. Dobzhansky studied the (variation) mutation in Population Genetics. T.H. Morgan (1910) began his genetical work with the fruitfly Drosophila melanogaster. He was an American Zoologist, and he was awarded with Nobel Prize for his research work on mutations.
According to modern concept, the mutation is considered to be a sudden change in the genotype. Small mutations are called as micromutations and large mutations as macromutations.