Mutation theory of Hugo de Vries

The salient features of mutation theory are as follows:
1. Mutations or discontinuous variations are the raw material of evolution.
2. Mutations appear all of a sudden. They become operational immediately.
3. Unlike Darwin’s continuous variations or fluctuations, mutations do not revolve around the mean or normal character of the species.
4. The same type of mutations can appear in a number of individuals of a species.
5. Accumulation of variations produces new species. Sometimes a new species is produced from a single mutation.
6. Useful mutations are selected by nature. Lethal mutations are eliminated. However, useless and less harmful ones can persist in the progeny.
7. Mutations appear in all conceivable directions.
8. All mutations are inheritable.
9. Evolution is a jerky and discontinuous process.