As explained in the Mutation theory by Hugo de Vries, mutation is a probable cause of evolution.
Yes.
Step-by-step explanation:
Hugo de Vries is also known as the father of Mutation who gave the Mutation theory regarding the evolution in the year of 1901. This theory stated that evolution is a discontinuous process and not smooth as explained by Darwin. This theory said that a mutation is the raw material for evolution and it is sudden in onset, but carried to progenies by means of reproduction. The lethal mutations are eliminated but the others are carried forward. Sometimes a single mutation can also evolve to a new species.
Although this theory explained the evolution of Ancon sheep and few others, but there were many points against this theory. Mutations are generally negative or recessive and are not as frequent as Hugo thought. This theory also couldn't explain the dependent relationships like symbiosis, parasitism etc. So mutation is one but not the only one process of evolution.