What are the causes of mutations in the human body?

The reason is the inevitable errors when rewriting hereditary information from the mother’s DNA molecule to the daughter one. The frequency of these errors increases when exposed to chemicals (some) ionizing radiation and when you get nasty on a crowded bus.

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.