metamorphosis vs radical alteration

metamorphosis

noun
  • A transformation, such as one performed by magic. 

  • A change in the form and often habits of an animal after the embryonic stage during normal development. (e.g. the transformation of a caterpillar into a butterfly or a tadpole into a frog.) 

  • A noticeable change in character, appearance, function or condition. 

  • A change in the structure of a specific body tissue. Usually degenerative. 

radical alteration

How often have the words metamorphosis and radical alteration occurred in a corpus of books? (source: Google Ngram Viewer )