family history vs family tree

family history

noun
  • An extension to genealogy in which the life and times of the people concerned are investigated. 

  • Information concerning the disorders suffered by the direct relatives of a patient; especially useful if the disorders are genetic. 

family tree

noun
  • A diagrammatic representation of a pedigree, illustrating the connections between a person's ancestors, offspring and other relatives 

  • The totality of someone's ancestors and offspring 

How often have the words family history and family tree occurred in a corpus of books? (source: Google Ngram Viewer )