ancestry vs progenitor

ancestry

noun
  • A series of ancestors or progenitors; lineage, or those who compose the line of natural descent. 

  • Condition as to ancestors; ancestral lineage; hence, birth or honorable descent. 

progenitor

noun
  • An ancestral form of a species. 

  • A forefather, any of a person's direct ancestors. 

  • A predecessor of something, especially if also a precursor or model. 

  • A founder. 

  • Someone who originates something. 

  • An individual from whom one or more people (dynasty, tribe, nation...) are descended. 

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