ancestry vs pecking order

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. 

pecking order

noun
  • The natural hierarchy of social status and dominance occurring in a group of birds. 

  • The usually informal hierarchy of authority or command, often partial or approximate, as determined by the especially natural propensity for domination of different members of a specific group over each other, such as older brothers and sisters over their younger siblings. 

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