commingle vs interbreed

commingle

verb
  • To become mixed or blended. 

  • To mix, to blend. 

interbreed

verb
  • To breed or reproduce within a heterogenous community, the products of which produce hybrids. 

  • To breed or reproduce within an isolated community. 

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