concomitance vs divergence

concomitance

noun
  • A concomitant. 

  • occurrence or existence together or in connection with one another, coexistence 

  • The Roman Catholic doctrine of the existence of the entire body of Christ in the Eucharist, under each element, so that the body and blood are both received by communication in one kind only. 

divergence

noun
  • The process in which two or more populations accumulate genetic changes (mutations) through time. 

  • the operator which maps a function F=(F₁, ... Fₙ) from a n-dimensional vector space to itself to the function ∑ᵢ₌₁ⁿ(∂F_i)/(∂x_i) 

  • The degree to which two or more things diverge. 

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