divergence vs synchronism

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. 

synchronism

noun
  • The tabular arrangement of contemporary events etc. in history. 

  • A temporal relationship between events. 

  • The state of being synchronous. 

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