Proposed Edit 2  "The book argues evidence for human beings on the earth for millions of years," 

 Since "Tertiary" does not refer to a period of time billions of years ago (or even hundreds of millions) it remains inappropriate to use the word "billion" in a summary of the contents of these two reviews. Neither do the two secondary sources being summarized use the term "central claim" anywhere in their presentations, rather deferring to the more accurate phrase, "FA argues." With such thoughts in mind, I would like to delete "billions" altogether, and replace "central claim" with "argues." Please respond with any reservations to this proposal. Thanks