The author mentions "ancient Mesopotamia" primarily in order to emphasize the extent to which the modification of nature by human culture preceded the industrial period

  2. [singular/uncountable] the degree to which something happens or is likely to happen

      the extent to which: The extent to which your diet is successful depends on your willpower.

      Languages vary in the extent to which they rely on word order.

      Thesaurus: features and qualitiessynonym 

请问老师，这几句中的 the extent to which这种结构如何理解的更加顺畅？