HISTORY HELP

In his work, Jared Diamond draws very careful links between cultural development and big geographical factors (specifically the key geographical differences between the Americas and Eurasia).  Identify 4 places in the material of the past 3 weeks, excluding material from the Americas, where von Sivers and/or McGuire build precise arguments about development and civilizations out of geographical considerations.  How exactly do we understand these factors to affect the civilization involved?  Do you see any instances in which the emphasis on geography obscures other important factors?