ABSTRACT
Many scholars, in many disciplines, writing since the 1960s have been so certain that the region is a distinctive and coherent entity that they have not bothered to define it. Southeast Asia is characterized by both high species richness and high level of endemism linked to its geological history. Deep evolutionary origins of flora and fauna have to be searched for in the tectonic-plate dynamics that occurred through geologic times, whereas more recent diversification origins are linked to the consequences of changing paleo-climates with sea level fluctuations. Hill is one of the scholars who has tried to define Southeast Asia both politically and geographically, emphasizing both its diversity and unity. There are eleven states in Southeast Asia inhabited by 600 million people. McGregor emphasized one main characteristic of Southeast Asia, which is its diversity: a high diversity in economical development among and within countries and a high diversity in political systems.
