Overkill of the North American Megafauna Thousands of years ago, in Nort...

The Development of Social Complexity For most of humanhistory, we have f...

Types of Social Groups（比前三篇简单太多了） Life places us in acomplexweb of relat...

Trade And Early State Formation Bartering（物物交换) was abasictrademechanism...

The Commercial Revolution in Medieval Europe Beginning in the 1160s, the...

Roman Cultural Influence on Britain（influence是关键） After the RomanEmpire’...