Agriculture becomes popular (1 jan 3000 ano antes da era comum – 1 jan 2500 ano antes da era comum)

Descrição:

They (Southeastern Asian migrants) settled in Northern New Guinea and made their own little communities, and started trading and communicating with local nomads. ("local nomads" does that make sense)

Trade and communication, as we all know, are the very best way to influence people. Soon enough, agricultural societies are popping up all over New Guinea, and everyone's cultivating some roots and keeping some animals.

(Do I still have to outline exactly what agriculture leads to? )

Briefly:

More food leads to more people. More people leads to settlements (so people don't move around so much) and specialization of labor. Specialization of labor leads to technological advancements and property. Property leads to social hierarchies, which lead to political and cultural (and economic, eventually) organizations. Technological advancements lead to more food. More food leads to more people.

Good? Good.