It allows people worldwide to identify the same species.
Smoking became very popular.
Changed diet kept people from starvation.
Corn fed livestock grew in places where other plants couldn't grow in
Explanation:
Rare property of obsidian that is advantageous to archaeologists is that it occurs in volcanic flows that are remarkably homogeneous in chemical composition within a flow, but preserve elemental signatures that are unique to volcanic centers, and in some cases individual flows.
Answer:
Historians John Thornton and Linda Heywood of Boston University have estimated that of the Africans captured and then sold as slaves to the New World in the Atlantic slave trade, around 90% were enslaved by fellow Africans who sold them to European traders.
