Weihrauchstraße
Trade, the voluntary exchange of goods and services, is seen as a characteristic that differentiates humans from other animals and has been cited as a practice that gave "Homo sapiens" a major advantage over other hominids. Evidence suggests early "H. sapiens" made use of long-distance trade routes to exchange goods and ideas, leading to cultural explosions and providing additional food sources when hunting was sparse, while such trade networks did not exist for the now extinct Neanderthals. Early trade likely involved materials for creating tools like obsidian. The first truly international trade routes were around the spice trade through the Roman and medieval periods. Other important trade routes to develop around this time include the Silk Road, Incense Route, Amber road, Tea Horse Road, Salt Route, Trans-Saharan Trade Route and the Tin Route.