1108 trade and exchange: primary source documents eastward, suggesting both population diff usion and exchange systems Because distances were often great and contact infrequent between societal territories, trade probably happened spontaneously In other northern locations, however, trade occurred regularly between coastal and inland groups to obtain staples that their own environments did not offer For example, during the Mesoamerican Classic Period (150–650 c.e.) sea mammal oil and blubber were traded by coastal peoples to interior peoples in exchange for furs of the caribou, fox, and wolverine A basic form of this exchange tradition probably dates back several thousand years A similar geographic exchange principle between interior and coast also was thought to exist in the southeastern region of North America In the Adena-Hopewell interaction sphere, centered in present-day Ohio with satellites spread throughout the greater Midwest, mound builders gathered periodically for funeral ceremonies and construction Evidence suggests that some form of exchange occurred, even if it was only labor Craft specialization, including pipes and polished stone artifacts, all highly transportable, offered prime opportunities for trade Researchers have found a surprising concentration of Adena-style artifacts, such as stone tubes, Adena points, birdstones, gorgets, and shell and copper beads as far east as the Chesapeake Bay Materials for Hopewell grave goods were brought in from great distances Other traded items include obsidian from what is today Yellowstone Park in Wyoming, conch and turtle shell, shark and alligator teeth from Florida, mica and chlorite from North Carolina and Tennessee, bluish flint from Indiana, and chalcedony from North Dakota While down-the-line, or intervillage, exchange systems may Greece have accounted for some of the imports, long-range trading or mining expeditions also seem to have been involved Evidence throughout the Andes region supports a tradition of long-distance trade In the period of 2000–1500 b.c.e trade between coastal Ecuador and Amazonia is supported by ceramic developments, figurine traditions, and the presence in coastal Ecuador of a type of coca indigenous to the Amazon regions In Peru evidence of long-distance trade is found in a medicine man’s outfit discovered near Lake Titicaca and dated to the fourth century b.c.e The outfit is attributed to a type of traveling herbalist called a callahuayas, whose business was the long-distance transfer of goods and ideas Remains of food, arts, and crafts at Chavín de Huántar, the center of the northern Peruvian Chavín culture (ca 900–ca 200 b.c.e.), indicate extensive outside relations, including a far-flung trade network presumably facilitated by llama trains In one example, obsidian from Huancavelica, some 290 miles south, was found at Chavín de Huántar See also agriculture; borders and frontiers; building techniques and materials; calendars and clocks; ceramics and pottery; cities; crafts; economy; empires and dynasties; employment and labor; exploration; food and diet; foreigners and barbarians; inventions; language; metallurgy; military; mining, quarrying, and salt making; money and coinage; roads and bridges; seafaring and navigation; ships and shipbuilding; slaves and slavery; social organization; storage and preservation; textiles and needlework; transportation; weights and measures; war and conquest; writing The Periplus of the Erythraean Sea: Travel and Trade in the Indian Ocean by a Merchant of the First Century, excerpt (ca first to third centuries c.e.) Of the designated ports on the Erythraean Sea, and the market-towns around it, the first is the Egyptian port of Mussel Harbor To those sailing down from that place, on the right hand, after eighteen hundred stadia, there is Berenice The harbors of both are at the boundary of Egypt, and are bays opening from the Erythraean Sea On the right-hand coast next below Berenice is the country of the Berbers Along the shore are the FishEaters, living in scattered caves in the narrow valleys Further inland are the Berbers, and beyond them the Wild-flesh-Eaters and Calf-Eaters, each tribe governed by its chief; and behind them, further inland, in the country towards the west, there lies a city called Meroe Below the Calf-Eaters there is a little market-town on the shore after sailing about four thousand stadia from Berenice, called Ptolemais of the Hunts, from which the hunters started for the interior under the dynasty of the Ptolemies This market-town has the true land-tortoise in small quantity; it is white and smaller in the shells And here also is found a little ivory like that of Adulis But the place has no harbor and is reached only by small boats Below Ptolemais of the Hunts, at a distance of about three thousand stadia, there is Adulis, a port