<P> Andean civilization lacked several characteristics distinguishing it from the pristine civilizations in the Old World . First, and perhaps most important, Andean civilizations did not have a written language . Instead, their societies used the quipu, a system of knotted and colored strings, to convey information . Few quipus survive and they have never been fully deciphered . Scholars differ on whether the knotted cords of the quipu were able only to record numerical data or could also be used for narrative communication, a true system of writing . The use of the quipu dates back at least to the Wari Empire (600 - 1000 CE) and possibly to the much earlier Norte Chico civilization of 2,500 BCE . </P> <P> Andean civilizations also lacked wheeled vehicles and draft animals . People on land traveled only by foot and the transport of goods was only by humans or llama, pack animals which could carry loads of up to one - fourth of their weight, a maximum of 45 kilograms (99 lb). Llamas were not big or strong enough to be used for plowing or as riding animals for adults . </P> <P> Moreover, Andean civilizations faced severe environmental challenges . The earliest civilizations were on the hyper - arid desert coast of Peru . Agriculture was possible only with irrigation in valleys crossed by rivers coming from the high Andes, plus in a few fog oases called lomas . In the Andes, agriculture was limited by thin soils, cold climate, low or seasonal precipitation, and a scarcity of flat land . Freezing temperatures may occur in every month of the year at altitudes of more than 3,000 metres (9,800 ft), the homeland of many of the highland Andean civilizations . </P> <P> Finally, the Andean civilizations lacked money . Copper axe - monies (also called "naipes") and Spondylus shells functioned as mediums of exchange in some areas, especially coastal Ecuador, but most of the Andes area had economies organized on reciprocity and redistribution rather than money and markets . These characteristics were especially notable during the Inca Empire but originated in much earlier times . </P>

The early civilization that arose in the south of mesopotamia is