Maize, which found its way to the Andes from Mexico, was often the most important crop at lower and intermediate elevations.
Crops grown by the Andeans were often unique to the region.
Moreover, Andean civilizations faced severe environmental challenges.
The earliest civilizations were on the hyper-arid desert coast of Peru.
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).