Ancient Andean Maize Makers: Finds push back farming, trade in highland Peru

Nearly 4,000 years ago, large societies emerged in the Andes Mountains of southern Peru that would culminate approximately 3,000 years later in the rise of the Inca civilization. Now, scientists have the first evidence that these Inca predecessors cultivated maize and imported plant foods from lowland tropical forests located 180 miles to the east.