Peru as loose confederation of cities scattered along the coast of northern Peru and southern Ecuador, the Chimu flourished from about 1140 to 1450. Their capital was at Chan Chan outside of modern-day Trujillo. In the highlands, both the Tiahuanaco culture, near Lake Titicaca in both Peru and Bolivia, and the Wari culture, near the present-day city of Ayacucho, developed large urban settlements and wide-ranging state systems between 500 and 1000 AD. In the 15th century, the Incas emerged as a powerful state which, in the span of a century, formed the largest empire in pre-Columbian America with their capital in
Pre-Columbian era Oceania of several cultivated plant species native to South America, such as the bottle gourd ("Lagenaria siceraria") or sweet potato ("Ipomoea batatas"). Direct archaeological evidence for such pre-Columbian contacts and transport have not emerged. Similarities noted in names of edible roots in Maori and Ecuadorian languages ("kumari") and Melanesian and Chilean ("gaddu") have been inconclusive. A 2007 paper published in "PNAS" put forward DNA and archaeological evidence that domesticated chickens had been introduced into South America via Polynesia by late pre-Columbian times. These findings were challenged by a later study published in the same journal, that cast doubt on the