in the world, the Gulf Stream. Fauna South America is one of the most biodiverse continents on Earth. South America is home to many unique species of animals including the llama, anaconda, piranha, jaguar, vicuña, and tapir. The Amazon rainforests possess high biodiversity, containing a major proportion of Earth's species. History Prehistory South America is thought to have been first inhabited by humans when people were crossing the Bering Land Bridge (now the Bering Strait) at least 15,000 years ago from the territory that is present-day Russia. They migrated south through North America, and eventually reached South America through the Isthmus of Panama. The first evidence for the existence of the human race in South America dates back to about 9000 BC, when squashes, chili peppers and beans began to be cultivated for food in the highlands of the Amazon Basin. Pottery evidence further suggests that manioc, which remains a staple food today, was being cultivated as early as 2000 BC. By 2000 BC, many agrarian communities had been settled throughout the Andes and the surrounding regions. Fishing became a widespread practice along the coast, helping establish fish as a primary source of food. Irrigation systems were also developed at this time, which aided in the rise of an agrarian society. South American cultures began domesticating llamas, vicuñas, guanacos, and alpacas in the highlands of the Andes circa 3500 BC. Besides their use as sources of meat and wool, these animals were used for transportation of goods. Pre-Columbian civilizations The rise of plant growing and the subsequent appearance of permanent human settlements allowed for the multiple and overlapping beginnings of civilizations in South America. One of the earliest known South American civilizations was at Norte Chico, on the central Peruvian coast. Though a pre-ceramic culture, the monumental architecture of Norte Chico is contemporaneous with the pyramids of Ancient Egypt. Norte Chico governing class established a trade network and developed agriculture then followed by Chavín by 900 BC, according to some estimates and archaeological finds. Artifacts were found at a site called Chavín de Huantar in modern Peru at an elevation of . Chavín civilization spanned 900 BC to 300 BC. In the central coast of Peru, around the beginning of the 1st millennium AD, Moche (100 BC – 700 AD, at the northern coast of Peru), Paracas and Nazca (400 BC – 800 AD, Peru) cultures flourished with centralized states