<P> It was also in this period that Andean communities first began to domesticate crops, genetically transforming various plant species from their wild counterparts . </P> <P> The Lithic Period was followed by what archaeologists have called the Pre-Ceramic Period, or alternatively the Late Archaic Period, and is characterised by increasing societal complexity, rising population levels and the construction of monumental ceremonial centres across the Andean region . It is the latter of these features that remains the most visually obvious characteristic of the Pre-Ceramic amongst archaeologists, and indicates that by this time, Andean society was sufficiently developed that it could organise large building projects involving the management of labor . The Pre-Ceramic Period also saw a rise in the population of the Andean region, with the possibility that many people were partially migratory, spending much of their year in rural areas but moving to the monumental ceremonial centers for certain times which were seen as having special significance . The Pre-Ceramic also saw climate change occurring in the Andean region, for the culmination of the Ice Age had led to an end of the glacial meltback which had been occurring throughout the Lithic Period, and as a result the sea levels on the west coast of South America stabilized . </P> <P> Despite these changes, many elements of Andean society remained the same as it had been in earlier millennia; for instance, as its name suggests, the Pre-Ceramic was also a period when Andean society had yet to develop ceramic technology, and therefore had no pottery to use for cooking or storage . Similarly, Andean communities in the Pre-Ceramic had not developed agriculture or domesticated flora or fauna, instead gaining most of their food from what they could hunt or gather from the wild, just as their Lithic Period predecessors had done, although there is evidence that some wild plants had begun to be intentionally cultivated . </P> <P> In the mountain drainage areas of the Andes, a series of ceremonial buildings were constructed that archaeologists have identified as being a part of what they called the Kotosh Religious Tradition . One of the most prominent of these sites was that at Kotosh, after which the religious tradition was named . Located on the bank of the Río Higueras, Kotosh was at an elevation of c. 2000 metres above sea level, and consisted of "two large platform mounds flanked by lesser constructions and a number of small structures on a nearby river terrace ." Another notable example of the Kotosh Religious Tradition can be seen at La Galgada in the Callejón de Huaylas, modern Peru, which again consists of two platform mounds and several surrounding structures . </P>

Where is it believed that the incan tribe began