The Aleutian Tradition began around 2500 BC and ended in AD 1800. Aleutian artifacts are made out of chopped stone, unlike the more common slate tools. Objects were traditionally made using a concept called core and flake that uses bifacially carved projectile points. The Aleutian people lived in semi-subterranean winter houses made from driftwood, whale bone, and peat. They used kayaks, atlatls and harpoons to kill sea mammals for sustenance. Around AD 1150 Aleutian houses increased considerably in size. Food was stored in special chambers inside the house and weaponry was becoming more common around these sites. The sustenance pattern changed from relying on sea mammals to eating mostly salmon. Long-distance trade also started increasing community with other local groups. Linguistics There are many hypotheses surrounding the linguistics of the Aleutian peoples. The Aleutian language has been considered by Joseph Greenberg to be a component of the Amerind family linguistic group. He proposed that the Amerind language group arrived in the Americas before 9000 BC with the NaDene group diverging around 7000 BC and the Aleut and Eskimo languages diverging around 2000 BC. Another argument is that NaDene, Eskimo, and Aleut linguistic features are more similar to those of the Chukchi in Siberia than to Amerind linguistic features. This hypothesis suggests that the NaDene, Eskimo, Aleut, and Chukchi peoples descended from a single population, placing the timing of human arrival in North America at 30,000 to 43,000 years ago. It is possible that the Chukchi were isolated from the other linguistic populations due to the rising sea levels and the Na Dene and Aleut-Eskimo diverged due to differing adaptations in result of coastal and inland occupation. This points to Aleut and Eskimo people being a part of the same language stock yet displaying differences in speech patterns similar to the differences between Russian and English. Settlement, society, lifestyle Archaeological evidence shows that the Aleut peoples once supported some of the largest hunter-gatherer sedentary settlements on earth. Aleut populations consisted of a highly varied hunter-gatherer economy that was based upon the resources of the land and water. Subsistence included a wide range of sea mammals including seal and walrus, along with the hunting of caribou and muskox and the gathering of wild vegetables. Within the Aleutian Islands villages grew slowly for about 2000 years after 2500 BC with numerous large settlements emerging during the first millennium. It is not clear why