indio is an attempt at an international indigenous language. Most words and grammar ideas come from but are not limited to several control languages -- Choctaw, Quechua, Nahuatl, Ojibwe, and many others including non-american languages -- Manchu (asia), Hadza (africa), Sami (scandinavia), Noongar (australia), Hawaiian (polynesian), and Maori (new zealand).The list of languages continues to grow along with the dictionary.
For a language to be included, the speakers must in some way not have conformed to modern society, have a background of Shamanism or some kind of cosmology mythology, be considered indigenous and not part of Roman Europe. Non American languages donate words related to themselves. For example, the word for Elephant comes from Hadza. The word for Reindeer comes from Sami. The word for Kangaroo comes from Noongar. The name for China comes from Manchu, and also Tungusic languages such as Nanai. Maoris and Pacific island peoples had good ancient astronomy, so all planet names come from them. Later in development of indio Maori words are becoming more important for other concepts like "energy" in physics.
indio uses Choctaw like Latin, a base for other languages and scientific words.
Historically, a variation of Choctaw/Muskogee was used by some tribes as a lingua franca.The MobilianTrade Language is thought to be derived from Choctaw.Another use of Choctaw was as a code for the US military during WW1.
Generally, words, grammar, and affixes were chosen not because of what language they came from, but for thier ability to be simplified into indio. Cheyenne and Cherokee, for instance, were difficult to transliterate. Cherokee is tonal, and indio isnt.