The linguistic diversity seen in a given area is based on the history of successive opportunistic settlements by immigrants according to a new study conducted by Brian Codding, an assistant professor of anthropology at the University of Utah, and Terry Jones, a professor of anthropology and chair of social sciences at California Polytechnic State University in San Luis Obispo, California, that was reported in the Aug. 19, 2013, issue of the journal Proceedings of the National Academy of Sciences.
The researchers examined the diversity of Native American languages in California and extrapolated the pattern and context to other areas of the world.
The majority of Native American peoples originally settled California between 12,000 and 4,000 years ago in three waves of immigration. These three waves of immigration are reflected in the diversity of language that certain areas have at present.
The researchers assert that higher language diversity occurred in areas that were more productive in terms of water, animals, and plants.
The first wave of Native Americans settled waterways. This group presented the largest number of language variants. Waterways were the most productive land areas. The second wave settled more marginal land including California's Central Valley and the Sierra Nevada. The third wave replaced some of the first wave in the most productive environments due to improved hunting and fishing technologies and the development of the concept of land ownership by an individual. The third wave also settled the most marginal lands including the deserts of southeast California and the Great Basin.
The conclusions the researchers reached were based on NASA satellite imaging that showed present day land productivity in terms of plants, water, and animals. The researchers also used the first recorded interactions of Native Americans with Europeans and the archaeological records that exist in California of the various Native American immigrant groups. Genetic sampling provided the physical relationships between groups of Native Americans that developed very different languages over time or that became distributed in several geographic locations.
Language variety and the multiplicity of language variants in a given area are the result of opportunistic settlement of the most productive land in terms of food sources and water availability.