Cultural Evolution Society 2021

Language phylogenies reveal a recent northern origin of the Utoaztecans

The Uto-Aztecan language family is one of the largest language families in the Americas. However, there is considerable debate about its origin. One scenario postulates a northern origin in Southern California, Arizona and Northern Mexico between 3,000-5,000 years ago. Another scenario argues for a similar time-frame but a southern origin in Mesoamerica and subsequent northerly spread into the American southwest. A third scenario proposes a much older origin around 8,900 in Nevada.

Here we use Bayesian phylogenetic and phylogeographic methods to analyse lexical data from 34 Uto-Aztecan and 2 Kiowa-Tanoan languages. We infer the age of Proto-Uto-Aztecan to be around 4,095 years ago (3,258 - 5,025 years), and identify the most likely homeland to be in or near what is now southern California. We reconstruct the most probable subsistence strategy in the ancestral Uto-Aztecan society using ethnographic data.

We use ancestral state inference on cultural and ethnographic data and find a high probability that the proto-Uto-Aztecans had low agricultural dependence, no casual or intensive cultivation, an absence of cereal crops, and a primary subsistence mode of gathering (rather than hunting or agriculture). Our results therefore support the northern origin scenario’s proposed timing, geography, and cultural practices, and are inconsistent with the southern and ancient origin scenarios.