Zuni, or Ashiwi, is a language isolate spoken by over 4500 people in New Mexico and much smaller numbers in parts of Arizona. It is now generally considered a language isolate. The Encyclopedia Britannica categorizes it as a Penutian language, and Bertha Dutton once posed the hypothetical that according to the Swadesh list, "If the Zuni language is a member of the Penutian language family, then it is a distant relative of the Tanoan languages (Tewi)." The Penutian Hypothesis was advanced by Alfred Kroeber and Roland B. Dixon and later refined by Edward Sapir, and was an attempt to reduce the number of unrelated language families in a culturally diverse area that was centered in California central coast. While this theory was plausible for some of