The languages of Tlingit, Haida, and Eyak are spoken along the northwest coast of British Columbia and Alaska, whereas the Athapaskan languages are spread throughout the west of Canada and the U.S. Pacific coast and Southwest. Eyak is northern-most of the three, spoken in traditional territories on the northern part of the Alaskan Panhandle. The traditional territories of the Tlingit reach below the Eyak to the coast just north of the Queen Charlotte Islands of British Columbia, now known as the Haida Gwaii, home to the Haida people.
The term "Na-Dene" is sometimes used to refer to the Athapaskan peoples specifically, which includes groups like the northern Dene and the Navajo. The term "Athapaskan" is not universally endorsed by peoples of that heritage; "Na-Dene" presents a more generalized but relevant term because it includes the common linguistic root for the word "people" or "person."
The Na-Dene peoples are also believed to have been the second wave of migration into North America, which occurred approximately 8,000 years ago. They are believed to have emigrated from Asia, possibly in boats. Migrations from the Northwest of Canada took populations south, eventually distributing Na-Dene peoples throughout the continent. About 1,500 years ago, the ancestors of the Navajo and Apache peoples reached the southern United States.
Edward Sapir coined the term "Na-Dene" in 1915 as a reference to a grouping of Tlingit, Haida, and Athapaskan. It is coined from the Haida name for house (na) and the Athapaskan and Tlingit word for person (dene). When Sapir gained access to Eyak language data, he recognized its relationship to Athapaskan and included it in the grouping as well. His theory was met with skepticism, but Michael Krauss later undertook a study that supported the relationship between Eyak and Athapaskan. The relationship between Tlingit and Eyak-Athapaskan is remote, but now considered well established. Whether Haida is related as well is still unclear due to the considerable time separating it from the other languages.
The Na-Dene grouping was supported by Joseph Greenberg in 1987 when he published an article containing a controversial assertion that all of the languages in the Americas belonged to three major groups, with Na-Dene being one of them. Although many linguists maintain that Old World and New World language stocks are not related, Greenberg postulated three migration waves that began at least 11,000 years ago with the Amerind, followed 6,000 to 8,000 years ago by the Na-Dene, and 3,000 years ago by the Eskimo-Aleut.
Greenberg's model supports the prominent Clovis first model of American aboriginal origins. According to this theory, the North and South American continents have been populated for approximately 12,000 years. Similar technology of Siberian populations and the Proto-Na-Dene group offered the link of timing and origins of the second Na-Dene migration.
The complexity and number of Native languages are an important indicator of how long the Americas have been occupied by human beings. Today, new evidence from archaeology and linguistic theory suggests a much longer human occupation in the Americas than previously thought. Prominent models by Joanna Nichols and Richard Rogers lend support to the archaeological evidence of human occupation in South America from about 30,000 years ago.
Fagan, Brian. 1995. People of the Earth: An Introduction to World Prehistory, 8th ed. New York: Thames and Hudson.; Greenberg, Joseph. 1987. Languages of the Americas. Stanford, CA: Stanford University Press.; Gruhn, Ruth. 1997. "Language Classification and Models of the Peopling of the Americas." In Archaeology and Linguistics: Aboriginal Australia in Global Perspective. Edited by Patrick McConvell and N. Evans, 99–110. Oxford: Oxford University Press.; Krauss, Michael. 1964. "Proto-Athapaskan-Eyak and the Problem of Na-Dene I: Phonology." International Journal of American Linguistics, Vol. 30 No. 2:118–131.; Nichols, Johanna. 1990. "Linguistic Diversity and the First Settlement of the New World." Language, Vol. 66, No. 3 (Sept. 1990), 475–521.; Rogers Richard A., Larry Martin, and T. D. Nicklas. 1990. "Ice-Age Geography and the Distribution of the Native North American Languages." Journal of Biogeography, Vol. 17, No. 2 (March 1990), 131–143.; Sapir, Edward. 1915. "The Na-dene Languages, a Preliminary Report." In American Anthropologist, New Series, Vol.17, No. 3 (July–Sept. 1915), 534–558.