Marooned for 15,000 years
Using the new correlations between languages method, the linguists found additional evidences to explain how North America was populated. Their study revealed that 15,000 years ago, the peoples that were to eventually populate North America got marooned on a plain that has now sunk.
From this viewpoint, they deduced that ancestors of Native Americans did not directly cross the land bridge that connected Siberia with Alaska. Instead, they stayed on the plain and lived there in isolation until the last ice age. The researchers suggested that this explains the variety of DNA mutations that are seen in Native Americans today.
Deep-sea cores taken from the Bering Strait were examined by archeologists. Their found that that there was a shrub tundra, a special ecological zone that existed in the area during the Last Glacial Maximum. This was the time when Earth experienced the lowest sea levels and the thickest glaciers. It was erroneous to call that specific area as a land bridge because it was actually a broad plain given the name Beringia that was comparatively warm where grazing animals existed and the land supported birch and spruce trees.
Relationship between languages
It was only now that the linguists were able to contribute to the synthesis of archeological and genetic data. Early linguistic reconstructions can only go back to 8,500 years ago whereas the first migrations to North America of the ancestral peoples happened about 15,000 to 10,000 years back. It was Dr. Edward Vajda that first documented the relationship between Na-Dene and the Yeniseian language group.
He said that Ne-Dene languages are spoken by the Apache and Navajo in the American Southwest as well as in Western Canada and Alaska, using the language’s structural features rather than vocabulary, which can easily change. This was further affirmed by the latest findings of Dr. Sicoli and Dr. Holton, that the two languages are related, descending from common languages that are now lost; the languages that were used in Beringia. Speakers of the language then migrated separately, some moving west to Siberia while the other group proceeded to North America.
Ancient fur tax records were the only source of knowledge of some of the Yeniseian languages. Part of the language group, the Kott, Assan, Arin nad Pumpokol have not been spoken for two hundred years. There are only about 200 living speakers of the only surviving language in the group, Ket.