Linguistics and human migration to the Americas...?

Question

I'm nearly finished reading "The Origin of Language" by Merritt Ruhlen and there is one aspect I don't understand.

In terms of the Renfrew and Greenberg models for language classification and the Indo-European expansion, I can understand how the evidence supports Indo-European languages largely supplanting Dene-Caucasian languages throughout Eurasia because the Indo-Europeans had agriculture.

However, what I don't understand is how they suggest that the first set of migrations to the Americas were of the Eurasiatic (Amerind family,) related to Indo-European) language families. While the Na-Dene language (part of the Dene-Caucasian family) migrated to the Americas only later.

This confuses me for two reasons..

1. If the spread of the Eurasiatic family was due to agriculture, why wasn't agriculture as widespread in the Americas as it was in Eurasia?

2. How did the Dene-Caucasian migration happen later if they were being overrun by the Eurasiatic peoples, only to supplant the Eurasiatic peoples in the Americas?

Wouldn't it make more sense if the Dene-Caucasian (Na-Dene) migration happened first (or concurrently,) especially considering the isolated pockets in what is now the south-east US? Given all the land available, the Eurasiatic (Amerind) peoples may have been just as inclined to fill the empty space rather than compete with the Na-Dene?

However, were the Eurasiatic peoples not agriculturalists? Did they simply give up agriculture because of the plentiful game in the Americas?

Am I missing something here? I realize these models are not universally accepted, but what is their justification for how this happened?

Answer 1

The Greenberg model is based upon classification of sounds and meaning within a language or language group.  The biggest hole in their theory is they lack sufficient data about the sounds in so many lost (dead) languages in the New World.

There is also an assumption made about how languages interact when two or more cultures meet.  Their assumption is that the language of the stronger culture will have a greater influence upon the resulting culture.

It is possible that the Na-Dene migrated to a location and subsequent influxes of Amerind peoples were not about to take these regions.

Much more data is needed, both linguistic and genetic before the real story can be told.