Oh...oh... So does this mean that modern-era European settlers who displaced Native Americans really displaced, well, other European settlers????? No wonder it's a controversial theory. Brace yourself for an onslaught of leftist anrthropologists to come out of the woodwork.

Second paragraph: their descendants drove horses across the grasslands? Not until the Spanish brought the horses, right? A little more research please.

Ever heard of Barry Fell?

@CCBC:

@CCBC: Thanks for the Barry Fell name. @ ghardy: "Drove" them across grassy plains does not mean "rode" them. This is a good overview of the answer to your question: http://www.madsci.org/posts/archives/jun2000/960351408.Zo.r.html

Ultimately, the genetic makeup of the humans responsible for making the tools found at these sites would have to be determined by an analysis of bone fossils, if such exist. Even then, analysis of tools and bones only gets you so far with various hypotheses. Nevertheless, it is fascinating.