I've read this theory and it does sound plausible. Now, I've also read that the Aztecs, Incas, Moche, etc,etc, never invented the wheel because there were no beasts of burden to pull wagons, etc. Why weren't there large mammals in South America? (There was a wheeled child's toy found in one of the ruins.)
Protein was a problem in South America. This may have lead to the practice of human sacrifice. Some anthropologists are convinced that it was driven by the need for protein, they ate the victims.
Take a good look at the Carribean and Gulf Coast regions. Also, the North Atlantic. Blam, the Solutrean and Clovis cultures may be related as well. Could Cro Magnons following the North Atlantic ice pack in search of seals and giant auks have made it to North America? With sea levels down so low, the distance appears to be not so daunting.
