Thor Heyerdahl, author of that piece, is well known for his diffusion hypothesis. His work with Ra and Kon-Tiki shows that migration was <i>possible</i> with even early technology. It doesn't mean it happened, or that the hypothesis has any truth to it. (FWIW, I enjoyed his books about the two journeys, and his book on Easter Island.)<p>The idea of an Egyptian/Aztec connection is often categorized as "hyperdiffusion", and has the unfortunate tendency to highlight similarities, without estimating if there were independent origins, or investigating differences. See <a href="http://scienceblogs.com/aardvarchaeology/2010/11/04/thor-heyerdahl-and-hyperdiffus/" rel="nofollow">http://scienceblogs.com/aardvarchaeology/2010/11/04/thor-hey...</a> for a more modern commentary on Heyerdahl.<p>Hyperdiffusion is nearly abandoned by academic research, for lack of evidence.