Are North American and South American "Indians" Genetically The Same?

I recently read “1491” and this surprised me, too. American Natives (north and south) have more genetic homogeneity than any other racial group.

What about native Peruvians?

I seem to remember that Some tribes in Peru seemed to have distinctly asian facial features:

The Theory is that thousands of years ago, storms blew ancient Japanese fisherman all the way across the Pacific and landed in South America.

(btw, an American astronaut of mixed Hispanic and Asian ancestry: Franklin Chang-Diaz:
http://www.spacefacts.de/more/astronauts/photo/chang-diaz_franklin_1.jpg)
Has anybody tested these peoples for distinctly Asian genetic markers?