http://news.nationalgeographic.com/news/2007/06/070604-chickens_2.html
Chickens aside, allegedly there are DNA links found in pre-Columbian human remains. I will look for more links later.
This is an interesting article, based on more traditional linguistic and archaeological methods.
http://pvs.kcc.hawaii.edu/rapanui/mapuche.html
Of course!, I had completely forgotten about Rapa Nui and the inhabitant of Easter Island.
Thanks for the links. Will try to visit the sites tomorrow.