Two articles in Current Biology of October 23rd 2014 both concern Polynesians reaching S America. The first one claims the indigenous Botocundos tribe of Brazil have a genomic history that is Polynesian – see www.eurekalert.org/pub_releases/2014-10/cp-gds101614.php … and in the second article it is said there was considerable genetic evidence of early contact between Polynesians and the Americas, especially with Easter Island. Archaeologists had suggested that between 30 and 100 people were all that was needed to establish the Easter Island population (including women and children). These could have been accommodated in two double hulled canoes, accidentally reaching the dot in the Pacific. However, they may now have to modify this conclusion as there was a transference of crops such as sweet potatoes from S America to Easter Island. Genome analysis now confirms there was contact with S America between AD1300 and 1500. After 1850 there was admixture with Europeans. It is likely that contact was regular as any canoe sailing east from Easter Island could not help but strike the coast of S America. This probably implies that Easter Islanders were also in regular contact with other islands in the Pacific and they were not a remote settlement on the edge of the world as recently implied by professor Brian Cox on one of his TV shows, comparing Easter Island with a remote speck of light in the sky, an exoplanet making itself known by the shadow it produces going round a distant star. Easter Island, the genetic evidence would suggest, was part of a major trade artery between Polynesia and S America and rather than being stranded in the middle of nowhere, Easter Island was the equivalent of an oasis in the Sahara, providing replenishments (water and fruit such as dates). Looking at it this way we can see how the rats became such a problem, brought to Easter Island on more than one occasion and going on to breed rapidly by feasting on ground nesting fledglings and eggs.
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