Easter Island, or Rapa Nui, in the SE Pacific, has spawned various theories and one of these is that the inhabitants, prior to the arrival of Europeans, was a mixture of Polynesian voyagers, and South Americans (the nearest land mass). In fact, a genetic test a few years ago, showed an 8 per cent South American ancestry. We are then told this study was based on 'modeling' – an area of genetic research that can be imprecise). In other words, they admit modeling is inexact – but only because they wish to drive their own piece of genetic research to the forefront. The more recent study shows no sign whatsoever of American ancestry amongst the inhabitants of Easter Island (from skeletal material preceding the arrival of the first Dutch ship). They were wholly Polynesian.
Note … in this criticism of modeling DNA change they point to a bottleneck in the 19th century due to an epidemic that struck the island (presumably a European derived illness). If this view is applied to other genetic studies which also do not take into account bottleneck events associated with catastrophic events one might open the proverbial can of worms. For example, the arrival of modern humans in Europe, supplanting Neanderthals, appears to show an overlap between the two groups. However, if the Neanderthals were subject to a mass die off (along with various animals) around 40,000 years ago (or possibly as late as 30,000 years ago) the idea that modern humans arrived while Neanderthals were still extent may be a false product of modeling. Modern humans may have arrived after the demise of the Neanderthals.